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1.
To clarify colonic fermentation during the perinatal period, 22 dairy calves less than 6 weeks old were used. They were given a milk replacer following colostrum feeding. A total 100 samples of normal feces including meconium were collected from the rectum of the calves. Fecal pH, alcohols, lactate and volatile fatty acids (VFAs) were analyzed. Higher ethanol and n -propanol concentrations were found in many fecal samples particularly in the first 2 weeks after birth, but these metabolites showed consistently lower concentrations thereafter. By contrast, higher concentrations of methanol were observed in some samples for all ages examined. Fecal VFA increased abruptly within a few days of birth, and mainly consisted of acetate and n -butyrate. During the first 2 weeks, the proportion of n -butyrate in VFAs decreased and that of propionate increased gradually. Proportions of VFAs were almost stable at 3–6 weeks of age (acetate, propionate and n -butyrate in increasing order). Higher concentrations of lactate and lower pHs were observed in the fecal samples during the first 2 weeks, and concentrations decreased thereafter. Accelerated colonic production of ethanol and n -propanol was confirmed during the early 2 weeks, in addition to organic acid fermentation as reported previously.  相似文献   

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For evaluation of physiologically significant organic anions in the colonic environment, 87 samples of normal feces were collected from the rectum of 15 calves less than 60 days old. The calves were fed milk replacer with free access to starter diet and hay. After fecal extraction with water, pH, D- and L-lactate, succinate, and volatile fatty acid (VFA) concentrations were determined. There was wide variation in fecal pH (4.3 to 7.7). Higher lactate concentrations were observed in feces samples with lower pH, and most of these samples were collected during the first 4 weeks of life. Elevated lactate concentrations included both the D- and L-isomers, and the D-isomer comprised approximately 30-50% of total lactate. Elevated succinate concentrations were observed in only 8 fecal samples, while other samples had lower or trace amounts of succinate. Elevated fecal succinate showed no relationship with fecal pH or VFA concentrations. Fecal VFA concentrations were lower in samples collected in the early postnatal stage, but fecal VFA concentrations were not necessarily related to age. We confirmed that fecal D- and L-lactate concentrations increased with a concomitant decrease of VFA in the acidic lumen of the colon, although acidic feces were not necessarily accompanied by elevated concentrations of lactate. In contrast, succinate production was not related to fecal pH or VFA concentrations.  相似文献   

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Normal fecal samples were taken from lactating cows fed either a total mixed ration (TMR; n = 30) or pasture‐based diet (20) and from dry cows fed mainly on hay (15). Diarrheic fecal samples (n = 51) were collected from 21 sick dairy cows. Fecal analyses of ammonia, urea, lactate and volatile fatty acid (VFA) levels were used to evaluate colonic fermentation. Most normal feces had reasonably neutral pH, however, alkaline feces were observed in diarrheic cows. Although fecal lactate is higher in cows on grazing pasture, lactate levels were generally lower in the cows in the present study. Fecal VFA levels were higher in lactating cows than in dry cows. Elevated fecal urea was observed in diarrheic cows, however, many fecal samples in normal and diarrheic cows contained no urea. Fecal VFA levels in diarrheic cows were lower than in normal lactating cows, but were approximately equivalent to those in dry cows. Grazing or dry cows showed higher acetate and lower n‐butyrate proportions compared with TMR‐fed or diarrheic cows. Higher proportions of branched chain VFAs were observed in diarrheic cows, and the lowest level was observed in grazing cows. The present results indicate that intracolonic nitrogen equilibrium and proteolytic fermentation are altered by diarrheic status.  相似文献   

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Trehalose, a nonreducing disaccharide consisting of d-glucose with α,α-1,1 linkage, was evaluated as a functional material to improve the gut environment in preweaned calves. In experiment 1, 173 calves were divided into two groups; the trehalose group was fed trehalose at 30 g/animal/d with milk replacer during the suckling period, and the control group was fed nonsupplemented milk replacer. Medication frequency was lower in the trehalose group (P < 0.05). In experiment 2, calves (n = 20) were divided into two groups (control group [n = 10] and trehalose group [n = 10]) based on their body weight and reared under the same feeding regimens as in experiment 1. Fresh feces were collected from individual animals at the beginning of the trial (average age 11 d), 3 wk after trehalose feeding (experimental day 22), and 1 d before weaning, and the fecal score was recorded daily. Fecal samples were analyzed for fermentation parameters and microbiota. The fecal score was significantly lower in the trehalose group than in the control group in the early stage (at an age of 14 to 18 d; P < 0.05) of the suckling period. Calves fed trehalose tended to have a higher proportion of fecal butyrate on day 22 than calves in the control group (P = 0.08). Population sizes of Clostridium spp. were significantly lower (P = 0.036), whereas those of Dialister spp. and Eubacterium spp. tended to be higher in the feces of calves in the trehalose group on day 22 (P = 0.060 and P = 0.083). These observations indicate that trehalose feeding modulated the gut environment and partially contributed to the reduction in medication frequency observed in experiment 1.  相似文献   

