Orchardgrass Hay Research Articles

Characteristics of Ruminal Fermentation of Wethers Fed Tofu Cake Silage with Ethanol

Tofu cake added with three levels of ethanol was made into silages and fed to four wethers to investigate characteristics of ruminal fermentation. The animals received a basal diet consisting of the second cut Orchardgrass hay and beet pulp (4:1) and either fresh tofu cake (control) or one of silages made of tofu cake added with ethanol at 2%, 4% and 6% levels was also fed so that it account for 20% of the whole ration. Feeding levels were determined based on metabolic body size and were restricted to 85% of voluntary intake levels. 1) The animals fed with tofu cake silages had different ruminal fermentation compared to those in the control. There were positive or negative linear effects of amount of ethanol added to tofu cake silage on ruminal pH, volatile fatty acid (VFA) and other parameters. 2) The higher the levels of ethanol added to tofu cake silage the higher the total VFA, acetic, valeric and caproic acid levels and adversely the lower the propionic acid levels. 3) The animals fed with tofu cake silages had significantly (P<0.01) higher ratios of propionic acid to acetic acid in the rumen fluid. 4) Rumen fluid taken from the animals fed with tofu cake silages had lower pH and lactic acid than that from the control. 5) Although there were no apparent increase in pH, total VFA level or any particular VFA levels in the rumen for the amount of tofu cake fed to the animals in this study, further investigations for optimum feeding levels of tofu cake are needed.

Influence of an anaerobic fungal culture administration on in vivo ruminal fermentation and nutrient digestion

Experiments were conducted to study the effect of administration of anaerobic fungal cultures or their enzymes on ruminal fermentation, microbial populations and enzyme activities in the rumen, and general nutrient digestion in sheep. Twelve mature sheep receiving 560 g of orchard grass hay and 240 g of concentrate per day were randomly assigned to three different treatments with four sheep per treatment. Control (FM) animals received 200 ml of the defined medium for fungal growth through rumen cannulae at 8.00 h each day (as a control treatment without added fungal enzymes and viable cells). The second group of animals (FE) were given 200 ml of supernatant from fungal culture incubated with an anaerobic ruminal fungus for 7 days (as a treatment for fungal enzymes in cultures without viable fungus). The third group (FC) was administered with an anaerobic fungal culture incubated for 7 days (as a direct-fed microbials (DFM) treatment with fungal enzymes and viable cells). Animals were exposed to each treatment for 15 days before rumen collection and digestion trials began. Direct administration of cultures of a polycentric fungal strain, Orpinomyces strain KNGF-2 isolated from a Korean native goat, to the rumen of sheep (FC) generally increased nutrient digestibility and nitrogen (N) retention resulting from an increase in numbers of bacteria and fungi in the rumen and by altering the patterns of volatile fatty acids (VFA) production. However, administration of fungal enzyme (FE) failed to improve nutrient digestibility and N retention, and ruminal fermentation parameters. Results indicate that these proteins may be rapidly degraded by ruminal microbes or that these enzymes could reduce the growth or activity of ruminal microbes. These are the first report of the effect of DFM originating from an anaerobic fungal culture. Such a development is particularly significant because this study demonstrates that the introduction of a microorganism with superior fibrolytic activity into the rumen can improve nutrient utilization in ruminants.

Effects of dry plant extracts on fermentation and methanogenesis in continuous culture of rumen microbes

Thirteen plant extracts, selected for their high flavonoid content, were screened on their action on fermentation and protozoa numbers in 1 l dual outflow fermenters supplied with a 50:50 orchard grass hay+barley diet. Using a 2 14−10 fractional factorial design, we tested each extract at the rate of 0.5 g per day. The corresponding organic matter inflow was equal to 3.4% of the basal hexoses fermentation rate. Lavandula officinalis enhanced acetate (C2), propionate (C3) and butyrate (C4) outflows (+9.2, +11.9 and +11.4%, respectively), while Solidago virgaurea acted mainly on C2 (+11.3%) and C3 (+15.8%). Achillea millefolium increased C2 relative outflow (+5.7%) to the detriment of C4 (−7.9%). Propolis increased C3 production by 10.3%. Branched chain volatile fatty acids productions were favoured by A. millefolium and lowered both by Arnica chamissonis and Fagopyrum esculentum. Gas production was increased by L. officinalis (CO 2: +11.9%; CH 4: +13.7%) and S. virgaurea (CO 2: +7.8%; CH 4: +7.7%), whereas it was lowered by Equisetum arvense (CO 2: −10.6%; CH 4: −14.2%). Methanogenesis also decreased with Salvia officinalis (−8.2%). Protozoa numbers were little affected by plant extracts. In conclusion, the extracts which could be selected for further evaluation were L. officinalis and S. virgaurea for promoting the extent of fermentation, and E. arvense and S. officinalis for their possible inhibitory action on methane production.

