Ruminal NH3-N Concentration Research Articles

The effect of euglena (Euglena gracilis) supplementation on nutrient intake, digestibility, nitrogen balance and rumen fermentation in sheep

This in vivo study was conducted to evaluate the effect of supplementation with different rates of euglena (Euglena gracilis) on nutrient intake, digestibility, nitrogen balance and rumen fermentation. Four rumen cannulated Corriedale wethers sheep with an average body weight of 44.25±3.86kg were arranged in a 4×4 Latin square design and fed a basal diet of Guinea grass (Panicum maximum) hay and concentrate mixture at the maintenance level with four different rates of euglena (0, 50, 100 and 150g/kgDM intake). The experiment was conducted over 80days in four 20day periods that consisted of 14days of acclimatization, 5days of measurement and 1 more day for rumen liquor sample collection. The data were subjected to polynomial regression analysis. Dry matter (DM), organic matter (OM), acid detergent fibre (ADF) and gross energy (GE) intake increased linearly (P<0.001) and quadratically (P=0.002) with increasing concentrations of euglena. Similarly, crude protein (CP) intake was increased linearly (P<0.001). Dry matter, OM, NDF, ADF and GE digestibility were not affected by supplementation of euglena (P>0.11) while apparent CP digestibility increased linearly (P=0.009). As a result, protein retention (g/d) was increased linearly (P<0.001) and quadratically (P=0.017) with increasing concentrations of euglena. Ruminal NH3-N concentration increased (linear, P<0.001) while ruminal protozoa population reduced linear, quadratic and cubic (P<0.008) with increasing doses of Euglena. Euglena supplementation at different concentration did not change (P>0.23) the total volatile fatty acid (VFA) concentration and the molar proportions of acetate, propionate, butyrate and the acetate: propionate ratio. The finding of this study indicated that the addition of euglena increased nutrient intake without affecting total tract digestibility. It has been also demonstrated that addition of euglena at a dose of 150g/kgDM improved CP retention by 31%, which may be associated with increased CP digestibility and efficiency of utilization. Thus, euglena supplementation up to 150g/kg DM of the diet could be a possible option for substitution of protein and energy sources.

Comparison of microbial protein synthesis and nutrient digestibilityof Medicago sativa and Prangos pabularia hay in sheep

The aim of this study was to compare feed intake, nutrients digestibility, protein fractions entering into the duodenum, and ruminal fermentation parameters of sheep fed Medicago sativa (alfalfa) and Prangos pabularia, locally called kerkol hays. In the study three ruminally and duodenally cannulated Morkaraman sheep were used. It was carried out as two periods within a 2x3 crossover experimental design. Daily intake of crude protein (CP) was higher (P less than 0.05) in sheep fed alfalfa than those fed kerkol hay. Digestibility of NDF and ADF were lower (P less than 0.05) in sheep fed alfalfa hay than those fed kerkol hay (P less than 0.05). The percentage of protein escaping ruminal degradation was higher (P less than 0.05) in sheep fed kerkol hay (30.73%) than those fed alfalfa hay (15.05%). Ruminal fermentation parameters were similar between groups, except ruminal NH3-N concentration. It is concluded that kerkol hay can be used as forage for sheep feeding.

Effects of Lactobacillus acidophilus supplementation for improving in vitro rumen fermentation characteristics of cereal straws

We explored and compared the effects of four doses (0, 0.25 × 107, 0.50 × 107, and 0.75 × 107 cfu/mL) of Lactobacillus acidophilus supplementation on ruminal fermentation characteristics of maize stover and rice straw. The maximum gas production (Vf) for maize stover and the rate of gas production during early incubation (FRD0) for rice straw were quadratic (p < .05) and linear (p < .01), respectively, and increased when supplemented with L. acidophilus. The L. acidophilus supplementation increased ruminal NH3-N concentration for maize stover (p < .01) and rice straw (p < .05), respectively. The supplementation level of L. acidophilus did not affect the production of volatile fatty acids (VFAs) except for valeric acid, nor did it affect CH4 production, IVDMD, IVNDFD, ruminal pH value, total volatile fatty acids (TVFAs) or the ratio of acetic to propionic acid (A:P). As a fermentation substrate, when compared to rice straw, maize stover increased in vitro gas production parameters (e.g. Vf, k, FRD0 and t0.5), IVDMD, IVNDFD, ruminal NH3-N concentration and TVFAs, whereas there was no (p > .05) difference in CH4 production, ruminal pH value or A:P between the two substrates. The results indicate that L. acidophilus increase in vitro gas production and ruminal NH3-N concentration when using either fermentation substrate, with the greatest increase observed at a dosage of 0.75 × 107 cfu/mL. Additionally, maize stover is superior to rice straw as a fermentation substrate or forage for ruminants. The present positive in vitro results should be tested using in vivo experiments in future.

Effects of Static or Oscillating Dietary Crude Protein Levels on Fermentation Dynamics of Beef Cattle Diets Using a Dual-Flow Continuous Culture System.

