Effects of wood kraft pulp feeding on feed digestibility and rumen fermentation of Japanese Black steer in the middle fattening stage

We investigated the effects of wood kraft pulp (KP) feeding on feed digestibility and rumen fermentation of Japanese Black (JB) steer in the middle fattening stage. The feeding experiment was carried out a replicated 3 × 3 Latin square design using six JB steers (16.2 ± 0.8 months of age). Steers were fed rice straw and three concentrated feeds: commercial formula feed (control), formula feed containing 7.5% KP on a dry matter (DM) basis (7.5% KP), and formula feed containing 15% KP on a DM basis (15% KP). Feed digestibility and rumen fermentation parameters were recorded for 3 days during the measurement period, after an adaptation phase of 11 days. There was no significant difference in DM intake per day among diets. A slightly higher digestibility of neutral detergent fiber was observed in steers fed 15% KP, compared with those fed other diets (P = 0.059). The butyric acid ratio in rumen fluid was higher in steers fed KP diets than in steers fed control (P = 0.083). The average ruminal pH was unaffected by KP diets. This study suggests that replacing 15% of concentrated feed with KP has little effect on feed digestibility and rumen fermentation in JB fattening steer.     

Effect of wood kraft pulp feed on digestibility,ruminal characteristics,and milk production performance in lactating dairy cows

The effect of wood kraft pulp (KP) feed on dietary digestibility, ruminal fluid pH, rumen fermentation characteristics, and milk production performance in lactating dairy cows was examined. Four lactating dairy cows were used for the feeding experiment by the cross‐over design. The control group and KP group were set up as treatments. The control group was fed total mixed ration (TMR) (40% roughage and 60% concentrate) and the KP group was fed TMR containing 12% KP that replaced half of the rolled corn in the control diet. The dry matter intake, digestibility of the feed components, and milk yield were not significantly different between control group and KP group. The number of times that the ruminal fluid pH was below 6.1 tended to decrease in the KP group compared to the control group (p < 0.10). The acetic acid ratio in the ruminal fluid of the KP group increased compared to the control group (p < 0.05) and the propionic acid ratio in the ruminal fluid of the KP group decreased compared to the control group (p < 0.05). The acetate:propionate acid ratio was increased in the KP group compared with the control group (p < 0.05). Lipopolysaccharide levels in the ruminal fluid of the KP group tended to decrease compared to the control group (p < 0.10). Based on these results, it was indicated that the use of KP feed for lactating dairy cows induced the same rumen fermentation characteristics as those in cows given a large amount of roughage without depressing milk productivity. Therefore, KP could be a valuable feed resource substitute for grains, which would also reduce the risk for subacute rumen acidosis.     

Effect of dietary concentrate content on feed intake,feed efficiency,and meat quality of Holstein steers fattened in a hot environment

The objective of this study was to investigate the effect of feeding high and low concentrate diets on feed intake and feed efficiency, the morphological characteristics of the rumen papillae, and meat quality of Holstein steers fattened under hot climate conditions in Oman. Ten male Holstein calves, of 5 months of age, were selected for the experiment. The animals were fed concentrate and Rhodes grass hay and were divided into two groups of high concentrate (HC, n = 5) and low concentrate diets (LC, n = 5), in which their feed intake, weight gain, and feed efficiency were evaluated across three growing periods. Feed intake and efficiency and average daily gain (ADG) of the HC group were significantly greater than for the LC group and were affected by the diet (p < .01) and the period (p < .001). Across the fattening periods, ADG declined in both groups, with ADG improved by 35% for steers on the HC diet compared to steers on the LC diet. Carcass meat quality was not affected significantly by the dietary concentrate level. In conclusion, our results can be used to make improvements in feed efficiency of Holstein steers under hot climate conditions.     

