Utilization of whole or extruded canola seed by sheep and dairy cattle
Grumpelt, Bernd Paul
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A total of four experiments were conducted to investigate the the potential utilization of (immature) Whole Canola Seed (WCS) by dairy cows. Experiment 1, manuscript 1, involved 4 ram lambs in a Latin Square design feeding trial to determine the digestibility of WCS. 0, 7, 14 or 21% WCS replaced a basal oat ration. These rations were fed in each of four three week periods. Because of consumption difficulties in the first period a fifth period was conducted. A sixth period was executed in which all lambs received 4.7% Raw Canola Oil replacing an equal amount of the basal ration. The apparent digestibility of WCS was determined to be 77.5% for crude protein, 67.2% for ether extract, 70.1% for gross energy and 78.7% for dry matter. Experiment 2, manuscript 1, involved 20 multiparous cows in a Lucas design experiment to determine if the WCS would be consumed by dairy cows and what effect the WCS would have on production parameters. Five treatment sequences were conducted, each of three weeks duration in four blocks. Diets treatments consisted of long hay fed at 2.0 Kg./cow/day, concentrate fed according to production at 1 kg of concentrate per day for every 2.0 Kg of milk for cows above 7.5 Kg of milk, and Ad libitum corn silage for blocks 1, 2 and 3 and Ad libitum fababean silage for block four, with either 0.0, 0.5, 1.0, 1.5 or 2.0 Kg of WCS top dressed daily in two equal feedings. The top dressing of WCS had a significant linear effect on dry matter intake (P.<0.01). WCS levels of 1.0 and 1.5 Kg./cow/day showed a trend for improved four percent Fat Corrected Milk yield (FCM) when cows in early lactation only were considered. Experiment 1, manuscript 2, was a nylon bag trial to determine if WCS was degraded by the rumen bacteria. The WCS was determined to be a potential source of by-pass protein and energy based on the dry matter loss of 23.3% and a crude protein loss of 18.1% from nylon bags incubated in the rumen of a Jersey steer. Experiment 2, manuscript 2, involved 37 cows blocked into a 3x2x2 factorial design. Three rations were employed to determine the effects of extruded or WCS on the productive parameters of dairy cows in early lactation. Extruded or WCS was incorporated into isonitrogenous rations to obtain 3.2% added fat in the total mixed rations. The experimental period was 12 weeks in duration. The mean (+-SE) starting time for all cows was 8 +- 1 days post-calving. Milk production and feed intake were measured daily. Weekly milk samples were analyzed for fat, protein and lactose percents. Polynominal regression equations were fitted to the data and the production and intake profiles were analyzed for differences. Cows consuming the Extruded Canola rations produced (P=0.0523) more milk, lower milk fat% (p<0.05) and more milk lactose (P=0.0526) than cows consuming the control ration. The control group consumed significantly (P<.05) less dry matter than the WCS or extruded rations. The WCS group produced more milk fat (P.<0.05) than the control group. significant differences in the milk fatty acid composition were noted between the control, extruded and whole canola seed groups.