Animal Science Seminar Series
Details on seminars are included in the expandable boxes below
Remote temperature monitoring in sheep - Tellisa Kearton
Tuesday 8th August 2017
Monitoring the health of extensively managed sheep can be difficult and labour intensive, so the development of remote and automated monitoring technologies may be of use in assisting producers in the early detection of illness and disease. The first part of this study involved examining the potential for temperature sensing microchips placed in peripheral areas of the body for detecting changes in core body temperature. The second part investigates the potential for the use of infrared thermography in the detection of skin inflammation in wooled areas of sheep. The results of these two studies show that placement of microchips influences their ability to accurately reflect core temperatures, and that the presence of wool longer than 1-2mm significantly impacts on the ability of infrared thermography to detect skin inflammation.
Assessing anxious states in sheep: a more practical method - Jessica Monk
Tuesday 25th July 2017
As animal welfare becomes an increasingly important consideration for society, we need to develop practical measures of welfare which take into account both physical and mental well-being. It can be very difficult to determine the effective or emotional state of animals and existing cognitive methods can be very time consuming and impractical in applied contexts. This study aimed to further validate and refine a cognitive method which has been pharmacologically validated as a measure of anxious states in sheep. The results of this study show the test can be refined and shortened to less than 3 minutes per sheep, allowing for faster assessment of anxious states in larger groups of animals.
Jessica is in the second year of her PhD studying the behavioural and physiological coping strategies that livestock use to deal with management induced stress.
Developing an ethically acceptable virtual fencing system for sheep - Danila Marini
Tuesday 25th July 2017
Can we use invisible fences to control sheep? There is increasing development in virtual fencing systems to contain and control the movement of livestock. Unlike traditional fencing that uses a physical barrier that animals can see and interact with, virtual fencing relies on animals interacting with the invisible fence through warning cues and negative stimuli. To ensure animal welfare is not compromised when using virtual fencing, animals must be able to associate a benign conditioned stimulus with an aversive stimulus. The aims of this study were to identify the minimum aversive stimulus that deters animals, and to develop a training method based on associative learning.
Danila completed a PhD investigating self-medication methods in sheep and cattle at the UNE and CSIRO. Danila currently works in animal behaviour and welfare with CSIRO Armidale, with a primary focus on sheep welfare. She is interested in the learning capabilities of livestock and how we can develop training protocols that could allow them to have control over their welfare.
Implementing a net energy system for poultry - Professor Bob Swick
Tuesday 4th July 2017
The poultry nutrition group at UNE has successfully developed equations to predict the net energy of feed ingredients based on metabolisable energy and measured chemical components. A series of metabolic experiments were conducted using closed circuit respirometer chambers to measure oxygen consumption, carbon dioxide generation and overall energy balance in both meat chickens and laying hens fasted and fed diets differing in nutrient and chemical composition. The data collected on heat production, metabolisable energy, body weight, and chemical composition of the diets was analysed using linear regression to develop equations for meat birds and layers to be applied to individual feed ingredients. New feeds were formulated using net energy and fed to birds in chambers to validate the equations. The results indicate that in addition to metabolisable energy, protein and fat are significant predictors of heat increment in poultry. The economic benefit to formulating using net energy over metabolisable energy depends on the relative price of various ingredients including fats and oils and more recently commercialised amino acids such as arginine, isoleucine and valine.
Bob Swick is a native of the USA. Prior to his current position he lived in Singapore and consulted for the American Soybean Association, Agrenco Bioenergy, Prince Agri Products and ADDCON. He received his PhD in animal nutrition from Oregon State University in 1981 and began his career at Monsanto Company working with methionine and feed preservatives. He later became Product Development Manager at Novus International. Bob has published over 250 technical papers, bulletins, reports and journal articles and holds a patent on a novel grain preservation system. His current research interests are in the area of poultry energetics, nutrient metabolism and gut health.
RNA-seq technology used to decipher the expression of key genes in the differentiation of satellite cells into Longissimus or Semimembranosus muscles from Hanwoo cattle - Sara de las Heras-Saldana
Tuesday 27th June 2017
RNA sequencing is a powerful tool that allows us to study the differences in gene expression and their association with different phenotypes, tissues, treatments or diseases. It provides us with a better understanding on how specific conditions impact biological processes and how abundances of different genes (transcripts) vary. This technique is based on counting the number of sequences that map to a reference genome and then the abundances of the genes in two different conditions (or tissues) are contrasted.
In beef cattle, the composition of the meat (texture, muscle fibres, etc.) changes from one muscle type to another; this is the reason why we were interested in studying the early biological triggers of muscle differentiation during development (myogenic process). Here we used Korean cattle (Hanwoo) to identify the genes and pathways that regulate these processes. A cell culture experiment using bovine muscle satellite cells from Longissimus dorsi and Semimembranosus was combined with a time-series RNA-seq analysis to measure the transcriptome expression levels during the differentiation of satellite cells (on days 0, 1, 2, 4, 7 and 14). Around 84% of the reads were mapped to the reference genome (Bos taurus UMD3.1). Several genes were differentially expressed across time and between tissues. Gene ontology analysis revealed that the main enriched terms were genes with functions necessary for regulation of cell cycle, mitosis, nuclear division, cell cycle checkpoints and DNA biosynthetic processes. The most important finding was the identification of Hoxc11, Sim2, Hoxc8, Hoxb9, Zic2, Zic4, Tbx4 and Hoxb4 genes that were differentially expressed between LD and SM across time, suggesting that they could be driving the specific characterization of each muscle.
