不同类型开食料对犊牛生长发育和瘤胃发酵的影响

试验旨在研究开食料类型对荷斯坦哺乳犊牛生长发育和瘤胃发酵参数的影响。选取30头刚出生的中国荷斯坦母犊牛,按照体重进行划分区组,随机分配到3个处理组中,各组分别饲喂颗粒状开食料、粉状开食料和口感化开食料。试验共80 d,其中1～50 d为哺乳期,按照正常程序饲喂常乳+自由采食开食料;51～60 d为过渡期,减少常乳饲喂量+自由采食开食料;61～80 d为断奶后期,自由采食开食料。犊牛从出生第7天开始饲喂开食料。每天记录开食料采食量,分别于试验第1天、第50天、第60天和第80天在早晨饲喂前称重犊牛体重,分别于第50天、第60天和第80天在犊牛采食开食料2 h后采集瘤胃液,测定挥发性脂肪酸浓度和NH3-N浓度。试验结果表明,不同物理形态的开食料对犊牛的体重、平均日增重和开食料采食量具有显著影响。给犊牛饲喂口感化开食料和颗粒状开食料显著增加了干物质采食量和平均日增重,以口感化开食料的饲喂效果最佳。给犊牛饲喂不同物理形态的开食料,对瘤胃pH值、乙酸、丙酸和丁酸浓度无显著影响,但是对瘤胃液氨氮浓度和总挥发性脂肪酸浓度具有显著影响。饲喂口感化开食料和颗粒状开食料显著降低了瘤胃液氨氮浓度,增加了瘤胃液总挥发性脂肪酸浓度。因此,在犊牛开食料的选择上,给犊牛饲喂口感化开食料可以提高犊牛生长性能,改善瘤胃发酵功能。     

Effects of supplementation level and particle size of alfalfa hay on growth characteristics and rumen development in dairy calves

The aim of this study was to assess the effects of particle size (PS) of alfalfa hay on growth characteristics and rumen development in dairy calves at two levels of alfalfa supplementation. Fifty newborn dairy calves (42.7 ± 2.2 kg BW) were used in a 2 × 2 factorial arrangement with the factors supplementation level (low, 8%; or high, 16% on DM basis) and PS (medium, 2.92 mm; or long, 5.04 mm as geometrical means) of alfalfa hay. In addition, a control group without alfalfa hay was used. Hence, treatments were: control (C); low level with medium PS (LM); low level with long PS (LL); high level with medium PS (HM) or high level with long PS (HL). Growth performance of alfalfa‐fed calves did not differ from control calves, but alfalfa supplementation decreased corneum thickness of the rumen wall. In alfalfa‐fed calves, post‐weaning starter intake was greater for LL calves than for LM calves. During the entire rearing period, starter intake was 26–32% higher for LL and HM calves than for LM calves. Pre‐weaning average daily gain was higher for LL and HM calves than for HL calves, but this effect was not persistent over the entire rearing period. Final body weight decreased from 86 to 79 kg when the level of long PS alfalfa hay increased from 8 to 16%, but increased from 78 to 87 kg when the level of medium PS alfalfa increased from 8 to 16%. Regardless of PS and level, morphometric characteristics of rumen wall were generally similar among alfalfa feeding groups, but corneum thickness decreased from 8.7 to 6.1 μm with greater PS at the low level. These results indicate that adequate, but not excessive, physical stimulation is required for appropriate rumen development and growth performance of dairy calves.     

