Effect of feeding fermented, ammoniated, condensed whey permeate on intake, digestibility, rumen fermentation, and acid-base balance in sheep

Abstract

Nine DLS rumen-cannulated wethers (69 kg avg BW) were used to study the effects of dietary supplementation with two types of fermented, ammoniated, condensed whey permeate on performance, rumen physiology and acid-base status in sheep fed high-grain diets. Sheep were fed three isonitrogenous (16% CP) diets according to a triple 3 × 3 Latin square design, with three 21-d periods each. One whey permeate contained ammonium lactate (AL) while the other contained ammonium propionate (AP). Urea was used as a source of NPN in the control diet (C). Diets, offered ad libitum, contained 78% barley and 18% dehydrated alfalfa meal. Dry matter and digestible energy intakes were about 15% higher for diets AL and AP than for diet C (P < 0.05). Dry matter digestibility was not affected by the treatments, whereas organic matter and energy digestibilities tended to be higher for diet AP than for diet AL (P < 0.07). Rumen fermentation was not affected by the treatments. Over a 4-h post-feeding period, sheep fed diet C had higher plasma concentrations of lactate (P < 0.06) and acetate (P < 0.04) but lower levels of plasma propionate (P < 0.06) than sheep fed the AL and AP diets. Plasma propionate 2 h after feeding was higher in sheep fed the AL diet versus the AP diet (P < 0.01). Sheep blood was mildly alkalotic despite the fact that sheep were fed a high-grain diet. The two types of fermented, ammoniated and condensed whey permeate were found to be good sources of NPN. Key words: Whey, rumen fermentation, acid-base balance, sheep