Effects of Lavandula officinalis and Equisetum arvense dry extracts and isoquercitrin on the fermentation of diets varying in forage contents by rumen microorganisms in batch culture.

The short-term actions of Lavandula officinalis and Equisetum arvense dry extracts, and of isoquercitrin, flavonoid present in Equisetum arvense, on in vitro fermentation by rumen microbes were studied in batch culture. The orchard grass hay:barley ratios in the three experimental diets were 100:0, 75:25, 50:50 on a DM basis. The production rates of all volatile fatty acids except isobutyrate were strongly influenced by the composition of the diet and to a lesser extent, by plant extracts, with significant interactions between both factors. When hay was the only substrate, the addition of L. officinalis and E. arvense enhanced the fermentation rate by 50%, through an increased release of acetate and propionate. On the contrary, with the two other diets, the fermentation rate was strongly lowered by isoquercitrin. Gas outputs were not significantly influenced by plant extracts.

The effect of physical form of orchardgrass hay on the passage of particulate matter through the rumen of sheep.

Four Texel wethers (60 to 64 kg) fitted with ruminal and duodenal cannulas were used to study the kinetics of particulate matter in the rumen and the series of processes involved in their selection and passage. They were fed, in eight equal meals, 1,200 g of a mixture of a chopped orchardgrass hay and ground (8-mm screen) and pelleted orchardgrass hay in 90/10, 50/50, 30/70, or 10/90 ratios, according to a 4 x 4 Latin square design. The particle size distributions in feed, chewed feed, and ruminal, reticular, and duodenal digesta were determined by a wet-sieving procedure. Indigestible lignin was used as an internal marker to trace the passage of particles through the rumen. Digesta flow measurement was performed using the double-marker technique. We used a three-pool model, which partitions particles through the large, medium, and small particle pools, to determine the passage of lignin through those pools. Particle pool sizes and rumen and pool mean retention times (MRT) of lignin and of the rumen MRT of an ideal marker introduced separately in each pool were corrected for the "filter bed" effect. Grinding and pelleting of hay decreased the MRT of the indigestible lignin pool in the rumen. Particle MRT decreased and then reached a plateau with increased proportion of ground/pelleted hay in the diet. The diet with a ratio of 50/50 of chopped and ground/pelleted hay was the most favorable for the exit of particles from the rumen because of both a higher outflow rate from the rumen of particles eligible to exit and a sufficient comminution rate of larger particles to supply particles that were able to pass. For all diets, the large-particle comminution rate was always higher than the small-particle outflow rate, indicating that comminution was not the limiting step for passage. These results were the consequence of the curvilinear and opposite evolutions of both the particulate lignin pool in, and outflow from, the rumen. Those results contribute to an improved explanation of the mechanisms involved in the outflow of particles from the rumen.

Effect of level of whole cottonseed on intake, digestibility, and performance of growing male goats fed hay-based diets.