The objective of this study was to evaluate the effects of increasing dietary crude protein (CP) levels and also comparing the effects of static versus oscillating dietary CP on ruminal nutrient digestibility, ruminal fermentation, nitrogen (N) metabolism, and microbial efficiency in beef cattle diets using a dual-flow continuous culture system. Eight fermenters (1,223 ± 21 mL) were used in a replicated 4 x 4 Latin square design with periods lasting 12 d each (8 d for adaptation and 4 d for sampling). Dietary treatments were: 1) 10% CP, 2) 12% CP, 3) 14% CP, and 4) 10 and 14% CP diets oscillating at 48-h intervals. Experimental diets consisted of 50% orchard hay and 50% concentrate. Fermenters were fed 72 g/d and solid and liquid dilution rates were adjusted to 5.5 and 11%/h, respectively. Data were analyzed using the MIXED procedure in SAS with α = 0.05. Apparent and true ruminal digestibilities of dry matter and organic matter were not affected (P > 0.05) by increasing dietary CP, nor by oscillating dietary CP. Total volatile fatty acids concentration and molar proportions of acetate, propionate, butyrate, valerate, iso-butyrate and iso-valerate were not affected (P > 0.05) by increasing or oscillating dietary CP. Ruminal NH3-N concentration increased linearly (P < 0.01) in response to increasing dietary CP. Total N, non-ammonia N, and rumen undegraded protein flows did not differ among treatments or between oscillating dietary CP and static 12% CP. Microbial N and NH3-N flows and microbial efficiency did not differ when comparing oscillating versus static CP (P > 0.05). However, there was a quadratic effect (P < 0.05) for these variables when dietary CP was increased. These results indicate that either ruminal microorganisms do not respond to oscillating CP levels or are capable of coping with 48-h periods of undernourishment.

Use of protected fat sources to reduce fatty acid biohydrogenation and improve abomasal flow in dry dairy cows

The objective of this study was to evaluate the effects of dietary fat supplementation on dry dairy cows feed intake, digestion, ruminal kinetics, biohydrogenation, and abomasal flow of fatty acids (FAs). Eight Holstein rumen and abomasum fistulated dry cows (average body weight of 614±59kg), were assigned to a replicated 4×4 Latin square design experiment, with 21-d periods. The experimental diets were: 1) control (CON): corn- and soybean meal-based diet, with no fat source; 2) soybean oil (SO) diet with 30g/kg dry matter (DM) of soybean oil; 3) whole raw soybean (WS) diet with 160g/kg DM of whole raw soybean grain; 4) calcium salts of fatty acids (CS) diet with 32g/kg DM of calcium salts of unsaturated FA. Fat-supplemented diets increased ether extract intake and digestibility without affecting DM intake. However, these diets promoted a decrease in DM and neutral-detergent fiber (NDF) total tract apparent digestibility. Fat sources decreased ruminal acetate to propionate ratio (C2:C3). In addition, SO diet increased ruminal propionate concentration and decreased C2:C3 in relation to protected sources of FA (CS and WS). Furthermore, cows fed CS diet exhibited higher ruminal pH, NH3-N and acetate concentration compared to those fed WS diet. Fatty acid supplementation did not alter serum glucose and urea concentration, but increased the serum cholesterol concentration. Although FA supplementation increased net energy intake of cows, energy and nitrogen balances, and microbial protein synthesis were not affected by the experimental diets. Fat supplementation had no effect on ruminal digestion neither on DM and NDF passage rates. Cows fed CS and WS diets presented higher DM and NDF ruminal digestion rates whether compared to SO one. Consequently, cows fed CS and WS had higher truly digestible NDF ruminal removal rate than those fed SO. Calcium salts of unsaturated FA increased DM and NDF rumen passage rate and decreased NDF digestibility in relation to WS diet. Fat-supplemented diets increased the abomasal flows of C18:2, trans C18:1, C18:0, C16:0 and total FA. The CS supplementation resulted in a higher abomasal flow of DM, total FA, trans C18:1, C16:0 and C18:3 when compared to WS one. On the one hand, FA supplementation increased C18:2 and C18:1 biohydrogenation rates; on the other hand, it protected FA sources decreased C18:2 and C18:1 biohydrogenation rates. In conclusion, fat-protected sources were effective to prevent FA from ruminal biohydrogenation.

Effect of Probiotic or Prebiotic Supplementation on the Productive Performance of Barki Lambs.

