Abstract #149

# 149
Effects of intensive whole-milk feeding in calves on subsequent growth of dairy heifers.
Camila Flávia de Assis Lage1, Mariana Magalhães Campos2, Fernanda Samarini Machado2, Paulo Campos Martins1, Luigi Francis Lima Cavalcanti*3, Marcelo Neves Ribas3, Luiz Gustavo Ribeiro Pereira2, Thierry Ribeiro Tomich2, Rafael Alves de Azevedo1, Sandra Gesteira Coelho1, 1Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil, 2EMBRAPA Dairy Cattle, Coronel Pacheco, Minas Gerais, Brazil, 3CNPq, RHAE – SEVA Engenharia, Projeto Intergado, Contagem, Minas Gerais, Brazil.

The effects of intensive whole milk feeding in calves on subsequent growth of Holstein-Gyr females was evaluated. Up to 56 d old, calves received 6 L/d of 4 different liquid diets consisting of whole milk with increasing addition of milk replacer (Sprayfo Violet SSP) to adjust the concentration of total solids (TS) to 13.5 (n = 15), 16.1 (n = 15), 18.2 (n = 13), 20.4% (n = 15). After weaning, animals were randomly housed in 4 paddocks, each one equipped with electronic feed and water bins (Intergado, Brazil) in Embrapa Dairy Cattle facilities, Brazil. Diet (70:30, corn silage:concentrate, 195 g CP/kg, DM basis) was fed ad libitum, twice a day, until 210 d old. The withers height (WH), hip height (HH), rump width (RW) and chest circumference (CC) measures were carried out fortnightly using a flexible tape measure and a teletape (Ketchum, Canada). WH and CC were analyzed as a completely randomized design with repeated measures using nonlinear mixed models approach. A regression model (Y(age) = A+(B-A) exp[–exp(–c × age)], where Y = response at a specific age, A = asymptote as age →∞, B = Y(0), and c = logarithm of the rate constant) was fit to the data, where age and function parameters were allocated as fixed effects while animal was considered as random. It was evaluated the necessity of adding random terms to model error dependence and heteroscedasticity by monitoring Schwarz criterion, estimates stability and correlation. HH and RW, due to their linear growth pattern, were analyzed by linear mixed models, allowing polynomial models of first and second degree orders to model variable change over time (α = 0.05). All variables were steadily influenced by age, but only WH and CC were influenced by TS. For both responses, the c parameter was linearly increased by TS, revealing that a more intensive feeding strategy increases the growth rate of these 2 traits. TS influenced all CC parameters, where increasing total solid level caused a linear decrease of A, while increased B. TS effects over parameters A and B should be interpreted with parsimony, because animals in the present study had not achieved their mature weight.

Key Words: milk replacer, intensive farming, heifer