Downregulation of ALAS1 by nicarbazin treatment underlies the reduced synthesis of protoporphyrin IX in shell gland of laying hens - Sami Samiullah
Tuesday 20th June 2017
Shell colour is an important trait for eggs and an understanding of pigment deposition will assist potential management of egg shell colour loss. We demonstrated that nicarbazin feeding down-regulated ALAS1 and reduced protoporphyrin IX (PP IX) in both shell gland and eggshell, indicating the role of nicarbazin in inhibiting the synthesis of PP IX. Additionally, the expression levels of the genes did not show sequential upregulation in the same order of diurnal time-points (TP) during egg formation. The gene SLC25A38, responsible for transporting glycine from cytoplasm to mitochondria, and the gene ALAS1,encoding rate-limiting enzyme (delta-aminolevulinic acid synthase 1), had higher expression at 15 hr, as compared with 2, 5 and 23.5 hr postoviposition. Interestingly, ABCB6, a gene encoding an enzyme responsible for transporting coproporphyrinogen III, showed higher expression level at 2 and 5 hrs. However, the expression of CPOX that converts coproporphyrinogen III to protoporphyrinogen III, and ABCG2 that transports PP IX out from mitochondria did not alter. Nevertheless, mitochondrial count per cell did not show consistent change in response to time-points postoviposition and nicarbazin feeding. The information obtained in the study sheds light on how nicarbazin disrupts the synthesis of PP IX.
Genetic variability of feed efficiency traits in Australian Angus Cattle - Antonio Torres-Vazques
Tuesday 13th June 2017
The interest for feed efficiency has increased at least over the last two decades. Not only because is important to increase food production due to the growing human population, but also because feed efficiency is related with the feed cost of production. Providing feed to animals is a major cost input in almost any animal production system. The efficiency of converting this feed into useable animal products, commonly referred to as feed efficiency, is becoming a common breeding objective to improve profitability. In order to include feed efficiency traits in the breeding goal or breeding objective, genetic parameters are needed for accurate and unbiased prediction of breeding values, as well as to develop selection indices, and to predict selection responses. We investigate the genetic parameters of some feed efficiency traits and its genetic correlations between traits. Potential exist to reduce beef cost by selecting for low values for residual feed intake in breeding programs, and the major cattle breed societies in Australia are measuring feed efficiency traits to include them into the Australian beef recording system “Breedplan”.
Antonio Torres-Vazquez is a veterinarian in his first year of his PhD. His research interest ranges from estimation of genetic parameters to optimization of breeding programs. Antonio has completed a Master in Science with specialization in Animal Breeding and Genetics and currently is investigating the genetic variability of feed efficiency traits in Australian Angus Cattle.
Salinity tolerance and water use of tropical and subtropical pasture species adapted to southern Queensland - Hayley Giles
Wednesday 7th June 2017
Salt tolerant pasture species represent a valuable opportunity to intensify agricultural production in low-rainfall areas where saline land and or water (e.g. mine-site dewatering) are allocated to pastoral systems. Inherently variable in ionic composition and concentration, the response of plants to saline soils and groundwater are difficult to predict. Existing and novel approaches were applied to tropical and sub tropical pasture species to identify: mechanisms of tolerance to root-zone salinity; the individual effects of osmotic stress (OS) and osmotic stress and ion toxicity (OST) on plant growth and water use and; practical upper salinity limits for soil solution salinities. Generally, salt tolerant tropical and subtropical pasture species, including some glycophytes, should be considered for intensification of agricultural production in areas where root-zone salinity is an issue. The ability of glycophytic pasture species such as lucerne and leucaena to exclude Na+ at the root level, when root-zone Ca2+ was adequate, has potential value under root-zone salinity. However, if OST occurred, severe reductions in growth and plant water use were observed, potentially limiting glycophytes to situations where low soil solution salinities (2-5 dS/m) and adequate Ca2+ availability can be maintained. The capacity of halophytic Rhodes grass to safely accumulate ions to high concentrations in plant tissues at moderately high root-zone salinity (16 dS/m), whilst maintaining adequate plant growth and water use, meant it was the best option (of the species tested) for cultivation in tropical and subtropical areas affected by root-zone salinity.
Hayley is an agronomist and Lecturer in Tropical Agriculture at The University of Queensland. Her research interests range from the systems level of ruminant livestock production down to cellular processes, studying the physiological responses of pastures to abiotic stress.
Hayley completed her PhD at the University of Queensland, studying the effects of root-zone salinity on plant production and water use of tropical and subtropical pasture species adapted to southern Queensland. She has experience in the intensive and extensive grazing systems of northern Australia, and agricultural research in South East Asia. Hayley has worked on a variety of research and extension activities associated with feed base improvement, plant breeding and toxicology.
Use of nitrate salts, canola oil and cyseamine as feed additives to reduce enteric methane emissions - Laura Villar
Tuesday 6th June 2017
Enteric methane (CH4) is produced by ruminants during the fermentation of the feed. At global level livestock emits in the atmosphere 18% of the total anthropogenic emissions. Livestock animals are rising to respond to the growing demand of food. Reduction of CH4 from livestock is possible through various strategies. Dietary strategy appears to have encouraging results on reducing CH4 without lowering the productivity of the animals. Nitrate salts and dietary oils have been among the most promising additives. Nitrate may also replace urea as a non-protein-nitrogen source in protein-deficient diets. More recently, cysteamine hydrochloride (CSH) has been shown as an effective antimethanogenic additive and may increase the productivity of animals in intensive systems. We investigated the effect of feeding nitrate, canola oil or CSH on CH4 emissions and the role of nitrate and CSH as feed additives in low-quality roughage diets.
Laura Villar is an Agricultural Engineer in her second year of her PhD. Laura is investigating the effect of feed additives on reducing methane emissions, focusing on nitrate metabolism in the rumen, using respiration chambers to measure methane production from ruminants. Laura received a scholarship from the National Institute for Agricultural Research from Argentina (INTA), where she has been involved with small ruminant research in extensive conditions in Patagonia for 10 years. After completion of her PhD, Laura plans to contribute ideas for methane mitigation strategies by using feed additives in Argentina.
