ABOMASAL BLOAT AND GAS PRODUCTION IN THE DIGESTIVE TRACT OF LAMBS

Abstract

The effect of different protein sources on gas production in the rumen, abomasum and intestine was studied in 26 lambs fed milk replacers. The sources of protein were either skim milk powder, rapeseed protein concentrate, Promosoy 100, or an experimental soybean protein concentrate. Rapeseed and soybean protein concentrates supplied 53% of the total protein in the diets. Milk replacers containing 15% DM were offered ad libitum at 37 °C, twice a day for 21 days. A high incidence of abomasal bloat was observed between the 15th and the 18th day of feeding but this was not related to the protein sources or to the quantity of milk replacer ingested. However, gas production by the gut contents from non-bloating lambs was higher when they were fed the two soybean protein concentrates (212 and 190 μL/mL/10 min) than from those fed the rapeseed and skim milk powder concentrates (125 and 118 μL/mL/10 min). Ruminal and abomasal gas productions of non-bloating lambs averaged 121 and 17 μL/mL/10 min, respectively, and were similar for the four diets. When bloat occurred, abomasal gas production was 4–15 times higher than in the non-bloaters (17 vs. 195 μL/mL/10 min) which confirmed the fact that the abomasum is an important site of gas production. A "maladjustment syndrome" probably related to a malfunction of the esophageal groove was observed in three lambs. In these lambs, gas production and pH in the rumen and in the abomasum were the same.