Effect of Bacillus subtilis C-3102 supplementation in milk replacer on growth and rumen microbiota in preweaned calves

We aimed to assess the effect of feeding Bacillus subtilis C-3102 on the growth and rumen microbiota in the preweaned calves. Twelve newborn Japanese Black calves were randomly allocated to either the control (n = 6) or the treatment (n = 6) groups in the present study. Calves in the treatment group were offered B. subtilis C-3102 supplemented milk replacer throughout the preweaning period. Rumen fermentation during the first 21 days of life seemed to be slightly suppressed by feeding B. subtilis C-3102. This fermentation shift was probably attributed to the lower abundance of the core members of rumen microbiota until 21 days of age in the calves fed B. subtilis C-3102. However, feeding B. subtilis C-3102 did not influence the abundance of the core members of rumen microbiota at 90 days of age. Distribution of Sharpea spp. and Megasphaera spp., which potentially contribute to low methane production and are regarded as beneficial rumen bacteria, was higher in the rumen of calves fed B. subtilis C-3102 at 90 days of age. These results suggest that B. subtilis C-3102 supplementation in milk replacer could potentially contribute to the improvement of feed efficiency after weaning via the establishment of beneficial rumen bacteria.     

Protein expression in dairy cows with and without subclinical hypocalcaemia

AIM: To determine differences in plasma proteomic profiles between healthy cows and those with subclinical hypocalcaemia within 12 hours after calving, and thereby explore the underlying biological mechanism of subclinical hypocalcaemia in dairy cows.

METHODS: Plasma samples were collected within 6 hours of calving from Holstein cows on a farm in Heilongjiang, China; 32 with subclinical hypocalcaemia (plasma calcium concentration 1.38–2.00?mmol/L and no clinical signs) and 59 control cows (plasma calcium concentration 2.10–2.8?mmol/L). Plasma samples were applied to weak cationic exchange protein chips for protein profiling by surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry (SELDI-TOF-MS), and the data were analysed using the PBS-IIC system. The amplitude of peaks for the two groups were compared using the Wilcoxon sum-rank test, and the mass-to-charge ratio of the peaks that differed was used to identify peptide fragments using the Swiss-Prot protein database.

RESULTS: Seven peaks were identified in the subclinical hypocalcaemia group that differed from those of the control group (p<0.001), that represented six unique proteins. Expression of serum albumin, fibrinogen alpha chain, amyloid beta A4 proteins and neurosecretory protein VGF were increased, and expression of apolipoprotein A-II and serum amyloid A proteins were decreased in the subclinical hypocalcaemic cows compared with control cows.

CONCLUSION: Use of SELDI-TOF-MS technology can effectively identify differences in plasma protein expression patterns in cows with subclinical hypocalcaemia. Neurosecretory protein VGF and amyloid beta A4 protein might represent useful biomarkers for diagnosis of subclinical hypocalcaemia.     

甘露寡糖添加方式对哺乳期犊牛瘤胃细菌菌群结构的影响

为利用16S rDNA技术研究甘露寡糖不同添加方式对哺乳期犊牛瘤胃细菌菌群结构影响,本研究选用出生日龄一致、体重接近、健康状况良好的荷斯坦公犊牛20头,随机分为4组。CR组为对照组,饮用乳及开食料中均不添加甘露寡糖;ORa组在饮用乳中添加5 g甘露寡糖,开食料中不添加甘露寡糖;ORb组在开食料中添加5 g甘露寡糖,饮用乳中不添加甘露寡糖;ORc组在饮用乳及开食料中各添加2.5 g甘露寡糖(混合添加)。应用16S rDNA测序技术,研究了甘露寡糖添加方式对犊牛瘤胃细菌构建的影响。结果表明:甘露寡糖添加方式会影响哺乳期犊牛瘤胃细菌总数,但对哺乳期犊牛瘤胃细菌菌群多样性未产生显著影响(P> 0.05)。在门水平上,与对照组相比,ORb组颗粒料中添加甘露寡糖显著降低了厚壁菌门与放线菌门的丰度(P <0.05),极显著提高了变形菌门的丰度(P <0.01),优势菌门增加为3种,分别为拟杆菌门、厚壁菌门与变形菌门。在属水平上,甘露寡糖不同添加方式导致哺乳期犊牛瘤胃细菌菌群结发生了改变,其中甘露寡糖不同添加方式对小杆菌属和脱硫弧菌属在瘤胃内丰度均产生了影响,但对ORa组与ORc组犊...     