Prenatal stress and neonatal behaviour in lambs - Lea Labeur
Tuesday 23rd May 2017
Even under the best management practices, stressful events can occur during an animal's life including pregnancy. Previous studies in humans and mammals have shown that certain stressful situations can impact negatively the foetus brain development which could result in impaired behaviour and cognitive abilities in the neonates. Early behaviours are primordial for newborn lambs to establish a bond with their dam as well as follow their dam and so for survival. We have investigated the effects of different mild stressors at different stages of pregnancy on lamb neonatal behaviour. We also compared these effects with those of the injections of stress hormone noradrenaline as an attempt to shed some light on the mechanisms behind the effects observed.
Genomic prediction for internal parasite resistance in Australian sheep - Mohammad Zaher al Kaladeh
Tuesday 16th May 2017
Traditional genetic improvement relies on the use of pedigree information and phenotypes of each animal to estimate its breeding values. This has led to substantial genetic gains in most livestock species, especially for the traits that are easy to measure. However, the process is often inefficient for expensive or difficult to measure traits such as parasite resistance. Genomic selection offers an alternative to conventional breeding programs and can increase the rate of genetic gain by using genomic information to predict the breeding values of selection animals. This study aimed to compare the accuracy of genomic prediction based on different SNP panel densities, with and without including genetic markers from quantitative trait loci (QTL) regions. The results show that accuracy of prediction can be improved by including QTL information explicitly in the prediction models.
The nutritionist’s dilemma of repressing Clostridium perfringens - Holy Zanu
Tuesday 9th May 2017
The use of antibiotics as growth promoters in animal feed began in the 1940s, with two scientific papers being widely cited as the first scientific papers to report a growth-promoting effect of feeding antibiotics. Subsequently, antibiotics quickly made in-roads into the poultry industry. The use of antibiotics in the light of their potential for the development of antibiotic resistance in bacteria was later investigated. It is suggested that sub-therapeutic levels of antibiotics in the diet of farm animals may pose certain hazards to humans and animal health. In particular, sustained feeding of antibiotics causes antibiotic resistance of enteric bacteria in the animal gut. Because of this and observation of resistance of disease causing bacteria in hospitals routine use of antibiotics for growth promotion have been banned in the EU. Animal nutritionists all over the world have been called to find non-antibiotic growth promotants as alternatives to antibiotics. Much research has been conducted in this regard, especially for potential infections that might occur as a result of feeding strategies such as the inclusion of poorly digested by-products such as meat and bone meal. Non-starch polysaccharides from wheat and barley have also been known to cause enteric problems in poultry diets. While NSPase enzymes are widely used in poultry feed there is paucity of information whether commercial enzymes could act to promote growth. An ongoing investigation is looking at the possibility of eliminating necrotic enteritis, a bacterial disease, in broilers fed diets with high levels of protein by-product (meat and bone meal) using phytase (a commercial enzyme). This seminar will focus on a brief history of antibiotics, development of resistance in bacteria and how exogenous feed enzymes might help reduce subclinical bacterial diseases in poultry.
The effects of pecking stones, housing system and age on plumage condition and health parameters of free range egg laying hens - Zafar Iqbal
Achieving low protein diets in the Australian meat chicken industry - Matthew Hilliar
The chicken meat industry is growing rapidly due to its affordability as an animal protein source and low production costs. Current broiler feed protein levels are correlated with high water consumption and wet litter, resulting in health and welfare issues. Domestic protein meals used in poultry feed can be unreliable or hold ant-nutritive factors causing a dependence on imported soybean meal, adding extra costs to feed formulations. Amino acid supplements are a viable option in fortifying low protein diets by meeting nutritional requirements of growing meat chickens that are lost when reducing dietary protein.
To maintain a cost-effective practice only a few amino acid supplements are used in the Australian meat chicken industry, however with a trend towards more amino acid supplements becoming affordable, research has been undertaken to assess the feasibility of their use on meat chicken performance. The implementation of low protein diets will reduce industry dependence on protein meals and the adverse health and welfare effects of higher protein diets. Recently at UNE, a study was completed investigating the effects of low protein diets fortified with essential and nonessential amino acids on meat chicken performance and water intake.
The role of amino acid in sustainable poultry production - Girish Channarayapatna
With the growing population and evolving dietary habits, meeting the world’s growing demand for high quality animal protein is becoming a global societal challenge. The conventional solution to compensate for protein deficiencies in poultry diet is the ‘more of the same’ approach, to add more plant based protein to the feed-when the real issue is the amino acid balance. As conventional feed ingredients for animal production are deficient in one of the essential amino acids, targeted supplementation of amino acid ensures healthy, balanced nutrition for optimum growth. Lowering the plant based protein requirements not only reduces the animal producers total feed cost but also helps conserve crop resources. The reduction in plant based protein intake also reduces the amount of manure as well as effluents that leads to eutrophication. Amino acids supplemented poultry diets thus contribute to more efficient animal production, reduce burden on the environment and a deliver healthier high quality protein for human consumption.
Girish Channarayapatna completed his PhD in 2009 from University of Guelph, Animal and Poultry Science Department, Canada. His main research focus during PhD was on mycotoxicoses in poultry. He joined Evonik in March 2010 as the Technical Sales Manager for Asia South region. Since 2014 he is heading the Technical Service Group for Evonik Animal Nutrition in Asia South.
Improving the nutritional value of vegetable protein meals for broiler chickens using new generation microbial enzymes - Medani Abdallah
Thursday 8th December 2016
The commercial poultry industry relies on a limited number of animal and vegetable protein ingredients. In general, animal protein sources have a higher nutritive value than vegetable sources but there are different constraints to the use of both sets of ingredients. Plant vegetable protein sources are poorer in nutritive value than animal protein, and their former may also contain anti-nutritive factors that limit the digestion of nutrients or directly affect animal health.
Soybean meal (SBM) is the premier plant protein used by the poultry industry around the world. The price of soybean meal do fluctuate but is generally high, particularly in importing countries. There are other vegetable protein sources of local importance around the world, for example, peanut, cottonseed, sesame seed and sunflower seed, some of these alternative sources are close to SBM and CM in nutritive value but they are either limited in supply or contain factors that inhibit productivity. Cottonseed meal (CSM) for example, is high in fibre and contains gossypol while sunflower seed meal (SFM) has a high level of fibre.
