Hay Organic Matter Research Articles

Effects of sheep breed and soybean meal supplementation on rumen environment and degradation kinetics

The aim of this study was to evaluate if the in vivo digestibility and intake differences, observed in previous studies, between Ile-de-France (IF) and Churra-da-Terra-Quente (CTQ) sheep breeds, were due to rumen environment and degradability differences. The intake, digestibility, rumen environment and degradability and urinary allantoin-nitrogen excretion were evaluated in 8 adult cannulated ewes (4 CTQ and 4 IF ewes). The animals were fed ad libitum hay – with and without a soybean meal supplementation (150g/kg ingested hay, dry matter basis). The organic matter intake per kg of body weight was higher (P<0.05) and the NDF and hay organic matter digestibility was lower in CTQ ewes (P<0.05), irrespective of supplementation. The rumen pH remained above 6.35 in all treatments, and the difference between the breeds was not biologically relevant. The ammonia nitrogen rumen content and the urinary allantoin-nitrogen excretion were similar (P>0.05), whether the breeds where fed hay or hay supplemented with soybean meal. The volatile fatty acid concentrations in the rumen were similar (P>0.05) for both genotypes. There was no breed effect (P>0.05) on the rumen protozoa population, although supplementation increased its number (P<0.001). As a result of the absence of differences in rumen content characteristics, there were no differences between the breeds (P>0.05) on rumen in sacco degradation results. Thus, the effective rumen degradation was lower in the CTQ breed, when its inherit lower outflow rate was used to calculate it. This study suggests that the native CTQ breed and the IF breed exhibit similar rumen conditions for the microbial degradation of fibrous feeds. Thus the higher intake and lower digestibility of the CTQ breed can only result from its inherit faster flow through the gastrointestinal tract.

Relationships between patterns of rumen fermentation measured in sheep and in situ degradability and the in vitro gas production profile of the diet

The relationship between the pattern of rumen fermentation in vivo and the gas production (GP) profile of different diets, and the in situ degradability of the component feeds was investigated. Three mature wethers were fed three diets in a randomised block design. Each diet consisted of hay and micronised maize. The relative proportions of hay:maize (dry matter (DM) basis) was 80:20, 50:50 and 20:80. Samples of rumen fluid were collected over 24 h and analysed for pH, short chain fatty acids (SCFAs) and protozoal population. In situ degradability of hay and maize organic matter (OM) was estimated. The GP profile of each diet was estimated with an automated pressure transducer using rumen fluid collected from the animal being fed that diet. The SCFA profile of the incubation medium was estimated after 72 h, and from these data the amount of ATP produced in vitro was predicted. The proportion of maize in the diet had no effect on the effective degradability of maize or the mean total SCFA concentration in the rumen. However, increasing the proportion of maize in the diet reduced hay OM effective degradability and molar proportion of acetate in the rumen. The opposite effect was observed with propionate, and the proportion of butyrate was not affected. The ratio of non-glucogenic:glucogenic SCFA (NGR) decreased as the proportion of maize increased. Differences between in vitro and in vivo measurements were significant for total SCFA concentration and acetate proportion. The time to maximum gas production rate and predicted ATP production were related to in vivo mean total SCFA concentration ( R 2=0.81), mean molar proportion of acetate ( R 2=0.59), propionate ( R 2=0.63) and butyrate ( R 2=0.86), NGR ( R 2=0.61) and the effective OM degradability of hay ( R 2=0.57). Results suggest that the GP technique predicts dynamic parameters of rumen fermentation, particularly the SCFA profile. This would reduce the need to use surgically modified animals when determining the effect of diet on the pattern of rumen fermentation.