Effect of wheat processing on rumen characteristics and rumen parameters in Holstein‐Friesian calves

In this experiment, effect of wheat processing on rumen conditions and development were investigated. Fifty‐six neonatal Holstein‐Friesian calves (22 male and 34 female) were fed calf starters and post‐weaning diets containing 35 (pre‐weaning) and 21.90% (post‐weaning) popped wheat (PW), steam‐flaked wheat (SFW), dry‐rolled wheat (DRW) or ground wheat (GW) till 12 weeks of age. Calves were weaned at the end of 9th week, and a post‐weaning‐specific starter diets were fed for 1 month. Rumen liquor was analysed in days 30, 60 and 90 of the experiment to determine volatile fatty acids (VFA), pH and ammonia nitrogen concentrations. Twelve male calves (three calves/treatment) were slaughtered, and digestive tract was emptied. Forestomach empty weight and rumen parameters were assessed. Results indicated that calves received PW had the highest total VFA, acetate, propionate, butyrate, ammonia nitrogen, rumen wall thickness, papilla width and density. Calves fed DRW experienced the lowest rumen pH throughout the experiment probably because high proportion of fine particles in GW. Calves consuming PW apparently had more functional rumen in comparison with other groups.     

亚急性瘤胃酸中毒奶山羊瘤胃上皮形态结构和通透性的变化

本试验旨在研究亚急性瘤胃酸中毒(SARA)对瘤胃上皮形态结构和通透性的影响。选用体况良好、体重相近的泌乳期萨能奶山羊9只,随机分为3组(对照组、SARA组、恢复组,n=3),对照组饲喂基础饲粮[非纤维性碳水化合物与中性洗涤纤维比(NFC/NDF)=1.40],SARA组和恢复组先后饲喂NFC/NDF为1.40、1.79、2.31、3.23的4种试验饲粮诱导SARA发生,每种饲喂15 d,恢复组奶山羊待SARA诱导成功后自由采食青干草30 d。对照组奶山羊分别在饲养30、60(与SARA组3只同时)和90 d(与恢复组3只同时)各屠宰1只。采集瘤胃腹囊部上皮组织用于石蜡切片、透射电子显微镜观察及尤斯灌流系统(Ussing chamber)研究。结果表明:1)组织切片结果显示,瘤胃上皮角质层厚度SARA组显著高于对照组和恢复组(P0.05),恢复组显著低于对照组(P0.05);颗粒层厚度对照组显著高于SARA组和恢复组(P0.05),但SARA组和恢复组之间无显著差异(P0.05);棘突层厚度3组之间无显著差异(P0.05);上皮总厚度恢复组显著低于对照组和SARA组(P0.05),但对照组与SARA组之间无显著差异(P0.05)。透射电子显微镜结果显示,SARA组瘤胃上皮紧密连接被破坏,细胞间隙增大,棘状层细胞线粒体出现降解并出现空泡。2)与对照组相比,SARA组和恢复组瘤胃上皮短路电流(Isc)、组织导电性(Gt)和辣根过氧化物酶(HRP)流速显著升高(P0.05),跨膜电位差(PD)显著降低(P0.05)。综合得出,SARA破坏了奶山羊瘤胃上皮形态结构的完整性,使瘤胃上皮通透性增加,导致瘤胃上皮屏障功能长期受损。     

The Effect of Subclinical Hypocalcaemia Induced by Na2EDTA on the Feed Intake and Chewing Activity of Dairy Cows

The effects of induced subclinical hypocalcaemia (SCHC) on feed intake and chewing activity during eating and rumination were studied in dairy cows. Two non-lactating and non-pregnant cows were subjected to three different treatments, with one test per day, such that the plasma free (ionized) calcium (_FCa) concentration was maintained at the eucalcaemic level or at one of two constant SCHC levels. The cows and test days followed a 2×3 crossover design. SCHC was maintained for 7 h by repeatedly infusing 5% Na₂EDTA so that constant _FCa concentrations of 0.8 mmol/L or 0.6 mmol/L in plasma were achieved. Control conditions were achieved by infusing isotonic saline. Feed intake and the number of the rumination periods were recorded during test days. The proportion of feed eaten during each test meal (EatPro) was related to the mean plasma _FCa. An almost linear decrease in EatPro was observed when the plasma _FCa was 0.6–0.9 mmol/L. The cows showed no other clinical signs of hypocalcaemia during Na₂EDTA-infusion. The time spent chewing during eating and rumination, and the number of rumination periods during a test day, decreased with a decline in plasma _FCa concentration.It was concluded that induced SCHC depresses the feed intake and ruminative activity of dairy cows.     