This study was carried out to evaluate the impact of dietary supplementation of probiotic (Diamond XP™) T1 or prebiotic (BioBoostTM) T2 on nutrient digestibility, rumen fermentation characteristics, productive performance and economic efficiency of Barki lambs. Lambs in control group offered a concentrate feed mixture (CFM) and clover hay without supplementation while, lambs in treatment (T1) and treatment (T2) were fed CFM supplemented with probiotic or prebiotic at rate of 10 g/ head/ day, respectively. Nine barki male sheep (47kg ± 2.5) were used for running metabolism trail. The animals were allocated into three equal groups. Three ruminally cannulated ewes (45 kg ± 3.2) were used to study the rumen liquor parameter, while growth performance trails were carried out with twenty four growing male Barki lambs (27.5 kg ± 0.75) used to determine the growth performance, feed conversion and economic efficiency.The obtained results could be summarized as follow: Animals given ration supplemented with probiotic recorded the highest values of (p<0.05) digestibility and nitrogen utilization followed by animals given ration supplemented with prebiotic, however those fed control ration had the lowest values. The same trend was observed with TDN and DCP values.No significant (p<0.05) differences among rations in ruminal pH values, were recorded while total volatile fatty acids (VFA’s) concentration and microbial protein synthesis had significantly (p<0.05) increased with probiotic supplement. The control ration recorded the highest ruminal NH3-N concentration. A positive impact of probiotics (DFM) and prebiotic supplementation on nutrient intake, feed conversion ratio and economic efficiency have been recorded. It could be concluded that feeding lambs on rations supplemented with either probiotic (DFM) or prebiotic at 10 g/h/d has beneficial effects on rumen parameters, digestibility coefficients, growth performance and economic efficiency of growing Barki lambs.

Effects of dietary fibrolytic enzymes on chewing time, ruminal fermentation, and performance of mid-lactating dairy cows

Exogenous fibrolytic enzymes (EFE) can increase ruminal digestion of neutral detergent fiber (NDF) and improve its fermentation for cattle. Twenty-four multiparous Holstein cows (33.72±7.63kg milk/d and 176±82.27days in milk – DIM, at the start of the experiment) were used in a replicated 4×4 Latin square experimental design. Increasing doses of a commercial product was used to evaluate the effect of xylanase activity (100 units per gram of product) on intake and total-tract digestion of nutrients, sorting index, chewing time, milk yield and composition, N use, and ruminal fermentation. Treatments consisted of 0, 8, 16 or 24g/d per cow of EFE product mixed into the concentrate. Corn silage was used as forage source. The basal diet had a forage-to- concentrate ratio of 50:50 (dry matter basis). Even though EFE supplementation had a positive linear effect on dry matter and NDF intake, it had no impact on total-tract digestion of nutrients. Moreover, this enzyme promoted a linear increase of the intake of feed with larger particle size (>19mm) and quadratically affected rumination and chewing activity (hours), reaching the highest values at intermediate doses (8g/d and 16g/d). Treatments had no effect on milk yield and composition; however, the N use efficiency was linearly decreased by EFE, reducing thus the ability to synthesize milk and quadratically decreasing N retention. No treatment effect was found on ruminal pH, whereas a negative quadratic effect on ruminal NH3-N concentration was significant. Regarding ruminal parameters, this enzyme supplementation provided linear increased in acetate, propionate, butyrate, and total short-chain fatty acids synthesis. As result, EFE supplementation improved DM and NDF intake, increasing the time spent chewing and ruminating, leading to a greater total short-chain fatty acids production in rumen. Nonetheless, EFE did not improve milk yield and composition of mid-lactating dairy cows.

Effects of extruding wheat dried distillers grains with solubles with peas or canola meal on ruminal fermentation, microbial protein synthesis, nutrient digestion, and milk production in dairy cows

Our objective was to examine the effects of feeding coextruded and nonextruded supplements consisting of wheat dried distillers grains with solubles with peas (WDDGS-peas) or canola meal (WDDGS-CM) on ruminal fermentation, omasal flow, and production performance in Holstein cows. Eight cows (4 ruminally cannulated) were used in a replicated 4×4 Latin square with 28-d periods and a 2×2 factorial arrangement of dietary treatments. Dietary treatments were coextruded or nonextruded mixtures of WDDGS-peas and WDDGS-CM that were included in total mixed rations at 15.1% [dry matter (DM) basis]. Diet had no effect on DM intake. Milk yield was greater in cows fed coextruded diets compared with those fed nonextruded diets. Milk fat content was greater in cows fed nonextruded diets compared with those fed coextruded diets, but milk fat yield was greater in cows fed coextruded diets compared with those fed nonextruded diets. Milk yield tended to be greater and milk protein yield was greater in cows fed WDDGS-peas compared with those fed WDDGS-CM. Cows fed nonextruded diets had a greater milk urea-N concentration compared with those fed coextruded diets. Cows fed coextruded diets had greater ruminal digestion of DM and tended to have greater ruminal digestion of organic matter compared with those fed nonextruded diets. Total-tract digestibilities of organic matter, crude protein, ether extract, and starch were greater, whereas that of acid detergent fiber and neutral detergent fiber tended to be greater in cows fed coextruded compared with those fed nonextruded diets. Total-tract digestibility of ether extract was lower whereas that of starch was greater and that of crude protein tended to be greater in cows fed WDDGS-peas compared with those fed WDDGS-CM. Total N excretion and milk N efficiency were unaffected by diet. Ruminal NH3-N concentration tended to be greater in cows fed WDDGS-CM compared with those fed WDDGS-peas. Ruminal propionate concentration was greater whereas plasma urea-N concentration tended to be lower in cows fed coextruded compared with those fed nonextruded diets. Plasma glucose concentration was greater in cows fed diets containing WDDGS-CM compared with those fed diets containing WDDGS-peas, but the difference in plasma glucose concentration between WDDGS-CM and WDDGS-peas was greater in cows fed coextruded diets compared with those fed nonextruded diets. In summary, feeding coextruded compared with nonextruded supplements or WDDGS-peas compared WDDGS-CM increased yields of milk, fat, and protein.