Twenty-four purebred Boer (Capra hircus hircus) and 12 male kids of 1/2 Boer breeding (initial BW 21 +/- .5 kg) were used in a randomized complete block design to study the effects of increasing level of whole cottonseed (WCS) on ADG, serum urea N, plasma gossypol, live grades, and intake of DM, CP, NDF, ADF, hemicellulose, cellulose, lignin, ether extract, and free gossypol. A subgroup of 16 purebred goats was used to determine digestibility using a 5-d total fecal collection. Goats were blocked by BW and then assigned at random to one of four diets containing 0, 8, 16, or 24% WCS. All diets contained 71% chopped orchardgrass (Dactylis glomerata L.) hay and 29% concentrate; WCS replaced corn and soybean meal to maintain calculated TDN and CP concentrations at 68 and 15% of DM, respectively. Concentrations of NDF in diet DM were 52.4, 55.9, 59.3, and 62.1% with increasing WCS, and the Ca:P ratio was maintained at 2:0. Goats were given ad libitum access to feed and water. Over the 90-d performance phase, DMI (P < .05), CP intake (P < .02), and ADG (P < .01) decreased linearly with increasing WCS in the diet, whereas ether extract (EE) intake increased in a cubic fashion (P < .01). Gain:feed decreased linearly (P < .02) with increasing level of WCS. Addition of WCS resulted in linear decreases in apparent digestibility coefficients of DM (P < .02) and NDF (P < .05), a linear increase in total plasma gossypol (P < .01), and a quadratic increase in serum urea N (P < .04). Apparent digestibility of CP was not affected by WCS level. At the 16 and 24% WCS levels, EE constituted 4.2 and 4.8% of total DMI, respectively. Adding WCS to diets for growing goats had detrimental effects on animal performance, and, based on the possible negative effects of dietary EE and NDF rather than gossypol, economics should dictate whether to use WCS in feeding programs.

Effects of protein concentration and source on nutrient digestibility by mature steers limit-fed high-concentrate diets.

Five ruminally fistulated 3-yr-old mature Holstein steers (average BW 691+/-23 kg) were used in a 5 x 5 Latin square experiment with a 2 x 2 + 1 fact orial arrangement of treatments. Effects of protein concentration and protein source on nutrient digestibility, excretion of DM and fecal N, ruminal fluid volume and dilution rate, ruminal characteristics, and in situ DM disappearance of whole shelled corn, ground corn, and orchardgrass hay were measured in steers limit-fed high-concentrate diets at 1.5% of BW. A negative control basal diet (NC; 9% CP) was supplemented to achieve either 11 or 14% CP; supplemental CP was either from soybean meal (11 and 14% SBM) or a 50:50 ratio of CP from urea and soybean meal (11 and 14% U). Dry matter and OM digestibilities were 5% greater (P < .07) for steers fed the SBM diets than for those fed the U diets. Starch digestibility did not differ (P > .10) among steers fed any of the diets. Nitrogen source did not affect (P > .10) apparent N digestibility or fecal N excretion; however, steers fed the NC diet had the lowest (P < .10) apparent N digestibility compared with those fed all other diets. Ruminal fluid volume was lower (P < .06) when steers were fed the NC diet compared with all other diets; there were no differences (P > .74) among diets for ruminal fluid dilution rate. In general, ruminal ammonia N and VFA molar proportions were not affected by protein source or concentration. Although CP concentration affected (P < .06) in situ DM disappearance of ground corn, CP concentration did not (P > .48) affect total tract digestion of DM or OM. This indicates that CP concentration may have affected site of digestion, but not extent of digestion. When mature ruminants were limit-fed a corn-based diet to meet primarily a maintenance function, protein source and concentration had little effect on measures of nutrient digestion.

Screening of factors favouring the maintenance of rumen protozoa in a dual outflow continuous fermenter

For the past years in Europe, the need for reliable alternative techniques to animal experimentation has been urged by ethical and legal prescriptions. In ruminant nutrition, dual outflow stirred-tank reactors (Hoover et al., 1976; Merry et al.,1987) have proved to be suitable for the accurate control of environmental conditions to study the metabolism of rumen microbes. Their ability to support a varied ciliate population, however, is uneven. As protozoa are major agents in the rumen microbial community, investigating the best set of general operating conditions to maintain their population at high levels is an important issue.The study was conducted in six dual outflow continuous fermenters (working volume of 1.11) supplied with 30 g/day of a pelleted diet made of 750 g orchard-grass hay and 250 g ground barley per kg. The vessels were inoculated with the rumen contents from four wethers, each equipped with a rumen cannula and given a similar diet. They were continuously infused with an artificial saliva containing: Na2HPO4.12H2O 6.157 g/l, NaHCO3 5.268 g/l, KHCO3 0.597 g/l, NaCl 0.305 g/l, HC1-cysteine 0.4 g/l and alcalinized to pH 10.0 with 1.63 g/l NaOH. The fermentation broth was separately complemented with 31.7 mg CaCl2, 47.5 mg MgCl2 and 0.755 g (NH4)2SO4 per day.

