Evaluating the Influence of the Inclusion of Liquid Brewers Yeast during Gestation on Ewe and Lamb Performance, Colostrum and Milk Quality, and Transfer of Passive Immunity in Lambs

Abstract

The microbrewery industry has experienced exponential growth since 2005. As a result, the by-products associated with this industry are becoming increasingly available. One of these by-products is liquid brewers yeast, which is produced in excess during the production of beer. For livestock producers that have access to microbreweries, a potentially economical way to feed their flock would to be repurpose the by-product that would otherwise be disposed. Similarly, microbreweries would benefit from repurposing the liquid brewers yeast as livestock feed, resulting in less waste and a more sustainable beer production system.Researchers have evaluated the effect of liquid brewers yeast supplementation in other species, especially cattle. Literature pertaining to its influence on performance measures, colostrum quality, and the transfer of passive immunity has been inconsistent. Furthermore, while research has investigated the use of liquid brewers yeast in cattle, there is currently limited research on feeding liquid brewers yeast to small ruminants. Due to the lack of literature published, small ruminant producers may be hesitant to utilize liquid brewers yeast in their sheep diets, even though there is an increasing availability of the potentially valuable feed ingredient. The objective of this research was to evaluate the effects of liquid brewers yeast on late gestation ewe and lamb performance, colostrum quality, and the transfer of passive immunity. In the first experiment, from 4 weeks prior to expected lambing to 4 weeks post-lambing, ewes were group housed and fed either a control diet, or the control diet with liquid brewers yeast included at a rate of 32 g of DM/hd/d. Findings of this research indicated no significant effect of liquid brewers yeast supplementation on ewe body weight (BW; P = 0.31), body condition score (BCS; P = 0.97), and F:G ratio at start of experiment (P = 1.00), prior to lambing (P = 0.82), post lambing (P = 0.94), and at the end of experiment (P = 0.79). Additionally, treatment did not have a significant effect on colostrum or milk quality at 2- or 4-wk post lambing (P = 0.22, P = 0.64, P = 0.13, respectively) or lamb ADG (P = 0.77). In the second experiment, ewes received an increased rate of 60 g of DM/hd/d of liquid brewers yeast. All ewes in this experiment were immunologically challenged with a parainfluenza-3 vaccine and antibody titer levels were monitored throughout the experiment. The supplementation of liquid brewers yeast did not result in significant differences