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.

Value of feather meal in a molasses-based liquid supplement fed to yearling cattle consuming a forage diet

Hydrolyzed feather meal (FM) was compared to other sources of CP to determine its value as a protein source in a molasses-based liquid supplement. Ruminal N escape values (measured in situ) for FM, ring-dried blood meal, cottonseed meal, and soybean meal approximated reported values. Ruminal N escape value for catfish meal was lower than values reported for other fish meals. In two trials (194 d), 84 yearling heifers were allotted to 12 pastures (3 pastures/treatment) and fed one of four supplements (1.7 kg of DM.heifer-1.d-1) containing either molasses and urea; molasses, urea,and FM; molasses, urea, FM, and catfish meal; or molasses, urea, FM, and catfish oil. Heifers were exposed to bulls for 60 d. In two trials, 112 steers were allotted to 16 pastures (4 Pastures/treatment) and fed one of four supplements (1.7 kg of DM.steer-1.d-1) containing molasses and urea; molasses, urea and FM; molasses, urea, FM and ring-dried poultry blood meal; or molasses, urea, and poultry feathers and blood hydrolyzed together. In all trials, cattle fed molasses containing FM had faster gains (P < .05) and heifers had heavier live weights at breeding (P < .05) and higher pregnancy rates (P < .05) than cattle fed molasses and urea. Combining poultry blood with molasses, urea, and FM improved (P < .05) steer gains in one of two trials. Combining catfish meal with molasses, urea, and FM did not improve (P > .05) ADG of pregnancy rate of heifers. Combining catfish oil with molasses, urea, and FM increased (P < .05) ADG in one trial and blood cholesterol and live weight of heifers at breeding in both trials. It is concluded that protein feeds, such as FM, that contain a large portion of ruminally undegradable protein may provide much of the CP in liquid supplements fed to growing cattle consuming moderate-quality forage. Adding catfish oil to a liquid supplement may improve ADG and live weight of yearling heifers at breeding.

Influence of grain type, tallow level, and tallow feeding system on feedlot cattle performance

Two experiments were conducted to evaluate the effects of grain type, tallow level, and tallow feeding system on finishing steer performance. Experiment 1 involved 256 yearling steers (359 kg) in a 4 x 2 factorial arrangement of treatments. Steers were assigned randomly to one of four tallow feeding systems: 1) 0% tallow fed throughout the experiment; 2) 4% tallow fed throughout the experiment; 3) 0% tallow fed d 1 through 33 and then 4% tallow fed until slaughter; and 4) 4% tallow fed d 1 through 33 and then 0% tallow fed until slaughter. Tallow treatments were applied to diets containing either dry-rolled corn (DRC) of high-moisture corn (HMC). No fat treatment x grain type interaction (P > .10) was observed. Steers fed 4% tallow throughout the experiment, only during d 1 through 33, or only during d 34 until slaughter were more (P < .10) efficient than steers fed 0% tallow. No differences in DMI or ADG were observed (P > .10). In Exp. 2, 120 large-framed steer calves (286 kg) were blocked by weight and allotted randomly within block to one of three treatments consisting of the addition fo 0, 2, or 4% tallow added d 1 and fed for 197 d. Feed efficiency of calves increased linearly (P < .05) with increasing tallow level. Daily gain was not different (P > .10), but DMI decreased linearly (P < .05) with increasing tallow level. This research indicates that tallow added during or after grain adaptation to DRC- or HMC-based diets fed to yearling steers will result in similar improvement in feed efficiency, and that including up to 4% tallow to diets fed to large-framed calves can significantly improve feed efficiency.

