Milk Production, Milk Composition and Energetic Efficiency of Hampshire and Corriedale Ewes Fed to Maintain Body Weight

Abstract

Nine purebred Hampshire and 10 purebred Corriedale ewes, 8 with twin lambs and 11 with single lambs, were used in a 2 × 2 factorial experiment to study the effects of breed and number of lambs suckled on milk production, milk composition and DE requirements for milk production when being fed to maintain a constant body weight, and to study the energetic efficiency of milk production during the first 12 weeks of lactation. Maintenance requirements were simultaneously determined using five nonpregnant, non-lactating ewes of each breed. The ewes were individually fed a ration of chopped hay and shelled corn, and their lambs were offered a creep ration ad libitum in adjoining individual creep pens. Hampshire ewes produced significantly (P<.01) more milk and milk calories than did the Corriedale ewes. Ewes with twin lambs produced significantly (P<.01) more milk than those suckling single lambs. Dry matter and fat concentrations were higher in the milk of Hampshire than of Corriedale ewes. Number of lambs suckled had no significant effect on milk composition, although the percent of milk fat tended to be lower in the ewes suckling twin lambs. When body weight was maintained, the Hampshire ewes required significantly (P<.05) more DE for milk production than the Corriedale ewes. The energy requirement differences between ewes suckling single and twin lambs were highly significant. Utilization of dietary energy for milk calorie yield was greater (P<.01) for Hampshire ewes. The difference between ewes with single and those with twin lambs was not significant. The effect of level of feed intake on ration digestibility is discussed in relation to feeding standards. Comparisons were also made between the relative merits of feeding the ewe extra DE for maximum milk production versus feeding the lamb this extra energy directly. Copyright © 1966. American Society of Animal Science . Copyright 1966 by American Society of Animal Science