Implementation of a Net Energy System for Laying Hens - Shahram Barzegar
Tuesday 29th November 2016
Dietary feed ingredients represent 65-75% of total production cost while energy represents approximately 50% of the total diet cost. Nutrients, when assimilated yield energy that is vital to every function in the body. The total amount of feed energy is gross energy. By subtracting the energy portion eliminated in urine and faeces metabolizable energy (ME) can be calculated and used for feed formulation. Globally, most if not all poultry feeds are formulated using the ME system. Metabolism of feed in the body leads to heat production. Part of this is used to keep the body warm and the rest is heat increment or wasted energy. The ME system doesn’t consider heat increment. Formulating feed on a net energy system would take heat increment into account and thus may be more precise than the ME system. In this project, after establishing the equation for NE prediction an experiment was conducted to compare the feed energy evaluating systems on layer performance and economics.
The effect of Ascaridia galli on the performance and egg quality of free-range laying hens - Nisha Sharma
Tuesday 7th November 2016.
Free- range egg production is getting popular in Australia as people are getting more concerned about awareness of hen welfare. This pressure encouraged Australian egg producers to house more free-range laying hens.
In free-range egg productions, hens are allowed to roam within a shed, and access a range. Subsequently, hens have the ability to express their natural behaviour. However, there are several challenges to be faced when housing free-range layers. For example, one of the most prevalent gastrointestinal parasite is Ascaridia galli. This parasite has been reported to decrease hen production and suspected to reduce egg quality. There is a lack of research on the impact of infection intensity on egg quality and a critical threshold that can be accepted. We investigated the impact of different infection levels with A.galli on hen performance (feed intake, body weight, egg weight, egg production) and egg quality parameters in free-range laying hens.
The role of different sources of fibre and feed particle size in broiler chicken - Sarbarst Qassim
Tuesday 1st November 2016.
The ban and voluntary removal of in-feed antibiotics in the poultry industry throughout the world have led to the emergence of wet litter and enteric disorders. This results in poor performance of the birds thus reduced productivity and profit for the industry. To tackle such problems, alternative strategies have been sought which include the modulation of gut microflora, augmentation of immune response and control of pathogens through management, nutritional strategies and/or feed additives. These measures have shown to improve the health and digestive efficiency and thus improve growth performance of broiler chickens.
One of those strategies is incorporating structural components of feed, such as coarse fiber or ingredient in the diet. It is well documented that feeding birds with structural components of feed, such as coarse fiber or ingredient, modulate the gastrointestinal tract specially increasing the gizzard size. Large and well-developed gizzard can increase its grinding activity, leading to pancreatic enzyme secretion through increased release of cholecystokinin from pancreas, increased proteolysis by pepsin, trypsin and other endogenous proteases in the small intestine and improved GIT motility. It has been hypothesised that the feeding birds with fibre improve nutrient digestibility, growth performance, gut health, litter quality and bird welfare via enhanced GIT tract function, greater digesta transit time and improve faecal quality.
Our study aimed to investigate the effect of different sources of fibres along with different feed particle sizes on gizzard development, growth performance, nutrient digestibility, bird welfare and litter quality. The talk will present our findings which show the potential to use course ingredients and fibre to improve gut health, litter quality and growth performance of birds.
The impact of two different hormonal growth promotants (HGPs) on the eating quality of feedlot finished steers - David Packer
The Meat Standards Australia (MSA) beef grading model predicts the eating quality outcome of different cuts by cooking method from commercial inputs of on-farm, carcass traits and processing inputs. Based on a body of Australian research in the mid-2000’s it was demonstrated that Hormonal Growth Promotants (HGPs) have undoubtedly a negative impact on beef eating quality over and above an effect on maturity (ossification) and fat content, in the order of three to six palatability points (MQ4). Subsequently, an adjustment of approximately four to five MSA index points is applied to any carcase that is presented for grading whereby the animal was treated with a HGP.
Since the introduction of the HGP adjustment, some industry stakeholders argued that the research conducted to establish the magnitude of the HGP adjustment did not allow for the hypothesised variable effects of different HGPs used in Australia. This was because, in the majority of the studies conducted, animals received multiple implants and/or were finished with a combination trenbolone acetate and oestradiol HGP implant. This made individual implant contribution to eating quality effects, difficult to distinguish, and therefore, to protect the consumer, the MSA pathways committee decided on one collective HGP adjustment.
This seminar will present findings from a trial which compared the meat from steers finished in a feedlot with three HGP treatment groups; Control (no implant), oestradiol only implant (21.1 mg oestradiol-17ß) or combination oestradiol and trenbolone acetate implant (200mg trenbolone acetate and 20mg oestradiol). Samples from these animals were tasted by untrained consumers for tenderness, juiciness, flavour and overall liking as a measurement of eating quality. Further laboratory meat quality assessments were conducted as supporting data. Results indicate these HGP implants have different impacts on eating quality measurements.
The foregut of poultry - are we neglecting its potential? - Inês Rodrigues
Ancestors of domesticated fowl used today for meat and egg production, such as chicken, turkeys, ducks, amongst others, share an obvious commonality - their natural habitat. In the jungle, the presence of a number of predators and the necessity to eat and to survive in spite of them, have been pivotal for the development of some of the domestic fowl’s characteristics. According to zoology studies performed from as early as 1928, primitive eating habits and behaviours of the red jungle fowl would protect these birds from harsh conditions in the jungle. As observed by Baker and Baker (1928) in India, “During the heat of the day they [red jungle fowl birds] sleep in the forest in some tree or clump of bamboos but from dawn to about 9 am and again from 3 or 4 pm until dusk they may be seen wandering about in the crops.”
Increasing demands of a growing, wealthier and fast-paced worldwide population make dependency on seed-eating birds, hiding and sleeping on treetops throughout most of the day, highly unrealistic. As such, in spite of innately exhibiting an intermittent feeding behaviour, broiler chickens have been reared in commercial operations throughout the past decades on either continuous or near continuous illumination (23 hours of light and 1 hour or dark) or with daily, human-like schedules (16 to 18 hours of light and 6 to 8 hours of dark) and fed ad libitum, and continue being so in most operations, in the certainty that this practice maximizes feed intake and growth rate (Lewis & Gous, 2007).
