Effects of feeding transgenic canola on apparent digestibility, growth performance and carcass characteristics of lambs

Abstract

. 2003. Effects of feeding transgenic canola on apparent digestibility, growth performance and carcass characteristics of lambs. Can. J. Anim. Sci. 83: 299-305. This study evaluated the effects of including meal from glyphosate-tolerant (Roundup-Ready ® ) canola (RRC) in barley-based diets for lambs on apparent digestibility of the diets, growth performance of the lambs, and carcass quality and composition. Four isonitrogenous diets were prepared that included canola meal [6.5%, dry matter (DM) basis] from four different sources (two commercially available canola blends, COM1 and COM2; a transgenic line, RRC and the parental non-transgenic line from which RRC was derived, PAR). Apparent digestibilities of the four diets were determined using eight mature wethers (67.8 ± 2.3 kg) in a replicated Latin square with four 21-d periods. No aspect of digestibility (DM, fibre, or nitrogen balance) was influenced by canola source. The growth trial involved 60 earlyweaned Arcott lambs (30 ewes; 30 wethers; initial age approximately 2 mo; initial weight 21.5 ± 1.0 kg). The lambs were blocked by weight and gender for assignment to treatments, and fed the diets until reaching or exceeding 45 kg body weight. Intake of DM was similar among lambs fed COM1, COM2 and PAR diets, and between PAR and RRC (COM1, COM2 > RRC, P < 0.05). Diet did not affect (P > 0.05) average daily gain or feed efficiency. Carcass yield grade was higher (P < 0.05) for COM1 and COM2 diets than for PAR or RRC, although carcass composition did not differ (P > 0.05) between PAR and RRC. Canola source did not affect (P > 0.05) meat tenderness, as determined by shear force, drip loss or intramuscular fat content. Meat colour of RRC-fed lambs did not differ from that of all other treatment groups. In this study, including canola meal prepared from glyphosate-tolerant canola did not alter diet digestibility, feed efficiency, growth performance, carcass characteristics or meat quality of lambs.Key words: Growth, lambs, meat quality, ruminant, transgenic canola Stanford, K., Aalhus, J. L., Dugan, M. E. R., Wallins, G. L., Sharma, R. et McAllister, T. A. 2003. Digestibilité apparente des aliments, performance de la croissance et paramètres de la carcasse chez les agneaux nourris de canola transgénique. Can. J. Anim. Sci. 83: 299-305. Les auteurs ont évalué l'incidence du tourteau de canola tolérant le glyphosate (Roundup-Ready ® ) (CTG) ajouté à la ration à base d'orge des agneaux sur la digestibilité apparente des aliments, la croissance des animaux ainsi que la qualité et la composition de la carcasse. Pour cela, ils ont préparé quatre rations isoazotées avec du tourteau de canola (6,5 % de la matière sèche (MS)) de quatre sources (deux mélanges de canola vendus dans le commerce, COM1 et COM2; une lignée transgénique, CTG; la lignée parentale non transgénique d'où était issue la précédente, PAR). Les auteurs ont établi la digestibilité apparente des quatre aliments avec huit moutons (67,8 ± 2,3 kg) dans le cadre d'une double expérience en carré latin menée pendan...

Growth performance, carcass characteristics and pork quality of pigs fed diets containing meal from conventional or glyphosate-tolerant canola

“…Compositional analyses of the sources of canola meal as previously reported by Stanford et al (2003) indicated that the PCC and RRC meal sources were similar in composition. Notably, the two commercial blends (COM1 and COM2) differed slightly in their dry matter content at approximately 900 g kg -1 compared with about 945 g kg -1 for the PCC and RRC canola meals.…”

“…Pigs are more susceptible to the negative goitrogenic effects of GL, which depresses their feed intake and growth, compared with other animal species (Tripathi and Mishra 2007). Lambs receiving diets formulated to include 6.5% of the same sources of canola meal, as in the present study, also had reduced feed and growth performance for animals fed the PCC and RRC variety sources (Stanford et al 2003). In this respect, Stanford et al (2003) reported lower (P < 0.05) dry matter feed intake and carcass yield grade for lambs fed meal from Roundup-Ready canola compared with the commercial non-transgenic canola sources, although carcass composition and meat quality were similar (P > 0.05) among the diets.…”

“…Since two pigs were removed from both the PCC and RRC diets, there was no evidence to suggest that insertion of genetic information coding for the CP4 EPSPS protein was responsible for the health problems. Genetic screening as described by Stanford et al (2003) confirmed that the transgenic CP4 EPSPS gene was present only in the RRC canola meal and corresponding grower and finisher diets.…”

“…The genetic integrity of all sources of canola meal and soybean meal used in the diets was tested for the presence of CP4 EPSPS as previously described by Stanford et al (2003). Following genetic testing, meal from two commercial, multi-variety blends of non-transgenic canola obtained from a different processing plant (COM1, COM2), the nontransgenic parental control from which the glyphosate-tolerant variety was derived (PCC) and the transgenic Roundup-Ready canola meal (RRC) were used to formulate grower (Table 1) and finisher (Table 2) diets according to National Research Council (1998) standards for nutrient requirements of pigs.…”

Opinion of the Scientific Panel on genetically modified organisms [GMO] on a request from the Commission related to the Notification (Reference C/NL/98/11) for the placing on the market of herbicide-tolerant oilseed rape GT73, for import and processing, u

“…It has been shown recently that incorporation of 6.5% (typical level for finishing lamb diets in western Canada) GM oilseed rape meal (event GT73) in a barley-based diet for lambs did not alter feed digestibility (dry matter, fibre, nitrogen balance), feed intake, feed conversion ratio, daily weight gain, carcass characteristics or meat quality of the lambs as compared to the diet containing the non-transgenic parent Westar (Stanford et al, 2003). Apparent digestibility of the diets was determined using eight mature wethers (67.8 ± 2.3 kg) in a replicated Latin square with four 21-day periods.…”