Matricaria chamomilla CH12 decreases handling stress in Nelore calves

Matricaria chamomilla CH₁₂ is a phytotherapeutic or homeopathic product, which has been used to reduce stress. Here, we examined its effect on preventing handling stress in bovines. Sixty Nelore calves were randomly distributed into two equal groups. One group was administered Matricaria chamomilla CH₁₂ in diet and the other the ''control'' was not. Animals in both groups were maintained unstressed for 30 days to adjust to the feeding system and pasture, and were then stressed by constraint on the 31th, 38th, 45th and 60th experimental days. Blood samples were taken on these days after animals had been immobilization in a trunk contention for 5 min. Stress was followed by analyzing serum cortisol levels. These peaked on the 45th day and then decreased, but not to baseline, on the 60th day. On the 45th day cortisol levels were significantly lower in animals fed Matricaria chamomilla CH₁₂, suggesting that this product reduces stress. These effects may be a consequence of its inhibiting cortisol production and its calming and anxiolytic effects.     

Forage and sugar in dairy calves' starter diet and their interaction on performance,weaning age and rumen fermentation

The effects of sugar and forage inclusion in calves' starter and their interaction on animal performance and rumen fermentation parameters were investigated. Twenty‐eight neonatal Holstein male calves 3 days of age with average body weights of 42 ± 4 kg were allocated to four different treatments. All calves were fed a similar basal diet consisting of milk and concentrate. The experimental treatments were: (i) basal diet with no supplementation (Control, hereafter designated by C), (ii) basal diet plus 5% granular sugar cane (Sugar, designated by S), (iii) basal diet plus 5% forage (Forage, designated by F) and (iv) basal diet plus 5% forage with 5% granular sugar cane (F × S). Supplement ingredients were used on a dry matter (DM) basis. Rumen fluid parameters were measured twice on days 35 and 70 of the study period. The calves were weaned when they could consume 1 kg of starter for three consecutive days. The results show that starter intake was not affected by treatment; however, the lowest ADG was observed with calves in the sugar treatment. Weaning age was affected by treatments, and forage showed to reduce milk consumption period down to its shortest. Forage–sugar interaction was found to have no effects on animal performance. The structural body indices as well as the health status of the calves were similar in different treatments. Rumen pH did not differ among the treatment groups. Among the rumen parameters, total VFA concentration and molar proportions of butyrate and propionate did not exhibit any significant differences among the treatments. However, ruminal acetate concentration decreased in calves that fed sugar cane during the early weeks of the study period. Comparison of forage and sugar included in the starter diets revealed that forage reduced weaning age, while sugar cane had a negative effect on calves' performance.     

Peritoneal fluid values and collection technique in young,normal calves

Peritoneal fluid from 10 healthy young male Holstein calves was analyzed three times (2 to 3 days, 12 to 15 days and 27 to 30 days) during the first month of life. A new technique for collection of peritoneal fluid from calves positioned in left lateral recumbency was developed. The technique was found to be reliable and without noticeable complications. Mean peritoneal fluid nucleated cell counts, red blood cell counts, and absolute counts for mononuclear cells, lymphocytes and eosinophils did not change significantly (P 相似文献   

反刍家畜瘤胃及肠道微生物研究进展

反刍家畜瘤胃及肠道微生物处于一个复杂的微生态系统,其多样性及营养代谢与该系统中的各项因素存在紧密联系。了解反刍家畜瘤胃及肠道微生物多样性变化和营养代谢机制,是通过人为干预手段改善动物福利、提高动物生产效率、提升动物产品质量、减少温室气体排放的基础。关于反刍动物瘤胃及肠道微生物多样性及营养代谢与单个环境因子的关系得到了广泛的研究并取得了一些进展,对指导生产实践和保护环境起到了一定作用。综述了近年来国内外反刍家畜瘤胃及肠道微生物多样性,以及微生物与宿主动物、日粮结构、环境因子相互作用及机制方面的研究进展,以期为探索瘤胃及肠道微生物在反刍动物营养代谢中的作用及其机制提供参考。     

Fecal excretion of alcohols and organic anions in neonatal dairy calves

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.     

