Typescript. / Digitized by Kansas Correctional Industries

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Digitized by Kansas Correctional Industries

No description available.

Two experiments measured winter feed waste when cows were fed forage on snow. In the first experiment, feed waste was different (P<0.01) when alfalfa meadow brome mixed hay was fed by bale unroller or bale processor; waste was12.9% vs.19.2%, protein losses were 23.3% and 21.5% respectfully. Feed waste, nutrient replacement and additional equipment costs increased winter feeding costs by $52.50 and $56.25 per head respectfully for a 175 day feeding period. Hay processed into portable bunk feeders, experienced 0% feed waste. In the second experiment, feed waste when barley cereal silage fed either as high moisture round bale silage or chopped pit silage was fed on snow was not different (P>0.05) at 23.2% and 26.8% respectfully. When chopped barley cereal silage or high moisture round bale silage was fed into bunks, feed waste was 0%. Protein losses were 27.1% and 24.2% for the pit and round bale silage. Feed waste, nutrient replacement and additional equipment costs increased winter feeding costs by $164.50 for pit silage and $126.00 for bale silage over a 175 day feeding period. / Animal Science

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 193-206).

Graduation date: 1993

Three experiments were conducted to determine the effects of source (experiment 1), frequency, and level (experiments 2 and 3) of energy supplementation on performance, forage utilization and intake, productivity, rumen fermentation, and nutrient digestibility of growing beef cattle fed stockpiled forage. In experiment 1 (EXP1) and experiment 2 (EXP2), 45 cross bred yearling steers were managed on stockpiled crested wheatgrass pasture over 70 days during summer/fall of 2011 and 2012. Steers were stratified by IBW (EXP1 = 334±1.2 kg; EXP2 = 358±1.8 kg) and allocated randomly to 1 of 9 crested wheatgrass pastures (5 steers/pasture). Each pasture was randomly assigned to 1 of 3 replicated (n = 3) treatments. In EXP1, two isonitrogenous and isocaloric by-product feed pellets that differed in starch and degradable fiber content were used in one of three supplementation strategies: 1) no supplement (CON), or supplemented at 0.6 % of BW with 2) low starch/high fibre (LS/HF) pellet (40.3% starch; 29.5% NDF DM basis) pellet, or 3) high starch/low fibre (HS/LF; 48.6% starch; 22.8% NDF DM basis) pellet. In EXP2 a by-product feed pellet was formulated to provide ruminal and post-ruminal energy (30.3 % NDF; 32.0 % starch; 7.2 % fat) supplementation strategies included: 1) daily (DLY) supplementation at 0.6 % of BW, 2) low-alternate (LA) supplementation at 0.9 % of BW, and 3) high-alternate (HA) supplementation at 1.2 % of BW. There was no effect (P > 0.05) of treatment on forage utilization in either experiment. In EXP 1, final BW and ADG were not different (P > 0.05) between LS/HF (435 kg; 1.4 kg d-1) and HS/LF (439 kg; 1.5 kg d-1). However, supplemented cattle had higher (P < 0.05) final BW and ADG than CON cattle (402 kg; 1.0 kg d-1). Supplementation increased production costs by 450 %. In EXP 2, no difference (P > 0.05) was observed for final BW and ADG among DLY (435 kg; 1.1 kg d-1), LA (424 kg; 0.9 kg d-1), and HA (428 kg; 1.0 kg d-1). Production costs were reduced by 23 % with alternate supplementation and LA had 19 % less production costs than HA. In experiment three (EXP 3), four ruminally cannulated beef heifers were individually fed a stockpiled grass hay and offered the same pelleted supplement as in EXP2. Treatments consisted of 4 supplementation strategies: 1) no supplement (CON), 2) daily (DLY) supplementation at 0.6% BW, 3) low-alternate (LA) supplementation at 0.9 % of BW, and 4) high-alternate (HA) supplementation at 1.2 % of BW. Forage intake, rumen fermentation parameters, and apparent total tract digestibility were measured. Three data sets were analyzed: 1) overall (average of all collection days), 2) day of supplementation (DS) and 3) non-supplementation day (NSD) for alternating treatments. Overall, hay DMI (kg d-1) was lower (P = 0.04) for DLY (7.1) vs. CON (8.1), but no different (P ≥ 0.11) for DLY vs. LA (6.9), or vs. HA (6.4). On DS, hay DMI (kg d-1) of DLY (7.3) differed (P < 0.05) vs. HA (6.0), but was not different (P = 0.16) vs. LA (6.4). On NSD, hay DMI (kg d-1) of DLY (7.0) was not different (P ≥ 0.48) to those of LA (7.3) and HA (6.9). Overall, total VFA concentration (mM) was lower (P < 0.01) for CON (69.2) vs. DLY (77.1); but not different (P ≥ 0.45) for DLY vs. LA (75.8) or HA (75.1). Rumen NH3 (mg/dL) was lower (P < 0.01) for CON (3.4) and higher (P < 0.01) for LA (5.8) vs. DLY (4.6), but not different (P = 0.37) for DLY vs. HA (4.3). Overall, ruminal pH was lower (P ≤ 0.04) for DLY (6.65) vs. CON (6.75) and HA (6.72), but similar (P = 0.18) for DLY vs. LA (6.70). On DS, ruminal pH was lower (P = 0.04) for HA (6.59) vs. DLY (6.64), but higher (P < 0.01) on NSD for HA (6.85) vs. DLY (6.67). Apparent DM, OM and GE digestibility coefficients were lower (P ≤ 0.03) for CON and LA vs. DLY, but no difference (P ≥ 0.36) for DLY vs. HA. These results indicate that beef steers grazing stockpiled crested wheatgrass were limited in energy intake and that supplementation of metabolizable energy improved animal performance regardless of the source of energy. Reducing the frequency of energy supplementation and level offered on alternate days do not affect animal performance and reduces the production costs of the system. Negative effects of alternate day supplementation on forage intake and rumen fermentation are reduced when a lower level is offered relative to simply doubling the daily amount of supplement.