Roles of certain parts of the digestive tract of chickens seem to have been lost with the evolution of time and commercial practices. Gizzards no longer serve their grinding purposes, having become more like transit organs and crops have lost their function with the abandonment of discontinuous feeding systems. Certainly, the importance of the crop in digestion will presumably be much affected by the proportion of feed that enters the crop and the amount of time it spends there.
What if regaining crop and gizzard functionality, by increasing particle size, reintroducing scheduled feeding and increasing dark periods, would enhance endogenous and exogenous enzyme activity, thus leading to better nutrient digestibility, less undigested feed in the caecum, less gut inflammation and therefore better performance and better animal health?
Effect of supplemental xylanase, arabinoxylans and xylo-oligosaccharides on necrotic enteritis challenged broilers - Chuck Keerqin
Arabinoxylan is a non-starch polysaccharide, and it is a common substrate in most xylans forming plant cell wall structure of cereal grains. The presence of arabinoxylans has been proven to implement various adverse effect in monogastric animals, for example, occurrence of insufficient digestion and unwanted fermentation. The poultry diets are pressed from cereal grains, including viscous grains, such as wheat, barley, rye and oats, which have a considerable amount of soluble non-starch polysaccharides. Therefore, xylanase products were widely used in the poultry production to i) partially depolymerise non-starch polysaccharides in the feed ingredient and ii) increase the nutritive value of grains by breakdown cell walls to release encapsulated nutrients. In spite of that, the excess amount of non-starch polysaccharides can destabilise normal gut microflora, thereby making intestinal environment vulnerable to the occurrence of necrotic enteritis.
Recent studies showed that arabinoxylan-oligosaccharides (AXOS), a depolymerisation of arabinoxylans by xylanase, could positively cultivate composition and activity of bacterial colonies in the gastrointestinal tract by selectively fermenting normal gut commensals. This particular finding may be an approach to strengthen the resilience of broilers against gastrointestinal pathogens and improve the nutrient utilisation from the feed ingredient.
The seminar will present findings from two experiments conducted at the UNE regarding the effect of xylanase inclusion as well as the supplementation of arabinoxylan and AXOS to broiler growth performance under necrotic enteritis challenge stress. Also, the response of gut viscosity and intestinal pH by arabinoxylans and AXOS supplementation will be discussed.
Optimizing the propagation and titration of infectivity of a putative Haemorrhagic Enteritis Vaccine - Forhad Hossein
Turkey haemorrhagic enteritis (HE) is caused by a group II avian adenovirus known as Haemorrhagic Enteritis virus (HEV). HE is an acute disease of young growing turkeys with a sudden onset of depression, bloody droppings and a potentially high death rate. HE virus is present in Australia and outbreaks in 7-8 week old broilers with mortality of 0.5-1% over a week. It is also considered to be a historical cause of loss of illness, production and mortality in commercial turkey operations typically causing splenomegaly, mortality and increased E. coli infections at around 8-12 weeks of age.
Similar virus causes marble spleen disease in pheasants and avian adenovirus splenomegaly (AAS) in chickens. The disease is controlled by live virus vaccination worldwide but not Australia although a relatively avirulent strain HEV086 was isolated 30 years ago. The vaccine is produced from lymphoblastoid cell line MDTC-RP19 that is not available in Australia. It’s not possible to import this cell line to produce vaccine due to quarantine restriction. In addition, Australia does not have SPF turkey to produce the HEV vaccine but has SPF chicken and SPF eggs. The recent studies at University of New England examined to grow the HEV virus in SPF chickens and eggs. The qPCR results showed that best chicken produce 10,000-130,00 doses of vaccine from liver and spleen combined. Moreover, virus grows in SPF eggs with low recovery dose.
Replacement value of raw soybean meal for commercial soybean meal in diets for broiler chickens - Mammo Erdaw
Most non-ruminant animal nutritionists would be familiar with the use of commercial soybean meal (SBM) in diets for poultry and pigs. Raw soybean meal (RSBM) is less commonly used due to high levels of anti-nutritive factors (ANF), particularly trypsin inhibitors (TI). The development of new highly potent microbial enzyme products offers an opportunity for the use of RSBM in areas where facilities for processing SBM are lacking.
In recent studies completed at the University of New England, PhD Student, Mammo Erdaw, examined the potential benefits of feeding RSBM in diets when supplemented with high-potency microbial enzymes.
The results showed that moderate dry- and wet-heating do not substantially reduce the levels of TI in RSBM, and diets were not substantially improved when cold- or steam-pelleted. Replacing SBM with RSBM at up to 25 % reduced body growth, due mainly to a reduction in feed intake and nutrient digestibility. The ingredient also increased endogenous losses of protein and amino acids, but did not affect the health of birds or the rearing environment. The negative effects of RSBM were reduced through dietary supplementation with microbial phytase and protease. A preliminary cost-benefit analysis also showed that RSBM could save feeding costs when it replaced SBM. Further studies are underway to directly assess the behaviour of proteins in RSBM, especially in the presence of the test protease.
Genotype by Birth or Rearing Type Interaction in the Growth Trajectory of Merino Lamb - Akhmad Dakhlan
Tuesday, 20th September 2016.
Birth type (BT) and rearing type (RT) influence lamb growth and development from zygote to birth (for BT) and from birth to adult (for BT and RT). BT and RT also constitute an environment that influence the expression of early growth of Merino lambs and its influence might continue along trajectory of their lives. There is genetic variation in growth rates of animals and this variation may change over the growth path of animals, with different genes being expressed at different times during development.