Silage or limit-fed grain growing diets for steers: II. Empty body and carcass composition

The influence of energy source (silage- or grain-based) on empty body and carcass composition and adipocyte cellularity independent of rate of gain was tested. Sixty-four Angus steers were allotted to either a forage (ad libitum) or grain (limit-fed) diet for a growing phase (145 d) followed by 45, 75, or 105 d of ad libitum access to a grain-based diet. Eight steers were slaughtered initially and eight from each treatment were slaughtered at the end of the growing phase, and at each of the termination dates. The silage growing diet consisted (DM basis) of 55% sorghum silage (approximately 24% dry matter), 22% alfalfa hay, 11% ground shelled corn, and 11% soybean meal. The grain-based growing diet was composed of 77% ground shelled corn, 5% soybean meal, 14% cottonseed hulls, 3% molasses, and 1% salt and mineral; it was limit-fed to produce the same rate of gain as the silage diet. No implants or ionophores were used. At the end of the growing phase, the steers fed grain were heavier and had a higher percentage of fat in the empty body (24 vs 19% fat) and the carcass (26 vs 21% fat) than did steers fed forage. Rate of gain during the growth phase was related positively to percentage of carcass fat; when corrected for fill, data for both diets fit one regression line for fat vs rate of gain. When adjusted for gain during the growing phase, fat content was not different in empty body or carcass, but internal fat was higher (P < .10) for steers fed grain. After 45 d on the finishing diet, carcass fat remained low (23%), but after 75 and 105 d, fat content reached 27%. Source of energy did not detectably affect carcass composition independent of rate of gain. Cell size of adipocytes from four adipose depots increased with time on feed but were not affected by diet during the growing phase. Lean Choice beef can be produced in only 45 d in the feedlot with medium-framed Angus cattle.

Effects of forage level and canola seed supplementation on site and extent of digestion of organic matter, carbohydrates, and energy by steers

The objective of this study was to determine the effects of fat supplementation from canola seed (CS) on ruminal fermentation and postruminal digestion of OM, carbohydrates, and energy of diets containing different levels of forage. Six ruminally and duodenally cannulated beef steers (354 kg +/- 18) were given ad libitum access to six isonitrogenous diets that were offered twice daily in a 6 x 6 Latin square design. Treatments were arranged as a 2 x 3 factorial with two forage levels (70 vs 30% of dietary DM as corn silage) and three forms of CS supplementation including no CS or CS added at 10% of dietary DM as whole CS treated with alkaline hydrogen peroxide or untreated crushed CS. Fat from CS provided 5% of dietary DM. The remaining dietary ingredients were corn, canola meal, molasses, and urea. No interactions (P > .05) between dietary forage level and CS supplementation were observed for ruminal characteristics or digestion of OM, carbohydrates, and energy in the rumen, postruminally, or in the total tract. Fat supplementation from CS did not affect (P > .05) DMI. With few exceptions, fat supplementation did not affect (P > .05) ruminal, postruminal, or total tract digestibilities of OM, structural and nonstructural carbohydrates, and GE. Ruminal disappearance of GE was decreased (P < .05) when diets were supplemented with fat from whole treated CS, and total tract digestibilities of OM and GE were decreased (P < .05) when diets were supplemented with fat from CS in either form. Ruminal pH, concentrations of NH3 N and total VFA, and molar proportions of acetate, propionate, and butyrate were not affected (P > .05) by fat supplementation. Results suggest that fat supplementation from CS (at 5% of dietary DM) as whole treated or untreated crushed had no negative effects on ruminal fermentation of OM, carbohydrates, or energy when steers were given ad libitum access to diets containing high or low forage.

Composition of ruminal bacteria harvested from steers as influenced by dietary forage level and fat supplementation