Validation of the main modeling methods for the estimation of marker mean retention times in the different compartments of the gastrointestinal tract in sheep.

Four Texel wethers (60 to 64 kg) fitted with rumen and duodenal cannulae were used to compare methods for estimating mean retention times (MRT) of digesta markers. They were fed, in eight equal meals, 1,200 g of a mixture of a chopped and ground (8-mm screen) and pelleted orchardgrass hay in the ratios 90/10, 50/50, 30/70, or 10/90 according to a 4 x 4 Latin square design. Mean retention time in the stomach and in the whole tract were estimated by orally delivering pulse doses of 170Tm-labeled chopped hay, 169Yb-labeled ground hay, and [51Cr]EDTA, followed by duodenal spot-sampling and total collection of feces; calculations were done using an algebraic method. Mean retention time in the abomasum was estimated following administration of a pulse dose of the markers (169Yb-labeled duodenal particles and [51Cr]EDTA) in the abomasum via the ruminal cannula through the reticulo-omasal orifice and collecting duodenal samples. The reference value for MRT in the reticulorumen (MRTRR) was calculated by subtracting MRT in the abomasum from MRT in the stomach. For all markers, fecal excretion curves were fitted to a two-compartment age-independent model, a gamma-2 age dependent-age independent two-compartmental model, and a multicompartmental model. Comparisons were made among parameters of the models and their anatomical or physiological attributes when these were clearly defined or easily calculated. The mean retention time in the reticulorumen (MRTRR) obtained from the multicompartment model was similar to those calculated with the algebraic method whatever the sampling site and the marker used.

Effect of ruminal cellulolytic bacterial concentrations on in situ digestion of forage cellulose.

To evaluate the effects of ruminal cellulolytic bacterial concentrations on in vivo cellulose digestion, varying percentages of flaked soybean hulls were substituted for orchardgrass hay in high-forage diets fed to sheep. In two experiments, total and cellulolytic ruminal bacterial concentrations were not affected by diet. No differences were found for in situ digestion of forage cellulose in the first experiment; however, in Exp. 2, ruminal pH and in situ cellulose digestion were lower (P<.01) with a 40% soybean hull diet. In Exp. 3 with four sheep, two diets were compared, one containing 19.6% cellulose from alfalfa meal and the other 64.3% purified wood cellulose. Ruminal pH was lower (P<.02), 9 and 24 h after feeding, for the high-cellulose diet. Total bacterial concentrations did not change with diet; however, the concentration of cellulolytic bacteria increased (P<.05) when the higher cellulose diet was fed. In situ cellulose digestion was not different between diets. In Exp. 4, 3% sodium bicarbonate was added to the high-cellulose diet, and it was fed twice a day. No differences were observed in pH between diets (P>.42). However, the concentration of total ruminal bacteria increased (P<.06), the concentration of cellulolytic bacteria increased (P<.03), and the percentage of cellulolytic bacteria increased (P<.04) when the buffered high-cellulose diet was fed. In situ digestion of alfalfa cellulose at 30 h was not different between diets (P>.60). These data indicate that the concentration of cellulolytic bacteria is not the limiting factor in the digestion of cellulose in the rumen.

Effect of Rumen-Undegradable Protein and Energy on Growth and Feed Efficiency of Growing Holstein Heifers1,2

