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Limited By:	Author = Diskin, Michael G.;

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Prevalence of Bovine Viral Diarrhoea Virus (BVDV), Bovine Herpes Virus 1 (BHV 1), Leptospirosis and Neosporosis, and associated risk factors in 161 Irish beef herds (2018)

Barrett, Damien; Parr, Mervyn; Fagan, John; Johnson, Alan; Tratalos, Jamie; Lively, Fra...

Prevalence of Bovine Viral Diarrhoea Virus (BVDV), Bovine Herpes Virus 1 (BHV 1), Leptospirosis and Neosporosis, and associated risk factors in 161 Irish beef herds (2018)

Barrett, Damien; Parr, Mervyn; Fagan, John; Johnson, Alan; Tratalos, Jamie; Lively, Francis; Diskin, Michael G.; Kenny, David A.

Abstract:

Background There are limited data available, in Ireland or elsewhere, to determine the extent of exposure to various endemic diseases among beef cows and factors associated with exposure to causative pathogens. The objectives of this study were to determine the herd and within herd prevalence of Bovine Viral Diarrhoea Virus (BVDV), Bovine Herpes Virus 1 (BHV-1), Leptospirosis and Neosporosis in a large scale study of commercial beef herds on the island of Ireland, and to examine herd level factors associated with exposure to these pathogens in these herds. Results The average number of cows tested per herd was 35.5 (median 30). Herd level seroprevalence to Bovine Herpesvirus-1(BHV-1), Bovine Viral-Diarrhoea Virus (BVDV), Leptospirosis and Neosporosis was 90%, 100%, 91% and 67%, respectively, while the mean within herd prevalence for the these pathogens was 40%, 77.7%, 65.7% and 5.7%, respectively. The stud...

http://hdl.handle.net/11019/1536

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Protein Nutrition and Fertility in Cattle. (2017)

Kenny, David A.; Diskin, Michael G.; Sreenan, J.M.

Protein Nutrition and Fertility in Cattle. (2017)

Kenny, David A.; Diskin, Michael G.; Sreenan, J.M.

Abstract:

End of Project Report
The objectives of the project were to determine the effects of dietary crude protein intake, on blood concentrations of ammonia and urea and on fertility, and on the possible biological mechanisms involved. Heifers were used in all experiments in order to avoid any confounding effects of lactation and, or, negative energy balance. The results are summarised as follows. • • • • 5 Blood urea and ammonia increased linearly with increases in dietary urea. Fermentable carbohydrate, in the form of molassed sugar beet pulp (MSBP), was more effective than barley in reducing blood urea concentration. Plasma ammonia concentrations were more variable but MSBP was again more effective than barley in reducing these. Embryo survival rate was not affected by either dietary crude protein (CP) or fermentable energy intake irrespective of whether animals were fed a silage diet supplemented with feed grade urea or were grazing pasture with a high crude protein content. Despit...

http://hdl.handle.net/11019/1371

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Shortening the interval to resumption of ovarian cycles in postpartum beef cows. (2017)

Diskin, Michael G.; Mackey, D.R.; Stagg, K.; Roche, J.F.; Sreenan, J.M.

Shortening the interval to resumption of ovarian cycles in postpartum beef cows. (2017)

Diskin, Michael G.; Mackey, D.R.; Stagg, K.; Roche, J.F.; Sreenan, J.M.

Abstract:

End of Project Report
• In beef cows the interval from calving to first ovulation, or postpartum interval, is affected by nutrition and by the suckling effect of the calf. • The suckling effect is the biggest determinant of this interval, comprising: (i) physical contact and (ii) maternal bonding between cow and calf. Restricted suckling and calf isolation induce a rapid resumption of oestrous cycles. • Prepartum nutrition is the next most important determinant of the postpartum interval. Cows that calve in poor body condition have a longer interval than cows that calve in good body condition. • Increasing the level of nutrition in the postpartum period has only a limited effect in shortening the postpartum interval. • In most cows the first postpartum ovulation is silent and is succeeded by a short oestrous cycle of approximately 8-10 days. The first observed oestrus occurs prior to the second ovulation. • When used in combination with calf isolation and restricted suckling, pr...

http://hdl.handle.net/11019/1400

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Single nucleotide polymorphisms in the insulin-like growth factor 1 (IGF-1) gene are associated with performance in Holstein-Friesian dairy cattle (2013)

Mullen, Michael P.; Berry, Donagh; Howard, Dawn J.; Diskin, Michael G.; Lynch, Ciaran O...

