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

Abstract

Effects of feeding canola screenings on apparent digestibility, growth performance and carcass characteristics of feedlot lambs. Can. J. Anim. Sci. 80: 355-362. Commercial coarse canola screenings (CS) were substituted for barley grain, and the resulting experimental diets (0, 20, 45, 70 and 95% CS, were evaluated in feedlot lambs, while the 0, 45 and 95% CS diets were evaluated in a digestibility study using Romanov × Suffolk lambs. The CS comprised 60% canola (as whole, broken and immature seeds), 25% weed seeds and 15% chaff/dust. The control diet (0% CS) contained 75% barley and 20% alfalfa (as a protein/fibre source). Dietary crude protein (CP) increased with inclusion of CS and was lowest for control and 20% CS diets (13%) and highest for the 95% CS diet (14.4%). Digestibilities of dry matter (DM), organic matter (OM), neutral detergent fibre (NDF) and acid detergent fibre (ADF) were reduced (P < 0.05) in the 95% diet as compared with the control diet. Nitrogen retention by lambs was three times higher in the control group than in the 95% CS group (P < 0.001). Growth and feed conversion efficiency in feedlot lambs were linearly reduced (P < 0.001) with increasing dietary CS, but so was saturation of carcass fat (P < 0.001), which may benefit human health. Reduced lamb performance with CS was likely related to its high contents of crude fat (9%, DM basis) and ash (14%, DM basis). Valuing CS at 86% of the cost of barley, incorporation of up to 45% CS in feeder lamb diets would be cost effective. , FDN et lignocellulose étaient significativement (P < 0,05) plus bas pour l'aliment à 95 % cr.c. que pour l'aliment témoin. Le niveau de réten-tion de l'azote chez les animaux était 3 fois plus élevé (P < 0,001) dans le groupe témoin que dans le groupe recevant l'aliment à 95 % cr.c. La croissance et l'efficacité alimentaire chez les agneaux à l'engraissement diminuaient (P < 0,001) en fonction linéaire inverse de la proportion de cr.c. dans l'aliment. L'accroissement de la proportion de CR.C. dans l'aliment produisait une baisse en fonction linéaire (P < 0,001) de la croissance et de l'efficacité alimentaire chez les animaux à l'engraissement, mais également, ce qui est peut-être bon pour la santé humaine, une baisse du taux de saturation des graisses de la carcasse. La baisse des performances zootechniques due à l'inclusion des cr.c. serait liée à leur forte teneur en graisse brute (9 % sur la m.s.) et en cendres (14 % sur la m.s.). Considérant le coût des cr.c. à 86 % de celui de l'orge l'inclusion de jusqu'à 45 % de criblures de canola dans l'aliment d'engraissement des agneaux serait rentable.

Carcass traits, meat yield and fatty acid composition of adipose tissues and Supraspinatus muscle in goats fed blend of canola oil and palm oil

“…Also, BCPO caused a linear increase in the proportion of C20:5n-3. The current observation is consistent with those of Stanford et al [ 54 ] who observed that increasing the level of canola screening in diets reduced the concentration of C14:0, C16:0, C16:1n-7, C18:0 and total SFA and enhanced that of C18:1n-9, C18:3n-3, total MUFA and PUFA in perirenal adipose tissue in lambs. In contrast, dietary rapeseed oil, linseed oil or hydrogenated rapeseed oil did not alter the fatty acid composition of perirenal adipose tissues in lambs [ 55 ].…”

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

“…Overall growth performance of these lambs was at least equal to previous reports for early-weaned lambs individually fed highconcentrate diets (Stanford et al 2000). Feed intake by lambs fed the RRC diet was reduced (P < 0.05) compared to the COM1 and COM2 diets, but intake did not differ between lambs fed RRC and PAR.…”