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Introduction
Current institution
Education
March 1989 - May 1995
Publications
Publications (352)
Background
Enterotoxigenic F4 Escherichia coli (F4-ETEC) pose an economic threat to the swine industry through reduced growth, increased mortality and morbidity, and increased costs associated with treatment. Prevention and treatment of F4-ETEC often rely on antimicrobials; however, due to the threat of antimicrobial resistance, antimicrobial use i...
It is indeed a great privilege to have been awarded the 2024 American Feed Industry Association Award in Nonruminant Nutrition Research. I am honored to follow in the footsteps of many great non-ruminant nutritionists in the industry. I commenced my career in the pork industry with a PhD in digestive nutritional physiology focusing on the newly wea...
Progeny born to primiparous sows (gilt progeny; GP) have lower birth, weaning and slaughter weights than sow progeny (SP). GP also have reduced gastrointestinal tract (GIT) development, as evidenced by lower organ weights. Therefore, the aim of this experiment was to quantify changes in GIT barrier function that occur in birth and weaning, represen...
Tail biting (TB) in pigs is a complex issue that can be caused by multiple factors, making it difficult to determine the exact etiology on a case-by-case basis. As such, it is often difficult to pinpoint the reason, or set of reasons, for TB events, Decision Support Tools (DSTs) can be used to identify possible risk factors of TB on farms and provi...
The weaning of pigs in most commercial pork production systems is an abrupt event performed at a fairly young age, i.e., mostly between 2.5 and 5 weeks of age. This practice induces a stress response, and its impact on behavior, performance and the gastrointestinal tract has been well described. Historically, there has been a focus on pre- and post...
Current interventions targeting antimicrobial resistance (AMR), a major impact on commercial pork production, focus on reducing the emergence of AMR by minimising antimicrobial usage through antimicrobial stewardship and a range of alternative control methods. Although these strategies require continued advancement, strategies that directly aim to...
Different cereal types, in combination with different protein sources, are fed to pigs after weaning, but their interactions and possible implications are not well researched. In this study, 84 male weaned piglets were used in a 21-day feeding trial to investigate the effects of feeding either medium-grain or long-grain extruded rice or wheat, in a...
Pork is one of the world's most frequently consumed red meats and provides substantial amounts of energy, macronutrients, and micronutrients to the diets of humans. Fresh lean pork contains critical nutrients important for the growth and development of children and adults. It can readily be included as a regular part of a healthy dietary pattern fo...
Progeny born to primiparous sows farrowing their first litter, often called gilt progeny (GP), are typically characterised by their poorer overall production performance than progeny from multiparous sows (sow progeny; SP). Gilt progeny consistently grow slower, are born and weaned lighter, and have higher postweaning illness and mortality rates th...
Sow body composition largely reflects the amount of lean and fat tissue stores in the body, and is measured, managed and reported because traditionally when sows mobilise body tissues in lactation to support piglet growth, adverse consequences in subsequent reproduction may be observed. These consequences are largely driven by metabolic changes exe...
A major priority for the swine industry is the need to successfully transition and then manage the young pig in the period after weaning. Antimicrobial compounds have traditionally been used to assist with this transition. However, bans and restrictions on some antimicrobial compounds and antimicrobial resistance have required different strategies...
Dietary and endogenous protein that become available for the microbiota in the hindgut can be metabolized via different routes. They can become building blocks for the microbial cells or enter different catabolic pathways. Protein degradation via fermentation pathways is seen as a non-preferred route as it results in the formation and release of me...
Gamma-aminobutyric acid (GABA) is a non-protein amino acid, a major inhibitory neurotransmitter in the central nervous system that stimulates feed intake and inhibits the hypothalamic-pituitary-adrenal (HPA) axis. We hypothesised that: (1) GABA supplementation in the diet would reduce markers of the stress response in weaned pigs injected with adre...
Feeding fibre and branched-chain amino acids (BCAA) to sows during late gestation and lactation, respectively, have been shown to improve litter weights at weaning. Therefore, supplementing primiparous sow diets with lucerne chaff, a feedstuff high in fibre, BCAA and tryptophan, may improve the performance of their progeny. Experiment 1 investigate...
