R. Bras. Zootec.. 01/Feb/2017;46(02):167-73.

Effect of soybean hulls on lactation curves and the composition of goat milk

Maximiliane Alavarse Zambom, Claudete Regina Alcalde, Ludmila Couto Gomes, Carlos Eduardo Crispim de Oliveira Ramos, Robson Marcelo Rossi, Daniele Cristina da Silva Kazama

DOI: 10.1590/S1806-92902017000200012


This study aimed to evaluate the effects of soybean hulls (SBH) as a ground corn
replacement (0, 50, and 100% SBH) on the parameters of the lactation curve and
on lactation curves and milk composition. Fourteen multiparous Saanen goats were
used during their lactation period, from kidding until the drying of their milk
on the 228th day of lactation, and were distributed in a completely randomised
design. The data was analysed using Bayesian methodology to minimise the effect
of the low number of animals and to allow for comparison of the curve parameters
estimated by Wood’s nonlinear model. The SBH had no effect on the initial milk
yield; nevertheless, the SBH reduced the rate of yield until lactation peak and
accelerated the declining rate of yield after lactation. The treatments did not
affect dry matter intake. The inclusion of SBH increased the fat content in the
milk, which was also influenced by the lactation stage of the goats. Effects
were observed on polyunsaturated fatty acids (PUFA), PUFA/total AG ratio, and
the n-6:n-3 ratio of goat milk fat. The lactation stage changed the content of
saturated fatty acid, monounsaturated fatty acid, and C18:2 (conjugated linoleic
acid). The SBH can therefore be used as a ground corn replacement in the diets
of lactating goats, as changes in the lactation curve parameters did not result
in changes in total yields. Nevertheless, if the milk fat increases, then as
quality rises, so could payment by quality, and thus an increase in profit
margins per liter of milk sold.

Effect of soybean hulls on lactation curves and the composition of goat milk