Nutritional status of adult ewes during early and mid-pregnancy. 2. Effects of supplementation with selenised yeast on ewe reproduction and offspring performance to weaning

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The objective of the present study was to determine the effect of plane of nutrition in early pregnancy (EP) and mid-pregnancy (MP), on the productive performance of 1-and 2-year-old ewes and their offspring. Over 2 successive years, between days 0 and 39 after synchronized mating (EP), 1-(n 5 117) and 2-(n 5 52) year-old ewes were allowed 60% (low, L-EP), 100% (medium, M-EP) or 200% (high, H-EP) of requirements for maintenance (M). Between days 40 and 90 (MP), 1-year-old ewes were allowed 140% (M-MP) or 200% (H-MP), while 2-year-old ewes were allowed 80% (M-MP) or 140% (H-MP) of their M requirement. After day 90, all ewes were fed to meet requirements for late pregnancy. Increasing the plane of nutrition between days 0 and 39 resulted in increases in live weight (LW) ( P , 0.001) and body condition score (BCS) ( P , 0.001) during the EP period (H-EP . M-EP . L-EP), differences that in 1-year-old ewes were sustained to lambing ( P , 0.05). On day 42 of gestation H-EP ewes had lower plasma progesterone concentrations than L-EP or M-EP ewes in 1-( P , 0.01) and 2-( P , 0.001) year olds. This was concomitant with diet H-EP tending to reduce the number of lambs born per ewe in both age groups ( P 5 0.06 and 0.07, respectively). Foetuses from 1-year-old L-EP ewes had smaller cranial ( P , 0.01) and abdominal ( P , 0.05) diameters at day 53 of gestation, with H-EP lambs tending to be heaviest at birth ( P 5 0.07). Similar findings were recorded for 2-year-old ewes. One-year-old ewes offered diet L-EP presented negative maternal behaviours more frequently ( P , 0.05), while the incidence of lamb mortality at 6 weeks tended to be greater for L-EP lambs ( P 5 0.07). In MP, 1-year-old ewes offered diet M-MP were associated with foetuses with bigger abdominal diameters at day 78 ( P , 0.05). However, there were no differences in lamb weight or size at term ( P . 0.05). These ewes exhibited more positive maternal behaviours (e.g. increased grooming frequency and duration; P , 0.05) than ewes offered diet H-MP, and their offspring were more successful in suckling ( P , 0.05). Results suggest that in young ewes, a temporary nutrient restriction in EP resulted in increased prolificacy. However, ewes and their offspring were lighter at birth and ewe maternal behaviour was poorer, resulting in increased lamb mortality. In MP, a medium plane of nutrition offered to 1-year-old ewes led to improved maternal and offspring behaviour.

Section: Experimental Designmentioning

confidence: 99%

Section: Measurementsmentioning

confidence: 99%

Effect of plane of nutrition of 1- and 2-year-old ewes in early and mid-pregnancy on ewe reproduction and offspring performance up to weaning

Muñoz

Carson

McCoy

et al. 2009

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“…Although symptoms of clinical Se deficiency are uncommon, Se inadequacy is widely reported throughout the United Kingdom and Ireland (Wang et al, 1987;Mee et al, 1994). Studies in sheep have reported increased live weight gain in lambs following Se supplementation both directly (Blaxter, 1963) and indirectly via their dams (Muñ oz et al, 2008 and. Feeding high PUFA diets can lead to increased oxidative stress in lambs; however, there is some evidence that feeding supranutritional levels of vitamin E help protect against lipid peroxidation, resulting in increased PUFA levels in the meat (Demirel et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Effects of supplementation with fish oil and barium selenate on performance, carcass characteristics and muscle fatty acid composition of late season lamb finished on grass-based or concentrate-based diets

