Effects of protein concentration in the diet on milk yield, change in body composition and the efficiency of utilization of body tissue for milk production in ewes

Cowan, RT; Robinson, John J.; McHattie, I.; Pennie, K.

doi:10.1017/s0003356100040538

Cited by 50 publications

(26 citation statements)

References 15 publications

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“…The empty carcass weight decreases during late pregnancy, mostly because of loss of adipose tissue lipid (58,59); hence, the decreased body weight of the ewes at day 2 postpartum was not unexpected. Food intake increases after birth, reaching a plateau between 2 and 3 wk postpartum (24,60). Nevertheless, ewes suckling two or more lambs lose ϳ5 kg in body weight, mostly because of loss of fat from adipose tissue during the first 5-6 wk of lactation (22,23,24,60).…”

Section: Discussionmentioning

confidence: 99%

“…Food intake increases after birth, reaching a plateau between 2 and 3 wk postpartum (24,60). Nevertheless, ewes suckling two or more lambs lose ϳ5 kg in body weight, mostly because of loss of fat from adipose tissue during the first 5-6 wk of lactation (22,23,24,60). Ewes suckling a single lamb do not appear to lose adipose tissue lipid, whereas ewes suckling three lambs lose an amount of adipose tissue lipid similar to those suckling two lambs (66).…”

Section: Discussionmentioning

confidence: 99%

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Leptin secretion and hypothalamic neuropeptide and receptor gene expression in sheep

Sørensen

Adam²,

Findlay³

et al. 2002

American Journal of Physiology-Regulatory, Integrative and Comp

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Sheep were fed ad libitum and killed at 6 and 18 days of lactation; ad libitum-fed nonlactating sheep were killed as controls. Despite increased food intake, lactating ewes were in negative energy balance. Lactation decreased plasma leptin and adipose tissue leptin mRNA concentrations. OB-Rb gene expression, determined by in situ hybridization, was increased in the hypothalamic arcuate nucleus (ARC) and ventromedial hypothalamic nucleus (VMH) at both stages of lactation. Neuropeptide Y (NPY) was increased by lactation in both the ARC and dorsomedial hypothalamus (DMH), although increased gene expression in the DMH was only apparent at day 18 of lactation. Gene expression was decreased for cocaine-and amphetamine-regulated transcript (CART) in the ARC and VMH and for proopiomelanocortin in ARC during lactation. Agouti-related peptide gene expression was increased in the ARC, and melanocortin receptor expression was unchanged in both the ARC and VMH with lactation. Thus the hypoleptinemia of lactation may activate NPY orexigenic pathways and attenuate anorexigenic melanocortin and CART pathways in the hypothalamus to promote the hyperphagia of lactation. hypothalamic neuropeptides; appetite NUTRIENT REQUIREMENTS ARE markedly increased during lactation to meet the demands for milk production (7,70). In most mammals, these additional requirements are met primarily by increasing food intake (7,20,70), but factors regulating the hyperphagia of lactation are not well understood. In addition, in many species, the increased intake is insufficient to meet the metabolic demands, resulting in a state of negative energy balance during early lactation when body lipid reserves are mobilized (7,69). In some species such as the rat, the degree of negative energy balance is usually slight, with animals mobilizing ϳ1 g fat/day (7). Domestic ruminants, however, usually exhibit a greater degree of negative energy balance during early lactation (7, 11), which can impact on their welfare and productivity (28), yet the regulatory mechanisms have not been elucidated.It is postulated that leptin, a peptide hormone secreted by adipose tissue (75), could play a role in the hyperphagia of lactation. Leptin acts on hypothalamic neuronal systems to regulate energy balance and neuroendocrine function; in particular, a reduction in circulating leptin is a potent signal of negative energy balance, activating compensatory orexigenic pathways in the hypothalamus (3-5, 35, 64). Key targets are neurons in the hypothalamic arcuate nucleus (ARC) expressing the signaling form of the leptin receptor (OB-Rb); these are the orexigenic peptides neuropeptide Y (NPY) and agouti-related peptide (AGRP) and the anorexigenic peptides proopiomelanocortin (POMC, precursor for melanocortins) and cocaine-and amphetamine-regulated transcript (CART) (4,5,31,62,64,72). Adipose leptin gene expression and serum leptin concentrations are reported to be reduced during lactation in the monogastric rat in most (16,36,39,56,65,74), but not all (17,19,61), studies. NPY (18,21,...

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Leptin secretion and hypothalamic neuropeptide and receptor gene expression in sheep

Sørensen

Adam²,

Findlay³

et al. 2002

American Journal of Physiology-Regulatory, Integrative and Comp

View full text Add to dashboard Cite

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“…Furthermore, this higher milk production may have been the result of a greater efficiency in the use of body reserves for milk production, due to a higher protein content in the ration (Cowan et al, 1981 ).…”

Section: Discussionmentioning

confidence: 99%

Level and quality of protein in rations for lactating ewes

Jaime¹,

Purroy²

1995

Ann. Zootech.

