Effect of biological Treatment of Barley Straw with Baker’s Yeast (Saccharomyces cerevisiae) on some productive performance of growing lambs.

Abstract

ABSTRACTThis study was conducted at the farm of Ruminants Research Station, Office of AgriculturalResearch, Ministry of Agriculture, Abu Ghraib – Baghdad. The experiment continued for 56 days,in addition to 14 days as preliminary period from 11/10/2015 until 06/12/2016 to study the effect oftreating barley straw with baker’s yeast (Saccharomyces cerevisiae) on some productiveperformance of growing lambs. Ten Awassi lambs used in this experiment with average initial weightof 38±0.50 kg and age 8-9 months. Lambs divided randomly into two equal groups and kept inseparate individual pens. Lambs fed individually on a unified concentrate diet (2.5% of body weight),while, roughages offered ad libitum. Each group fed on roughages (barley straw), as follows:1. The first group fed untreated barley straw plus concentrate mixture and operated as control2. The second group fed barley straw treated with baker’s yeast (Saccharomyces cerevisiae) at rate0.5% (5 kg / tones).Animals weighed every two weeks before morning feeding. The digestibility experimentperformed in the seventh week. Rumen liquor collected at fifth week of the experiment at three times(before feeding, after three and six hours from feeding). Results showed different effects amongtreatments. The yeast not significantly affected the feed intake, average daily gain (15 – 28 d), invivo digestibility, and rumen fermentation (pH and NH3-N). Moreover, there was significant decrease(P <0.05) in daily weight gain during 29 - 42 d with baker’s yeast compared with control (107.14and 160.71g/d, respectively), while a significant increase (P <0.05) found in daily weight gain in the(1 – 14 d and 43 – 56 d) with baker’s yeast (103.57 and 178.57 g/d, respectively) compared withcontrol (48.33 and 142.86 g/d, respectively). We conclude that treatment with baker’s yeast notimproved feed conversion ratio, feed intake, intake of different nutrients, weight gains, digestibilityand rumen fermentation (pH and NH3-N concentration).