Thirty-two Holstein heifers were used to determine the effect of energy and rumen-undegradable protein (RUP) on growth and feed efficiency. Treatment diets were in a 2×2 factorial consisting of two energy concentrations (supporting 0.6 or 0.9kg of average daily gain) and two percentages of RUP (30 or 50% of crude protein). Isonitrogenous diets based on corn silage, alfalfa silage, orchardgrass hay, corn, soybean meal, blood meal, and minerals were fed. Treatment diets were fed until 385 d of age, constituting phase 1 of the trial. During phase 2 (until calving), heifers were housed together and fed a common diet for 0.7kg of average daily gain. Dry matter intake (kilograms per day) during phase 1 was 4.46, 5.42, 7.38, and 5.95 for heifers fed low energy and low RUP, low energy and high RUP, high energy and low RUP, and high energy and high RUP diets, respectively. Average daily gain (kilograms) during phase 1 was 0.62, 0.74, 1.01, and 0.96, respectively. Dry matter intake and gain were higher for heifers receiving high energy diets. Dry matter efficiency was higher for heifers fed high energy and high RUP diets. Apparent total digestible nutrient efficiency was higher for heifers fed high RUP diets. Average daily gain during phase 2 was 0.53, 0.43, 0.33, and 0.50kg, respectively. Overall average daily gain was not affected by energy or RUP levels during phase 1 because the slow growth of heifers during phase 1 was compensated by faster growth during phase 2.

Relationships Between Crude Protein and Determination of Nondispersible Lignin

The objective of this study was to examine the relationships between crude proetin (CP), acid detergent fiber (ADF), ADF CP, and acid detergent lignin CP and measures of lignin, neutral detergent fiber (NDF), and digestibility. Specifically, the study examined whether a relationship existed between these measures and the CP content of feed or the residual CP found in ADF or acid detergent lignin. Sixty-seven samples (15 alfalfa hay, 16 tall fescue hay, 15 orchardgrass hay, 10 vegetative corn plants, and 11 vegetative wheat plants) were collected at different maturities for study. Samples were analyzed for CP, NDF, digestibility, and lignin (acid detergent, permanganate, chlorite, and acetyl bromide). In addition, batches of ADF and acid detergent lignin were prepared for CP determination. Results of correlations between the feed CP, ADF CP, or acid detergent lignin CP and measures of lignin, NDF, or digestibility were found to be highly dependent on feedstuffs. In some instances, such as the correlations between acid detergent lignin CP and lignin, NDF, or digestibility, different feedstuffs produced equally close, but opposite (positive versus negative) correlations for the same relationship. Consideration of the type of material involved, maturity, or the assay was of little help in explaining the results. Overall, CP contamination was a significant problem for the determination of ADF and lignin concentrations.

Effect of Level of Wet Corn Gluten Feed and Corn Grain on Nutrient Digestibility and Performance

Thirty-six multiparous Jersey cows averaging 95 d postpartum were used in a 14-wk trial to study wet corn gluten feed and corn grain levels in rations based on hay for their effects on nutrient digestibility and milk production and composition. Cows were assigned randomly to one of six experimental TMR diets based on alfalfa and orchardgrass hay. Wet corn gluten feed was fed at 10, 20, or 30% of dietary DM. Two levels of corn grain (low or moderate) were fed within each level of wet corn gluten feed. Substituting wet corn gluten feed for hay decreased ruminal ammonia and total VFA concentrations and molar proportions of butyrate and increased propionate and valerate. Molar proportions of acetate and acetate to propionate ratio decreased whereas molar proportions of propionate and valerate and nutrient digestibility increased as corn grain increased. An interaction between level of wet corn gluten feed and corn grain was observed for apparent digestibility of CP and ADF because of lower digestibility of the 30% wet corn gluten feed diet with moderate levels of corn grain. Yield of milk protein increased linearly with increasing levels of wet corn gluten feed. Milk yield tended to be higher when moderate levels of corn grain were fed.

Effect of concentrates in a hay diet on the contribution of anaerobic fungi, protozoa and bacteria to nitrogen in rumen and duodenal digesta in sheep