This can be explored at a quantitative genetic level by estimating the genetic correlation between growth traits measured at different ages. Random regression models (RRM) have been used to analyse and describe the genetic variation over the growth trajectory of cattle, pig and sheep whereas this models have also been used to describe variation in test day yield along the lactation curve. Genotype by birth or rearing type interaction can be identified when breeding values for growth expressed in singles rank differently than breeding values expressed in twins.
This study explores the genetic model underlying the growth path singles and twins and how the pre- and post-natal environment affects the expression of genetic merit for different parts of the growth curve.
Australian canola meal quality and its application in broiler chickens diet - Medhi Toghyani
Tuesday, 13th September 2016.
Rapeseed production, including canola varieties, ranks second among oilseed crops worldwide. Canola seed production in Australia has grown from 1.9 to 3.6 million metric tons over the past 5 years. Canola meal (CM) is a co-product of the canola seed-crushing industry and is widely used as a secondary protein source along with soybean meal (SBM) in broiler diets. It has a good balance of essential amino acids and is higher in methionine and cysteine on a protein basis than SBM. However, CM energy and digestibility of amino acids is typically lower than SBM. Anti-nutritional factors such as glucosinolate and sinapine may also restrict its use to less than full replacement of SBM in poultry diets. The fibre components of CM have been shown to be negatively correlated to energy digestibility of the meal.
The outlined project has examined variation in feeding value of experimentally produced and commercial sources of Australian canola meals. The project has endeavoured to develop commercial ties with the crushing industry to evaluate opportunities for product improvement. Commercially acceptable methods to enhance nutritional value of CM have been examined. These include modifications of processing parameters, the use of newly developed commercially available enzymes and the possibility of using extra supplemental amino acids in CM-based diets for broiler chickens.
Development of a resilience metric in livestock - Jessica Monk
Tuesday, 30th August 2016.
Resilience is the ability of an animal to cope with short-term challenges and return to its pre-challenge state. Strategies aiming to identify and select resilient animals that can better cope with our production systems are expected to improve both the productivity and welfare of our livestock. This thesis aims to better understand the resilience phenotype in livestock and identify potential measures of resilience which are practical and applicable on farm. The first experiment conducted as part of this thesis aimed to better understand the relationships between the different components of resilience in sheep.
Three years of investigation into infectious bursal disease virus of chickens - what we have learnt - Kanchana Jayasundara
Tuesday, 21st June 2016.
Infectious bursal disease is first reported in 1957 in Gumboro area, Delaware, USA and disease is caused by IBDV. Since then IBDV was distributed rapidly throughout the world. The current reach study was designed to test following broad objectives:
- Define differences between Australian classical and variant strains,
- Determine independent effects of age resistance and presence of maternal antibodies,
- Detection of IBDV vRNA in environmental samples,
- Test transmission of IBDV by contaminated dust,
- Determine temperature-time combinations required to inactivate IBDV in heaped litter.
Performance of broiler chickens on wheat-based diets supplemented with microbial enzymes - Mohammed Al-Qahtani
Tuesday, 14th June 2016.
Cereal grains typically constitute the largest proportion of practical diets for poultry. Wheat is the predominant cereal grain used by the poultry industry in Australia and Europe. Wheat, like most temperate cereal grains, contains high levels of insoluble non-starch polysaccharides (NSP), in addition to phytic acid, the main reservoir of phosphorus in grains. Diets for meat chickens are routinely supplemented with microbial enzymes targeting NSP and phytic acid, and new enzyme products are continuously being produced and tested for introduction into the market. This presentation will outline a project that was developed to evaluate the response of poultry on diets containing wheat, maize or sorghum. Preliminary results that have been obtained from the trials on wheat will be presented.
Mitochondrial quantification and expression of genes associated with protoporphyrin IX synthesis in the shell gland of laying hens in response to nicarbazin - Samiullah
Tuesday, 31st May 2016.
Mitochondrial quantification was performed in the shell gland of laying hens treated with nicarbazin using a quantitative PCR assay. Furthermore, expression of seven genes associated with protoporphyrin IX (PP IX) synthesis and/or deposition was examined in order to assess whether the treatments can lead to differential expression of the genes. The results showed that the mitochondrial concentrations per cell were significantly lower in the nicarbazin-fed group at 15 hr post-oviposition time. In the control group, the expression of ALAS1, FECH and SLC25A38 were significantly different at different stages post-oviposition. In the nicarbazin group, the expressions of all genes except CPOX were significantly different at different stages of post-oviposition. Comparing the effect of drug on the expression stabilities of the genes, ALAS1 was significantly down regulated in the nicarbazin fed groups. The PP IX content per gram of shell gland tissue was significantly lower (P<0.05) in the nicarbazin-fed birds compared with the control group. The amount of PP IX in whole eggshell decreased with day effect in the nicarbazin group, in a linear pattern, but it remained constant in the control group. However, egg weight and shell thickness were not significantly different between the control and nicarbazin-fed groups. It can be concluded that the mitochondrial concentrations in the shell gland were altered by nicarbazin only at 15 hr post oviposition, and the expression of some genes associated with PP IX synthesis and/or deposition were affected by post-oviposition time. The expression level of ALAS1 gene was significantly down regulated in the nicarbazin-fed groups that resulted in lower production of PP IX appeared in the eggshells.
Gene Expression Profile of Satellite Cells - Differentiation from Longissimus dorsi and Semimembranosus muscles - Sara de las Heras-Saldana
Tuesday, 24th May 2016.
Hanwoo cattle are known for their high meat quality, particularly their high marbling (intramuscular fat) ability compared to most other breeds. Meat flavor and tenderness are largely determined by intramuscular fat composition, muscle fiber characteristics and connective tissue structures. All of these factors differ largely between muscle types but it is not well known how this differentiation occurs and what are the genes and pathways that regulate the process. To better understand the myogenic processes involved in differentiation of Hanwoo muscle types we performed a time-series RNA-seq experiment to measure transcriptome expression levels during the development of muscle satellite cells (MSC) in Longissimus dorsi (LD) and Semimembranosus (SM).
