Winter housing and its effect on rnilk production

Ernesto Jahn B.1, Agustín Vidal V.1, Hugo Vyhmeister B.1, Walter Bonilla E.1 y Pablo Millas A.2

Thirty nine Hoistein cows were assigned in a randomized block design to 3 treatments: 1. Complete housing; 2. No housing, with covered feed bunk; and 3. No housíng, with uncovered feed bunk. The 125 days experiment was conducted at Los Angeles, Chile, during the winter period. AlI cows were fed daily corn silage ad libitum; 5 kg red dover hay; 4 kg concentrate, during the first two months and 2 kg thereafter; and 0.2 kg mineral mixture. Daily 4% F.C.M. was 14.6, 14.9, and 15.4 kg/day (P > 0,05); live weight losses were -0.06, -0.21 and -0.10 kg/day (P > 0.05); reproductive efficiency was 100, 92 and 77%; dry matter intakewas 15.4, 15.3 and 16.2 kg/day; feed conversion was 0.94, 0.97 and 0.95 kg 4% F.C.M./kg dry matter consumed, all these for treatments 1, 2, and 3, respectively. Although feeds in treatment 3 became wet, this had no effect on dry matter intake.

1 Estación Experimental Quilamapu (INIA), Casilla 426, ChiIlán, Chile.
2 Casilla 426, ChilIán, Chile.