Promising tropical grasses and legumes as feed resources in Central Tanzania V. Effect of supplementing Cenchrus ciliaris hay with leaves from four legumes on intake and digestibility by growing Mpwapwa bulls

In Trial 1, six growing Mpwapwa bulls (mean age 1.5 years, mean body weight 158 kg) were used in a 6 × 6 Latin square design to study the effect on intake and digestion of supplementing Cenchrus ciliaris cv. Kongwa hay with four different legume leaf proteins. Hay alone and fish meal (FM) treatments were included as negative and positive control treatments, respectively. The grass hay was fed allowing above 40% refusal to maximize selectivity and contained 5.1% crude protein (CP), 76.1% neutral detergent fibre (NDF), 9.9% lignin and 3.1% silica. The protein sources were dried leaves of Macroptilium atropurpureum cv. Siratro (MAS), Macrotyloma axillare (MAA), Neonotonia wightii cv. Mpwapwa (NWM), Stylosanthes scabra cv. Seca (SSS) and FM. The protein sources were fed aiming at supplying approximately 150 g CP/day. The legume CP contents varied from 18.6–20.6% and the FM contained 54.7%. In Trial 2 in a completely randomised block design, 8 bulls were used to measure the digestibility of the legumes alone. Selective feeding resulted in consumption of hay containing 6.2% CP. The apparent digestibility of organic matter (OM) and NDF were 58.3 and 62.5%, respectively. Supplementing the hay resulted in intake of a diet with CP ranging from 8.0–8.5%. Despite the increased CP intake, neither the digestibility of OM nor NDF increased significantly, implying that the protein was not a first limiting factor for fibre digestion. The grass hay OM intakes varied between 21.0 and 22.2 g/kg body weight (BW) per day (77.3–86.0 g/kg BW 0.75/d) and were not improved by protein supplementation. Significant improvements ( P < 0.001) in daily intakes of total OM and CP were observed by supplementation, although total NDF was not improved. All protein supplements except MAS improved ( P < 0.05) digestible OM intakes compared to the unsupplemented hay. Calculated digestible and metabolizable energy values for the diets were not improved by supplementation. However, an improvement in total energy and protein intake may be obtained as a result of supplementation. It is concluded that it is beneficial to use MAA, NWM, SSS and also FM in C. ciliaris-based diets to improve total intake of CP by growing bulls. Total intake of OM and digestible OM may also be improved, but the levels are only on the order of 10%. The use of legume supplements and allowing ample feed refusals may result in an estimated daily BW gain of 200–400 g.

Effect of time of supplementary feeding on intake, apparent digestibility and rumen fermentation of grass hay by sheep

AbstractEffects of time of supplementation on forage intake, nutrient apparent digestibility and rumen fermentation were studied with 12 mature castrated male sheep (wethers) offered grass hay from 16.30 h to 09.30 h and supplemented with a cereal-based concentrate given at either 09.30 or 16.00 h. Voluntary intake of hay organic matter (OM) was decreased by feeding the concentrate (P&lt; 0·01). Offering concentrate at 09.30 h after hay was available, increased intake of hay and total OM compared with offering it at 16.00 h before hay was available (P&lt; 0·05). Daily pattern of hay intake was not changed when concentrate was offered at 09.30 h compared with feeding hay alone, but concentrate given at 16.00 h resulted in a lower hay intake between 16.30 and 18.00 h. Sheep offered concentrate at 09.30 h had higher rumen ammonia levels than those offered concentrate at 16.00 h, but there were no differences in the apparent digestibility of the nutrients, rumen pH and molar proportions of the main volatile fatty acids. There were also no differences between groups in the blood plasma concentrations of 3-hydroxybutyrate (30HB), nonesterified fatty acids (NEFA) and glucose. It is concluded that feeding supplement after rather than before a period of intake of forage or a bout of grazing may offer a means of minimizing reduction of forage intake as a consequence of feeding concentrate.