Cognitive testing in free-range laying hens - Dana Campbell
Free-range systems are perceived to improve hen welfare through providing outdoor access but not all hens choose to use the range. The outdoor range is typically more spatially complex than indoor environments, thus outdoor-preferring hens might have improved cognitive abilities compared to indoor-preferring hens during cognitive tests. Indoor-preferring and Outdoor-preferring hens were assessed with a novel detour-reaching task and in a reverse T-maze. Indoor hens showed slower latencies to learn indicating poorer cognitive abilities compared to Outdoor hens but differences may be modulated by reducing fear through habituation to novel environments.
Hot sheep, cold sheep: Position of sensing microchips for detecting core temperature changes in sheep - Tellisa Kearton
Tuesday, 5th April 2016.
New technologies are presenting opportunities for remote sensing of core body temperature in animals. If a protocol can be established, then these technologies can be used to monitor fever and inflammation in livestock in the paddock. To test for suitable implant sites, eleven crossbred ewes were implanted with temperature sensing microchips positioned in the neck muscle and tail regions, sites potentially suitable for remote temperature monitoring. Temperature measurements were taken at regular intervals from the microchips and from vaginal (core) temperature using iButton and thermocouple sensors. Temperature change was recorded over baseline and treatment periods where sheep were exposed to challenges designed to increase (i.v. lipopolysaccharide) and decrease (cold water gavage tube) core temperature. Results were analysed and compared between traditional temperature measurement methods and microchips for ability to reflect core temperature and changes in core temperature.
Identification of genomic regions associated with parasite resistance in Australian sheep - Mohammed Zaher al Kaledeh
Tuesday, 15th March 2016.
Gastrointestinal parasites are one of the most important health problems affecting sheep. Breeding sheep for enhanced resistance has been suggested as a viable method of parasite control, and the identification of genes for parasite resistance would greatly accelerate the genetic improvement. The aim of the study was to identify genomic regions underlying variation in parasite resistance in a large population of Australian sheep, using Genome-wide association studies (GWAS) and regional heritability mapping (RHM) approaches.
The use of genomic data in a dairy buffalo breeding program - Rommel Herrera
Tuesday ,15th March 2016.
With the availability of the Affymetrix 90K buffalo SNP Chip, this thesis will explore the use genomic data in a dairy buffalo breeding program. I will first look at the structure of the genetic diversity of buffalo populations. I will then identify SNPs and candidate genes associated with milk traits using genome-wide association study. Subsequently, I will test the accuracy of genomic prediction for milk traits. Finally, I will look into the implementation and optimization of a dairy buffalo breeding program using genomic selection.
Energy utilisation in pigs and poultry - Dr Jean Noblet
Monday, 7th March 2016.
Dr Jean Noblet worked at INRA (for "Institut National de la Recherche Agronomique") in France from 1977, most recently as Director of Research. He is located near Rennes (Brittany). He has "Ingénieur Agronome" and PhD degrees from the National Institute of Agronomy in Paris and the University of Paris. In 2000, he received the "Non-ruminant Nutrition Award" of the American Society of Animal Science. His research has concerned energy and protein nutrition of swine and, more recently, of poultry and calves with achievements in calorimetry methods, evaluation of energy content (net energy concept, for instance) of pig feeds, factorial quantification and modelling of energy requirements in pigs, calves or poultry and thermoregulation of pigs. He was the Editor-in-Chief of Animal journal from 2012 to 2014. He has authored or co-authored about 200 reviewed papers or book chapters, about 400 communications and 2 software applications on pig production: InraPorc and EvaPig. He retired from INRA at the start of 2016.
The value of assessing lifetime productivity and breeding worth in commercial livestock - Bruno Santos
Bruno will speak about a collaboration initiative between Australian and New Zealand institutions, as well as private organisations, interested in quantifying production and economic benefits of recording and selection in commercially managed sheep flocks of multi-tiered breeding schemes.
The effect of feed additives and range on grass impaction in free range layers - Zafar Iqbal
Tuesday 9th February, 2016.
Free-range egg production is rapidly growing in Australia with an estimated retail value market share of 48 %. Laying hens exposed to pasture range may experience reduced performance, poor enteric health and increased mortality. In addition, egg quality can also be affected, indicated by the increased number of damaged and misplaced eggs as well as decreased egg shell quality. These effects may be related to excessive fiber digestion and reduced nutrient uptake. The addition of multi-enzymes or organic acids to free-range layer diets may improve the digestion of nutrients, thus increasing performance, gut health and egg quality. We conducted a study to investigate the effect of range types and feed additives on performance and egg quality and performance of ranging laying hens.
Can adaptation to nitrate supplementation and provision of fermentable energy reduce nitrite accumulation in rumen contents in vitro? - Victoroire de Raphelis-Soissan
Tuesday 2nd February, 2016.
Supplementing ruminants with dietary nitrate reduces methane emissions, but can expose animals to nitrite toxicity risks. This study investigated if adaptation to dietary nitrate and supplementation of fermentable energy sources (glucose or glycerol) reduce accumulation of nitrite in vitro. There was no effect of additional energy sources on nitrite accumulation, adaptation of rumen fluid donors to dietary nitrate even increased accumulation of nitrite. In vivo verification is needed to assess the role of adapting ruminants to nitrate supplementation on risks of nitrite toxicity.
Effects of stress during pregnancy on lambs vigour traits - Lea Labeur
Lamb survival is a welfare issue as well as a considerable economic loss. Shearing during pregnancy can improve lambs birthweight which is correlated to their survival. Does shearing impacts other lamb vigour traits? Other husbandry procedures can put ewes under pressure. What are the effects of stress during the pregnancy on lamb vigour traits? This project studies the effects of different stressors at different stages of pregnancy on lamb vigour traits such as performance traits (birthweight and frame measurements), latency to display some behaviours, and thermoregulatory traits.