Objectives of this study were 1) to characterize the relationship between beef cattle efficiency, namely residual feed intake (RFI), and digestive, microbial, and fermentation parameters in growing beef calves and 2) to examine the effects of added dietary hydrolysable or condensed tannin on animal performance and efficiency, fermentation and carcass and non-carcass traits. To accomplish the first objective, multiple RFI studies were conducted and in all studies RFI was calculated as the difference between actual and expected dry matter intake (DMI) based on average gaily gain (ADG) and body weight0.75(BW). A total of 187 head selected out of a population of 600 head of growing beef calves were evaluated for diet and nutrient digestibility, ruminal and fecal volatile fatty acids (VFA) concentrations and methane producing activity (MPA). Low RFI calves consumed less DMI and had lower feed conversion ratios (FCR) as compared to high RFI calves. Low RFI calves also had higher diet and nutrient digestibilities compared to high RFI calves. Residual feed intake was negatively correlated with diet and nutrient digestibilities such that more efficient animals had higher digestibilities. Low RFI calves tended to have lower ruminal propionate and higher acetate:propionate ratios when fed a high-forage diet. Calves with divergent RFI did not have different gross microbial populations as evidenced by the Firmicute:Bacteriodetes ratio, but low RFI calves tended to have higher fecal Prevotella spp. and lower fecal Spirochaetes and ruminal Cyanobacteria. The importance of these subtle shifts in microbial ecology is not evident at this time and more research is needed to fully elucidate the interaction of host and microbes to fully grasp the importance of minor microbial deviations. No differences in 3 h MPA were detected in low vs. high RFI calves but low RFI calves had higher fecal MPA when sampled at 24 h; however, calculated methane emissions were lower for low RFI calves. Tannin supplementation had no effect on animal performance and efficiency, ruminal fermentation VFA concentrations, MPA, or ammonia concentrations in finishing beef steers. There was also no detrimental effect of tannins on carcass traits; however, hydrolysable tannin supplementation resulted in increased empty rumen mass. Results from these studies indicate that diet and nutrient digestibility are affected by RFI such that more efficient calves had higher DMD, microbial ecology is responsive to RFI such that minor microbial shifts were observed, and tannin supplementation, at the current inclusion rate, had no effect on animal and carcass performance.

Wet distiller’s grains with solubles are the most common feedstuff generated by the ethanol industry, and this feedstuff has been utilized by the feedlot industry. Exploration of the effect of dietary distiller’s inclusion on the form and quantity of protein or nitrogen (N) has received little attention. Assessment of degradable N needs in diets containing wet distiller’s grains with solubles (WDGS) is needed to aid the cattle feeding industry in managing feed costs and potential environmental issues. In Exp. 1, 525 yearling steers (initial weight = 373 ±13 kg) received treatments in a 2 × 3 1 factorial. Factors included corn WDGS (15 or 30 percent of DM) and non-protein N (NPN; 0, 1.5, or 3.0 percent of DM) from urea. The control diet without corn WDGS contained 3.0 percent NPN (1.06 percent urea) and cottonseed meal. Overall gain efficiency among steers fed 15 percent corn WDGS was greatest for 1.5 percent NPN and least for 0 percent NPN (P = 0.07, quadratic), whereas gain efficiency decreased linearly (P < 0.09) as NPN increased in the 30 percent WDGS. Dressing percent was greater (P < 0.01) for the control diet than for 15 percent or 30 percent WDGS. In Exp. 2, 296 steer calves (initial BW = 344 ± 12 kg) were adapted to a common finishing diet, blocked by BW, and assigned to treatments. Experimental diets included a control diet without WDGS (contained 3 percent NPN from urea, and cottonseed meal) and 15 percent WDGS with either 1.50, 2.25, or 3.00 percent NPN (0.52, 0.78, and 1.04 percent urea, respectively, on a DM basis). Overall gain efficiency on either a live or adjusted basis was not different among treatments (P > 0.15). Dietary NPN concentration did not influence growth performance (P > 0.21). Results suggest that optimum performance for cattle fed 15 percent WDGS occurred when the diet contained between 1.5 percent and 2.25 percent NPN. However, removing all supplemental NPN was necessary to support optimum performance in diets containing 30 percent WCDG.