Abstract 442

Tarrero,-R; Peron,-N; Santiago,-N; Lam,-F; Pedroso,-R; Lavandeira,L

Centro de Investigacion para el Mejoramiento Animal, Cotorro, Havana, Cuba.

Revista-Cubana-de-Reproduccion-Animal. 1982, 8: 2, 25-31; 3 ref.

For approx. 300 days, 29, Holstein-Friesian X zebu heifers were given a molasses-urea diet plus 250 g fish meal daily and had restricted access to pasture during the night (group 1), 26 heifers remained on pasture and received supplements of 1.2 kg concentrates per day (group 2), and 20 heifers remained on pasture with daily supplements of 1.2 kg concentrates during the dry season and of green forage during the rainy season (group 3). In the 3 groups resp., age of females at the beginning of the trial averaged 240, 280 and 313 days, body weight 116.8, 120.8 and 120.2 kg, and chest circumference 110.1, 111.25 and 111.1 cm. Daily gain averaged 519, 493 and 479 g resp. (P<0.05), and age at 1st mating (carried out at a body weight of 260-280 kg) 17, 19 and 20.9 months (P<0.01). The number of females inseminated in the 3 groups was 27, 16 and 13, and 70.3, 81.2 and 76.9% of inseminated heifers conceived to the 1st insemination.