Influence of feeding a grass hay diet during the early stage of the fattening period on growth performance,carcass characteristics,and meat production in Japanese Black steers

The present study investigated the influence of feeding a large amount of grass hay to steers from the early to middle fattening period on growth, carcass characteristics, and meat characteristics. Steers were randomly divided into grass hay‐fed (GHF, n = 6) and concentrate‐fed (CF, n = 6) groups. The dressed weight of the GHF steers was lower than that of the CF steers, but the final body weight was not significantly different between the groups. The GHF steers had decreased subcutaneous fat and rib thickness compared with the CF steers. Lipid content, monounsaturated fatty acids, and drip loss in the muscles were lower in the GHF steers than in the CF steers. Furthermore, n‐3 polyunsaturated fatty acids were higher in the GHF steers compared with the CF steers. The GHF steers had lower body weight during the middle fattening stage, which may have occurred as a result of muscle growth suppression caused by increased Myostatin expression; an increase in daily gain during the finishing period may have occurred as a result of muscle growth activation caused by decreased Myostatin expression. Feeding steers a grass hay‐based diet during the early fattening period possibly maintains the quantitative productivity of beef similarly to feeding a concentrate‐based diet.     

The effects of protein sources supplemented with urea-treated potato pulp (PP) silage and feeding levels of the PP silage-based concentrate on feed intake, digestibility and ruminal fermentation in beef steers

Six Japanese Black (Wagyu) steers (average initial weight 467 ± 45 kg) fitted with a ruminal cannula were used in a split‐plot design experiment comprising a 3 × 3 Latin square design (whole‐plot) and a randomized block design (subplot). The whole‐plot treatments were three different feeding levels of urea‐treated potato pulp (PP) silage‐based concentrate: 1.00%, 1.75% and 2.50% of body weight (BW) (on a dry matter (DM) basis). The subplot treatments consisted of the concentrate formulated to contain either soybean meal (SBM) as a rapidly rumen‐degraded protein source or corn gluten meal (CGM) as a slowly degraded protein source. Dry matter intake tended to be lower (P = 0.071) for CGM (8.9 kg/day) than for SBM (9.4 kg/day). Protein sources had no significant effect on digestibility and in situ degradation. Ruminal ammonia nitrogen (NH₃‐N) was lower (P = 0.033) for CGM (7.5 mg/dL) than for SBM (9.5 mg/dL). Protein sources did not affect ruminal pH and the total volatile fatty acids (VFA) concentrations. The molar proportions of ruminal acetate and valerate were higher (P = 0.032) for CGM than for SBM. The maximum daily intake of the PP silage‐based concentrate expressed as a percentage of BW was approximately 1.4% of BW. Dry matter intake was higher (P = 0.046) for steers fed at 1.0% of BW of the PP silage‐based concentrate than for steers fed at 1.75% or 2.5% of BW of the concentrate. The feeding levels of the PP silage‐based concentrate had no effect on DM and nutrients digestibility, except for crude protein (CP) digestibility. CP digestibility tended to be lower (P = 0.071) for steers fed at 1.75% of BW of the PP silage‐based concentrate than for steers fed at 1.0% or 2.5% of BW of the concentrate. The feeding levels of the PP silage‐based concentrate also did not affect the in situ degradation parameter of hay and PP silage. The feeding levels of the PP silage‐based concentrate did not affect ruminal pH, NH₃‐N and total VFA concentrations. The molar proportion of acetate was highest for steers fed at 1.0% of BW of the concentrate. In conclusion, in the urea‐treated PP silage‐based concentrate, CGM seems to be more effective than SBM for stabilizing the ruminal NH₃‐N concentration and to be advantageous for fiber digestion in the rumen. The feeding levels of the PP silage‐based concentrate did not change the amount of VFA production in the rumen and the DM digestibility.     

Influence of rice whole‐crop silage diet on growth performance,carcass and meat characteristics and muscle‐related gene expression in Japanese Black steers

The present study investigated the influence of a diet largely comprising rice whole‐crop silage (rWCS) on growth performance, carcass and meat characteristics, and expression of genes involved in muscle growth of Japanese Black steers. Steers were randomly separated into rWCS‐fed (rWCS ad libitum and restricted feeding of concentrate) and concentrate‐fed groups. Total digestible nutrient intake and daily gain (DG) decreased in rWCS‐fed steers in comparison with concentrate‐fed steers, whereas dressed carcass weight and final body weight did not significantly differ between the groups. Decreases in drip loss in the muscle of rWCS‐fed steers may be caused by α‐tocopherol and β‐carotene in muscle. Feeding large amounts of rWCS to steers may maintain quantitative productivity of beef steers equally to a concentrate‐based diet, and improve the qualitative productivity. Results of gene expression suggest that activation of skeletal muscle growth in rWCS‐fed steers may occur at the late fattening period owing to a decrease in myostatin and increase in myosin heavy chain gene expression. Preadipocyte factor‐1 and myostatin genes may be strongly involved in the control of lipid accumulation. This rearing system would allow beef production to switch to rWCS‐based diets from concentrate‐based diets.     