Effects of four cereal grains on intake and ruminal digestion of harvested forage by beef steers

Effects of grain supplements on intake and digestion of roughage diets have been studied extensively, but studies comparing these effects among different grains are limited. Our experiment compared the effects of four cereal grains on roughage intake and ruminal digestion. Five separately penned ruminally cannulated beef steers (average body weight (BW) 194 kg) were used in a 5 × 5 Latin square design; treatments included prairie hay, or prairie hay plus supplemental barley, corn, sorghum or wheat. Each grain was dry rolled and fed to provide 0.25% BW as starch to a basal diet of prairie hay (in vitro organic matter digestibility, 56 g 100 g −1; crude protein, 10.8 g 100 g −1 of organic matter). Urea was added to grains to ensure that supplements were isonitrogenous. Grain supplementation did not affect ( P > 0.10) hay organic matter intake, although digestible organic matter intake was increased ( P < 0.10) by supplementation. Ruminal pH was not affected ( P > 0.10) by grain supplementation. Ruminal ammonia-nitrogen was increased ( P < 0.10) by grain supplements containing urea (barley, corn, and sorghum). Ruminal fluid volume and dilution rate was not affected ( P > 0.10) by grain supplementation, nor were particulate passage rate, ruminal or intestinal retention time, or gastrointestinal dry matter fill. Total tract mean retention time was decreased ( P < 0.10) by barley, corn and wheat supplementation, but unaffected ( P > 0.10) by sorghum. A treatment × sampling time interaction ( P < 0.05) was detected for proportions of ruminal acetate and propionate. Acetate was decreased ( P < 0.01) by barley and increased ( P < 0.01) by sorghum. 4 h after supplementation. At 8 h after supplementation, wheat decreased ( P < 0.10) acetate proportions, while sorghum increased acetate proportions ( P < 0.01). Propionate proportions were not affected ( P > 0.10) by treatments. Wheat supplementation increased ( P < 0.01) ruminal butyrate at 2 and 12 h after supplementation, but sorghum decreased butyrate proportions at 2, 8 and 12 h after supplementation. Barley increased ( P < 0.10) total volatile fatty acid (VFA) concentrations at 4 h after supplementation, but VFA concentrations were not affected by other grains. Grain supplementation increased ( P < 0.10) in sacco organic matter disappearance of prairie hay at 48 h of incubation. We conclude that grain supplementation, to provide 0.25% of BW as starch, did not affect hay intake adversely, and slightly increased in sacco digestion of hay organic matter. More readily fermentable grains (barley and wheat) affected ruminal VFA proportions and concentrations.

Effects of additions of sodium bicarbonate, salt, Aspergillus oryzae culture extract, niacin, lysine or phenylalanine to ground corn-based supplements on feed intake and digestion by Holstein steers consuming bermudagrass ( Cynodon dactylon) hay

Holstein steers were fed bermudagrass ( Cynodon dactylon) hay ad libitum and ground corn-based supplements, to determine if various additives might improve feed intake and/or digestion. Five steers (199 and 260 kg initial and final body weights, respectively) used in the first study (Latin square) were not supplemented (Control) or received 0.75% body weight (BW; dry matter basis) daily of corn in one or two meals (1M and 2M, respectively) or corn once daily with added sodium bicarbonate (0.02% BW, dry matter basis; BUFF) or sodium chloride (0.15% BW, dry matter basis; SALT). Hay organic matter (OM) intake was lower with than without supplementation ( P < 0.05) and lower for SALT than 2M ( P < 0.06; 6.38, 5.85, 5.67, 5.42 and 5.17 kg day −1 for Control, 1M, 2M, BUFF and SALT, respectively). Digestible OM intake was greater ( P < 0.05) with than without supplementation (3.33, 4.08, 4.24, 4.08 and 4.17 kg day −1 for Control, 1M, 2M, BUFF and SALT, respectively). In the second study (Latin square), six steers (156 and 251 kg initial and final BW, respectively) were not supplemented (Control) or received a ground corn-based supplement (approximately 1.0% BW of corn dry matter) alone (Basal) or with culture extract from Aspergillus oryzae (CUEX), niacin (NIA), lysine (LYS) or phenylalanine (PHE). Supplement treatments depressed ( P < 0.05) hay OM intake similarly (4.57, 3.82, 3.73, 3.83, 3.99 and 3.86 kg day −1 for Control, Basal, CUEX, NIA, LYS and PHE, respectively). Digestible OM intake was 2.90, 3.88, 3.87, 3.90, 4.09 and 3.79 kg day −1 (standard error 0.077) for Control, Basal, CUEX, NIA, LYS and PHE, respectively. No additive markedly affected intake or digestion. The long period of corn consumption with added salt apparently tended to elevate digestion but to depress total intake.

