Feeding Value of Corn Silage Estimated with Sheep and Dairy Cows Is Not Altered by Genetic Incorporation of Bt176 Resistance to Ostrinia nubilalis

Abstract

A genetically modified Bt176 corn hybrid (Rh208Bt)--providing control of European corn borer damage--and the conventional isogenic hybrid (Rh208)--harvested as whole plant silage--were evaluated in three separate feeding trials to verify that the in vivo feeding value was substantially equivalent among modified and conventional hybrids. In the first trial, after a week of preexperiment, two sets of six Texel sheep, housed in digestibility crates, were fed silage sources of Rh208 and Rh208Bt hybrids, and silage of three additional control varieties of low, intermediate, and high feeding value (Rh289, Adonis, and Adonis bm3) for 1 wk. Feed offered to sheep was adjusted to maintenance requirements based on metabolic body weight. Agronomic and biochemical traits were similar among the Rh208 and Rh208Bt hybrids. Organic matter digestibility (67.1 and 67.6%), crude fiber digestibility (52.9 and 54.2%), and neutral detergent fiber digestibility (50.2 and 49.0%) were not significantly different among Rh208 and Rh208Bt hybrids. In the second trial, two sets of 24 Holstein cows were fed silage from Rh208 and Rh208Bt corn hybrids for 13 wk, 9 wk after calving, and including 2 wk of preexperiment. Fat-corrected milk yield (31.3 and 31.4 kg/d), protein content (31.7 and 31.6 g/kg) and fat content (36.7 and 37.0 g/kg) in milk of dairy cows were unaffected by hybrid source. Body weight gains of cattle were not different. However, intake was significantly higher in cows fed Rh208Bt silage. In the third trial, five midlactation multiparous Holstein cows were successively fed the silage from Rh208 and Rh208Bt corn hybrids 2 or 3 wk. Data were considered only for the last week of each period. There were no significant effects on protein fractions, fatty acid composition, or coagulation properties of milk between Rh208 and Rh208Bt fed cattle. Cattle and sheep can perform equally well with a conventional or a genetically modified Bt176 corn silage.

Pancreatic response of rats fed genetically modified soybean

“…Additionally, the published nutritional evaluations are quite heterogeneous. GM-corn (Barriere et al, 2001;Brake et al, 2003;Brake and Vlachos, 1998;Donkin et al, 2003;Erickson et al, 2003;Hammond et al, 2004;Hammond et al, 2006;Ipharraguerre et al, 2003;Seralini et al, 2007;Yonemochi et al, 2002), potato (Hashimoto et al, 1999;Seek et al, 2005), tomato (Chen et al, 2003), soybean and other crops (Melander et al, 2003) have been evaluated for nutritional quality and gross aspect of organs and no adverse effects on health have been found. However, at the microscopic and ultramicroscopic levels, there were cellular changes attributable to GM food intake (Ewen and Pusztai, 1999;Fares and El-Sayed, 1998;Malatesta et al, 2003;Malatesta et al, 2002aMalatesta et al, , 2002bTudisco et al, 2006;Vecchio et al, 2004).…”

Effects of Feeding Calves Genetically Modified Corn Bt11: A Clinico-Biochemical Study

“…Consequently, the Cry toxin has become a genetic resource for developing insect-resistant, genetically modified (GM) plants including Bt11 [2]. Before the introduction of Bt11 corn, there were several studies to assess its safety based on livestock performance [1,4,5]. However, there is little knowledge available on the clinicobiochemical effects of feeding Bt11 to cattle.…”

Safety Evaluation of Bt Plants

“…Furthermore, the slaughter results revealed no significant differences between the fattening bulls fed silage made from the Bt or nontransgenic corn 2 . There were no significant differences in fat-corrected milk yield, protein content, fat content, protein fractions, fatty acid composition, or coagulation properties of milk between Bt and conventional isogenic-corn-fed cows 3 . Effects of Bt corn on rumen functions that play an important role in digestion and absorption were also examined, and ruminal pH, acetate: propionate ratio, in situ digestion kinetics of NDF (neutral detergent fiber), efficiency of milk production, and daily body weight gain were unaffected by the transgenic corn 22 .…”