Utilization of whole rape (Canola) seed and sunflower seeds as sources of energy and protein in calf starter diets

Abstract

In Experiment 1, 50 Holstein calves were given five diets containing 0, 12 or 18% whole Canola seed (WCS), 18% extruded WCS or 18% WCS mixed and pelleted as a source of energy and protein for a 16-week growth trial. Apparent digestibility of the diets was determined with 7- and 15-week-old male calves. Calves receiving the 0% WCS (control) diet gained weight faster ( P < 0.05) than those given the 12% WCS, 18% extruded WCS or 18% WCS mixed and pelleted diets, but at a similar rate to those given the unpelleted 18% WCS diet. Extrusion of the WCS or pelleting the mixed diet did not improve the dry matter (DM) intake or average daily gains (ADG) of the calves. Apparent digestibility of crude protein (CP), acid-detergent fibre (ADF) and energy of calf starter diets was slightly higher at 15 than at 7 weeks old. Extrusion of the Canola seed depressed ( P < 0.05) the apparent digestibility of DM, CP and energy, and reduced the ( P < 0.05) digestibility of ADF by the 15-week-old calves. Pelleting the mixed diet or extrusion of the WCS improved ( P < 0.05) the digestion of crude fat at Weeks 7 and 15 of the growth trial. In Experiment 2, 33 young Holstein calves were fed on three starter diets containing 0, 10 and 20% whole sunflower seed (WSS) for a 16-week growth trial. No differences ( P < 0.05) were observed for ADG and DM intake by calves among the three treatments, whereas digestibility of ether extract increased significantly ( P < 0.05) with each level of WSS added to the diet. These experiments suggest that 10% whole sunflower seed or 12–18% whole Canola (rape) seed can be incorporated in starter grower diets of Holstein calves. However, there did not appear to be an improvement in feed efficiency or calf performance when fat was included in these rations as whole seeds. Ether extract digestion of WCS by calves was increased when the seed coat was broken.