The effect of dietary inclusion of yeast culture on digestion in the sheep

ABSTRACTSix mature sheep, each fitted with a rumen cannula, were assigned to six diets in a 6 × 6 Latin-square design experiment to examine the effects of a yeast culture on ruminal metabolism, rumen liquid outflow rate, fibre digestion in the rumen and overall nutrient digestibility. The yeast culture (YC) was a commercial product composed of a yeast (Saccharomyces cerevisae) and the media on which it grew and dried so as to maintain its fermentative capacity. The six dietary treatments were three diets differing in hay dry matter (DM): concentrate DM ratio (90: 10, 65: 35 and 40: 60 designated low, medium and high concentrate respectively) each given either without or with a supplement of 4 g/day of YC. Treatment periods were of 3 weeks duration. There were significant effects of dietary forage: concentrate ratio on rumen function (P&lt; 0·05). Rumen pH, rumen liquid outflow rate, rumen ammonia concentration, total volatile fatty acids concentration, and molar proportions of acetate, propionate and butyrate were not significantly affected by the inclusion of YC (P&lt; 0·05). Supplemental YC did not affect the overall nutrient digestibility of organic matter, neutral-detergent fibre or gross energy measuredin vivo. However, at every forage:concentrate ratio, YC increased the disappearance of hay organic matter from nylon bags incubated in the rumen for 24 h (P&lt; 0·05). The values with and without YC were 0·482 and 0·432 for the low, 0·423 and 0·366 for the medium, and 0·360 and 0·321 for the high concentrate diets respectively. However, YC had no effect on hay disappearance when bags were incubated for 48 h. YC appeared to increase the initial rate of forage digestion in the rumen without altering overall food digestibility or the patern of production of fermentation end products.

Effect of level and frequency of maize supplementation on the utilization of low-quality grass hay by beef cows

Twelve Hereford cows and four ruminally cannulated Hereford × Angus heifers were used in four simultaneous 4 × 4 Latin squares to evaluate the effect of level and frequency of maize supplementation on the digestibility and intake of low-quality grass hay. Maize supplements were fed at two levels (1.4 or 2.0 kg day −1) and two frequencies (daily or twice the daily amount on alternate days) in a 2 × 2 factorial arrangement of treatments for a 56-day trial. Grass hay (5.0% crude protein, 46.2% acid detergent fiber) was coarsely chopped (5-cm screen) and offered free choice. Interactions between level and frequency of maize supplementation were not significant ( P > 0.10). Increasing maize supplementation from 1.4 to 2.0 kg day −1 decreased ( P < 0.01) hay organic matter (OM) intake, and digestibility of hay OM and all fiber constituents. Supplementation frequency did not affect ( P < 0.59) hay OM intake. Alternate day supplementation, however, tended to decrease digestibilities of total ( P < 0.20) and hay ( P < 0.23) OM which lowered ( P < 0.03) digestible OM intake by an average of 222 g day −1. For heifers fed 4.1 kg on alternate days, ruminal pH was lowest (< 6.25 for 12 h) on feeding days, but highest on non-feeding days. Ruminal ammonia concentrations peaked at 3 h post-supplementation, but remained < 1.0 mg dl −1 until the subsequent feeding. Thus, low ruminal ammonia concentrations of cows supplemented on alternate days may have limited the favorable effects of increased ruminal pH on cellulolytic activity. Decreased ( P < 0.13) total volatile fatty acid concentrations coupled with lower digestible OM intake implies that cows fed maize supplements on alternate days utilized their diet less efficiently. Consequently, beef cattle producers should attempt to feed small quantities of maize supplements on a daily basis.