Two sheep, cannulated at the rumen and the duodenum, were given diets of chopped orchard grass hay (H) and 3 parts grass hay to 2 parts concentrates (M). The the pools and flows of anaerobic fungi, protozoa, liquid-associated bacteria (LAB) and solids-associated bacteria (SAB) were measured. The anaerobic fungi contributed only 11–35 g N/kg of the microbial-N in the rumen and 7–27 g N/kg of the microbial-N flowing to the duodenum. Inclusion of concentrates in the diet increased fungal zoospore counts and biomass and, in sheep 1, resulted in a more than four-fold increase in rumen protozoal counts: the protozoal contribution to its microbial N increased from 41 to 66% in the rumen and from 4 to 15% in duodenal flow. For sheep 2, there was an almost two-fold increase in protozoal counts and their contributions to its rumen and duodenal microbial N increased from, respectively, 35 to 57% and 7 to 9%. These changes were associated with a decrease in the yield of rumen microbial-N from 31 to 25 g/kg OM digested in the stomach for sheep 1 but an increase from 37 to 42 g/kg OM digested in the stomach for sheep 2. In addition, there were decreases in non-ammonia-N (NAN) flow to and digestion in the intestines of sheep 1 but increases in sheep 2. Protozoa obtained 40–58% of their N from bacteria. When diaminopimelic acid was used as the marker, bacterial-N was overestimated in rumen digesta and appeared to be underestimated in duodenal digesta. The ratio of duodenal NA 15N to either rumen or duodenal LAB- 15N underestimated the contribution of microbial-N to duodenal NAN. The mean retention times (MRT) of protozoa were much longer than those of digesta particles, reflecting protozoal sequestration in the rumen. On the hay diet, the apparent MRTs of LAB were the same as those for SAB and particles whereas, when concentrates were included in the diet, the MRTs of LAB were similar to those of solutes in sheep 2 and between those of solutes and particles in sheep 1; apparent MRTs of SAB were always similar to particle MRT. These results and the calculated generation times of LAB and SAB were consistent with the conclusion that, on the hay diet, LAB were probably SAB “in transit” between particles but, with the inclusion of concentrates, they were predominantly starch-utilizing organisms whose proliferation in the rumen of sheep 1 was limited by predation by its large protozoal population. Ammonia was produced in and absorbed from the omasum and the 15N-incorporation data were consistent with the growth of LAB in the omasum.

Vitamin A repletion in thoroughbred mares with retinyl palmitate or beta-carotene.

Forty-five Thoroughbred mares used in an 8-mo depletion study were kept for an additional 20 mo on the same three forage diets (15 mares each): 2-yr-old orchardgrass hay and vitamin A-free concentrate on a drylot (HC); pasture, orchardgrass/alfalfa hay, and vitamin A-free concentrate (PHC); or pasture and orchardgrass/alfalfa hay only (PH). Each diet group was divided into three subgroups, and mares (n = 5) in each group were given either retinyl palmitate (A) at twice the NRC (1989) recommended daily intake, the equivalent amount of vitamin A in the form of water-dispersible beta-carotene (B), or the vehicle (C). Vitamin A status was monitored with serum retinol and a relative dose response (RDR) test every 60 d. In the C subgroups, retinol concentration was 18.65 +/- .84 micrograms/dL (mean +/- SE) and the RDR was 16.26 +/- 1.72% over the 20 mo. Retinol and RDR fluctuated seasonally regardless of supplementation. Vitamin A status, based on serum retinol (P = .001) and RDR (P < .001) values, was lower in the HC than in the PH and PHC. Vitamin A status, based on retinol (P = .05) and RDR (P = .013) values, was improved by retinyl palmitate supplementation in all diet groups, but not by water-dispersible beta-carotene supplementation. Supplementation of the HC mares with vitamin A matched the serum retinol, but not the RDR, of the two pasture, control subgroups. Thus, replete vitamin A status in previously depleted mares was barely obtained by supplementation with twice the currently recommended daily intake of vitamin A.

Ruminal undegradability of blood meal and effects of blood meal on ruminal and postruminal digestion in steers consuming vegetative orchardgrass hay.