不同颗粒日粮对滩羊育肥羊生长性能、养分表观消化率及血清生化指标的影响

旨在探究不同颗粒日粮对育肥羊生长性能、养分表观消化率及血清生化指标的影响。选取体重相近、（70±10）日龄的滩羊羯羔羊60只,随机分为4组：对照组（n=15）、试验Ⅰ组（n=15）、试验Ⅱ组（n=15）、试验Ⅲ组（n=15）。对照组饲喂自配全混合日粮（40%自配精饲料+60%自配粗饲料）,试验Ⅰ组饲喂50%自配全混合日粮（20%自配精饲料+30%自配粗饲料）+50%育肥羊全混合颗粒饲料,试验Ⅱ组饲喂育肥羊全混合颗粒饲料,试验Ⅲ组饲喂45%颗粒化精补料+55%草颗粒饲料。饲喂试验预试期16 d,正试期87 d。测定各组育肥羊的试验初重和试验末重,计算试验期间的平均日增重。记录各组育肥羊的采食情况,计算平均日采食量和料重比。饲喂试验结束时,采用常规方法测定并比较各组干物质、有机物、粗蛋白质和中性洗涤纤维的表观消化率,以及血清生化指标。结果表明,试验Ⅱ组的平均日增重最高,显著（P<0.05）高于试验Ⅰ组和试验Ⅲ组,极显著（P<0.01）高于对照组;试验Ⅱ组的平均日采食量显著（P<0.05）低于试验Ⅰ组和对照组;试验Ⅱ组的料重比最低,分别比对照组、试验Ⅰ组和试验Ⅲ组降低了60.63%、35.69%、9.41%。试验Ⅱ组的干物质、有机物、粗蛋白质和中性洗涤纤维的表观消化率均高于其他3组,其中,粗蛋白质的表观消化率与其他3组差异均显著（P<0.05）。各组育肥羊血清生化指标差异均不显著（P>0.05）。综上提示,饲喂全混合颗粒日粮能够改善滩羊育肥羊生长性能,提高养分表观消化率,对育肥羊健康无明显影响。     

Effects of high protein levels in concentrate feed during the early fattening stage on physico-chemical composition and sensory characteristics of M. longissimus in Japanese Black heifers

The effects that high levels of protein in concentrate feed has during the early fattening stage on physico-chemical composition and sensory characteristics of M. longissimus in Japanese Black heifers were investigated. Four sets (8 head) of identical twins of Japanese Black heifers were divided into two groups: a group fed high levels of protein in concentrate feed in the early fattening stage (HCP); and a control group. Moisture, fat, protein, cooking loss, Warner-Bratzler shear force and fatty acid composition of M. longissimus were similar in both groups. Levels of free amino acid (FAA), aspartic acid, glutamine, taurine and histidine were lower in the HCP group than in the control group ( P  < 0.05). Levels of glutamic acid, serine, asparagine, threonine and total FAA in the HCP group tended to be lower than in the control group ( P  < 0.1). There were no significant differences between the sensory characteristics (juiciness, tenderness, fattiness, flavor and overall acceptability) of the two groups. These results suggest that the use of high levels of protein in concentrate feed during the early fattening stage does not affect the sensory characteristics of Japanese Black beef, but does alter the FAA content.     