The objective of this study was to examine the effects of dietary forage level and fat supplementation on the chemical composition of mixed ruminal bacteria (MRB). Six ruminally cannulated beef steers (354 kg +/- 18) were given ad libitum access to six diets (13.2% CP; DM basis) that were offered twice daily in a 6 x 6 Latin square design. Treatments were arranged as a 2 x 3 factorial with two forage levels (70 vs 30% of dietary DM as corn silage) and three forms of fat supplementation including no canola seed or canola seed added at 10% of dietary DM as whole treated with alkaline hydrogen peroxide or untreated crushed. Canola seed contributed 5% added fat to the total diet. The remaining dietary ingredients were corn, canola meal, molasses, and urea. No interactions (P > .05) between dietary forage level and canola seed supplementation were observed. Concentrations of OM, N, and all amino acids were higher (P < .05) in MRB from steers fed low forage than in MRB from steers fed high forage. Concentrations of purines and GE and the N:purines ratio in MRB were not affected (P > .05) by dietary forage level or canola seed supplementation. Canola seed supplementation did not affect (P > .05) concentrations of OM, N, or most of the amino acids in MRB. Concentrations of four essential amino acids (i.e., isoleucine, leucine, lysine, and phenylalanine) in MRB were decreased (P < .05) due to canola seed supplementation. Dietary forage level did not affect (P > .05) concentrations of long-chain fatty acids in MRB.(ABSTRACT TRUNCATED AT 250 WORDS)

Different strains of Saccharomyces cerevisiae differ in their effects on ruminal bacterial numbers in vitro and in sheep

A ruminal simulation device (Rusitec) was used to compare the effects of Saccharomyces cerevisiae strains NCYC 240, NCYC 694, NCYC 1026, NCYC 1088, and Yea-Sacc (a commercial product containing S. cerevisiae) on ruminal fermentation. S. cerevisiae NCYC 240, NCYC 1088, NCYC 1026, and NCYC 694 were grown on malt extract at 30 degrees C in aerated fed-batch culture and harvested along with spent growth medium by freeze-drying. Each vessel received daily 20 g of a basal diet consisting of hay, barley, molasses, fishmeal, and a minerals/vitamins mixture at 500, 299.5, 100, 91, and 9.5 g/kg of DM, respectively. Yeast preparations (500 mg/d) were added along with the feed. S. cerevisiae NCYC 240, NCYC 1026, and Yea-Sacc stimulated total and cellulolytic bacterial numbers, whereas S. cerevisiae NCYC 694 and NCYC 1088 had no effect on the numbers of bacteria. The effects of S. cerevisiae NCYC 240, NCYC 1026, and Yea-Sacc on ruminal fermentation were further investigated in vivo using ruminally cannulated sheep fed 1.5 kg/d of the diet used in Rusitec, supplemented with 2 g/d of yeast culture. All treatments tended to stimulate total and cellulolytic bacterial numbers. However, the stimulation was only statistically significant for S. cerevisiae NCYC 1026 with total bacterial numbers and S. cerevisiae NCYC 240 with cellulolytic bacteria (P < .05). Increased bacterial numbers were associated with an increase in the rate of straw degradation in the rumen and a nonsignificant (P > .05) increase in the excretion of purine derivatives in the urine, measured as an index of microbial nitrogen leaving the rumen.(ABSTRACT TRUNCATED AT 250 WORDS)

Interaction of feed intake level on comparative ruminal and total tract digestion of dry-rolled and steam-flaked corn

Four Holstein steers (208 kg) with "T" cannulas in the rumen and proximal duodenum were used in a 4 x 4 Latin square design experiment to evaluate the interaction of feed intake level on comparative ruminal and total tract digestion of dry-rolled and steam-flaked corn. The basal diet contained (DM basis) 6% alfalfa hay, 6% sudangrass hay, 75% corn, 2% yellow grease, 5% cottonseed meal, 3% cane molasses, and 3% supplement. The corn portion of the diet was provided as either dry-rolled (density = .54 kg/L) or steam-flaked (density = .36 kg/L). Dry matter intake was restricted to allow for .64 vs 1.28 kg/d of weight gain (1.6 vs 2.4% of BW). Ruminal digestibility of OM, starch, and feed N were not affected (P > .10) by DMI. Postruminal digestion of OM and N and total tract digestibility of OM and DE decreased (P < .05) as DMI was increased. Total tract starch digestibility was not influenced (P > .10) by DMI. Steam flaking corn increased (P < .05) ruminal digestibility of OM and starch and postruminal and total tract digestibility of OM, starch, N, DE, and ME. Increasing DMI and steam flaking decreased (P < .05) ruminal pH and molar proportion of acetate. It is concluded that corn processing is the primary factor influencing site and extent of starch digestion. Decreasing DMI increases DE value of the diet; however, ME value is not affected because of increased energy loss as methane.

