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106 results on '"Gordon, A.W."'

22. Effects of plane of nutrition of ewes in early and mid-pregnancy on performance of the offspring: female reproduction and male carcass characteristics

Author

Munoz, C., Carson, A.F., McCoy, M.A., Dawson, L.E.R., Wylie, A.R.G., and Gordon, A.W.

Subjects
Ewes -- Health aspects, Sheep breeding -- Methods, Animal nutrition -- Research, Zoology and wildlife conservation
Abstract

This study investigated the effects of different planes of nutrition in early pregnancy (EP) and mid-pregnancy (MP) of crossbred ewes on carcass characteristics of male offspring and reproductive performance of female offspring. During EP (d 1 to 39 after synchronized mating) ewes were allocated 60% (low, L-EP), 100% (medium, M-EP), or 200% (high, H-EP) of their energy requirements for maintenance. Between d 40 and 90 (MP), ewes were then allocated 80% (MMP) or 140% (H-MP) of their maintenance energy requirement. After d 90, all ewes were fed to fully meet energy requirements for late pregnancy. Male offspring (n = 83) were reared on a grass-based system and slaughtered at 42, 46, or 50 kg of BW. Female offspring (n = 60) were reared on a grass-based system, mated at 8 too, and performance recorded until weaning of their first lamb crop. Concentrations of leptin, an adiposity indicator, in female offspring varied with the plane of maternal nutrition in early pregnancy. The L-EP offspring had greater leptin concentrations than H-EP offspring (P = 0.04), with M-EP offspring showing intermediate concentrations. Reproductive performance of female offspring was not affected by maternal plane of nutrition (P [greater than or equal to] 0.16). Female H-EP offspring gave birth to heavier lambs (generation 2 offspring) than M-EP (P = 0.006) with L-EP offspring intermediate. Male offspring of L-EP dams showed a trend toward poorer carcass conformation (P = 0.06) and increased fat classification (P = 0.07), consistent with increased fat depths over the loin (P = 0.02). There was a significant interaction between plane of nutrition in early pregnancy and mid-pregnancy for female offspring BW at 2 mo postmating and 16 wk postlambing (P [greater than or equal to] 0.04), and for male offspring perinephric and retroperitoneal fat and tissue depth (P [greater than or equal to] 0.02). For dams offered diet L-EP during early pregnancy, diet H-MP gave heavier offspring with more perinephric and retroperitoneal fat. In contrast, for dams offered diet H-EP during EP, diet M-MP gave offspring that were heavier or fatter or both. Maintenance level of nutrition in EP followed by M-MP or H-MP treatments resulted in offspring intermediate in fatness and BW. The data indicate that adaptations in EP and MP to compensate for nutritional deprivation or nutritional excess can alter the BW, adiposity, conformation, and leptin concentrations of offspring. Such changes have potential to alter health and lifetime productive performance. Key words: adiposity, fetal programming, leptin, nutrition, sheep doi: 10.2527/jas.2009-1842

Published
2009

27. Regional, socioeconomic and behavioural- impacts on consumer acceptability of beef in Northern Ireland, Republic of Ireland and Great Britain

Author

Chong, F.S., primary, Farmer, L.J., additional, Hagan, T.D.J., additional, Speers, J.S., additional, Sanderson, D.W., additional, Devlin, D.J., additional, Tollerton, I.J., additional, Gordon, A.W., additional, Methven, L., additional, Moloney, A.P., additional, Kerry, J.P., additional, and O'Sullivan, M.G., additional

Published
2019
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38. Dairy cow performance and nutrient utilisation when offered high or low digestibility grass silages at two levels of total diet crude protein

Author

Craig, A., Gordon, A.W., and Ferris, C.P.

Abstract

The hypothesis of this study was that grass silage digestibility would influence the response of dairy cows offered diets differing in crude protein (CP) content. Thirty-two mid-lactation Holstein dairy cows were used in a 2 period (21-d adaption phase, 7-d measurement phase), partially balanced change-over experiment. Four treatments were organized in a 2 × 2 factorial arrangement, comprising 2 grass silages differing in digestible organic matter in the dry matter (D-value; 748 and 668 g/kg DM, High-Dand Low-D, respectively) and 2 total diet CP levels (target 145 g/kg DM and 175 g/kg DM, High CPand Low CP,respectively). The latter were achieved using 2 iso-energetic concentrates which differed in CP level (173 and 228 g/kg DM). Silages and concentrates were mixed and offered as a total mixed ration in a 50:50 DM ratio. At the end of the feeding study, nutrient utilization was measured using 4 cows per treatment. Except for milk urea nitrogen there were no interactions between silage digestibility and total diet CP for cow performance and nutrient utilization. The High-D silage improved cow performance and increased nitrogen-use-efficiency (NUE). Reducing total diet CP also increased NUE, but there were negative impacts on cow performance. While there were benefits of offering grass silage with a high digestibility, responses to total diet CP were similar at both levels of silage digestibility.

Published
2024
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