Effect of feeding Acacia nilotica pods to sheep on nutrient digestibility,nitrogen balance,ruminal protozoa and rumen enzymes activity

This study was conducted to evaluate the effect of supplying two levels of Acacia nilotica (A. nilotica) pods to rations of sheep on nutrient digestibility, nitrogen balance and rumen liquor parameters (pH, total protozoa count, protein concentration and enzymes activity). Twelve mature rams (50 ± 1.25 kg B.W.) were distributed into three groups, each with four rams. Animals in group one were considered as a control which fed a basal diet, consisting of concentrate mixture and Egyptian clover. The second group and the third one received the same basal diet with supplying the concentrate mixture by 1.5% and 3.0% of A. nilotica pods meal respectively. The experiment lasted for 3 weeks. It was found that supplementation of A. nilotica pods to the concentrate mixture at a rate of 1.5% and 3.0% significantly improved the total feed intake compared to the control. The digestibility of dry matter and crude fibre was significantly reduced with A. nilotica supplements, whereas the digestibility of crude protein was significantly improved. All of nitrogen intake and N‐retained were significantly increased in rams fed on concentrates with 1.5% and 3.0% A.  nilotica pods when compared to the control. The pH of ruminal fluid was not affected by the dietary treatments. Nevertheless, the total rumen protozoa count was significantly decreased in A. nilotica pods supplemented groups. Also, the rumen protein concentration and the ruminal enzymes activity, especially α‐amylase, cellulase and protease, were lower in A. nilotica pods supplemented treatments. In conclusions, inclusion of low levels of A. nilotica pods (1.5% and 3.0%) in the concentrates can be used as a natural protein protectant in ruminants by forming tannin protein complexes in the rumen to maximize the amino acids available in the lower digestive tract. Also, these levels can increase the protein digestibility as well as the N‐retained in the body .     

Effects of substituting kraft pulp with corn silage on dry matter intake,ruminal mat formation,rumen fermentation,and rumination activity in non‐lactating cows

The present study examined the effects of substituting kraft pulp (KP) with corn silage (CS) on dry matter intake (DMI), ruminal mat and rumen fermentation characteristics, and rumination. Four non‐lactating, rumen‐cannulated Holstein cows were fed a CS diet comprising 36% grass silage (GS) and 64% CS or a KP diet comprising 36% GS, 57% KP, and 7% soybean meal. DMI was significantly lower in cows fed the KP diet than in those fed the CS diet (p < 0.05), whereas rumination time did not significantly differ between the treatments. Dry matter content in the rumen immediately before and 3 h after feeding was significantly higher in cows fed the KP diet than in those fed the CS diet (p < 0.05). The consistency and thickness of the ruminal mat did not significantly differ between the treatments. The ruminal mean retention time of feed particles tended to be longer in cows fed the KP diet than in those fed the CS diet (p < 0.10). The ruminal digestion rate of KP was comparable to that of GS and CS. Because ruminal mat was formed and rumination was stimulated, KP was considered to have the equivalent physical effectiveness as CS.     

Effects of limit‐feeding diets with different forage‐to‐concentrate ratios on nutrient intake,rumination, ruminal fermentation,digestibility, blood parameters and growth in Holstein heifers

The objective of this study was using a wide range of dietary concentrate levels to investigate the major effects of limit‐feeding on heifers. Twenty‐four Holstein heifers were blocked into six groups and fed with one of four diets containing different levels of concentrate (20%, 40%, 60% and 80% on a dry matter (DM) basis) but with same intakes of metabolizable energy for 28 days. Increasing levels of dietary concentrate caused decreased (P ≤ 0.02) intakes of dry matter (DMI) and neutral detergent fiber and total rumination time, but increased (P < 0.01) nonfiberous carbohydrates intake, ruminal concentrations of NH₃‐N, propionate and butyrate, and digestibility of DM and crude protein. Dietary concentrate levels had no significant effect on most plasma concentrations and body measurements. The corrected average daily gain (CADG) and feed efficency (ADG/DMI, CFE) were linearly increased (P < 0.01) with increasing dietary concentrate levels when gut fill impact was removed. In conclusion, heifers limit‐fed high concentrate diets increased most ruminal fermentation parameters, CADG and CFE with similar body growth and blood metabolites as heifers fed low concentrate diets, and had the potential to be used as an effective feeding strategy in dairy heifers.     

