Effect of Seasonal Herbage Allowance on Bolus Weight of Cattle

Abstract

Technology has recently made it possible to count forage boli consumed daily in ruminants. This technique can presently be used to measure grazing time and rates of nutrient intake. However, to determine total daily intake, the influence of inherent variations in bolus weight and associated forage conditions must be known. An attempt was made to determine if degree of uniformity in forage boli weights were statistically nonsignificant to be counted and used as a measure of daily dry matter intake of an animal. Herbage allowances varying from 15.4 to 3.4 kg DM/100 kg BW/day did not have a significant effect on bolus weights in mature cows grazing bahiagrass pastures during mid-summer and early winter (P≤0.05). Cow size and season of the year also had no significant effect on bolus weight. Bolus weight of the cows averaged 4.4 +/- 0.1 g across seasons and cows.