Effect of genetic,maternal nutrition in late gestation (fetal programing)and rate of growth until finish phase on age of puberty, carcass characteristics and meat quality

• Grant number: 11/13400-1
• Support Opportunities: Regular Research Grants
• Start date: October 01, 2011
• End date: September 30, 2013
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Production
• Principal Investigator: Alexandre Vaz Pires
• Grantee: Alexandre Vaz Pires
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated researchers: Gerson Barreto Mourão ; Michael L. Day ; Roberto Sartori Filho

Abstract

Three experiments will be conducted at the "Estação Experimental Agrozootécnia Hidelgard Georgina Von Pritzelwitz" located in the district of Irerê-Paquerê (Londrina - PR) belonging to the "Fundação de Estudos Agrários Luiz de Queiroz (Fealq)", to assess the effects of supplementation on productive and reproductive performance of Nelore cows and their calves raised on pasture. The first trial (final third of gestation) - will be conducted with 500 pregnant cows (from 13 Nelore bulls) in the final third of gestation, distributed into two treatments with 250 cows each. The control group (without protein supplementation in the pre-partum) will receive only mineral. The other group (with protein supplementation in the pre-partum) cows will receive a supplement of 0.5 kg soybean meal + mineral mix, to determine the effects of protein supplementation in the pre-partum on productive and reproductive performances of their offspring until the age of puberty, body condition score of cows (between the start of treatment and calving). The second trial (from the 2nd month after birth to weaning) - 250 cows and 250 calves (half of each treatment of Experiment I) will be allotted in a 2x2 (2 cows pre-partum and 2 calves initial management system). Group I = control group (no creep-feeding) with only access to mineral mixture, and Group II = Supplementation with energy in creep-feeding (formulated with corn, soybean meal, minerals, vitamins and monensin). In the post-partum period, cows in both treatments will only have access to pasture and a mineral mixture. The third trial (after weaning) - calves will be allocated again to form a second factor (feedlot or pasture after weaning). The objectives of these experiments will assess: 1 - The effect of supplementation of the mother (pre-partum) and of the calf during nursing and post-weaning on growth, age at puberty, carcass characteristics and meat quality. 2 - The effect of pre-partum supplementation of cows and creep-feeding of the calves on cow's post-partum performance, body condition score of cows and pregnancy rate. 3 - To assess maternal ability of mothers (by weight gain of calves) on weaning weight and on age of onset of puberty in their progeny. Therefore, it is possible to assess quantitatively the effects of different weight gain rates of calves during growth on the somatotrophic - reproductive axis, where the results may be related to the effects of supplementation on age to attain puberty, carcass characteristics and meat quality of young Nellore bulls. (AU)