Publications by authors named "Alan G Fahey"

Background: Improving feed efficiency is the most important goal for modern animal production. The regulatory mechanisms of controlling feed efficiency traits are extremely complex and include the functions related to host genetics and gut microbiota. Short-chain fatty acids (SCFAs), as significant metabolites of microbiota, could be used to refine the combined effect of host genetics and gut microbiota.

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The objectives of this study were to evaluate the effects of (1) protein supplementation strategy, (2) cow genotype and (3) an interaction between protein supplementation strategy and cow genotype on milk production and nitrogen (N) utilisation efficiency (milk N output/ total dietary N intake × 100; NUE) in late-lactation, spring-calving grazing dairy cows. A 2 × 2 factorial arrangement experiment, with two feeding strategies [13% (lower crude protein; LCP) and 18% CP (higher CP; HCP) supplements with equal metabolisable protein supply] offered at 3.6 kg dry matter/cow perday, and two cow genotype groups [lower milk genotype (LM) and higher milk genotype (HM)], was conducted over 53 days.

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The breeding of sport horses to compete in the Olympic disciplines of show jumping, eventing, and dressage is fast becoming a global industry with the increased use of reproductive technologies, including artificial insemination and embryo transfer. Reproductive technologies have facilitated the dissemination of genetics from elite horses across multiple countries and breeds as breeders are no longer limited by location. Due to this increased level of crossbreeding, there is an increased need for estimated breeding values (EBVs) for sport horse performance that can be compared across breeds and countries.

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Residual feed intake (RFI) is a measure of the feed efficiency of animals. Previous studies have identified SNPs associated with RFI. The objective of this study was to compare the GBLUP model with the GA-BLUP model including previously identified associated SNPs.

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Ovulation has been described as an inflammatory event, characterized by an influx of leukocytes into the ovulatory follicle and changes in the expression profile of immune factors in both the theca and granulosa tissue layers. Since information on this process is limited in cattle, our objective was to elucidate the contribution of the immune system to dominant follicle luteinization, ovulation and corpus luteum (CL) formation in cattle. Beef heifers (n = 50) were oestrous synchronized, slaughtered and ovarian follicular or luteal tissue collected during a 96 h window around ovulation.

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Diets low in seafood omega-3 polyunsaturated fatty acids (PUFAs) are very prevalent. Such diets have recently been ranked as the sixth most important dietary risk factor-1.5 million deaths and 33 million disability-adjusted life-years worldwide are attributable to this deficiency.

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Background: Lamb diets can alter the fatty acid (FA) profile of muscle and adipose tissue, which may affect the sensory quality and consumer acceptability of the meat. In this study, lambs received one of four pre-slaughter diets: a barley / maize / soya-based concentrate (C), supplemented with a saturated fat source (Megalac®) (SAT), or supplemented with protected linseed oil (PLO); or a by-product (citrus pulp / distillers' grain / soya-based) diet (BPR). Intramuscular FAs and adipose tissue branched-chain FAs were measured and consumer evaluation (hedonic liking and attribute intensity) was undertaken with cooked lamb.

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Animal production factors can affect the sensory quality of lamb meat. The study investigated the effect of diet composition and duration of consumption on the proximate analysis, volatile profile and sensory quality of lamb meat. Ninety-nine male Texel × Scottish Blackface lambs were raised at pasture for 10 months before being assigned in groups of 11 to one of the following treatments: 100% Silage (S) for 36 (S36), 54 (S54) or 72 (S72) days; 50% Silage - 50% Concentrate (SC) for 36 (SC36), 54 (SC54) or 72 (SC72) days; 100% Concentrate (C) for 36 (C36) or 54 (C54) or 72 (C72) days.

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Meiotic recombination is an important contributor to genetic variation and ensures proper chromosome segregation during gametogenesis. Previous studies suggest that at least 1 crossover (CO) per chromosome arm is important to avoid mis-segregation. While the total number of COs per spermatocyte is known to differ in mice, this is only beginning to be evaluated in sheep.

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Unlabelled: The aim of this study was to assess the effect of castration and slaughter age on the volatile profile of cooked meat from Scottish Blackface (SB) and Texel × Scottish Blackface (T × SB) lambs. M. longissimus thoracis et lumborum was sampled at slaughter and subjected to volatile analysis by SPME-GC-MS.

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Rations (DM basis) for spring-born male lambs consisting of concentrates ad libitum (), 50:50 (50% concentrate:50% forage), and forage ad libitum () were evaluated across feeding periods of three durations (36, 54, and 72 d). Lambs on CON diets were offered ad libitum access to concentrate along with 400 g of fresh weight silage (daily), while 50:50 diets were offered 0.9 and 3.

