Nutritive value of diets containing inactive dry yeast for lactating Saanen goats

Twenty-four Saanen goats, 15 multiparous and nine primiparous, were distributed in a completely randomised design in a factorial arrangement (3 diets × 2 parities). The treatments were soybean meal (SB), soybean + dry yeast (SBDY), or dry yeast (DY) as a protein source in the diet, and ground corn, mineral supplement, and corn silage (400 g/kg). The study was conducted to evaluate the nutritive value of diets containing inactive dry yeast as a protein source postpartum, postpeak, and during late lactation in dairy goats. To estimate the faecal excretion of indigestible material, neutral detergent fibre was used as an internal marker. The diets did not affect dry matter intake (DMI). However, DMI and nutrient intake were higher for multiparous goats compared with primiparous goats. The digestibility of dry matter and total digestible nutrients (TDN) were higher for primiparous goats in the postpartum period. In the postpeak and late lactation periods, there were no differences in digestibility of DM and nutrient between parities. The TDN was similar in the diets in the postpeak period and at lactation end. The goats fed the DY diet had lower urea nitrogen in blood. The use of inactive dry yeast to substitute soybean meal in diets for primiparous and multiparous lactating Saanen goats is a good alternative for maintaining the nutritional value of diets.