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试验旨在研究使用复合微生态制剂部分替代饲粮中抗革兰氏阴性菌抗生素硫酸黏杆菌素对断奶仔猪生长性能、腹泻率以及粪便微生物的影响。选用28日龄健康长大二元杂交断奶仔猪320头(断奶日期与体重接近),随机分为4个处理,每个处理5个重复,每个重复16头(公母各半)。试验期30 d。试验结果显示:在生长性能方面,替代2组在试验末重、平均日增重上分别高于对照组8.72%(P<0.05)和17.24%(P<0.05),在料重比上比对照组降低5.78%(P<0.05),但是与抗生素组之间没有显著差异(P>0.05)。与对照组相比,饲粮中添加1 000 mg/kg复合微生态制剂能显著降低断奶仔猪腹泻频率(P<0.05)。在对粪便微生物的影响方面,饲粮中添加1 000 mg/kg复合微生态制剂饲喂30 d能显著提高断奶仔猪粪便中乳酸菌含量9.75%(P<0.05),显著降低大肠杆菌含量13.22%(P<0.05)。因此,在断奶仔猪饲粮中添加复合微生态制剂能够替代抗生素类添加剂硫酸黏杆菌素,可达到显著提高仔猪生长性能、降低仔猪腹泻频率、改善仔猪肠道健康的功效,其最适添加剂量为1 000 mg/kg。  相似文献   

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The object of this work was to study the effects of crossbreeding on meat quality and fatty acid profile of Holstein calves. Samples were taken from Longissimus thoracis (LT) muscle of 36 calves of three different groups (Holstein crossed with Rubia Gallega (HF×RG), Holstein crossed with Limousine (HF×LI) and Holstein crossed with Belgian Blue (HF×BB)). Significant differences were observed in carcass weight and killing out percentage (P < 0.001) among, groups reaching the highest values in the HF×BB group (228 kg and 59.4%, respectively), while the cross with Limousine presented the lowest values for carcass weight (191 kg) and the cross with Rubia Gallega showed the lowest killing out percentages (54.9%). Meat from HF×RG animals was redder (a* 13.31) and lightest (L* 39.55) than meat from HF×LI and HF×BB groups. With regard to fatty acid profile, the saturated fatty acids were the most abundant fatty acid, followed by monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids in the three groups. Crossbreeding did not affect the proportion of fatty acid. Finally, live weight, cold carcass weight, killing out, shear force, L* from LT, b*from LT, a* from fat, b* from fat, C14:0, C15:0, C16:0, C18:0, C18:3n‐6, MUFA and price‐to‐sales ratio were the selected variables from discriminant analysis to classify the types of crossbreeding.  相似文献   

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This experiment was conducted to evaluate the effects of plant extract YGF251 supplementation in different protein level diets on growth performance, nutrient digestibility, blood profiles, fecal microbial shedding, and fecal gas emission in growing pigs. A total of 144 pigs (24.72 ± 1.54 kg) were randomly assigned to the treatments in a 2 × 3 factorial arrangement of dietary protein levels (15.50%, 14.00% or 12.50%) and plant extract YGF251 levels (0 or 0.05%) with 6 replications per treatment and 4 pigs per pen. Pigs fed low protein diets had reduced average daily gain (p < 0.05) and increased feed conversion ratio (p < 0.01) compared with pigs fed high protein diets. The apparent total tract digestibility of nitrogen was decreased (p < 0.05) when reducing dietary protein level. Fecal ammonia and hydrogen sulfide emissions were reduced (p < 0.05) when reducing dietary protein level. In conclusion, the results of the current study indicated that reducing dietary protein level impaired growth performance and nitrogen digestibility but reduced ammonia and hydrogen sulfide emissions in growing pigs. Dietary supplementation with 0.05% herbal extract YGF251 was not effective in improving growth performance, nutrient digestibility, or in decreasing gas emission in different protein diets.  相似文献   

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Thirty calves were randomly assigned to two treatments and fed until weaning [42 days (d) of age]. Treatments were a control group (n = 15), which did not receive Megasphaera elsdenii (Me0) and a M. elsdenii group, which received a 50‐ml oral dose of M. elsdenii NCIMB 41125 (108 CFU/ml) at day 14 day of age (Me14). Calves were given colostrum for the first 3 day followed by limited whole milk feeding. A commercial calf starter was offered ad libitum starting at day 4 until the end of the study. Fresh water was available throughout the study. Feed intake and growth were measured. Blood samples were collected via jugular venipuncture to determine β‐hydroxybutyrate (BHBA) concentrations. Fourteen male calves (seven per group) were euthanised on day 42 and digestive tracts harvested. Reticulo‐rumen weight was determined and rumen tissue samples collected from the cranial and caudal sacs of the ventral and dorsal portions of the rumen for measurements of papillae length, papillae width and rumen wall thickness. Dosing with M. elsdenii NCIMB 41125 improved starter dry matter intake (DMI), weaning body weight (BW) and tended to improve average daily gain. Calves in Me14 group had greater plasma BHBA concentration than Me0‐calves during the last 3 weeks of the trial and had at day 42 greater reticulo‐rumen weight, papillae width and papillae density compared to Me0. No differences in rumen wall thickness or papillae length were observed between the two groups. Total volatile fatty acids, acetate and propionate production did not differ between treatments, but butyrate production was greater in Me14 than Me0. Dosing M. elsdenii NCIMB 41125 showed benefit for calves with improved feed intake and rumen development suggesting increased epithelium metabolism and improved absorption of digestive end products.  相似文献   