Genetic selection of pigs over recent decades has sought to reduce carcass fat content to meet consumer demands for lean meat in many countries (e.g.: Australia). Due to the impacts of genetic changes, it is unknown whether the carcass fat measures are still responsive to energy intake. Thus, the present experiment aimed to quantify the relationshi...
Genetic selection of pigs over recent decades has sought to reduce carcass fat content to meet consumer demands for lean meat in many countries (e.g.: Australia). Due to the impacts of genetic changes, it is unknown whether the carcass fat measures are still responsive to energy intake. Thus, the present experiment aimed to quantify the relationshi...
Post weaning diarrhea (PWD) caused by enterotoxigenic strains of E. coli (ETEC) remains a major problem in the industry, causing decreases in performance and survival of weaned pigs. Traditionally, antimicrobials have been used for its mitigation/control. This study tested the hypothesis that a combination of two organic acid (OA)-based commercial...
Weaning piglets usually involves mixing of non-littermate pigs into a new environment that causes social and physical stress due to the vigorous fighting and contributes to the post-weaning growth check. Dexamethasone (DEX) is a synthetic corticosteroid shown to attenuate stress responses via negative feedback on the hypothalamic-pituitary-adrenal...
The gastrointestinal tract microbiota is involved in the development and function of many body processes. Studies demonstrate that early-life microbial colonisation is the most important time for shaping intestinal and immune development, with perturbations to the microbiota during this time having long-lasting negative implications for the host. P...
Serum creatinine (SCr) in humans has proven to be a reliable biomarker of body protein breakdown and/or muscle mass change. This study set out to investigate the potential of SCr to indicate a loss in sow muscle mass over lactation, validated against 3 methyl histidine (3MH) and blood urea nitrogen (BUN), markers of dietary and/or body protein brea...
The aim of this experiment was to determine whether administration of an anti-inflammatory compound to sows prior to farrowing would, via reduced pain and inflammation, increase piglet survival and growth. At day 114 of gestation, multiparous sows were randomly allocated to one of the following treatments: Control (n = 43), which received 10 mL sal...
For many decades, antimicrobial compounds such as antibiotics and some mineral compounds have been used in pork production to promote pig growth and survival after weaning through mitigation of subclinical and clinical diseases, such as enterotoxigenic strains of Escherichia coli. Bans and restrictions in the use of some antimicrobial compounds has...
Strains of enterotoxigenic Escherichia coli (ETEC) causing post-weaning diarrhoea (PWD) in piglets have a widespread and detrimental impact on animal health and the economics of pork production. Traditional approaches to control and prevention have placed a strong emphasis on antimicrobial use (AMU) to the extent that current prevalent porcine ETEC...
Objective: To determine if feeding a larger diameter pellet increases creep feed intake and growth rate of piglets during lactation, especially that of gilt progeny (GP) compared to sow progeny (SP), and stimulates feed intake after weaning. Materials and methods: Over two repli-cates, GP and SP (n = 2070) were allocated to two creep feed treatment...
The ability to accurately estimate fat mass and fat-free mass (FFM) has the potential to improve the way in which sow body condition can be managed in a breeding herd. Bioelectrical impedance spectroscopy (BIS) has been evaluated as a practical technique for assessment of body composition in several livestock species, but similar work is lacking in...
Dietary tryptophan (Trp) is a precursor for serotonin, a neuromediator involved in stress responses. Tryptophan competes with other large neutral amino acids (LNAA: tyrosine, isoleucine, leucine, valine, and phenylalanine) to cross the blood-brain barrier, therefore regulation of circulating LNAA can influence Trp availability in the cortex and ser...
Gilt progeny (GP) exhibit poorer growth compared with sow progeny (SP), particularly in the pre-weaning and post-weaning period. Late gestation/lactation sow diets and weaner diets were supplemented with 0.5% Polygain (POL), a sugarcane extract rich in polyphenols, to collectively improve GP growth in these periods. Gilts (n = 60) and sows (n = 68,...