Single nucleotide polymorphisms in the insulin-like growth factor 1 (IGF-1) gene are associated with performance in Holstein-Friesian dairy cattle (2013)

Mullen, Michael P.; Berry, Donagh; Howard, Dawn J.; Diskin, Michael G.; Lynch, Ciaran Oliver; Giblin, Linda; Kenny, David A.; Magee, David A; Meade, Kieran G; Waters, Sinead M.

Abstract:

Insulin-like growth factor 1 (IGF-1) has been shown to be associated with fertility, growth, and development in cattle. The aim of this study was to (1) identify novel single nucleotide polymorphisms (SNPs) in the bovine IGF-1 gene and alongside previously identified SNPs (2) determine their association with traits of economic importance in Holstein-Friesian dairy cattle. Nine novel SNPs were identified across a panel of 22 beef and dairy cattle by sequence analysis of the 5′ promoter, intronic, and 3′ regulatory regions, encompassing ∼5 kb of IGF-1. Genotyping and associations with daughter performance for milk production, fertility, survival, and measures of body size were undertaken on 848 Holstein-Friesian AI sires. Using multiple regression analysis nominal associations (P < 0.05) were identified between six SNPs (four novel and two previously identified) and milk composition, survival, body condition score, and body size. The C allele of AF017143 a previously published SNP ...

http://hdl.handle.net/11019/351

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Studies relating to Polyunsaturated Fatty Acid (PUFA) Supplementation and Fertility in Cattle (2015)

Childs, Stuart; Kenny, David A.; Sreenan, J.M.; Diskin, Michael G.

Studies relating to Polyunsaturated Fatty Acid (PUFA) Supplementation and Fertility in Cattle (2015)

Childs, Stuart; Kenny, David A.; Sreenan, J.M.; Diskin, Michael G.

Abstract:

End of project report
Reproductive inefficiency has a significant impact on the economic performance of both dairy and beef herds, particularly in seasonal calving systems. Nutrition plays a fundamental role in reproduction. Furthermore, there is emerging evidence that supplemental dietary polyunsaturated fatty acids (PUFA) may increase cow fertility independent of their role as energy substrates. A number of studies have reported enhanced reproductive performance in dairy cows following dietary supplementation with sources of n-3 PUFA. However the possible mechanisms involved have not been identified and there is some inconsistency in the published literature on this topic. The objective of the research reported was to conduct a holistic examination of the effects of dietary long-chain n-3 PUFA supplementation on metabolic and reproductive responses in cattle. Such information is essential for the appropriate formulation of diets to enhance cow reproductive performance and in p...

http://hdl.handle.net/11019/932

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Studies relating to protein expression in the uterus of the cow (2015)

Costello, L.M.; Hynes, A.C.; Diskin, Michael G.; Sreenan, J.M.; Morris, Dermot G.

Studies relating to protein expression in the uterus of the cow (2015)

Costello, L.M.; Hynes, A.C.; Diskin, Michael G.; Sreenan, J.M.; Morris, Dermot G.

Abstract:

End of project report
Embryo loss is a major cause of reproductive wastage in the cow. The majority of embryo loss occurs in the first 16 days after fertilisation when the embryo is critically dependent on the maternal uterine environment for survival. Despite the central role of uterine fluid in the normal growth and development of the embryo, there is limited information on the protein composition of these fluids. The main objectives of the studies in this thesis were to examine the protein composition of the bovine uterus during the oestrous cycle and to examine the relationship between the concentration of systemic progesterone and uterine protein expression in the cow. In the first study, the concentration of retinol-binding protein (RBP) in the bovine uterus was found to vary across the cycle and was 5-15-fold higher (P<0.001) on Day 15 than Days 3, 7 and 11. Additionally, the concentration of uterine RBP seems to be regulated in a local manner as the concentration in t...

http://hdl.handle.net/11019/934

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The effects of altering milking frequency and/or diet in early lactation on the energy balance, production and reproduction of dairy cows. (2017)

Murphy, J.J.; Mee, John F; McNamara, S.; Patton, Joe; Kenny, David A.; Diskin, Michael ...

