Effect of feeding hydroponic barley sprouts to sheep on feed intake, nutrient digestibility, nitrogen retention, rumen fermentation and ruminal enzymes activity

This study was conducted to evaluate the effect of feeding hydroponic barley sprouts to sheep on dry matter intake, nutrient digestibility, nitrogen balance, rumen fermentation parameters and ruminal enzymes activity. The barley sprouts were prepared in a hydroponic sprouting unit under controlled environment. Barley grains were first washed, soaked for one day using tap water, and then covered with a wet towel for another one day for germination. Thereafter, they were spread out in trays and were irrigated three times daily by tap water. The trays contained green fodder were removed after 8 days and the harvested carpets were exposed to air ventilation, then weighed and shredded to small pieces before feeding to the animals. Twenty mature rams (50 +/- 1.30 kg bw) were randomly distributed into four groups, each with five rams. The rams in group 1 and 2 were fed on Egyptian clover and hydroponic barley sprouts only, respectively, while the animals in group 3 and 4 were offered the same forage sources used in previous groups but with supplying a concentrate mixture. The experiment lasted for three weeks. It was found that feeding of sprouted barley alone reduced total DM intake by about 61.5% than that of the clover alone, but this effect was ameliorated when fed with the concentrate. However, the digestibility of different nutrients was increased in sprouted barley diet by an average of 10.0% compared to the clover. The nitrogen retention % was similar in rams fed barely sprouts or clover without concentrate. Total volatile fatty acids and propionate production was higher by 18.5% and 8.31%, respectively, in rumen of rams fed the sprouts alone or with concentrate than the clover alone. In addition, feeding of barley sprouts increased the total rumen protozoa count by about 31.3% and most of ruminal enzyme activities (45.0, 9.0 and 23.2% for amylase, cellulose and protease, respectively) compared to the clover. Providing the concentrate with sprouted barley or clover improved the nutrients digestibility (by about 14.0%) and nitrogen retention (by 46.0%) as well as amylase (by 60.0%) and urease (by 15.0%) activity in comparison to feeding of these ingredients alone. In conclusion, feeding of barley sprouts alone to sheep reduced the DM intake, however, it can improve the nutrients digestibility, rumen fermentation and ruminal enzyme activities. Moreover, use of sprouted barley in sheep diets could result in better digestibility and fermentation results than the clover. Feeding of concentrate with sprouted barley increased its positive effect on nutrients digestibility and rumen fermentation and improved the total DM intake. Thus, it can be recommended to feed the hydroponic barley sprouts with the concentrate to obtain an optimal DM intake as well as a high animal performance.