EFFECT OF AMMONIA TREATMENT OR PROTEIN SUPPLEMENTATION ON RUMINATION BEHAVIOR IN SHEEP GIVEN BARLEY STRAW

A study was conducted to compare the effects of ammoniation and protei n supplementation of barley straw on rumination behaviour of sheep. Fo ul wethers were allocated to four diets offered ad libitum in a 4 x 4 Latin-square design. The diets were, untreated barley straw + molasses meal (diet 1), untreated barley straw + soya-bean meal + molasses mea l (diet 2), ammonia-treated barley straw + molasses meal (diet 3) and ammonia-treated barley straw + soya-bean meal + molasses meal (diet 4) . Animals were kept in metabolism crates throughout each 16-day experi mental period and allowed free access to water and a mineralized salt lick. The first 11 days of each period were for adaptation to the harn esses and diets while the last 5 days were used for rumination studies . Animals given diets 3 and 4 had slower eating rates compared with th ose given diets I and 2. Rumination index and duration of each ruminat ion period was lower for sheep consuming diets 3 and 4 than for those on diets I and 2 but riot significantly so (P > 0.05). Rumination time per 100 g neutral-detergent fibre (NDF) intake teas significantly low er (P < 0.01)for diets containing ammoniated straw. Animals given ammo niated straw diets also regurgitated fewer boluses per unit NDF intake than did those or? untreated straw diets. The results showed that inc reased intake and digestibility, which is usually associated with ammo niated straws, was due to sheep doing less work per unit of time to br eak down straw for digestion. In this way, potentially digestible tiss ues within a given amount of straw is more readily exposed. The forego ing suggests that ammonia treatment results in less rumination so that ruminants given ammonia-treated straw diets do less work ruminating.