Effects of urea treatment of potato pulp and inclusion levels of potato pulp silage in supplements on digestibility and ruminal fermentation in beef steers

Six Wagyu (Japanese Black) steers fitted with a ruminal cannula were used in a split‐plot design experiment comprising a 3 × 3 Latin square design (whole plot) and a randomized blocks design (subplot) to determine the effect of the treatment of potato pulp (PP) with urea and the effect of inclusion levels of PP silage in feed supplement on digestibility, ruminal in situ degradation and ruminal fermentation. The whole plot consisted of 20%, 50% and 80% PP silage (dry matter (DM) basis), with PP silage replacing formula feed. The subplot included untreated or 0.5% (on an as‐fed basis) urea‐treated PP. The treatment of PP with urea showed no effect on DM intake and digestibility. The percentage of the rapidly degradable DM fraction of the urea‐treated PP silage was higher (P < 0.01) and the percentage of its slowly degradable DM fraction was lower (P < 0.01) than for the untreated PP silage. Ruminal ammonia concentration was greater (P < 0.01) for steers fed urea‐treated PP silage than that for steers fed the untreated PP silage. The treatment of PP with urea caused a decrease in the molar proportion of acetate and an increase in the proportion of propionate in ruminal fluid after feeding. The rate of DM degradations in hay (linear, P < 0.01) and in PP silage decreased (linear, P < 0.01) as the inclusion level of PP silage increased. Increasing the inclusion level of PP silage in supplement decreased the effective degradability of DM in hay (linear, P < 0.05) and in PP silage (linear, P < 0.05). An increase in the amount of PP silage increased the molar proportion of acetate (linear, P < 0.01) and decreased the butyrate proportion (linear, P < 0.05) in ruminal fluid. The results suggest that urea treatment of PP facilitates microbial access to starch of PP silage in the rumen and that surplus level of PP silage in supplement have adverse effect on ruminal digestion.     

The effects of urea‐treated potato pulp (PP) ensiled with beet pulp or wheat bran pellets to reduce moisture of PP and flake density of corn grain supplemented with the PP silage on digestibility and ruminal fermentation in beef steers

The effects of adding beet pulp or wheat bran to urea‐treated potato pulp (PP) in order to reduce moisture of PP silage and flake density of corn grain on digestibility and ruminal fermentation in beef steers were studied in a split‐plot design experiment. The whole‐plot treatments were PP silage mixed with 0% added pellets (CON), 9% (as‐fed basis) beet pulp pellets (BP) or 9% (as‐fed basis) wheat bran pellets (WB) as water‐absorbing materials. The subplot treatments consisted of supplements formulated to contain either high‐density corn (HDC) or low‐density corn (LDC). BP steers consumed more (BP vs WB, P = 0.011) concentrate than did WB steers, whereas hay intake did not differ between the treatments. Dry matter (BP vs WB, P = 0.023) and organic matter (BP vs WB, P = 0.029) digestibility were higher for BP steers than for WB steers. Starch digestibility was higher (P = 0.006) for LDC than for HDC. There were no differences in the concentration of ruminal ammonia nitrogen among the treatments. Molar proportions of ruminal acetate were higher for BP steers than for WB steers (BP vs WB, P = 0.030). Conversely, molar proportions of propionate were lower for BP steers than for WB steers (BP vs WB, P = 0.044). Flake density of corn did not affect ruminal characteristics. In conclusion, from the viewpoint of feed intake and digestibility, BP is superior to WB as a moisture control material for urea‐treated PP silage, and flake density of corn supplemented with urea‐treated PP silage does not alter ruminal fermentation.     

Effect of inclusion of HMBi in the ration of goats on feed intake,nutrient digestibility,rumen bacteria community and blood serum parameters

The objective of this experiment was to test the effect of supplementation of analogues of methionine 2-hydroxy-4-methylthio butanoic acid isopropyl ester (HMBi) on growth, digestibility, antioxidant index, abundance and composition of rumen bacterial community in Xiangdong Black Goats. Thirty-six growing Xiangdong Black Goats were divided into four groups in such a way that each group had three replicate and each replicate had three animals. Experimental groups were assigned four levels of HMBi in basal diet: 0% HMBi (on dietary DM basis); 0.05% HMBi; 0.10% HMBi and 0.20% HMBi. Goats fed 0.10% HMBi in basal diet had higher average daily weight gain (p < .05). Goats fed 0.05% HMBi had higher apparent digestibility of gross energy (p < .01). The group 0% HMBi supplementation had a higher level of superoxide dismutase and malondialdehyde (p < .01). The goats fed 0.20% HMBi in basal diet had a higher level of insulin and leptin (p < .01) than 0% HMBi supplementation goats. 16S rRNA high-throughput sequencing analysis revealed similarities in the community composition, species diversity and relative abundance of dominant bacteria at the phylum and genus levels among the four groups. In conclusion, HMBi supplementation has no negative effect on apparent digestibility, antioxidant index and the ruminal bacteria composition. Therefore, 0.10% supplementation of HMBi is recommended in the diet of goats to improve the growth performance.     