Effect of roasting on site and extent of digestion of soybean meal by sheep: I. Digestion of nitrogen and amino acids

Six mature wethers (BW 72 kg) with ruminal, duodenal, and ileal cannulas were fed a control (no added soybean meal [SBM]) diet or diets containing unheated SBM or SBM roasted at 165 degrees C for 75, 150, 180, or 210 min in a 6 x 6 Latin square experiment. Concentrations of indicators of heat exposure (ADIN, ADF, NDF) in SBM increased with increasing roasting time. Duodenal flows of total N, non-bacterial N, and SBM N increased (P < .05) linearly with increased roasting time. Small intestinal (SI) digestibility (percentage entering SI) of total N and SBM N was influenced quadratically (P < .05) by roasting time; SI digestibilities were modestly increased by heating SBM to 150 min, then declined dramatically when SBM was heated for 180 and 210 min. These responses resulted in a quadratic (P < .05) increase in quantity of total and SBM N disappearing in the SI; quantities increased as SBM was heated to 150 min and remained unchanged when SBM was heated for 180 and 210 min. These responses resulted in a quadratic (P < .05) increase in quantity of total and SBM N disappearing in the SI; quantities increased as SBM was heated to 150 min and remained unchanged when SBM was heated for 180 and 210 min. Duodenal flows and SI digestibilities of total and non-bacterial amino acids (AA) and of most individual AA followed patterns similar to those observed for N. Maximum quantities of total and individual AA disappeared from the SI when wethers were fed SBM roasted at 165 degrees C for 150 min. Evaluation of the effects of heat treatment on the nutritive value of a protein source for ruminants should include considerations for both ruminal protein escape and SI availability of escaped protein and for the nature of the AA supply absorbed from the SI.

Effect of molasses-based liquid supplements on digestibility of creeping bluestem and performance of mature cows on winter range

Poor quality of tropical range forage leads to excessive weight loss and poor reproductive performance of beef cows. This research measured 1) the digestibility by steers fed creeping bluestem (Schizachyrium scoparium var. stoloniferum) diets supplemented with cane molasses (0 or 20% of diet DM) and(or) added CP (no added CP, urea, or soybean meal) and 2) the performance of mature cows grazing creeping bluestem range and supplemented with 1.6 kg/(cow.d) (DM basis) of either molasses-urea or molasses-cottonseed meal-urea, each containing 30% CP (DM basis). Bluestem averaged 4.7% CP and 37.0% in vitro OM digestion. In the digestion trial, diets supplemented with molasses had greater (P < .01) apparent OM digestibility but lower (P < .01) apparent NDF, ADF, and hemicellulose digestibilities than diets not supplemented with molasses. Apparent OM digestibility of diets supplemented with soybean meal was greater (P < .05) than that of diets supplemented with urea but not different (P > .05) from the control. While grazing range, mature cows supplemented with molasses-urea lost less (P < .05) body condition (-1.7 vs -1.3) than cows supplemented with molasses-cottonseed meal-urea. Treatment did not affect cow weight loss on range (P = .85) or pregnancy rate (P = .51). Cows supplemented with molasses-urea tended to wean a heavier calf (P = .09). When fed at 1.6 kg/(cow.d) to mature cows grazing range, a molasses-based supplement containing urea was of equal value to one containing a natural protein.