Fecal D- and L-lactate, succinate and volatile fatty acid levels, and relationships with fecal acidity and diarrhea in neonatal calves

To clarify the significance of fecal organic anions in neonatal diarrhea, a total of 252 fecal samples (91 diarrheic, 161 normal) were collected from 136 dairy calves (including three crossbreds) less than 4 weeks old. Fecal pH, D‐ and L‐lactate, succinate and volatile fatty acid (VFA) were analyzed. In normal feces, lactate was highest and VFA was lowest at week 1 of age, and lactate progressively decreased and VFA progressively increased with advancing age. In diarrheic samples, although higher pH and lower lactate levels were confirmed at week 1, samples at weeks 3–4 showed lower pH and VFA accompanied by higher lactate of D and L‐isomers. In diarrhea, fecal butyrate was significantly lower at all stages, but succinate levels did not differ significantly. The proportion of lactate to organic anions (sum of lactate, succinate and VFA) in diarrheic feces was lower at week 1, and higher in weeks 2–4, while that of VFA to organic anions showed the opposite pattern. Strong relationships were observed between fecal pH and lactate, and VFA proportions in organic anions, though the relationship was weak in diarrhea. Most of the elevated lactate was observed in fecal samples with lower VFA. However, succinate had no relationship with VFA or lactate levels.     

添加烟酸条件下绵羊瘤胃发酵底物降解动力学变化特征

试验用瘤胃液来自3只安装永久性瘤胃瘘管的绵羊,饲喂玉米-豆粕型基础日粮.通过体外试验,添加450 mg/kg烟酸,测定在不同培养时间内培养液中NH3-N浓度、瘤胃细菌N产量、原虫数量、总VFA量及乙酸、丙酸、丁酸产量和乙酸/丙酸值的降解动力学特征.结果表明:添加烟酸可提高培养液NH3-N利用率;培养液中细菌N、原虫数、总VFA量及乙酸、丙酸、丁酸产量随采样时间变化而呈不同的动力学变化趋势;但乙酸/丙酸值则不受采样时间变化的影响,与对照组相比差异不显著(P>0.05).     

分解代谢物控制蛋白A对瘤胃中牛链球菌碳水化合物代谢的调控作用

分解代谢物控制蛋白A(CcpA)是低GC含量的革兰氏阳性菌基因转录的抑制或激活因子,对瘤胃微生物代谢具有调控作用。瘤胃中主要乳酸产生菌——牛链球菌(S.bovis)中的CcpA与磷酸转移酶系统(PTS)有着密切关系,对碳源次序代谢利用及碳水化合物代谢的多种关键酶具有重要的调控作用。本文综述了有关CcpA对S.bovis碳水化合物的代谢调控的研究进展,旨在为后期进一步研究S.bovis代谢产酸机制、防控反刍动物瘤胃酸中毒提供思路和参考。     

