Grain processing: effects on mixing, prehension, and other characteristics of feeds.

The primary objective of most grain processing of cattle diets is to increase starch availability. Evaluation of processing methods is usually based on ruminal or total tract starch disappearance and relative production rates (ADG, DMI, and gain: feed) demonstrated by cattle. Grain processing alters the mixing characteristics of grains and also influences steer preference for a grain and the manner in which grain is consumed. It is possible that mixing characteristics and selective eating influence production rates independent of starch availability when processed grains are fed. The magnitude of influence may depend upon the physical characteristics of other diet ingredients and feed intake. These relationships may work to improve or worsen production efficiencies. There is sufficient evidence to justify a closer evaluation of the influence of grain processing and feed ingredient combinations on mix quality, eating behavior, and true nutrient intakes of group-fed cattle.

Effect of protein level and source in molasses slurries on the performance of growing cattle fed hay during winter.

Four molasses slurries of varying protein level and source were fed in two performance trials (Year 1, 105 d; Year 2, 92 d) to growing cattle (Year 1, 230 kg; Year 2, 247 kg). Treatments were CONTROL (hay only), MOL (molasses-corn meal), MOL-UREA (molasses-urea-corn meal), MOL-SBM (molasses-soybean meal), and MOL-BF (molasses-urea-corn meal blood meal-hydrolyzed feather meal). Animals on all treatments were offered bermudagrass hay (Year 1: 12.8% CP, 50% TDN; Year 2: 12.8% CP, 54% TDN) and a complete mineral mixture free choice. Each treatment was fed to three pens each year with seven animals/pen. Slurries were offered at 2.1 kg/d (DM) and effects on forage intake, ADG, condition score (1 to 9), hip height, and plasma urea nitrogen were monitored. Treatment effects for Years 1 and 2 were analyzed separately due to treatment x year interactions (P < .15) with respect to ADG, hip height change, condition score change, and feed cost of gain. Supplementation increased (P < .001) ADG over CONTROL in Year 1 (.41 vs .06 kg/d) and Year 2 (.69 vs .25 kg/d), increased hip height change by .02 cm/d (P < .001) in Year 1 and by .01 cm/d (P = .012) in Year 2, and decreased (P < .001) loss of body condition in Years 1 and 2. Molasses-urea showed no advantage over MOL in Years 1 and 2. Natural protein (MOL-SBM and MOL-BF) increased ADG by .10 kg/d in Year 1 (P = .001) and by .06 kg/d in Year 2 (P = .077) compared with MOL-UREA. Daily gain was improved by MOL- BF by .05 kg/d (P = .109) in Year 1 and by .08 kg/d (P = .063) in Year 2 compared with MOL-SBM. Results indicate that growing cattle fed bermudagrass hay during winter respond positively to energy supplementation in the form of molasses. The addition of animal source protein enhanced this response.