Rumen protected fat in kline barley or corn diets for beef cattle: digestibility, physiological, and feedlot responses
1991
Hill, G.M. | West, J.W.
A rumen protected fat product composed of Ca salts of fatty acids (CAF) was evaluated in beef cattle diets. Dietary treatments in a metabolism trial (six steers, 251 +/- 15 kg) and Feedlot Trial 1 (15 individually fed heifers, 355 +/- 11 kg) consisted of 62.1% corn and 3.2% soybean meal (C), 32.6% corn and 33.1% Kline barley (CB), and 28.2% corn, 33.1% barley, and 4.5% CAF (CBF) on a DM basis. Apparent DM and OM digestibilities were higher (P < .05) and NDF digestibility was lower (P < .05) for C than for CB and CBF. Apparent ether extract digestibility was higher (P < .01) for CBF than for CB. Retention of N was higher (P < .05) for C than for CB and CBF. On d 42, Feedlot Trial 1 ruminal fluid acetate:propionate ratio was lower (P <.01) for C than for CB and CBF, and the ratio was lower (P < .01) for CB than for CBF. Treatments did not affect (P > .10) ADG and DMI of heifers, but feed/gain was lower (P < .05) for C than for CB and CBF, and feed/gain was higher (P < .05) for CBF than for CB. In Feedlot Trial 2, steers and heifers were fed the C diet or a 57% corn, 21.4% peanut hull, 4.1% soybean meal, and 4.5% CAF diet (CF) on an ad libitum basis for 50 d. Ruminal fluid acetate and propionate were unaffected (P > .10) by dietary treatments. Cattle ADG tended to be lower (P >.10), DMI was lower (P <.05), and feed/gain tended to be improved (P > . 10) for CF compared with C. Kline barley has potential as a feed grain for cattle, but CAF may not improve beef cattle performance, especially when diets contain barley.
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