Author
PAULA, EDUARDO - University Of Nevada | |
DANES, MARINA - University Of Wisconsin | |
LOBOS, NELSON - University Of Wisconsin | |
Zanton, Geoffrey | |
Broderick, Glen | |
FACIOLA, ANTONIO - University Of Nevada |
Submitted to: Journal of Dairy Science
Publication Type: Abstract Only Publication Acceptance Date: 4/9/2015 Publication Date: 7/14/2015 Citation: Paula, E.M., Danes, M.A., Lobos, N.E., Zanton, G.I., Broderick, G.A., Faciola, A.P. 2015. Effects of replacing soybean meal with canola meal or treated canola meal on performance of lactating dairy cows [abstract]. Journal of Dairy Science. 98(suppl 2):387. Interpretive Summary: Technical Abstract: Canola meal (CM) has been shown to be a more effective crude protein (CP) source than soybean meal (SBM) for lactating dairy cows. Treating CM may increase its rumen undegradable protein (RUP) fraction and improve the amount of absorbable amino acids. The objective of this study was to evaluate the effects of feeding treated CM (TCM) on performance of dairy cows. Forty-five Holstein cows were blocked by parity and days in milk (DIM), and used in a study of randomized complete block design. Cows were fed a control diet for a 2-week covariate period and then switched to the experimental diets for a 12-week study. Treatments differed only in CP source and were: SBM, CM, and TCM. All diets contained [dry matter (DM) basis] 30% alfalfa silage, 30% corn silage, 4% soy hulls, 2.4% mineral-vitamin premix, and 16% CP. SBM diets contained 25% high-moisture corn (HMC) and 8.6% SBM; CM diets contained 22% HMC, and 11.4% CM. Data were analyzed using the mixed procedure of SAS. Orthogonal contrasts were used to compare effects of different protein sources (SBM vs. CM + TCM) and (CM vs. TCM). There were no statistical differences in DMI and milk yield among diets; however, CM diets had numerically higher milk yields. Compared to SBM, both CM diets decreased milk urea nitrogen (MUN) concentration (P = 0.02). There were no significant differences in milk composition and yields among treatments. Results from this study suggest that CM diets may improve nitrogen utilization, as indicated by reduced MUN. Although the large numeric differences in milk production were not statistically significant, these differences may be important from a practical standpoint. |