The present study investigated the effects
of supplementing a low protein (LP) diet supplemented
with key essential amino acids (AA) to broilers
on growth performance, intestinal tract function, blood
metabolites, and nitrogen excretion when the animals
were maintained under various sanitary conditions for
35 D after hatching. Three hundred eighty-...
[This corrects the article DOI: 10.1186/s40104-019-0366-1.].
This experiment was conducted to determine the optimum standardised ileal digestible (SID) ratio of tryptophan (Trp) to lysine (Lys; Trp:Lys) for commercially housed pigs fed without a dietary antibiotic, but including pharmacological levels of zinc oxide in the immediate post-weaning period. The hypothesis tested was that pigs would positively res...
An infection model with enterotoxigenic Escherichia coli (ETEC) harbouring the F4 fimbriae can be used to assess the impacts that various challenges associated with weaning (e.g., dietary, psychological, environmental) have on the expression of post-weaning diarrhea. The objective of this study was to develop a novel inoculation method for administ...
Evolving technological change in pork production supporting expectations of improved productivity, sustainability and flexibility - Volume 13 Issue 12 - J. F. Patience, J. R. Pluske
Progeny of primiparous sows (gilts) have poor production performance compared to those of multiparous sows. This has been attributed to underlying biological events that occur early in life. We specifically focused on the development of the gastrointestinal tract (GIT) and its function in sow vs gilt progeny (SP vs GP) reared under commercial condi...
1,3-Butanediol (BD) is a ketogenic substance that can improve piglet growth and survival and potentially increase performance in gilt progeny when provided as a dietary supplement during late gestation. Gilts (n = 77; parity 1) and sows (n = 74; parities 2 and 3) were fed either a standard commercial gestation diet or a diet supplemented with 4% BD...
Background:
This study investigated the validity of the DNA-marker based test to determine susceptibility to ETEC-F4 diarrhoea by comparing the results of two DNA sequencing techniques in weaner pigs following experimental infection with F4 enterotoxigenic Escherichia coli (ETEC-F4). The effects of diet and genetic susceptibility were assessed by...
Gilt progeny (GP) often have restricted growth performance and health status in comparison to sow progeny (SP) from birth, with the underlying mechanisms responsible for this yet to be fully understood. The current study aimed to compare differences in growth and development between GP and SP in the first 24 h after birth and in the peri-weaning pe...
Gilt progeny (GP) are born and weaned lighter than sow progeny (SP) and tend to have higher rates of mortality and morbidity. This study quantified the lifetime growth performance differences between GP and SP and, additionally, evaluated whether segregating GP and SP in the grower-finisher period compared to mixing them within common pens reduced...
Feeding conjugated linoleic acid (CLA) or medium-chain fatty acids (MCFA) to dams has been shown to improve progeny growth and survival, and hence may be particularly advantageous to gilt progeny. Primiparous (n = 129) and multiparous sows (n = 123; parities 3 and 4) were fed one of four diets from day 107 of gestation (107.3 ± 0.1 days) until wean...
It is important to understand the biological factors influencing the poorer lifetime performance of gilt progeny in comparison to sow progeny and determine whether this may be partially due to differences in lactation performance between primiparous and multiparous sows. It was hypothesized that primiparous sows would have lower levels of immunoglo...
Psychosocial stress is a major factor driving gastrointestinal-tract (GIT) pathophysiology and disease susceptibility in both humans and animals. Young weaned pigs typically undergo psychosocial and environmental stressors associated with production practices, including separation from their dam, mixing and crowding stress, transport and changed te...
Microalgal biomass grown in wastewater can be a sustainable source of animal feedstock. We have previously shown the feasibility of mass algal cultivation on undiluted anaerobic digested piggery effluent (ADPE). In this study, we evaluated the nutritional value, pathogen load, in vitro digestibility and potential physiological energy (PPE) of ADPE-...
A total of 300 nursery pigs (initially 5.9 ± 0.05 kg BW) were used in a 42-d growth trial to evaluate the effects of feeding a therapeutic level of chlortetracycline (CTC) with or without direct fed microbials (DFM) on growth performance and antimicrobial resistance (AMR) of fecal Escherichia coli. CTC is a broad-spectrum in-feed antibiotic commonl...
