Feed intake restriction, conception rate and parturition to conception interval in crossbred Gir-Holstein cows1
Anim Reprod, vol.2, n2, p.135-138, 2005
The purpose of this study was to evaluate the effects of feed restriction and subsequent body weight loss on the number of services per conception in crossbred, Gir-Holstein cows with body condition scores (BCS) ranging from 3.5 to 4.1 (1 = very thin and 5 = fat). The mean milk production during the first month of lactation was 11.9 kg/milk/day. Cows received either a post-partum diet to meet maintenance and production needs (Group I, n=25) or were submitted to feed restriction from parturition to conception (Group II, n=25), which consisted of 1 AU/ha of Brachiaria decumbens pasture, during the dry season, without concentrate supplementation. All animals were inseminated in the first estrus 45 days post-parturition. Ovarian cyclic luteal activity (OCLA) was evaluated by rectal palpation, observation of estrous behavior (twice daily) and blood progesterone levels. The difference in the interval from parturition to first estrus was greater in the Group II (46.3 days) than Group I (55.4 days). In conclusion, feed restriction and subsequent body weight loss (13.2%) did not retard the reestablishment of OCLA in Gir-Holstein crossbred cows with a high BCS at parturition. The first estrus occurred before 56 days post-partum in the feed-restricted group and this group had a greater number of services per conception and days to first service compared to the control group.
Post-partum, feed restriction, services per conception, service period