Further studies on the response of lactating ewes to dietary protein

Abstract

Four experiments were made during early lactation on individually penned Finnish Landrace x Dorset Horn ewes, each suckling two lambs. In Experiment 1, 14 ewes of mean body weight 74 ± 2-4 kg received daily, 1-9 kg dry matter, 20 MJ of metabolizable energy and 300 g of crude protein from a diet (H) containing hay, barley and fish meal. Reduction of the daily crude protein intake of half the ewes to 225 g by replacing fish meal with barley (diet L) in week 2 of lactation resulted in a decrease (P< 0-01) in daily milk yield of 0-53 kg (17 %) compared with no change for ewes remaining on diet H. The effect was reversed by returning the ewes to diet H at the end of week 3. In Experiment 2 the use of four ewes fitted with abomasal cannulae showed that the additional non-ammonia nitrogen reaching the abomasum when fish meal was given was used with an efficiency of 0-51 for the production of milk nitrogen. In Experiment 3, involving 20 ewes, a restriction in protein intake for more than 10 days in early lactation by replacing the fish meal with barley depressed subsequent milk yield. In Experiment 4, 24 ewes were given either fish meal, soya bean meal or groundnut meal as protein supplements. In early lactation fish meal was superior by 0-40 and 0-43 kg of milk per day to soya bean meal and groundnut meal respectively, and this was attributed to the greater quantity of non-ammonia nitrogen reaching the abomasum in the fish meal compared with the soya bean meal and groundnut meal supplements. The commercial significance of the results is discussed.

Level and quality of protein in rations for lactating ewes

“…The (Chilliard et al, 1987), were of the same magnitude as those found by Robinson et al (1979) in ewes with 2 lambs submitted to a level of energy restriction similar to that of this trial. The highest NEFA concentrations corresponded to the highest milk productions (r = 0.44; P < 0.01 On the other hand, the average concentration of NEFA was significatively correlated with the BCs losses (r= 0.81; P < 0.001 which confirms NEFA concentration as a good indicator of fat mobilization.…”

“…On the other hand, as the degradability of dietary protein in the rumen decreases, the amount of milk produced by the ewe increases (Robinson et al, 1979;GonzAlez et al, 1982 (Penning et al, 1988;Ngongoni et al, 1989;Hadjipanayiotou, 1992 production as a covariate to correct the total milk production. On the 8th day after lambing, they were distributed into 6 homogeneous treatments in terms of live weight (LW = 40.4 ± 5.28) and body condition score (BCs = 2.4 ± 0.32) at lambing (Russel et al, 1969), following a 2 x 3 factorial model, with 2 levels of CP in the ration and 3 main protein sources of different degradability in the concentrate.…”

The Effect of Fiber -Protein Levels on Milk Parameters, Linear Body Measurements and Udder Dimensions of West African Dwarf Sheep at First Lambing

“…This result was found to be consistent with the report by Robinson et al [11], which states that an increase in dietary protein concentration without a change in energy intake will increase the milk yield if ewe has not reached her potential yield. The average protein content is slightly lower than 5.8 g/l obtained by Sakult and Boylan, [12] in temperate and 5.52%, 6.07%, and 5.43% reported in tropical breeds of sheep [3,13].…”

Leptin secretion and hypothalamic neuropeptide and receptor gene expression in sheep

“…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).…”

“…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).…”