Effects of dietary crude protein and rumen-degradable protein concentrations on urea recycling, nitrogen balance, omasal nutrient flow, and milk production in dairy cows

The objective of this study was to determine how interactions between dietary crude protein (CP) and rumen-degradable protein (RDP) concentrations alter urea-nitrogen recycling, nitrogen (N) balance, omasal nutrient flow, and milk production in lactating Holstein cows. Eight multiparous Holstein cows (711±21kg of body weight; 91±17d in milk at the start of the experiment) were used in a replicated 4×4 Latin square design with a 2×2 factorial arrangement of dietary treatments and 29-d experimental periods. Four cows in one Latin square were fitted with ruminal cannulas to allow ruminal and omasal sampling. The dietary treatment factors were CP (14.9 vs. 17.5%; dry matter basis) and RDP (63 vs. 69% of CP) contents. Dietary RDP concentration was manipulated by including unprocessed or micronized canola meal. Diet adaptation (d 1–20) was followed by 8d (d 21–29) of sample and data collection. Continuous intrajugular infusions of [15N15N]-urea (220mg/d) were conducted for 4d (d 25–29) with concurrent total collections of urine and feces to estimate N balance and whole-body urea kinetics. Proportions of [15N15N]- and [14N15N]-urea in urinary urea, and 15N enrichment in feces were used to calculate urea kinetics. For the low-CP diets, cows fed the high-RDP diet had a greater DM intake compared with those fed the low-RDP diet, but the opposite trend was observed for cows fed the high-CP diets. Dietary treatment had no effect on milk yield. Milk composition and milk component yields were largely unaffected by dietary treatment; however, on the low-CP diets, milk fat yield was greater for cows fed the low-RDP diet compared with those fed the high-RDP diet, but it was unaffected by RDP concentration on the high-CP diets. On the high-CP diets, milk urea nitrogen concentration was greater in cows fed the high-RDP diet compared with those fed the low-RDP diet, but it was unaffected by RDP concentration on the low-CP diets. Ruminal NH3-N concentration tended to be greater in cows fed the high-CP diet compared with those fed the low-CP diet, and it was greater in cows fed the high-RDP diet as compared with those fed the low-RDP diet. Nitrogen intake and both total N and urea-N excretion in urine were greater for cows fed the high-CP diet compared with those fed the low-CP diet. However, N balance and urinary excretion of purine derivatives were unaffected by dietary treatment. Urea-N entry rate (UER) was greater in cows fed the high-CP diet compared with those fed the low-CP diet; however, UER was unaffected by dietary RDP concentration. The proportion of urea-N recycled to the gastrointestinal tract (as a percentage of UER) was greater in cows fed the low-CP diet compared with those fed the high-CP diet. In summary, reducing dietary CP concentration decreased urinary N excretion but had no effect on milk yield, thus resulting in an overall improvement in milk N efficiency.

Effects of crude glycerin from waste vegetable oil supplementation on feed intake, ruminal fermentation characteristics, and nitrogen utilization of goats.

This experiment was evaluation of the effects of increasing concentrations of crude glycerin from waste vegetable oil (CGWVO) in diets on feed intake, digestibility, ruminal fermentation characteristics, and nitrogen balance of goats. Four crossbred male (Thai Native × Anglo Nubian) goats, with an average initial body weight (BW) of 31.5 ± 1.90kg, were randomly assigned according to a 4 × 4 Latin square design. The dietary treatments contained 0, 2, 4, and 6% of dietary dry matter (DM) of CGWVO. Based on this experiment, there were significantly different (P > 0.05) among treatment groups regarding DM intake and digestion coefficients of nutrients (DM, OM, CP, EE, NDF, and ADF), which goats receiving 6% of CGWVO had lower daily DMI and nutrient intake than those fed on 0, 2, and 4% of CGWVO. Ruminal pH, NH3-N, and blood urea nitrogen (BUN) concentration were unchanged by dietary treatments, except that for 6% of CGWVO supplementation, NH3-N, and BUN were lower (P < 0.05) than for the diets 0% of CGWVO, while the differences between the diets 0, 2, and 4% of CGWVO were not significant. The amounts of N absorption and retention were similar among treatments, except that for 6% of CGWVO which N absorption was lower (P < 0.05) than among treatments while the difference between the diets 0, 2, and 4% of CGWVO were not significant. Based on this study, CGWVO levels up to 4% in total mixed ration could be efficiently utilized for goats. This study was a good approach in exploiting the use of biodiesel production from waste vegetable oil for goat production.

