Milk-yield and milk-composition of flemish milksheep, suffolk and texel ewes and their crossbreds
Peeters, R × Buys, Nadine Robijns, L Vanmontfort, D Vanisterdael, J #
Elsevier science bv
Small ruminant research vol:7 issue:4 pages:279-288
Milk production (MP) and milk composition (MC) were investigated in 72 ewes of West European sheep breeds: Flemish Milksheep, Suffolk and Texel and their crossbreds, during the first 45 days of lactation and related to postnatal growth of their lambs. Without correction for significant influences. mean daily MP was 1.35 +/- 0.47 kg and milk fat, protein and lactose contents were 9.00 +/- 1.29, 4.85 +/- 0.36, and 5.62 +/- 0.25%, respectively. Breed, age of ewe and number of lambs suckled influenced MP significantly (P < 0.05). Flemish Milksheep ewes had the highest average daily MP (3.33 +/- 0.29 kg), while Texel ewes produced the lowest amount (1.10 +/- 0.15 kg). The other genotypes had 1. 5 kg MP. Two-year old ewes produced 200 g/day more milk than one-year olds. Ewes rearing twins had a higher MP of 400 g/day compared to ewes suckling singles. MC was not significantly influenced by genetic and physiological effects. MP and MC did not vary with circadian rhythms, i.e. a.m. vs. p.m. Significant correlations (P < 0.0001) indicated that ewes with a high MP in early lactation also continued for a good performance at 45 d postpartum. Early postnatal growth of lambs was dependent on genotype of lamb, birth weight and number of lambs suckled (P < 0.05). Purebred Milksheep lambs realized a high growth rate (306 +/- 37 g/d). Crossbred lambs approximated Milksheep, while purebred Texel lambs showed the slowest weight gain. These results were associated with milk uptake and conversion by lambs. Twin lambs grew slower than singles. Regression analyses showed that lambs had to have a chance to suck at least five times/d after 4 h of separation before a good estimation of the realized MP was obtained.