The effect of yeast cell wall derivative on broiler performance, immune system, major gut bacteria and cecal short chain fatty acid changes during subclinical necrotic enteritis challenge - Danny Xue
Necrotic enteritis (NE) caused by Clostridium perfringens is one of the most economic important diseases in areas of the world where antibiotic growth promoters (AGP) have been banned. After experiencing an increase in the incidence of NE in Europe after banning routine use of AGP, it was apparent that an opportunity existed to find safe replacement additives. Mannan-oligosaccharides (MOS) derived from yeast cell walls have been shown to be potential AGP replacements. These prebiotics control pathogen invasion through competitive exclusion and modulation of the immune system. This study was be conducted to examine if an advanced MOS product, Actigen® might alter immune response, major gut bacterial groups or hindgut metabolites and may further explain its protective mode of action. It was hypothesized that the cytokine interleukin-1 (IL-1) might increase in challenged birds due to inflammatory response and that IL-10 might increase in challenged birds given Actigen® as this cytokine is involved with immune regulation in the intestine. The effect of challenge and additives on gut microflora and short chain fatty acids (SCFA) was also examined.
An epidemiological study on Inclusion Body Hepatitis in commercial broilers in Fiji - Robin Rahul Achari
Wednesday 28th October, 2015.
In this study, data from 2008 to 2014 from a poultry enterprise in Fiji was analysed to investigate the patterns of occurrence, impact on performance and risk factors associated with Inclusion Body Hepatitis (IBH) disease outbreak caused by Fowl Adenovirus serotype 8 (FAdV-8). The disease pattern statistical analysis of risk factors is discussed in detail in this paper.
Could drench efficacy be a host related factor? - Cara Metcalf
Tuesday 20th October, 2015.
An interesting aspect of drench resistance is that as resistance develops, a large and unexplained variation in drench efficacy exists among animals in the same treatment group. This project was performed to determine if these differences in drench efficacy are associated with the way in which individual sheep metabolise drenches. The purpose of this experiment was to determine that there will be a broad range in blood plasma FBZ concentrations in response to an industry standard dosage of anthelmintic and that this will be positively correlated to the drench efficacy within sheep to the FBZ treatment.
Cara Metcalf is a fourth-year Agricultural Science student at the University of Queensland. She has been conducting her final year internship at UNE with Associate Professor Lewis Kahn.
Imperfect vaccines and evolution of pathogen virulence: A case study of Marek’s disease in chickens - Steve Walkden-Brown
Strategies to increase canola meal inclusion rate in broiler chickens diet - Mehdi Toghyani
Epidemiological investigations into an acute paralysis syndrome of broiler chickens - Brendan Sharpe
Tuesday 15 September, 2015.
Brendan presented the findings of detailed epidemiological investigations of farm cases of an acute paralysis syndrome that has been observed in Australian broiler chicken flocks since 2010.
Eggs - Professor Julie Roberts
Tuesday 8 September, 2015.
Professor Roberts will give an overview of the current and recent research in egg production being conducted at the University of New England.
Pain-relief options in sheep: potential role of self-medication - Danila Marini
Introducing guardian alpacas to a sheep flock – examining guarding behaviours in alpacas and behavioural responses in sheep - Paige Matthews
Tuesday 11 August, 2015.
The use of guardian animals as a form of wild dog and fox management is becoming increasingly popular in Australia, however there seems to be a lack of knowledge in regards to the use of alpacas. This seminar will outline my aims and the methods I will use to gain a better understanding of how guardian alpacas work and the behavioural responses of the sheep they are guarding. This project aims to provide knowledge to producers on how to utilize these guard animals in their flock management.
Partitioning production loss due to Trichostrongylus colubriformis into direct and immune-mediated components in grazing meat-breed lambs - Michelle Dever
Thursday 6th August, 2015.
Parasitism from gastrointestinal nematodes (GIN) is one of the most costly endemic sheep diseases in Australia with majority of the cost attributed to production loss. To counteract the effects of GIN, sheep producers are encouraged to adopt integrated GIN control programs, including a greater emphasis on selecting rams with negative Australian Sheep Breeding Value for worm egg count. The acquisition phase of immunity to GIN is costly and has been associated with reduced voluntary feed intake and inefficiencies in nutrient utilisation. The hypothesis tested in this experiment was that T. colubriformis infection would reduce growth rates of grazing meat-breed lambs; however production loss would be reduced by suppression of the host immune response.
What’s in a bleat: application of the human and rodent cry analysis model to the lamb neonate - Chris Morton
Distress vocalisation features including latency, vocalisation rate, fundamental frequency and other acoustic parameters are commonly recognised to reflect neurobehavioral integrity in both the human and rodent neonate. Application of methods used to elicit and analyse distress vocalisations in these species were used to assess acoustic parameters of neonate lambs and associated impact on maternal-infant behaviour. This research has important implications in assessment of neurodevelopmental deficit and understanding failed maternal-young interactions in ungulate and other mammalian species.
Spending money to make money: Opportunities and barriers to increasing beef production and profitability in East Java - Dr Fran Cowley
Smallholder beef cattle production in East Java is typically predicated upon maximising profit by minimising inputs. It appears that East Java is approaching carrying capacity for cattle grown on low quality feeds produced in the immediate vicinity of individual farms. Fortunately, Indonesia produces significant quantities of crop by-products which can be purchased and used as high-quality cattle feeds. Initial analysis shows that even with the additional investment required to purchase feeds, farm production and profits can be improved by feeding these by-products. However, farmer access to credit for purchasing these feeds remains a barrier to adoption.
Impact of early access to specific nutrients or additives on the susceptibility of broilers to necrotic enteritis - Chuck Keerqin
Clostridium perfringens induced necrotic enteritis is an economically catastrophic disease in poultry production by causing suppressed growth increased flock mortality and impaired welfare. Contaminated poultry products may also bring potential negative implication for human consumption. Antibiotics are, by far, the only practical approach for maintaining the health of the birds. However, various alternatives to antibiotics have appeared promising in the use for food-producing animals since the antibiotics are phasing out from animal feed worldwide due to the emergence of the antibiotic-resistant bacterium. Early access to specific nutrients or additives may mount a natural defence to broiler gut development against necrotic enteritis.