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The effects of feeding different dosages of metabolite combination of L. plantarum RS5, RI11, RG14 and RG11 strains (Com3456) on the performance of broiler chickens was studied. A total of 504 male Ross broilers were grouped into 7 treatments and offered different diets: (i) standard corn‐soybean based diet (negative control); (ii) standard corn‐soybean based diet +100 ppm neomycin and oxytetracycline (positive control); (iii) standard corn‐soybean based diet + 0.1% metabolite combination of L. plantarum RS5, RI11, RG14 and RG11 strains (Com3456); (iv) standard corn‐soybean based diet + 0.2% of Com3456; (v) standard corn‐soybean based diet + 0.3% of Com3456 (vi) standard corn‐soybean based diet + 0.4% of Com3456 and (vii) standard corn‐soybean based diet + 0.5% of Com3456. Supplementation of Com3456 with different dosages improved growth performance, reduced Enterobacteriaceae and increased lactic acid bacteria count, and increased villi height of small intestine and fecal volatile fatty acid concentration. Treatment with 0.4% and 0.2% Com3456 had the best results, especially in terms of growth performance, feed conversion ratio and villi height among other dosages. However, the dosage of 0.2% was recommended due to its lower concentration yielding a similar effect as 0.4% supplementation. These results indicate that 0.2% is an optimum level to be included in the diets of broiler in order to replace antibiotic growth promoters.  相似文献   

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In this study, the viral genome extraction performance of automatic nucleic acid extractors and manual nucleic acid extraction kits was compared. We showed that compared with manual kits, the automatic extractors showed superior genome extraction performance using bovine viral diarrhea virus (BVDV) genome-positive cattle sera and bovine coronavirus/infectious bovine rhinotracheitis virus-spiked cattle nasal swabs. In addition, the subgenotyping of BVDV strains detected in Tokachi Province in Japan during 2016–2017 was performed. Results showed that most of these BVDV strains belonged to subgenotype 1b, while few strains belonged to subgenotypes 1a and 2a. This study showed the high applicability of automatic nucleic acid extractors in extracting multiple viral genomes and the dominant subgenotype of BVDV in Tokachi.  相似文献   

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The use of n-3 fatty acids is often recommended to manage pruritus. The purpose of this study was to determine the effect of various doses of n-3 fatty acids at different n-6:n-3 ratios on plasma fatty acids, clinical response and inflammatory mediators in pruritic dogs. After baseline assessment, dogs were randomly assigned to receive diets varying in both total n-3 and n-6 fatty acid dose and n-6:n-3 ratio. The total clinical score decreased significantly in all four diet groups after 8 weeks with no difference between groups. Plasma fatty acid changes generally mirrored the fatty acid content of the test diets, although alterations appeared to depend on both the dose of n-3 fatty acids and the n-6:n-3 ratio. In this clinical trial, which controlled dietary intake of fatty acids, n-3 fatty acid supplementation did not appear to have an added benefit on clinical signs over thorough clinical management.  相似文献   

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Objectives of this study were to compare fatty acid (FA) composition of ruminal bacterial (B) and protozoal (P) cells, and to investigate effect of protozoa on FA profile in the rumen of cattle. Three cows were used to prepare ruminal B and P cells. Four faunated and three defaunated cattle (half‐siblings) were used to study effect of protozoa on ruminal FA profile. Proportions of C16:0 and C18:0 in total fatty acids in B cells were 20.7% and 37.4%, whereas those in P cells were 33.4% and 11.6%, respectively. Proportions of trans‐vaccenic acid (VA) and cis‐9, trans‐11 conjugated linoleic acid (CLA) in B cells were 3.9% and 1.0%, and those in P cells were 5.5% and 1.6%, respectively, being higher in P cells. Proportions of C18:1, C18:2 and C18:3 in P cells were two to three times higher than in B cells. Proportions of unsaturated fatty acids, VA and CLA in B cells of faunated cattle were higher than those of defaunated. VA and CLA in the ruminal fluid of faunated were also 1.6 to 2.5 times higher than those of defaunated. This tendency was similar for cell‐free fraction of ruminal fluid. These results indicate that protozoa contribute greatly in VA and CLA production in the rumen.  相似文献   

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