Effect of Feeding Rumen-Protected Methionine With Calcium Salts and Yeast on Productive Performance of Lactating Ewes When Fed Barley Straw

Abstract

A comparative study was conducted to examine the capacity of rumen-protected methionine and calcium-salts to enhance milking performance of Awassi ewes when fed barley straw to be comparable with those ewes fed Alfalfa hay. Aqueous ammonia and yeast culture were also tested for their further ability to promote animals performance when fed straw. Forty-four Awassi ewes were randomly assigned into four dietary treatment groups in a completely randomized design. Ewes were fed with 1 kg/head/day concentrate ration supplemented with alfalfa hay (CON) or either ammonia treated (ASTRW) or untreated barley straw (STRW) supplemented with calcium-salts and rumen protected methionine at a level of 50 g and 5 g/head/day respectively. In the fourth diet, 30 g/head/day of yeast culture was added to ammonia treated supplemented straw (AYSTRW). The experiment started after weaning and lasted for 70 days thereafter. Milk yield, milk composition, body weights, feed intake, milk fatty acids and some blood parameters were studied as production variables. There were no significant differences (p>0.05) between ewes in milk and energy corrected milk production, feed consumption, weight increase, feed efficiency, milk fat, milk fatty acid composition, milk and blood urea and blood Serum triglycerides. The current results indicated that supplementing barley straw with rumen -protected methionine and calcium salts was sufficient for Awassi ewes produced modest milk production to maintain milk yield and quality without any detrimental effects on animal performance comparable with ewes fed alfalfa hay as a source of forage.