Influence of Body Condition and Restricted Suckling on Post‐partum Reproductive Performance of Zebu Cows (Bos indicus) in the Humid Tropics

Resumption of Post‐partum Ovarian Activity Monitored by Plasma Progesterone in Anoestrous Zebu (Bos indicus) Cattle Following Temporary Weaning and Progestogen Treatment

“…The role of climate, especially heat stress, on reproduction has been subjected to a number of reviews (Thatcher 1974;Collier et al 1982), and it is generally accepted that high environmental temperatures reduce the reproductive efficiency of all classes of livestock. However, part of this seasonal variability can be attributed to the availability of pasture which affects the nutritional condition of the animal (Montgomery 1985;Bolaiios et al 1996). Wells et al 1981 showed that cows gaining weight were more likely to resume ovarian activity early in the post-partum period than cows losing weight, and De Los Santos et al (1979) demonstrated that poor body condition significantly affected the fertility results of synchronized cattle and that the restriction of dietary energy late in the pre-partum period or early in the post-partum period reduced the number of animals returning to oestrus within a well-defined breeding season.…”

Índices reprodutivos e características de desempenho em bovinos de corte infectados pelo Herpevírus Bovino 1

“…BoHV-1 reagent or non-reagent pregnant animals gained weight and improved body condition during the breeding season, even with most of the cows in lactation, as seen by the mean weight gain obtained. Although lactation has a suppressive effect on ovulation, this is less evident in animals that present moderate body condition scores at calving, or animals that did not present a drastic weight loss after calving 19,22 . Lactation is very demanding on the organism and together with the inhibition of GnRH release during milking, it makes difficult for cows presenting body condition scores below four to return to heat 27 .…”

“…Body condition score is an indirect evaluation of the effect of nutrition on reproduction. A body condition score equal to five or six at calving is necessary for females to present ovarian activity at the beginning of the breeding season, besides a quicker return to heat 19,20,21,22 . The absence of data demonstrating the reproductive and productive effects of BoHV-1 in non-vaccinated beef cattle bred under extensive management and adapted to tropical conditions lead to the design of the present study.…”

Índices reprodutivos e características de desempenho em bovinos de corte infectados e não infectados pelo Herpesvírus bovino tipo 1 (HVB-1).

“…Por este motivo incluiu-se na metodologia do presente trabalho a realização do escore corporal conjuntamente à avaliação sanitária e reprodutiva do rebanho, para excluir possíveis efeitos nutricionais que pudessem estar interferindo na fertilidade dos animais. A condição corporal de 5 a 6 no parto é desejável para que matrizes apresentem atividade ovariana no início da próxima estação de monta, sendo assim retornam mais rapidamente ao primeiro cio e desta forma emprenham mais rapidamente (RICHARDS et al, 1986;SELK et al, 1988;RICE, 1991e LIMA, 2000 pronunciado em animais com moderada condição corporal ao parto ou em animais que não apresentam uma drástica perda de peso pós-parto (BOLAÑOS et al, 1996).…”

“…O efeito supressivo do estímulo da amamentação sobre a atividade ovariana durante o período pós-parto é menos pronunciado em animais com moderada condição corporal ao parto ou em animais que não apresentam uma drástica perda de peso pós-parto (BOLAÑOS et al, 1996). (RAZOOK et al, 1988).…”