Effect of feeding transgenic cottonseed (Bt-cry1Ac gene) on nutrient utilization,production performance and blood biochemical status in lactating dairy cows

Abstract

The study was made to compare the effect of transgenic (Bt, Cry1Ac) linted whole cottonseed (WCS) on nutrient intake and utilization, milk production and biosafety with that of isogenic (on Bt) WCS. Lactating multiparous cows (16) adapted to non Bt cottonseed based concentrate mixture (40%) were divided randomly in 2 groups of 8 each. Non- Bt group (control) continued on same ration while in Bt group, non-Bt WCS in concentrate mixture was replaced with Bt WCS in a feeding trial of 4 weeks. BW gain, nutrient intake and digestibility, milk yield and composition, body condition score, and blood parameters did not vary significantly between the groups. Non detection of Bt protein (Cry1Ac) in milk or blood plasma indicated the degradation of the protein in the gastrointestinal tract of cows. It was concluded that Bt (Cry1Ac) cottonseed is as safe and nutritious as conventional cottonseed, when fed to lactating crossbred cows for 4 weeks.