Substitution of Wheat for Corn in Beef Cattle Diets: Digestibility, Digestive Enzyme Activities, Serum Metabolite Contents and Ruminal Fermentation.

The objective of this study was to evaluate the effect of diets containing different amounts of wheat, as a partial or whole substitute for corn, on digestibility, digestive enzyme activities, serum metabolite contents and ruminal fermentation in beef cattle. Four Limousin×LuXi crossbred cattle with a body weight (400±10 kg), fitted with permanent ruminal, proximal duodenal and terminal ileal cannulas, were used in a 4×4 Latin square design with four treatments: Control (100% corn), 33% wheat (33% substitution for corn), 67% wheat (67% substitution for corn), and 100% wheat (100% substitution for corn) on a dry matter basis. The results showed that replacing corn with increasing amounts of wheat increased the apparent digestibility values of dry matter, organic matter, and crude protein (p<0.05). While the apparent digestibility of acid detergent fiber and neutral detergent fiber were lower with increasing amounts of wheat. Digestive enzyme activities of lipase, protease and amylase in the duodenum were higher with increasing wheat amounts (p<0.05), and showed similar results to those for the enzymes in the ileum except for amylase. Increased substitution of wheat for corn increased the serum alanine aminotransferase concentration (p<0.05). Ruminal pH was not different between those given only corn and those given 33% wheat. Increasing the substitution of wheat for corn increased the molar proportion of acetate and tended to increase the acetate-to-propionate ratio. Cattle fed 100% wheat tended to have the lowest ruminal NH3-N concentration compared with control (p<0.05), whereas no differences were observed among the cattle fed 33% and 67% wheat. These findings indicate that wheat can be effectively used to replace corn in moderate amounts to meet the energy and fiber requirements of beef cattle.

Effects of feeding canola meal or wheat dried distillers grains with solubles as a major protein source in low- or high-crude protein diets on ruminal fermentation, omasal flow, and production in cows

The objective of this study was to determine the effects of feeding canola meal (CM) or wheat dried distillers grains with solubles (W-DDGS) as the major source of protein in diets varying in crude protein (CP) content on ruminal fermentation, microbial protein production, omasal nutrient flow, and production performance in lactating dairy cows. Eight lactating dairy cows were used in a replicated 4×4 Latin square design with 29-d periods (21d of dietary adaptation and 8d of measurements) and a 2×2 factorial arrangement of dietary treatments. Four cows in 1 Latin square were ruminally cannulated to allow ruminal and omasal sampling. The treatment factors were (1) source of supplemental protein (CM vs. W-DDGS) and (2) dietary CP content (15 vs. 17%; DM basis). Diets contained 50% forage and 50% concentrate, and were fed twice daily at 0900 and 1600 h as total mixed rations for ad libitum intake. Dry matter intake and milk yield were unaffected by dietary treatments; however, milk yield in cows that were fed CM was numerically greater (+1.1kg/d) when compared with cows fed W-DDGS. Feeding CM increased milk lactose content compared with feeding W-DDGS. Milk urea nitrogen and ruminal NH3-N concentrations were greater in cows fed the high-CP compared with those fed the low-CP diet. The rumen-degradable protein supply was greater in cows fed the high-CP when compared with those fed the low-CP diet when diets contained CM, whereas rumen-degradable protein supply was lower in cows fed the high-CP when compared with those fed the low-CP diet when diets contained W-DDGS. Total N flow at the omasal canal was not affected by diet; however, omasal flow of NH3-N was greater in cows fed CM when compared with those fed W-DDGS. The rumen-undegradable protein supply was greater in cows fed the low-CP when compared with those fed the high-CP diet when diets contained CM, whereas rumen-undegradable protein supply was lower in cows fed the low-CP when compared with those fed the high-CP diet when diets contained W-DDGS. Omasal flow of fluid-associated bacteria was greater and that of particle-associated bacteria tended to be greater in cows fed CM when compared with those fed W-DDGS; however, omasal flow of total microbial nonammonia N was unaffected by dietary treatment. Omasal flows of threonine and tryptophan were greater, whereas that of histidine and lysine tended to be greater in cows fed CM when compared with those fed W-DDGS. Our results show that when dairy diets are formulated to contain 15 or 17% CP, CM or W-DDGS can be used as the major source of protein and achieve similar levels of milk production.