Effects of essential oils,yeast culture and malate on rumen fermentation,blood metabolites,growth performance and nutrient digestibility of Baluchi lambs fed high‐concentrate diets

The experiment was conducted to evaluate the effects of dietary supplementation with a mixture of essential oils (MEO), yeast culture (YC) and malate on performance, nutrient digestion, rumen fermentation and blood metabolites of lambs fed high‐concentrate growing diets. For this purpose, twenty Baluchi lambs (17.3 ± 0.5 kg body weight and 3 months old) were randomly assigned to four dietary treatments in a completely randomized design with five lambs per treatment. The treatment groups were as follows: (i) control: basal diet without any additive, (ii) basal diet plus 400 mg/day MEO (thymol, carvacrol, eugenol, limonene and cinnamaldehyde), (iii) basal diet with 4 g/day YC and (iv) basal diet plus 4 g/day malate. No differences between the dietary treatments were observed in dry matter intake, average daily gain or feed conversion ratio (p > 0.05). Compared with control and malate treatment, lambs fed MEO and YC had an improved crude protein digestibility (p < 0.05). Yeast culture significantly increased (p > 0.05) cell wall digestibility compared to the other treatments. No differences were observed between treatments with respect to nitrogen balance or ruminal pH and ammonia concentrations (p > 0.05). No differences were observed between treatments with respect to ruminal total volatile fatty acid concentration and molar proportions of acetate, butyrate and valerate. Molar proportion of propionate was higher (p < 0.05) for YC and malate compared to control and MEO. Plasma glucose concentration was higher (p < 0.05) in lambs fed YC and malate than in lambs fed the control or the MEO diet. Blood concentration of triglycerides significantly decreased when feeding the MEO and YC diets (p < 0.05). It was concluded that YC may be more useful as a feed additive for manipulation of rumen fermentation in lambs fed with high‐concentrate diets than MEO and malate, because YC enhanced crude protein and cell wall digestibility, ruminal molar proportion of propionate and plasma glucose concentration.     

Effects of feeding different levels of concentrate on growth and carcass characteristics in younger Japanese Black cattle

The effects of a higher concentrate feed during the raising period on the growth and carcass of Japanese Black cattle being fattened at a younger age were investigated using three pairs of artificially bred identical twins and three pairs of full‐sibs. The animals were fed the concentrate at 2.4%/day (2.4% group) and 1.2%/day (1.2% group) comparative bodyweight (BW) during the raising period. The BW and subcutaneous fat thickness were measured every month using ultrasonic equipment. The animals were slaughtered at the age of 24 months. The BW of the 2.4% group from the age of 6–10 months appeared to be higher than that of the 1.2% group (P < 0.1). The subcutaneous fat of the 2.4% group from the age of 7–11 months was thicker than that of the 1.2% group (P < 0.1). After those ages, the BW and subcutaneous fat of the two groups did not differ and there was no difference in the carcass characteristics between the two groups. Using a higher concentrate feed during the raising period for younger fattening of Japanese Black cattle influenced growth from the late half of the raising period to the early part of the fattening period.     

Effects of clay on fat necrosis and carcass characteristics in Japanese Black steers

Twenty 10‐month‐old Japanese Black steers were used to evaluate the effects of clay on fat necrosis and carcass characteristics. Ten steers (Clay group) were fed the clay (50 g/day) during 10–30 months of age. The other 10 steers (Control group) were not fed it. There was no significant difference in body weight or average daily gain between the two groups (P > 0.05). The occurrence of fat necrotic mass in the Clay group (30%) was lower (P < 0.05) than that in the Control group (90%) at slaughter. The size of necrotic masses in the Clay group was smaller (P < 0.05) than that in the Control group. There was no significant difference in the marbling score, beef color, Longissimus muscle area or subcutaneous fat thickness between the two groups. These results suggest that the clay prevented the occurrence of fat necrosis and did not affect the carcass characteristics in Japanese Black steers.     