Progeny from primiparous sows (gilt) have lower birth weights, higher mortality and poorer performance than the progeny from multiparous sows. The reasons for this are complex but may involve poorer quality colostrum and impaired gastrointestinal tract (GIT) barrier function. With evidence that events early in life impact whole‐of‐life mortality an...
Differences between gilt (GP) and sow progeny (SP) in terms of gut structure and function and digestive capacity may contribute to reduced growth in GP. We hypothesised that colostrum and milk from gilts would contain lower levels of lactose than that of sows, and GP would have lower specific lactase activity in the small intestine than SP with a l...
Gilt progeny are lighter at birth and sale than sow progeny, maybe due to differences in colostrum and milk composition and volume between gilts and sows. Conjugated linoleic acid (CLA) and medium-chain triglycerides and their fatty acids (MCFA) are high energy feed ingredients that when fed to the dam could improve colostrum and milk composition,...
Epidemiological studies have demonstrated that exposure to farm environments during childhood can be linked to reductions in the incidence of immune disorders, but generating an appropriate model is difficult. 108 half-sibling piglets were born on either extensive (outdoor) or intensive (indoor) farms: at 1 day old, a subset of piglets from each li...
A total of 757 pigs (PIC 337 × 1050; initially 27.6 kg body weight) were used in a 117-d experiment to determine the effects of added Cu from tribasic copper chloride and diet type on growth performance, carcass characteristics, energy digestibility, gut morphology, and mucosal mRNA expression of finishing pigs. Pens of pigs were allotted to 1 of 4...
Research has demonstrated medium chain fatty acids (MCFA) are bactericidal and potential antibiotic alternatives. However, it is unknown how the type or level of MCFA impact bacteria growth. This can be tested through a minimum inhibitory concentration (MIC) benchtop assay, which identifies the lowest concentration of a chemical that prevents visib...
Research has confirmed that a 2% inclusion rate of a blend of C6:0, C8:0, and C10:0 in swine diets and ingredients can reduce Salmonella enterica serotype Typhimurium. However, it is unclear how the chain length and concentration of medium chain fatty acids (MCFA) impacts bacteriostatic properties. This can be tested through a minimum inhibitory co...
Medium chain fatty acids (MCFA), have been researched extensively to reduce the likelihood of animal feed being contaminated by biological pathogens, including bacteria and viruses. Medium chain fatty acids have shown to be bactericidal and bacteriostatic by incorporating themselves into the lipid membrane of bacteria, which alters the cell membran...
An optimally functioning gastrointestinal tract (GIT) clearly is of importance to the overall metabolism, physiology, disease status and performance of pigs of all stages of growth and development. Recently, the ‘health’ of the GIT (‘gut health’) has attracted much attention despite the lack of a clear definition to the term or its aetiology, altho...
Across the globe, producers are moving from individual housing to group housing for sows during gestation. Producers typically group sows of a range of parities together, although the impacts are largely unknown. This study examined the behavioral expression at mixing for young, midparity, and older sows. Ten mixed-parity groups were filmed at mixi...
Disease and enhanced microbial load are considered to be major factors limiting the performance and overall efficiency of feed use by pigs in Australian piggeries. It is recognised that pigs exposed to conventional housing systems with high microbial loads grow 10–20% more slowly than do gnotobiotic pigs or pigs kept in ‘clean’ environments. Conseq...
Regulation of feed intake is under complex control, involving physical, chemical, hormonal and neuronal responses. Understanding the regulation of feed intake in farm animals is key to optimisation of intake to meet production and profitability goals. Fundamental mechanisms regulating feed intake include constraints imposed by the gut, systems moni...
Background
In this experiment, intermittent suckling (IS) with or without the co-mingling (CoM) of piglets was studied as a method to stimulate solid feed intake and reduce post-weaning stress. Methods
Three weaning regimes using 30 multiparous sows were compared: (1) conventional weaning (CW) (n = 10 litters), where piglets had continuous access t...
Gilt progeny (GP) are born and weaned lighter than sow progeny (SP) and have higher rates of mortality. This study aimed to quantify the performance and survival differences between GP and SP throughout the entire production cycle from birth to sale. Furthermore, the study looked at the effects of segregating GP and SP compared with commingling dur...