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The practice of crossbreeding using a terminal sire and the use of intact rather than castrated animals has the potential to increase the productivity of lambs produced from the hill sheep sector. The objective of this study was to compare the production and carcass characteristics of purebred Scottish Blackface () and Texel cross Scottish Blackface () ram and wether lambs fed on a concentrate diet and slaughtered at different ages. Two hundred spring born male lambs (average birth age ± SD 9.

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Kerry cattle are an endangered landrace heritage breed of cultural importance to Ireland. In the present study we have used genome-wide SNP array data to evaluate genomic diversity within the Kerry population and between Kerry cattle and other European breeds. Patterns of genetic differentiation and gene flow among breeds using phylogenetic trees with ancestry graphs highlighted historical gene flow from the British Shorthorn breed into the ancestral population of modern Kerry cattle.

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Background: Milk fat is important in terms of economic value and in its potential to provide information concerning cow diet and health. Under current milk payment schemes in Ireland farmer income is directly linked to milk fat production.

Methods: A descriptive analysis of milk fat depression (MFD) as calculated from test day milk recording data across all milk recording herds from 2004 to 2014 was undertaken.

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Background: Analysis of data collected from pig farms may be useful to understand factors affecting pig health and productive performance. However, obtaining these data and drawing conclusions from them can be done at different levels and presents several challenges. In the present study, information from 688 batches of growing-finishing (GF) pigs (average initial and final body weight of 19.

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The increasing world population means that there is a requirement to expand global food production. Looking at the Republic of Ireland as an example, the risks and opportunities associated with the expansion of food production are outlined, particularly in relation to zoonoses transmission. A One Health approach to sustainable food production is required to avert a potential public health problem associated with increased agricultural expansion.

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Mastitis is an inflammation-driven disease of the bovine mammary gland that occurs in response to physical damage or infection and is one of the most costly production-related diseases in the dairy industry worldwide. We performed a genome-wide association study (GWAS) to identify genetic loci associated with somatic cell score (SCS), an indicator trait of mammary gland inflammation. A total of 702 Holstein-Friesian bulls were genotyped for 777,962 single nucleotide polymorphisms (SNPs) and associated with SCS phenotypes.

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Article Synopsis
  • Despite research on cow fertility, the impact of the maternal immune system during cattle pregnancy is not fully understood, prompting a study to assess various immune cell types in bovine endometrial tissue.
  • Samples were taken from beef heifers on specific days of the estrous cycle or pregnancy, analyzed for immune cells and mRNA levels of key immune factors.
  • Results showed a prevalence of B-cells and moderate presence of T-cells in endometrial tissue, with notable changes in natural killer (NK) cells during pregnancy, indicating a Th2 immune environment that adjusts in response to embryo presence.
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The follicle is a unique micro-environment within which the oocyte can develop and mature to a fertilisable gamete. The aim of this study was to investigate the ability of a panel of follicular parameters, including intrafollicular steroid and metabolomic profiles and theca, granulosa and cumulus cell candidate gene mRNA abundance, to predict the potential of bovine oocytes to develop to the blastocyst stage in vitro. Individual follicles were dissected from abattoir ovaries, carefully ruptured under a stereomicroscope and the oocyte was recovered and individually processed through in vitro maturation, fertilisation and culture.

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Prenatal stress can alter the serotonin (5-HT) system in the developing and adult brain and lead to mood and behavioral disorders in children and adults. The chicken provides a unique animal model to study the effects of embryonic stressors on childhood and adolescent behavior. Manipulations to the egg can be made in the absence of confounding maternal effects from treatment.

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In mammals, successful pregnancy is dependent in part on the adaptation or regulation of the maternal immune system to prevent the rejection of the embryonic semiallograft. A modification in Th cell function and secretion is a requirement for the establishment and maintenance of pregnancy. Although there is strong evidence from studies in humans and mice linking successful pregnancy with the predominance of Th2-type immunity, the situation in cattle remains unclear.

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Background: Contemporary dairy breeding goals have broadened to include, along with milk production traits, a number of non-production-related traits in an effort to improve the overall functionality of the dairy cow. Increased indirect selection for resistance to mastitis, one of the most important production-related diseases in the dairy sector, via selection for reduced somatic cell count has been part of these broadened goals. A number of genome-wide association studies have identified genetic variants associated with milk production traits and mastitis resistance, however the majority of these studies have been based on animals which were predominantly kept in confinement and fed a concentrate-based diet (i.

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Selective breeding for speed in the racehorse has resulted in an unusually high frequency of the C-variant (g.66493737C/T) at the myostatin gene (MSTN) in cohorts of the Thoroughbred horse population that are best suited to sprint racing. Here we show using a combination of molecular- and pedigree-based approaches in 593 horses from 22 Eurasian and North-American horse populations, museum specimens from 12 historically important Thoroughbred stallions (b.

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