Pilocarpine and digestive efficiency in beef cattle fed a high-concentrate diet

The effect of pilocarpine HCl, a parasympathetic muscarinic agonist, on digestive characteristics was evaluated in growing beef steers fed a high-grain diet. Oral doses of 0, 2 or 4 mg/kg BW were administered daily to each of eight steers immediately prior to offering an 88% concentrate: 12% hay diet in this three-period crossover design (19 d/period). Treatments did not improve digestibilities of dry matter, organic matter and nitrogen, ruminal liquid volume and fractional dilution rate, body weight gain or feed efficiency. Although daily voluntary feed intake was not altered by treatment (P = .25), there was a dose-dependent slowing of the rate at which feed was consumed (P less than .01). Also, ruminal fluid pH was increased with increasing dose (5.36, 5.55 and 6.11 respectively; P = .10). These observations indicate that the digestive improvements due to pilocarpine reported to occur in mature, nongrowing cattle consuming a high-forage diet are not observed in growing steers fed a production-type diet.     

Effects of inclusion levels of pelleted silvergrass (Miscanthus sinensis Andress.) in the diet on digestibility,chewing activity,ruminal fermentation and blood metabolites in breeding Japanese Black cows

To examine the effects of inclusion levels of pelleted silvergrass (PS) in the diet on digestibility, ruminal fermentation and nutrient status of breeding Japanese Black cows, four cows were allotted to a 4 × 4 Latin square design experiment. Treatments were control fed a diet consisting of 89.4% Sudangrass hay and 10.6% soybean meal on a dry matter (DM) basis, and PS18, PS27 and PS45 fed the diet replaced with 18%, 27% and 45% of control with PS, respectively. The total digestible nutrients (TDN) content of PS was 45.6% on a DM basis. The TDN intakes were significantly decreased by increasing PS level in the diet (P < 0.05), but were higher than the TDN requirement of maintenance cows in all treatments. The total chewing time was decreased significantly by increasing PS level in the diets (P < 0.05). However, the pH and concentration of volatile fatty acid in the ruminal fluid and serum metabolite concentrations were not significantly different among the treatments. The results suggested that including PS up to 45% in the diet did not have adverse effects on the ruminal fermentation and nutrient status in breeding Japanese Black cows at the maintenance stage.     

Effect of Silage Sugarcane Leaf Replacing Different Ratio of King Grass on Growth Performance,Nutrient Apparent Digestibility and Serum Biochemical Indices of Hainan Black Goats

The aim of this study was to investigate the effect of silage sugarcane leaf replacing different ratio of King grass on growth performance,nutrient apparent digestibility and serum biochemical indices of Hainan Black goats.A total of 20 3-month-old Hainan Black goats with an average weight of (6.96±0.49) kg were selected (half male and hale female) and randomly divided into 5 groups with 4 replicates per group and 1 goat per replicate.The goats in the control group were fed the basal diet including concentrate and roughage,roughage was King grass.The goats in the groups 1 to 4 were fed with the equal concentrate,roughage (fresh King grass) was replaced with 25%,50%,75% and 100% silage sugarcane leaf,respectively.The pre-test period lasted for 5 days and the trial period lasted for 30 days.The results showed that compared with control group,the average feed intake of crude feed and average feed intake of total dry matter in group 3 were significantly increased (P< 0.05),there were no significant differences in the average daily gains,average feed intake of concentrate and F/G among all groups (P> 0.05).Compared with control group,the apparent digestibility of Ash and P in group 3 were significantly increased (P< 0.05),the apparent digestibility of Ash,NDF,ADF and Ca in group 4 were significantly increased (P< 0.05).No significant difference was showed between groups 3 and 4 (P> 0.05).There were no significant differences in serum biochemical indices among all groups (P> 0.05).In conclusion,silage sugarcane leaf replaced certain percentage of King grass in roughage could improve the growth performance and nutrient apparent digestibility to some extent,and had no bad effect on the serum biochemical indices of goats,the optimal proportion of silage sugarcane leaf in roughage was 75%.