Annett

Carson

Fearon

et al. 2011

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The objectives of this study were to investigate the effects of fish oil supplementation on performance and muscle fatty acid composition of hill lambs finished on grass-based or concentrate-based diets, and to examine the interaction with selenium (Se) status. In September 2006, 180 entire male lambs of mixed breeds were sourced from six hill farms after weaning and finished on five dietary treatments: grazed grass (GG), grass 10.4 kg/day cereal-based concentrate (GC), grass 10.4 kg/day cereal-based concentrate enriched with fish oil (GF), ad libitum cereal-based concentrate (HC) and ad libitum fish oil-enriched concentrate (HF). Within each treatment, half of the lambs were also supplemented with barium selenate by subcutaneous injection. At the start of the trial, the proportion of lambs with a marginal (,0.76 mmol/l) or deficient (,0.38 mmol/l) plasma Se status was 0.84 and 0.39, respectively. Compared with control lambs, GG lambs treated with Se had higher ( P , 0.01) plasma Se levels, whereas erythrocyte glutathione peroxidase activity was higher ( P , 0.01) for Se-supplemented lambs fed diets GG and GF. However, Se supplementation had no effects on any aspect of animal performance. Fish oil increased ( P , 0.05) levels of 22:5n-3 and 22:6n-3 in the Longissimus dorsi of HF lambs but otherwise had no effect on the health attributes of lamb meat. There were no significant effects of fish oil on dry matter intake, animal performance or lamb carcass characteristics. Daily carcass weight gain (CWG; P , 0.001), carcass weight ( P , 0.01) and conformation score ( P , 0.01) increased with increasing concentrate inputs. Lambs fed concentrate-based diets achieved a higher mean CWG ( P , 0.001), dressing proportion ( P , 0.001) and carcass weight ( P , 0.011), and were slaughtered up to 8.3 days earlier ( P , 0.05) and at 1.2 kg lower ( P , 0.05) live weight than pasture-fed lambs. However, carcasses from grass-fed lambs contained lower levels of perinephric and retroperitoneal fat ( P , 0.05), and had less fat over the Iliocostalis thoracis ( P , 0.001) and Obliquus internus abdominis ( P , 0.05). Meat from grass-fed lambs also had lower levels of 18:2n-6 and total n-6 fatty acids compared with those finished indoors. The results of this study demonstrate that fish oil supplementation has some benefits for the health attributes of meat from lambs fed concentrate-based diets but not grass-based diets. Supplementing Se-deficient lambs with barium selenate will improve Se status of lambs fed zero-concentrate diets, but has no additional benefit when lambs are already consuming their daily Se requirement from concentrates or when fish oil-enriched diets are fed.

“…Foetuses from Se-supplemented ewes had greater body weights. Munoz et al (2006) fed an additional 500 mg organically bound Se daily from 14 days before mating to day 90 of pregnancy. Initial mean GPx activities ( ,33 U per ml red blood cells) were in the low to marginal range.…”

mentioning

confidence: 99%

The potential for improving physiological, behavioural and immunological responses in the neonatal lamb by trace element and vitamin supplementation of the ewe

Rooke¹,

Dwyer²,

Ashworth³

2008

Neonatal lamb mortality represents both a welfare issue (due to the considerable suffering and distress) and an important production inefficiency. In lambs, approximately 80% of mortality can be attributed to the starvation-mismothering-exposure complex and occurs in the first 3 days after birth. It was the object of this review to determine the micronutrient(s) most likely to have a positive effect on neonatal lamb survival when included above the requirement for that micronutrient. Micronutrients discussed were Co, Cu, I, Fe, Mn, Se, Zn, vitamins A and E and n-3 fatty acids. For Co, Fe, Mn and Zn, there was no evidence of positive responses to supplementation. Cu and I had toxicity thresholds that were sufficiently close to requirement that supplementing above requirement presented a risk of inducing toxicity. In the case of vitamin A, while serum concentrations indicated that sub-optimal status did exist, long-term buffering from liver stores (from grazing) makes experimentation difficult and practical benefits to supplementation unlikely. Therefore, the most likely candidates for supplementation were Se, vitamin E and fatty acids. Fatty acid supplementation with fish oils or docosahexaenoic acid-containing algal biomass consistently improved lamb vigour but it is unlikely that supplementation will be economic. Positive responses to Se supplementation throughout gestation were recorded. However, in many studies the Se status of control ewes was marginal and there is a need for more studies where control ewes are clearly adequate in Se. Positive responses to vitamin E supplementation above requirement in the last-third of gestation were observed but the optimum dietary inclusion of vitamin E and period of feeding during pregnancy still require clarification.Keywords: lamb mortality, sheep, supplementation, trace elements, vitamins IntroductionNeonatal lamb mortality is a significant welfare and production concern. Mortality of live-born offspring can be as high as 25%, which extrapolates to more than four million lamb deaths annually in the UK. Lamb mortality represents both a welfare issue (due to the considerable suffering and distress) and an important production inefficiency (Mellor and Stafford, 2004). In lambs, approximately 80% of mortality can be attributed to the starvation-mismotheringexposure complex and, as a consequence, the vast majority of pre-weaning deaths occur in the first 3 days after birth (Haughey, 1993). Thus the neonatal period is critical for ensuring pre-weaning survival. Since considerable technological and management changes have failed to improve these mortality figures, examining the behaviour and adaptations of the animals may be a more fruitful route to improving neonate survivability. The nutrition of the ewe is an important factor that may influence ewe and lamb behaviour and therefore survival of the lamb.Under-nutrition of the ewe has an important influence on the lamb at the extreme being manifested as intra-uterine growth retardation (IUGR). The effects of under (and over)...