title: Effect of pre- and post-partum feed supplementation on the productive and reproductive performance of grazing primiparous Brahman cows.
abstract: This experiment studied the combined effect of pre- and post-calving feed supplementation on the productive and reproductive performance of primiparous Brahman cows. The animals were 4 years old (420 kg live weight) and pregnant, and grazed rotationally on Stargrass (Cynodon nlemfuensis) pastures. Supplementation was given before and after (T1, n = 15), only before (T2, n = 15) or only after (T3, n = 16) calving, and there was an unsupplemented control (T4, n = 16). The supplement (1.5 kg/animal per day, 13.4 MJ digestible energy/kg dry matter and 20% crude protein) was given for 45 days before and/or after calving. Changes in body weight and body condition score and the productive behaviour of the calves were similar (p > 0.05) among treatments. The concentration of urea in the plasma was low in the control group (T4) before and after calving. The animals in all the groups had a poor reproductive performance. The percentage of cows in oestrus was higher (p < 0.05) in T1 (73.3%) than in T3 (37.5%). The interval from calving to conception (148.7 +/- 53.7 days) and the pregnancy rate (48.5%) were similar (p > 0.05) among the treatments. The level of supplementation offered before and/or after calving did not improve the pregnancy rate.
authors.affiliation: Colegio Superior Agropecuario del Estado de Guerrero, Iguala, México.
authors.forename: R
authors.initials: R
authors.lastname: Soto
authors.forename: I
authors.initials: I
authors.lastname: Rubio
authors.forename: C S
authors.initials: CS
authors.lastname: Galina
authors.forename: E
authors.initials: E
authors.lastname: Castillo
authors.forename: S
authors.initials: S
authors.lastname: Rojas
mesh_terms: D000821:Animal Feed; D000822:Animal Husbandry; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000831:Animals, Newborn; D001947:Breeding; D002417:Cattle / Q000502:physiology*; D019587:Dietary Supplements; D005260:Female; D008297:Male; D008800:Mexico / Q000453:epidemiology; D010298:Parity; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology / Q000662:veterinary*; D011270:Pregnancy, Animal / Q000502:physiology*; D012098:Reproduction / Q000502:physiology*