EFFECT OF L-CARNITINE ADMINISTRATION ON GROWTH PERFORMANCE, RUMEN AND BLOOD PARAMETERS AND CARCASS TRAITS OF GROWING Rahmani LAMBS

The current study was carried out at Animal Experimental Station and the Laboratory of Physiology and Biotechnology, belonging to the Animal Production Department, Faculty of Agriculture, Mansoura University, during the period from September to December 2014. The aim of this experiment is to study the effect of daily oral administration of free L-canitine (LC) at two levels (350 and 700 mg/h/d) during an experimental period of 63 days on growth performance, rumen and blood parameters, and carcass quality of growing Rahmani lambs. A total of nine Rahmani lambs weighing 33.9±0.69 kg and about 10 months old were assigned according to body weight into 3 groups which were then assigned at random to receive the three experimental treatments. Animals in the 1 st group (G1) were fed the control diet (14.4% CP). The 2 nd and 3 rd groups were fed the same diet, but orally treated with LC at levels of 350 (G2) and 700 (G3) mg/h/d for 63 days as an experimental period. Growth performance parameters, rumen and blood parameters at slaughter and carcass traits were determined. The obtained results revealed that overall feed intake by lambs in G2 and G3 was reduced by about 2.4 and 6.1% as compared to the controls during the whole feeding period. Live body weight of lambs in G2 and G3 was slightly lighter than that in the control group during all intervals of the experimental period. Averages of total and daily body gains of lambs were not significantly affected by LC treatment, although total gain was slightly higher in G2 and slightly lower in G3 than in G1. Feed conversion was almost the best in G2 than in G3 and G1 during feeding intervals or during the experimental period. Ruminal pH value and NH3-N concentration decreased (P<0.05) in G2 as compared to that in G1, being 6.88 and 8.88 mg/dl, and 7.2 and 17.77 mg/dl, respectively. However, pH value and NH3-N concentration insignificantly decreased to 7.06 and 13.62 mg/dl in G3, but did not differ significantly from those in G2 and G1. Total VFA’s concentration in rumen liquor increased (P<0.05) by about 34.7% in G3 as compared to G1. While, nearly similar VFA’s concentration was obtained for G2 and G1 (16.33 mEqui./dl). Only concentration of total proteins in blood plasma decreased (P<0.05) in G2, while triglycerides concentration decreased (P<0.05) in G2 and G3 by about 52.6 and 50.3% as compared to G1, respectively. Concentration of thyroid hormone (T3) insignificantly increased in G2 and G3 (1.95 and 1.68 ng/ml) as compared to 1.6 ng/ml in G1, respectively. The LC had no effect on urea-N concentration in blood plasma. Carcass traits were not significantly affected by LC treatment, although there was an increase in dressing percentage of lambs in both treatment groups (G2 and G3, being 48.13 and 50.94% as compared to 47.93% in the control lambs, respectively. It could be concluded that LC treatment slightly improved feed conversion as a result of improving rumen

Effects of corn-based reduced-starch diets using alternative carbohydrate sources on performance of lactating Holstein cows

Increases in grain prices have led to renewed interest in feeding reduced-starch diets to lactating dairy cows. An experiment was conducted to determine the effects of altering carbohydrate sources and reducing dietary starch on lactational performance, feeding behavior, and ruminal measures of Holstein dairy cows. Fifteen multiparous cows (6 ruminally cannulated) were blocked and assigned to 1 of 5 squares and used in a replicated 3×3 Latin square design with 21-d periods. Cows were fed 1 of 3 experimental diets: a control diet containing 20% brown midrib corn silage, 20% conventional corn silage, and 10% hay crop silage (CON); a reduced-starch high-forage diet containing 53% brown midrib corn silage and 10% hay crop silage (HFOR); and a reduced-starch diet containing the same forages as CON with partial replacement of corn meal by nonforage fiber sources (HNFFS). The CON diet contained (% of dry matter) 26.0% starch and 34.7% neutral detergent fiber (NDF), whereas the HFOR and HNFFS diets contained 21.4 or 21.3% starch and 38.3 or 38.0% NDF, respectively. Dry matter intake tended to be greater for cows fed the CON diet (28.2kg/d) compared with those fed the HFOR diet (27.2kg/d). Dry matter intake for cows fed the HNFFS diet was intermediate (27.7kg/d). Milk yield was greater for cows fed the CON diet (51.6kg/d) compared with those fed the HFOR diet (48.4kg/d), but milk fat content tended to increase for cows fed the HFOR diet (3.98%) compared with those fed the CON diet (3.66%). Consequently, fat-corrected and solids-corrected milk yields were unaffected by dietary treatments. Total chewing, eating, and rumination times were similar across all dietary treatments. Rumination time per kilogram of DM was greatest for the HFOR diet, intermediate for the HNFFS diet, and least for the CON diet, whereas rumination time per kilogram of NDF was greatest for the CON diet and least for the HNFFS diet. Mean ruminal pH, NH3-N (mg/dL), and total volatile fatty acid concentrations (mM) were similar across all dietary treatments. Molar proportion of ruminal acetate (mol/100mol) was increased for cows fed the HFOR diet compared with cows fed the CON diet. Microbial N yield measured by urinary purine derivatives was unaffected by dietary treatment. Reduced-starch diets containing greater amounts of high quality, highly digestible forage or nonforage fiber sources in place of corn meal resulted in similar fat-corrected or solids-corrected milk yield for high-producing dairy cows in the short term.

