title: Effects of energy supplementation on productivity of dual-purpose cows grazing in a silvopastoral system in the tropics.
abstract: The aim of the present work was to evaluate milk yield, postpartum (pp) ovarian activity and pregnancy rate in dual-purpose cows grazing Cynodon nlemfuensis and browsing L. leucocephala, with or without energy supplementation. Twenty-four Bos taurus × B. indicus cows were divided in two groups from calving to 70 days post-calving: supplemented group (SG) with ground sorghum grain offered at 0.4% of live weight at calving and control group (CG) without supplement. There was a trend for milk yield (kg day(-1)) to be greater (p = 0.08) for SG (10.55 ± 0.51) compared to CG (9.53 ± 0.61), although without differences in fat (0.42 ± 0.02 vs. 0.38 ± 0.03 kg day(-1)), protein (0.29 ± 0.02 vs. 0.29 ± 0.02 kg day(-1)) or lactose (0.49 ± 0.02 vs. 0.49 ± 0.03 kg day(-1)) concentration. Populations of large, medium and small follicles were similar between treatments. Percentage of cows which showed corpus luteum tended to be greater in SG (50%), compared to CG (33%). Supplemented cows tended to have a shorter calving-first corpus luteum interval (40 ± 10 vs. 51 ± 10 days) and had a significantly higher (χ (2) = 0.03) pregnancy rate (42% vs. 0%). It is concluded that energy supplementation helped to improve ovarian activity and pregnancy rate. Since supplementation did not avoid loss of body condition, the higher pregnancy rate in SG suggests beneficial effects of supplementation probably mediated by metabolic hormones.
authors.affiliation: Facultad de Medicina Veterinaria y Zootecnia, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Michoacan, Mexico.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Tinoco-Magaña
authors.forename: Carlos Fernando
authors.initials: CF
authors.lastname: Aguilar-Pérez
authors.forename: Roger
authors.initials: R
authors.lastname: Delgado-León
authors.forename: Juan Gabriel
authors.initials: JG
authors.lastname: Magaña-Monforte
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Ku-Vera
authors.forename: Jose
authors.initials: J
authors.lastname: Herrera-Camacho
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000822:Animal Husbandry / Q000379:methods*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle / Q000502:physiology*; D004043:Dietary Fiber / Q000008:administration & dosage; D019587:Dietary Supplements; D002149:Energy Intake; D007887:Fabaceae / Q000737:chemistry; D005260:Female; D007774:Lactation; D008800:Mexico; D008892:Milk / Q000737:chemistry* / Q000378:metabolism*; D010053:Ovary / Q000502:physiology*; D049590:Postpartum Period; D011247:Pregnancy; D018873:Pregnancy Rate; D011897:Random Allocation; D045868:Sorghum / Q000737:chemistry
chemical_list: D004043:Dietary Fiber