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Summary — The effect of 2 levels of crude protein in the ration (110 and 90% of theoretical requirements) and of 3 main protein sources in the concentrate (faba beans, soybean cake and fish meal) on changes in live weight and body condition score, milk production, plasma concentration of non-esterified fatty acids and urea, and lamb growth was studied in 36 lactating Rasa Aragonesa ewes rearing 2 lambs submitted to an energy restriction level of 30% of their theoretical requirements. The average decreases in live weight and body condition score of the ewes were not significantly affected by the two effects studied. The ewes that were given the higher protein level produced more milk, fat, protein, total dry matter and blood urea concentration than those that received the lower level (P< 0.05). A trend towards significance was observed in the maximum concentrations of non-esterified fatty acids according to the protein source (P= 0.07) (P < 0, 05). Une tendance vers la signification a été obser vée dans la concentration maximum des acides gras non estérifiés selon la source de protéine utilisée (P = 0,07). Il n'a pas eu de différences significatives dans la croissance des agneaux.protéine / état corporel / production laitière / brebis / agneaux

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“…The growth performance of triplet lambs was better than that of twin lambs only with EB silage. Cowan et al (1981) observed higher milk yields with fish meal supplements only during weeks 4 to 6 of lactation, but lamb performance was not reported. In the present study, lamb weight at 6 wk was 1.1 kg higher for ewes receiving EB silage or the 21% CP concentrate compared with FB silage or the 15% CP concentrate, respectively.…”

Section: Discussionmentioning

confidence: 81%

Effects of maturity of silage and protein content of concentrates on milk production of ewes rearing twin or triplet lambs

Roy¹,

Laforest²,

Castonguay³

et al. 1999

Can. J. Anim. Sci.

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. 1999. Effects of maturity of silage and protein content of concentrates on milk production of ewes rearing twin or triplet lambs. Can. J. Anim. Sci. 79: 499-508. Fifty-one Outaouais Arcott ewes were used to study the effects of silage maturity, protein level and number of lambs suckled on milk production and lamb growth in a 2 × 2 × 2 factorial design experiment. Ewes were given ad libitum access to either an early-bloom (EB) or full-bloom (FB) bromegrass silage supplemented with 725 g d -1 of a 15 or 21% CP concentrate. Number of lambs suckled were two or three per ewe. During the 6 wk of lactation, ewes receiving the EB silages consumed more DM (2.07 vs. 1.74 kg d -1 , P < 0.01), and gained more (1.3 and -2.7 kg, P < 0.05) than ewes fed FB. Ewes that raised three lambs had greater silage intake (2.00 vs 1.86 kg d -1 ) and lost more weight during lactation (-2.8 vs. +0.3 kg) than those suckling twins. Milk yields of ewes offered the EB and FB silages were 2.42 and 2.28 kg d -1 , respectively (P < 0.05), for the first 4 wk of lactation. Ewes that raised three lambs produced less milk (2.25 vs. 2.43 kg d -1 ) than those nursing twins (P < 0.05). Milk fat content (8.2%) was not influenced by treatments, whereas milk protein content was higher (P < 0.05) from ewes receiving the EB silage compared with the FB silage (5.05 vs. 4.76%). At 4 and 6 wk of age, twin lambs were 2.6 kg (9.5 vs. 6.9 kg) and 3.5 kg (12.0 vs. 8.5 kg) heavier (P < 0.01) than triplet lambs for EB and FB silages, respectively. However, at the end of the 6-wk period, ewes nursing triplets weaned 1.3 kg more lambs than did ewes nursing twins (P < 0.05). Lambs from ewes that received the EB silage were 1.1 kg heavier at 6 wk (P < 0.05) than those from ewes fed with the FB silage. Also, lambs from ewes receiving the 21% CP concentrate were 1.1 kg heavier at 6 wk (P < 0.05) than the lambs from ewes fed the 15% CP. Litters were heavier at 6 wk with 21% CP concentrate compared with 15% (25.1 vs. 24.1 kg, P < 0.05), and triplet litters were heavier (P < 0.01) than twin with the EB silage. Within litter weight variation (weight difference between the biggest and the smallest lambs in a litter) proved to be greater (P < 0.05) with triplets (4.2 kg) than twins (2.2 kg). In conclusion, providing a higher quality silage (lower ADF and higher CP contents) improved ewe feed intake, milk production, lamb growth and litter weight, while feeding a higher protein concentrate only improved lamb growth with the lower quality silage.Key words: Ewe, lamb, growth, milk production, silage, protein, triplet Roy, A., Laforest, J. P., Castonguay, F. et Brisson, G. J. 1999. Effets de la maturité de l'ensilage et du niveau de protéines du supplément sur la production laitière de brebis allaitant deux ou trois agneaux. Can. J. Anim. Sci. 79: 499-508.Cinquante et une brebis Arcott Outaouais ont été utilisées dans une étude factorielle 2 × 2 × 2 sur les effets de la maturité de l'ensilage, du niveau de protéines du supplément et du nombre d'agneaux allaités sur la production l...

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Effects of protein concentration in the diet on milk yield, change in body composition and the efficiency of utilization of body tissue for milk production in ewes

Cited by 50 publications

References 15 publications

Leptin secretion and hypothalamic neuropeptide and receptor gene expression in sheep

Leptin secretion and hypothalamic neuropeptide and receptor gene expression in sheep

Level and quality of protein in rations for lactating ewes

Effects of maturity of silage and protein content of concentrates on milk production of ewes rearing twin or triplet lambs

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