EFFECT OF RATIONS INCLUSION GUAVA BY-PRODUCTS WITH OR WITHOUT PROBIOTIC ON GROWTH PERFORMANCE OF GROWING GOAT KIDS

لإhis study aimed to determined effect of guava by-product (GBP) substitution at level 20% of concentrate feed mixtures with or without commercial probiotic (Enviva®PRO) on the performance of growing goat kids. Twenty-four growing Zaraibi male kids weighted 15 kg body weight in average and 7 months old; assigned to three groups (8 in each). Feeding trial lasted for 90 days. Animals were fed clover hay plus CFM (R1), CFM including 20% GBP (R2) or supplemented with probiotic, 5g/h/day (R3). Results showed insignificant differences in most nutrients and fiber fractions digestibilities and TDN values among treatments. Ruminal pH and TVFAs values did not differ significantly among treatments. While, ruminal NH3-N concentrations were significantly (p<0.05) higher with R2 and R3 compared to R1. Results indicated that neither GBP nor probiotic had an adverse impact on goats health which all blood parameters were within the normal range. There were no significant differences among treatments in total and average daily gain. Both R2 and R3 had lower total DM and TDN intake compared to R1. Meanwhile R3 group had the best feed conversion and the highest economical efficiency. It could be concluded that guava by-product (GBP) at level 20% of CFM and probiotic supplementation (5g/h/d) in growing kids goats rations had no adverse effects on productive performance with enhancing in economical efficiency.

Effects of partial replacement of dietary starch from barley or corn with lactose on ruminal function, short-chain fatty acid absorption, nitrogen utilization, and production performance of dairy cows

In cows fed diets based on corn-alfalfa silage, replacing starch with sugar improves milk production. Although the rate of ruminal fermentation of sugar is more rapid than that of starch, evidence has been found that feeding sugar as a partial replacement for starch does not negatively affect ruminal pH despite increasing diet fermentability. The mechanism(s) for this desirable response are unknown. Our objective was to determine the effects of replacing barley or corn starch with lactose (as dried whey permeate; DWP) on ruminal function, short-chain fatty acid (SCFA) absorption, and nitrogen (N) utilization in dairy cows. Eight lactating cows were used in a replicated 4×4 Latin square design with 28-d periods and source of starch (barley vs. corn) and level of DWP (0 vs. 6%, DM basis) as treatment factors. Four cows in 1 Latin square were ruminally cannulated for the measurement of ruminal function, SCFA absorption, and N utilization. Dry matter intake and milk and milk component yields did not differ with diet. The dietary addition of DWP tended to increase ruminal butyrate concentration (13.6 vs. 12.2mmol/L), and increased the Cl−-competitive absorption rates for acetate and propionate. There was no sugar effect on minimum ruminal pH, and the duration and area when ruminal pH was below 5.8. Minimum ruminal pH tended to be lower in cows fed barley compared with those fed corn (5.47 vs. 5.61). The duration when ruminal pH was below pH 5.8 tended to be shorter (186 vs. 235min/d), whereas the area (pH×min/d) that pH was below 5.8 was smaller (47 vs. 111) on the corn than barley diets. Cows fed the high- compared with the low-sugar diet had lower ruminal NH3-N concentration. Feeding the high-sugar diet tended to increase apparent total-tract digestibility of dry matter and organic matters and increased apparent total-tract digestibility of fat. Apparent total-tract digestibility of N tended to be greater in cows fed barley compared with those fed corn, whereas apparent total-tract digestibility of acid-digestible fiber was greater in cows fed corn compared with those fed barley. In conclusion, partially replacing dietary corn or barley starch with sugar upregulated ruminal acetate and propionate absorption, suggesting that the mechanisms for the attenuation of ruminal acidosis when sugar is fed is partly mediated via increased SCFA absorption.

Effects of dietary crude glycerin supplementation on nutrient digestibility, ruminal fermentation, blood metabolites, and nitrogen balance of goats.

This experiment was conducted to evaluate the effects of increasing concentrations of crude glycerin (CGLY) in diets on nutrient utilization, ruminal fermentation characteristics, and nitrogen utilization of goats. Four male crossbred (Thai Native×Anglo Nubian) goats, with an average initial weight of 26±3.0 kg, were randomly assigned according to a 4×4 Latin square design with four 21 days consecutive periods. Treatments diets contained 0%, 5%, 10%, and 20% of dietary DM of CGLY. Based on this experiment, there were no significant differences (p>0.05) among treatment groups regarding DM intake and digestion coefficients of nutrients (DM, OM, CP, EE, NDF, and ADF). Likewise, mean serum glucose, BHBA, and PCV concentrations were not affected (p>0.05) by dietary treatments, whereas serum insulin concentration linearly increased (L, p = 0.002) with increasing the amount of CGLY supplementation. Ruminal pH, NH3-N, and BUN concentration were unchanged by dietary treatments, except for 20% of CGLY, NH3-N, and BUN were lower (p<0.05) than for the diets 10% of CGLY, while the difference between the diets 0%, 5%, and 20% of CGLY were not significant. The amount of N absorption and retention were similar among treatments. Based on this study, CGLY levels up to 20% in total mixed ration could be efficiently utilized for goats and this study elucidates a good approach to exploiting the use of biodiesel production for goat production.