Four crossbred steers (360 +/- 3 kg) cannulated at the rumen and duodenum were used in a 4 x 4 Latin square design to examine the effects of supplemental blood meal (BM) on voluntary intake, digesta kinetics, ruminal fermentation, site and extent of digestion, and bacterial protein synthesis in steers fed vegetative orchardgrass hay (Dactylis glomerata L.). The levels of BM supplementation were 0, .07, .13, and .20 kg/d. Voluntary intake of OM (8.35 kg/d) was not significantly affected by BM supplementation. No significant effects of BM supplementation were detected for OM flow to the duodenum or digestion in the rumen or lower tract. However, total tract OM digestibility decreased 2.2 percentage units at .20 kg/d of BM intake (lower with vs without BM; P < .10). Total N intake and flow to the duodenum linearly increased (P < .10) with increasing BM level from 251 to 277 g/d and from 158 to 199 g/d, respectively. Ammonia N and bacterial N flows to the duodenum were not affected (P > .10) by BM supplementation. As a result, nonammonia N flow to the duodenum increased linearly (P < .10) with increasing BM supplementation. Ruminal escape N from BM was 83.5, 85.3, and 87.2% for .07, .13, and .20 kg/d of BM, respectively. Apparent bacterial efficiency and true bacterial efficiency were not affected (P > .10) by BM supplementation. Total amino acid and total essential amino acid flows to the duodenum were increased (P < .10) by dietary inclusion of BM. Duodenal flows of all essential amino acids except lysine and valine and of all nonessential amino acids except alanine and proline were increased (P < .10) by BM inclusion in the diet. In summary, supplementation with BM increased ruminal escape N and duodenal flows of total and most essential amino acids.

Effects of feeding a high-grain diet at a restricted intake on lactation performance and rebreeding of ewes.

Fifty-six mature Polypay ewes were used in two experiments to examine the effects of feeding a high-grain diet at a restricted intake on milk production and composition, lamb performance and out-of-season breeding. Ewes were fed either a high-grain diet (85% concentrate and 15% forage) or a high-forage diet. The high-forage diets were 68% forage and 32% concentrate in Experiment 1 and 80% forage and 20% concentrate in Experiment 2. Forage forage and 20% concentrate in Experiment 2. Forage source was orchardgrass hay (Experiment 1) or alfalfa cubes (Experiment 2). Feed intake of the high-grain diet was restricted by 20% (compared with ewes fed high forage) so that intake of energy was similar for both dietary groups. Daily milk production was 19% higher (P < .05) in Exp. 1 and 8% higher (P < .10) in Exp. 2 for ewes fed high grain than for those fed high forage (2.71 vs 2.28 kg/d and 3.18 vs 2.95 kg/d in Exp. 1 and 2, respectively). Milk protein percentage and daily amount of milk protein were higher (P < .05) and the percentage of milk fat was lower (P < .03) for ewes fed the high-grain diet than for those fed the high-forage diet. Diet did not affect milk fat production (grams/day) or lamb growth rate. In both experiments blood insulin concentration was higher for ewes fed the high-grain diet than for those fed the high-forage diet; however, no improvements in reproductive performance were observed. Limit feeding high-grain diets is an effective alternative to forage for lactating ewes.

Influence of altering ruminal degradation of soybean meal protein on in situ ruminal fiber disappearance of forages and fibrous byproducts.

The objective was to determine the effects of altering ruminal CP degradation of soybean meal (SBM) by roasting (Exp. 1) on ruminal characteristics and extents of in situ disappearance of DM, OM, and fiber components (Exp. 2). A control diet (8.2% CP) containing oat hulls, corn silage, starch grits, ammoniated corn cobs, and molasses was supplemented to 17.1% CP with unroasted SBM (SBM-0) or SBM roasted at 165 degrees C for 75, 150, or 210 min (SBM-75, SBM-150, and SBM-210, respectively). In Exp. 1, SBM was incubated for 0, 2, 4, 8, 12, 16, and 24 h in the rumen of two steers that were fed the SBM-0 diet. Extents of ruminal CP degradation and rates of N disappearance decreased (P < .05) linearly with increasing roasting time of SBM. In Exp. 2, five ruminally cannulated steers were used in a 5 x 5 Latin square design and were fed the five diets listed above during five 11-d periods. On d 11, five substrates (alfalfa hay, orchardgrass hay, corn silage, soy hulls, and wheat straw) were incubated in the rumen for 24 h. Extents of in situ disappearance of DM, OM, and fiber (NDF, ADF, cellulose, hemicellulose, and total dietary fiber) were analyzed as a split-plot design. No substrate x diet interaction (P > .05) was observed for any of the measurements evaluated. Extents of in situ disappearance (24 h) of DM, OM, and fiber were highest (P < .05) when the control diet was fed and were lowest (P < .05) when the SBM-0 diet was fed. Decreasing the availability of SBM protein in the diet by roasting increased (P < or = .10) extents of in situ disappearance of DM, OM, and fiber linearly. These extents were similar for steers fed the control diet or the diet containing SBM-210. Ruminal concentrations of NH3 N, branched-chain VFA, and valerate were highest (P < .05) and ruminal pH lowest (P < .05) when the SBM-0 diet was fed. Results indicated a rapid ruminal fermentation of both protein and readily available carbohydrates of SBM (resulting in pH below 6.0) during the first 4.5 h after feeding the SBM-0 diet. Making both protein and readily available carbohydrates of SBM more slowly fermentable by roasting slowed early fermentation processes, maintained higher ruminal pH, and encouraged earlier and faster ruminal fiber digestion.

