Persistência da lactação e composição do leite em ovelhas leiteiras das raças Lacaune e East Friesian.

The objective of this study was to evaluate the lactation persistency and milk composition in East Friesian and Lacaune dairy ewes. Twenty one East Friesian and forty six Lacaune ewes on 44±7.2 days in milk (DIM) were used in a rotational system grazing paddocks of Panicum maximum jacq. cv. 'Aruana'. Milk yield (MY) was measured every four days throughout the experiment (92 days). Milk samples for composition analysis were collected on days 1, 25, 50, 75, and 92. The best fit prediction equations for MY were MY=1.42-0.02* DIM, r²=0.20 for East Friesian; and MY=2.03-0.08* DIM, r²=0.22 for Lacaune. At the beginning of the experimental period Lacaune MY was 30% higher. Lacaune ewes showed lower persistency and higher milk yield (1.67 vs. 1.35kg day-1, P<0.001), milk fat yield (114.80 vs. 102.85g day-1, P<0.001) and protein yield (82.82 vs. 73.10g day-1, P < 0.001). East Friesian ewes had greater milk fat (7.31 vs. 6.86%, P<0.0008) and protein concentrations (5.18 vs. 4.93%, P<0.001). Overall, the East Friesian ewes showed more persistency than Lacaune, but the milk yield and milk yield composition was greater in Lacaune. [ABSTRACT FROM AUTHOR]