Influence of Salix babylonica and Leucaena leucocephala leaf extracts on ruminal fermentation characteristics, urinary purine derivative excretion and microbial protein synthesis of lambs

Sixteen growing Katahdin×Pelibuey lambs (24±0.3kg body weight) were used to study the effects of oral administration of extracts of Salix babylonica (SB) and Leucaena leucocephala (LL) leaves on ruminal pH, total and individual volatile fatty acids (VFA) and NH3-N concentrations, as well as ruminal protozoal counts, urinary purine derivatives (PD) excretion and estimated microbial protein synthesis. Lambs were fed a total mixed ration (TMR) containing 219 and 141gkg−1 of CP and NDF, respectively. Four treatments (4lambs/treatment) were Control (no extract added), SB (SB extract at 30mld−1), LL (LL extract at 30mld−1) and SBLL (mixture of SB at 15mld−1+LL at 15mld−1). Extracts were administered orally to each lamb before the morning meal daily. Measurements were on days 22 (P1), 43 (P2) and 63 (P3) of the experiment. Ruminal pH increased (P=0.014) with SBLL extract and decreased with SB. The ratio of acetate to propionate was higher (P=0.042) with SBLL compared to the control. Ruminal NH3-N concentration was not affected by extract administration (P=0.309) or experimental period (P=0.087). Protozoal counts were not affected (P=0.489) by extract addition but decreased (P<0.001) in P3 compared with P1 and P2. Uric acid concentration increased (P<0.001) with individual extracts of SB and LL compared with the control or SBLL. Excretion of other purine derivatives (allantoin, xanthine, and hypoxanthine), creatinine and microbial protein synthesis were not changed (P>0.05) by extracts administration. Overall, oral administration of S. babylonica and L. leucocephala extracts, or their 1:1 mixture, to lambs for 63d had only minor effects on ruminal fermentation, urinary purine derivative excretion and microbial protein synthesis.

Short communication: Effects of molasses supplementation on performance of lactating cows fed high-alfalfa silage diets

Twelve Holstein cows were used in a replicated Latin square experiment to determine the effect of adding dried molasses to high-alfalfa silage diets on dairy cow performance. Three isonitrogenous diets were formulated with a 68:32 forage:concentrate ratio, with alfalfa silage as the only forage source. Dietary treatments were a control diet with no added molasses and 3 and 6% dried molasses diets. Three lactating Holstein cows fitted with ruminal cannulas were used to determine the effects of dietary treatments on ruminal fermentation. Dietary treatments had no effect on dry matter (average 23.3kg/d), crude protein (average 4.4kg/d), or neutral detergent fiber (average 7.4kg/d) intake. Milk yield, energy-corrected milk (average 35.4kg/d), and 4% fat-corrected milk (average 33.8kg/d) were not influenced by dietary treatments. Cows fed the control diet produced milk with less milk urea nitrogen concentration than those fed molasses-supplemented diets. Ruminal pH, NH3-N concentration, and total volatile fatty acids were not different among dietary treatments. The molar proportion of acetate linearly increased, whereas the molar proportion of propionate linearly decreased as the level of dried molasses increased. It was concluded that addition of dried molasses to high-alfalfa silage diets at 6% of the diet (dry matter basis) increased milk urea nitrogen but had no effect on animal performance.

Feed intake, nutrient digestibility and ruminal fermentation activities in sheep-fed peanut hulls treated with Trichoderma viride or urea

This study aimed to assess impacts of fungal treatment on the nutritional value of peanut hulls (PH) or urea at the rate of 5 kg/100 g of PH. Fermented sugar beet pulp inoculated with Trichoderma viride was supplemented to PH at rates of 5.0, 10.0 and 15.0 g/100 g air dry of PH and mixed well before aerobic incubation for 21days. Organic matter (OM) content of PH declined with increased levels of fermented sugar beet pulp inoculums, while crude protein (CP), ether extract (EE), and ash increased. Fiber contents were decreased with both treatments of fermented sugar beet pulp and urea. Total N of PH increased with urea treatment, which reduced the true protein N to total protein N ratio. In sacco degradabilities of dry matter (DM), OM, and CP with urea treatment increased compared with fungal treatment. The DM intake of peanut hulls treated with fungus (PHF) was higher (P < 0.05) than with peanut hulls treated with urea (PHU). Digestibility of OM, CP, neutral detergent fiber, and non-fiber carbohydrate by native breed Ossimi sheep with PH were higher (P < 0.05) than with PH or urea treated PH. The intakes, losses, and balance of N increased (P < 0.01) with PHF versus PH feeding. Feeding PHF increased (P < 0.01) ruminal concentrations of NH3-N, acetic acid, butyric acid, and the acetic to propionic acid ratio. Bacterial and protozoal counts increased (P < 0.05) with feeding PHF or PHU versus PH. Overall, this fungal treatment of peanut hulls created a higher nutritive value feed for ruminants.