同一飼料を与えたトカラ種山羊とサフォーク種めん羊の消化率の比較

A comparison of digestion was made between Japanese native Tokara buck kids (Tokara) and Suffolk ram lambs (Suffolk) fed alfalfa hay cube digestion trial, orchardgrass hay digestion trial and mixed feed trial consisting of 4 parts rice straw to 3 parts of wheat bran (rice straw. wheat bran digestion trial) for the purpose of ascertaining the digestible performance of each feed, respectively. In this experiment, the same four Tokara and the same four Suffolk lambs were used, respectively, aged five to seven months. The experimental feeds were adjusted to supply a no refusal, and also the amounts were the same per metabolic body size for each of the digestion trials. The results were as follows : (1) The digestibility coefficients in percentages for all components of the experimental feeds were lower in the Tokara than in the Suffolk except for crude protein and nitrogen free extracts in the alfalfa hay cube digestion trial.(2) Components showing significant differences were crude fiber, acid detergent fiber and neutral detergent fiber in all digestion trials. In addition to this, components demonstrating significant differences were dry matter and gross energy in the alfalfa hay cube digestion trial, dry matter, crude fat and gross energy in the orchardgrass hay trial, and crude fat in the rice straw. wheat bran digestion trial, respectively.(3) The nutritive values per dry matter were lower for total digestible nutrients and digestible energy in the Tokara than in the Suffolk in all of the digestion trials, but the orchardgrass hay digestion trial alone showed significant differences.(4) Digestible crude protein per dry matter was similar for the Tokara and the Suffolk. They were not significant in any digestion trial.(5) Nitrogen balance was similar for the Tokara and the Suffolk in all digestion trials.(6) Relative to the Suffolk, it was concluded that the apparent digestibility of feed for the Tokara was low, especially of fibrous components.

Effects of Cobalt on In Vitro Fiber Digestion of Forages and By-Products Containing Fiber

Cobalt glucoheptonate as a source of Co to enhance ruminal fiber digestion was evaluated in two in vitro digestibility experiments. In Experiment 1, Co supplementation (0, 5. and 10ppm) of five substrates (leaf and stem fractions of alfalfa and orchardgrass hays and ground corn) was evaluated under two dietary conditions (ruminal fluid taken from steers fed alfalfa hay or a high concentrate diet) for 24 or 48h of fermentation in a 3 × 5 × 2 × 2 factorial arrangement. In Experiment 2, four concentrations of Co (0, 10, 20, and 30ppm) were added to five substrates (alfalfa hay, orchardgrass hay, corn cobs, recycled newsprint treated with HC1, and cellulose casings) and were incubated with ruminal fluid from steers fed alfalfa hay for 24 or 48h of fermentation in a 4 × 5 × 2 factorial arrangement. No interactions among treatments were observed for digestibilities of DM, OM, or NDF in both experiments or for VFA concentrations in Experiment 1. Supplementation with Co did not increase digestibilities of DM, OM, or NDF in either experiment or concentrations of VFA in Experiment 1. In Experiment 1, in vitro digestibilities of DM, OM, and NDF were higher for inoculum from steers fed alfalfa versus concentrate. In Experiment 2, digestibilities of DM, OM, and NDF were highest for alfalfa hay and lowest for recycled newsprint treated with HC1. Cobalt concentrations that were above minimum requirements did not improve digestion of DM, OM, or fiber.