Determining the net energy value of wet and dry corn gluten feed in beef growing and finishing diets

One growing and two finishing trials evaluated the feeding value of corn gluten feed for cattle. In the growth trial, calves were fed (DM basis) one of two control diets (44% dry-rolled corn [DRC], 50% alfalfa hay, 5% molasses, 1% supplement or 33% DRC, 33% alfalfa hay, 33% corn silage, 1% supplement), diets containing 49 or 65% wet corn gluten feed (WCGF) with alfalfa hay and supplement, or a diet containing 61% WCGF with cornstalks and supplement. Calves fed diets containing 49 or 65% WCGF with alfalfa hay gained faster (P < .10) and more efficiently (P < .10) than calves fed the two control diets. In finishing trial 1, yearling steers were fed 92.5% concentrate diets containing (DM basis) 79% DRC, a combination of DRC and 35 or 70% WCGF, a combination of DRC and 70% dry corn gluten feed (DCGF) with or without added water, or a combination of high-moisture corn (HMC) and 70% WCGF. Steers fed 35 or 70% WCGF in combination with either DRC or HMC had gains and efficiencies similar (P > .10) to those of steers fed DRC. Inclusion of water in the 70% DCGF diet reduced DMI (P < .10) and daily gain (P < .10) but did not affect (P > .10) feed efficiency. In Trial 2, WCGF replaced either 20, 40, 60, 80, or 100% of the DRC and molasses (DM basis). Feed efficiency was not different (P > .10) among diets.(ABSTRACT TRUNCATED AT 250 WORDS)

Digestion characteristics of beef steers fed silage and different levels of energy with or without protein supplementation

Six large-framed crossbred steers averaging 262 kg were used in a 6 x 7 incomplete Latin square design to study the effect of feeding a source of readily available energy (molasses) in combination with highly degradable protein (canola meal) on ruminal characteristics, digestibility, and in situ disappearance of DM and N. The seven dietary treatments were offered for ad libitum consumption and consisted of 1) timothy silage alone or mixed (on a DM basis) with 2) 7.5% molasses, 3) 15% molasses, 4) 7.5% canola meal, 5) 5.5% canola meal and 7.5% molasses, 6) 3.6% canola meal and 15% molasses, or 7) 15% canola meal. The total N content of supplements containing 7.5% canola meal, 5.5% canola meal and 7.5% molasses, and 3.6% canola meal and 15% molasses was similar. Molasses supplementation decreased (P < .05) ruminal ammonia N concentration and digestibility of energy and fiber. Canola meal supplementation increased (P < .05) N and energy digestibility but decreased ADF digestibility compared with feeding unsupplemented timothy silage. Feeding 15% compared with 7.5% canola meal increased (P = .05) DM digestibility and tended (P = .07) to increase energy digestibility. Combining 7.5% molasses and 5.5% canola meal did not improve DM digestibility, but adding 15% molasses decreased (P < .05) energy and fiber digestibility of the diet, which may explain lower ADG obtained for beef steers fed such levels of molasses in other research.

Growth and carcass characteristics of beef steers fed silage and different levels of energy with or without protein supplementation

Fifty-six large-framed crossbred steers averaging 227 kg were used in an experiment including a growing period (24 wk) and a finishing period ending when the steers had approximately 4 to 10 mm of fat thickness (Canadian grade A1). Steers were individually fed and assigned to a completely randomized design with seven treatments for the growing period. From the end of the growing period until slaughter, all steers received the same basal diet. Half of the steers from each treatment used in the growing period received a supplement containing protein and the other half a supplement containing protein and fat. Treatments during the growing phase consisted of 1) timothy silage alone or mixed (on a DM basis) with 2) 7.5% molasses, 3) 15% molasses, 4) 7.5% canola meal, 5) 5.5% canola meal and 7.5% molasses, 6) 3.6% canola meal and 15% molasses, or 7) 15% canola meal. The total N intake from supplements 2, 5, or 6 was similar. Compared with silage fed alone, canola meal supplementation increased (P < .05) ADG, whereas molasses had no effect. Combining molasses and canola meal did not improve ADG compared with feeding only canola meal on an isonitrogenous basis. Canola meal supplementation compared with feeding only silage during the growing phase reduced (P < .05) days on feed, and molasses tended (P = .059) to reduce it. Carcass data were generally similar among treatments.(ABSTRACT TRUNCATED AT 250 WORDS)