Prebiotics and probiotics have attracted considerable interest as alternatives or replacements for growth-promoting antibiotics and/or some heavy metals in diets for pigs, particularly in the post-weaning period where the newly weaned pig is subject to considerable challenges in its new environment. This chapter briefly reviews the microbiota of th...
Objective: To quantify the performance of gilt progeny in the F1 breeding herd at a large swine farm in New South Wales, Australia (Rivalea Australia Pty Ltd).
Materials and methods: Performance data on all gilts selected for entrance to the commercial breeding herd from January 2014 until December 2015 were included in this study. Comparisons wer...
We investigated the effect of different pre-weaning interventions on performance, aspects of behaviour, and selected neuroendocrine, inflammatory and immune indices in 593 weanling pigs (59 litters, weaning age 22 ± 1.7). Measurements were taken at various time points two weeks before and after weaning. Sugar absorption tests (20% mannitol and 20%...
Progeny born to gilts are generally born lighter, grow slower, and have higher rates of mortality and morbidity than their sow progeny counterparts. These differences are thought to be a result of the physical underdevelopment of the gilt herself, as well as decreased piglet consumption of colostrum (and milk) that is lower in levels of immunoglobu...
The present study was conducted to determine the effect of reducing dietary n-6:n-3 PUFA ratio on the performance, inflammatory response and gut morphology of PWD challenged with sanitary and poor sanitary conditions in weaned pigs, and to test the hypotheses that (1) exposure to an poor sanitary environment will increase indices for inflammatory r...
This experiment tested the hypothesis that pigs challenged with an enterotoxigenic strain of E. coli (ETEC) would require a higher sulphur amino acids (SAA) to Lys ratio (SAA:Lys). Pigs (n = 120) weighing 7.4 ± 0.52 kg (mean ± SD) and weaned at 27 d (Pietrain genotype, mixed sex) were stratified into 1 of 6 treatments based on weaning weight, sex a...
The production performance and financial outcomes associated with weaner diet complexity for pigs of different weight classes at weaning were examined in this experiment. A total of 720 weaner pigs (360 entire males and 360 females) were selected at weaning (27 ± 3 d) and allocated to pens of 10 based on individual weaning weight (light weaning wei...
Background
Three experiments were conducted to examine the overall hypothesis that addition of medium chain triglycerides (MCT) and cysteamine hydrochloride (CSH) into the diets of young and growing pigs would stimulate the endogenous somatotropic axis to improve growth and performance. ResultsIn Experiment 1, weaner pigs were given either a 5 d di...
This study tested the hypothesis that intermittent suckling (IS) with or without an older weaning age would improve post-weaning gastrointestinal tract (GIT) carbohydrate absorptive capacity in pigs while reducing post-weaning stress and aspects of the inflammatory response. Three weaning regimes using primiparous sows were compared: (1) convention...
Efficient utilization of dietary protein is affected by many factors including the animal's physiological requirements for amino acids, genetic potential for protein deposition, digestion/absorption of dietary amino acids, use of antibiotics, and metabolism/partitioning of absorbed amino acids. Although other factors are equally important for prote...
Simple Summary
Predation of piglets by red foxes is a significant risk for outdoor/free-range pork producers, but is often difficult to quantify. Using remote sensing cameras, we recorded substantial evidence of red foxes taking piglets from around farrowing huts, and found that piglets were most likely to be recorded as “missing” over their first...
Background: This experiment was conducted to test the hypothesis that vitamin E (Vit E) and acetylsalicylic acid (ASA), a cyclooxygenase-2 (COX-2) inhibitor, will additively reduce the production of the immunosuppressive molecule prostaglandin E 2 (PGE 2) and hence reduce inflammatory responses in weaner pigs experimentally infected with an enterot...
The growth and development of the gastrointestinal tract (GIT) of the young pig, both before and after parturition, is critical for the ani-mal’s future growth and development, efficiency of feed conversion to body depots, and, ultimately, its survival. The perinatal development of the GIT encompasses a prenatal phase, a neonatal phase, and the pos...