The effects of altering milking frequency and/or diet in early lactation on the energy balance, production and reproduction of dairy cows. (2017)

Murphy, J.J.; Mee, John F; McNamara, S.; Patton, Joe; Kenny, David A.; Diskin, Michael G.; O'Mara, Frank P.

Abstract:

End of Project Report
It has been suggested that negative energy balance (NEB) in the immediate post-partum period is potentially an important factor in the association between increasing milk output and declining reproductive performance. The objective of this project was to design an experimental model that could be used to impose different degrees of NEB immediately after calving and to examine the effect of this model on dry matter intake (DMI), milk production, energy balance (EB), metabolic and reproductive hormonal profiles, the onset and pattern of post-partum ovarian cyclicity and reproductive physiology around AI. Two experiments were carried out to evaluate the effects of milking frequency and diet on DMI, production, energy balance and blood metabolites and hormones in the first 4 weeks after calving and subsequent reproduction. Reducing milking frequency from either thrice or twice daily to once daily reduced DMI but also reduced milk production. This resulted in a ...

http://hdl.handle.net/11019/1337

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The integration of ‘omic’ disciplines and systems biology in cattle breeding (2013)

Berry, Donagh; Meade, Kieran G; Mullen, Michael P.; Butler, Stephen T.; Diskin, Michael...

The integration of ‘omic’ disciplines and systems biology in cattle breeding (2013)

Berry, Donagh; Meade, Kieran G; Mullen, Michael P.; Butler, Stephen T.; Diskin, Michael G.; Morris, Dermot G.; Creevey, Christopher J.

Abstract:

Enormous progress has been made in the selection of animals, including cattle, for specific traits using traditional quantitative genetics approaches. Never the less, considerable variation in phenotypes remains unexplained, and therefore represents potential additional gain for animal production. In addition, the paradigm shift in new disciplines now being applied to animal breeding represents a powerful opportunity to prise open the ‘black box’ underlying the response to selection and fully understand the genetic architecture controlling the traits of interest. A move away from traditional approaches of animal breeding toward systems approaches using integrative analysis of data from the ‘omic’ disciplines represents a multitude of exciting opportunities for animal breeding going forward as well as providing alternatives for overcoming some of the limitations of traditional approaches such as the expressed phenotype being an imperfect predictor of the individual’s true genetic mer...

http://hdl.handle.net/11019/379

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Viability of in vitro produced cattle embryos. (2017)

Morris, Dermot G.; Diskin, Michael G.; Sreenan, J.M.

Viability of in vitro produced cattle embryos. (2017)

Morris, Dermot G.; Diskin, Michael G.; Sreenan, J.M.

Abstract:

End of Project Report
Embryo transfer is being increasingly used in the cattle industry. As well as direct embryo transfers, many embryo-based biotechnologies have the potential to improve cattle production efficiency through enhanced breeding strategies, by facilitating the introduction of desirable traits such as disease resistance and through the production of desirable medical or pharmaceutical products in the milk. These biotechnologies are, however, dependent on a supply of viable in vitro produced (IVP) embryos. While the in vitro fertilization rate is high (80%) in cattle, only about 30 transferable embryos, or blastocysts, are produced from every 100 fertilized oocytes. A major factor affecting the viability of IVP embryos is their failure, in a high proportion of cases, to undergo normal development to the blastocyst stage in the manner of in vivo embryos. The major problem relates to a failure of the cells of IVP embryos to form a compact cell mass when they are 5 - 6...

http://hdl.handle.net/11019/1381