Mohanta Ranjan K, Singhal Kamal K, Tyagi Amrish K, Rajput Y S, Prasad Shiv
Dairy Cattle Nutrition Division, National Dairy Research Institute, Karnal, India.
Trop Anim Health Prod. 2010 Mar;42(3):431-8. doi: 10.1007/s11250-009-9439-z. Epub 2009 Aug 24.
The effects of feeding transgenic (Bt) whole cottonseed (WCS) were studied in lactating cows. Twenty multiparous crossbred cows (Karan Swiss x Karan Fries) in early lactation were given a concentrate mixture containing 40% crushed delinted non-transgenic (non-Bt) WCS, 2 kg wheat straw and green fodder ad lib for a 15-day adaptation period. Thereafter, the cows were divided in two similar groups of 10 each on the basis of milk yield, body weight (BW) and date of calving. The non-Bt control group continued on same ration, while for the Bt group the non-Bt WCS was replaced by transgenic WCS, in a feeding trial of four weeks. The diets provided a minimum of 2 kg cottonseed/cow/d. Mean DMI/100 kg BW and milk yield of non-Bt and Bt groups was 3.48 and 3.45 kg and 11.4 and 12.0 kg/d, respectively. Intake of nutrients, digestibility, milk production and body condition score (BCS) did not differ between the groups (P > 0.05), but BW gain was higher (P < 0.05) in the Bt group than the non-Bt group, probably as a result of hoof problem in two cows of non-Bt group, which when compared excluding two animals from each group did not differ significantly (P > 0.05). Transgenic protein (Cry1C) was not detected in the weekly milk samples or in blood plasma at the end of the experiment, showing that delinted WCS containing Cry1C protein can safely be fed to lactating cows.
研究了给泌乳奶牛饲喂转基因（Bt）全棉籽（WCS）的效果。20头处于泌乳早期的经产杂交奶牛（卡兰瑞士牛×卡兰弗里生牛）在15天的适应期内，被给予一种精料混合料，其中包含40%粉碎去绒的非转基因（非Bt）WCS、2千克麦秸以及随意采食的青饲料。此后，根据产奶量、体重（BW）和产犊日期，将奶牛分为两个相似的组，每组10头。在为期四周的饲养试验中，非Bt对照组继续饲喂相同的日粮，而Bt组则用转基因WCS替代非Bt WCS。日粮为每头奶牛每天至少提供2千克棉籽。非Bt组和Bt组每100千克BW的平均干物质采食量（DMI）分别为3.48千克和3.45千克，日产奶量分别为11.4千克和12.0千克。两组之间的营养物质摄入量、消化率、产奶量和体况评分（BCS）没有差异（P>0.05），但Bt组的体重增加更高（P<0.05），这可能是由于非Bt组有两头奶牛出现蹄部问题，若排除每组的这两头动物后进行比较，则差异不显著（P>0.05）。在每周采集的牛奶样本以及实验结束时的血浆中均未检测到转基因蛋白（Cry1C），这表明含有Cry1C蛋白的去绒WCS可以安全地饲喂给泌乳奶牛。