不同长链脂肪酸组合对体外瘤胃细菌发酵和群体结构的影响

本试验旨在研究不同长链脂肪酸组合对体外培养瘤胃细菌发酵和群体结构的影响。以3头瘤胃瘘管奶牛提供瘤胃液,对照(A)组底物含5%脂肪酸钙,试验组培养底物中硬脂酸、油酸、亚油酸和亚麻酸的含量分别为1.5%、1.0%、0.5%和1.5%(B组),1.5%、1.0%、1.5%和1.0%(C组),1.0%、1.5%、1.5%和0.5%(D组)以及1.5%、0.5%、0.5%和1.0%(E组)。在培养后0、3、6、12、18、24 h采集培养液,测定p H、氨氮浓度和瘤胃细菌含量。结果表明:1)培养液p H在组间的差异不显著(P0.05);C组的培养液氨氮浓度显著高于B、D组(P0.05)。2)除白色瘤胃球菌,其他菌属含量在组间存在显著差异(P0.05)。其中琥珀酸拟杆菌、生黄瘤胃球菌、蛋白溶解梭菌和嗜淀粉瘤胃杆菌含量在B组较高;C组溶纤维丁酸弧菌、埃氏巨球菌、降解淀粉瘤胃球菌以及瘤胃总细菌含量显著高于其他各组(P0.05)。培养液埃氏巨球菌含量最高,为优势菌。综合得出,脂肪酸组合对瘤胃总细菌和大部分细菌种属含量有显著影响,这与发酵模式有关。     

构树在肉牛瘤胃中降解特性的研究

为使构树能够作为非常规饲料用于反刍动物养殖生产中,以3头安装有永久瘘管的24月龄安格斯肉牛为试验动物来探究构树在瘤胃中的降解特性和营养价值,使用瘤胃尼龙袋法测定构树的叶、去叶枝条、125~135 cm及145~155 cm高全株构树在瘤胃内的降解率和降解参数并计算瘤胃能氮平衡参数。结果表明:1) 叶的粗蛋白质(CP)水平高达23.18%,显著高于其他3种形态构树(P<0.05),全株构树的CP含量显著高于去叶枝条(P<0.05),而酸性洗涤纤维(ADF)则呈现相反规律,其中125~135 cm全株ADF含量低于145~155 cm全株(P>0.05);2) 叶的干物质(DM)、有机物(OM)、CP和ADF的有效降解率(ED)均显著大于125~135 cm和145~155 cm全株(P<0.05),三者又均显著大于去叶枝条(P<0.05),四者DM的ED均在40%以上,叶为65.82%;3) 叶的瘤胃降解蛋白(RDP)与过瘤胃蛋白(RUP)之比显著高于其他3种形态构树(P<0.05),说明叶的RDP含量高于RUP含量,而其他3种形态构树RUP含量高于RDP含量;4) 叶的瘤胃能氮平衡值(RENB)为负(-22.27 g·kg^-1),去叶枝条、125~135 cm及145~155 cm全株的RENB为正,分别为28.79、30.87和27.74 g·kg^-1。结论:4种形态构树的营养价值依次为叶>125~135 cm全株>145~155 cm全株>去叶枝条。其中,构树叶可作为蛋白质饲料使用,其他3种形态构树可以粗饲料的形式使用,4种形态构树均有成为优质饲料资源的潜力,但是在使用时应注意保持能氮平衡。     

Blood biochemical values in Japanese Black calves in Kagoshima Prefecture,Japan

To obtain blood biochemical basic data of Japanese Black calves in Kagoshima Prefecture, Japan, blood sampleswere obtained from 582 clinically healthy calves on 27 farms. Calves were divided into three stages: thesuckling stage (between 14 and 90 days of age, n=191), the early growing stage (between 91 and 180 days ofage, n=200) and the late growing stage (between 181 and 270 days of age, n=191). The mean concentration oftotal cholesterol, triglyceride, nonesterified fatty acids, calcium and zinc, and the mean activities ofγ-glutamyltransferase and alkaine phospatase in the suckling stage were significantly higher than those in theearly and late growing stages (P<0.01). The mean concentration of total protein, albuminand globulin increased gradually with growing. The mean concentration of beta-hydroxybutyrate in the sucklingstage was below 150 µmol/l, however, it elevated above 400µmol/l in the early and late growing stages. The mean concentration ofcopper concentration was above 70 µg/dl in all stages. The meanconcentration of zinc was between 90 and 110 µg/dl in all stages. Theseresults suggest that the blood biochemical values of Japanese Black calves vary with growing stages, and theblood parameters obtained in this study are considered useful as indices for health management of JapaneseBlack calves.