不同季节高寒草甸牧草瘤胃发酵特性和体外消化率分析

本文旨在探讨不同生育时期高寒草甸牧草的牦牛瘤胃体外发酵参数及CH₄产量。通过测定返青期、青草期和枯草期3个生育时期牧草的营养品质、瘤胃发酵参数和CH₄产量。结果表明：青草期牧草总能（Gross energy，GE）、粗蛋白（Crude protein，CP）和粗脂肪（Ether extract，EE）等均显著高于返青期和枯草期（P<0.05）；青草期牧草在各发酵时间点的体外干物质消化率（Dry matter digestibility，DMD）、粗蛋白消化率（Crude protein digestibility，CPD）和有机物质消化率（Organic matter digestibility，OMD）均显著高于返青期和枯草期（P<0.05）；青草期牧草12，24和48 h瘤胃NH₃-N、乙酸、丙酸、异丁酸、丁酸和异戊酸含量显著高于返青期和枯黄期（P<0.05）；不同发酵时间牧草总产气量和CH₄产量变化规律为：返青期>青草期>枯草期。综上所述，青草期草地生物量最高，牧草营养品质和体外消化率最高，CH₄排放最低，瘤胃发酵模式最优。建议选择青草期牧草放牧。     

营养菌剂对枯草期和青草期绵羊的增重试验

用自制的营养菌剂在枯草期和青草期对青海省湖东种羊场的种羊和土种羊分别进行灌服试验，１５ｄ灌服１次，枯草期灌服８次，青草期灌服７次，每次每只羊５ｍｌ，结果表明，在枯草期，种羊试验组平均增重４．０３ｋｇ，对照组增重３．１４ｋｇ，土种羊试验组平均增重０．０１ｋｇ，对照组增重－１．２１ｋｇ；在青草期，种羊试验组平均增重４．１５ｋｇ，对照组增重３．４０ｋｇ，土种羊试验组平均增重１．７２ｋｇ，对照组增重１．３     

二郎山白山羊春季牧食行为的研究

1997年春季在内蒙古乌盟察右前旗测定了二郎山白山羊的牧食行为，包括昼夜行为活动节律，采食和饮水、反刍、排泄行为等。测定结果表明：二郎山白山羊的适应性较强，昼夜行为活动以卧息时间最长，其次为采食和反刍时间。采食量亩136公斤干草。昼夜反刍时间为276.22分，反刍周期数为19.50个，重天食团数为255个，每个食团咀嚼的平均次数和时间分别为46.83次和40.34秒，夜间的反刍周期数和反刍时间均多于白天，昼夜排粪次数为6.17次，排粪量0.80公斤，排尿次数为5.17次。     

放牧绵羊行为生态学研究：Ⅲ不同放牧时期对放牧绵羊牧食行为的影响

在较低放牧率和限牧时间条件下，不同放牧时期对绵羊牧食行为的影响有：（１）当放牧时间缩短时，绵羊通过缩短反刍行为的时间而保持采食时间的相对稳定，并通过调整各采参数数以保持进食速率和日采食量的相对稳定，对饮水行为影响不大；（２）９月份反刍周期数和总反刍食团数量少，反刍时间最短；６月份每个食团咀嚼次数最少，咀嚼时间最短；（３）７月份排尿次数量多，每次排尿时间最长；９月份居中；６月份量少。排粪行淡差异不显     

不同物候期牧草对放牧牦牛瘤胃内环境参数及瘤胃微生物多样性的影响

本试验在测定不同物候期牧草营养价值的基础上,研究不同物候期牧草对放牧牦牛瘤胃内环境参数及瘤胃微生物多样性的影响。分别于返青期、青草期和枯草期采集牧草样品,测定牧草常规营养成分含量。选取平均体重为(108.06±2.86) kg的10只3岁全年放牧的健康青藏高原牦牛(公母各5只)进行序号标记,分别在返青期、青草期和枯草期清晨放牧前空腹经口腔采集瘤胃液,用于分析瘤胃内环境参数和瘤胃微生物多样性。结果显示:牧草中粗蛋白质含量在青草期显著高于返青期和枯草期(P0.05),中性洗涤纤维含量在枯草期高于青草期和返青期(P0.05)。瘤胃液氨态氮、乙酸、异丁酸、丁酸、总挥发性脂肪酸含量均在青草期最高;瘤胃液总挥发性脂肪酸含量在枯草期显著低于青草期和返青期(P0.05)。不同物候期牧草对瘤胃微生物多样性有影响,青草期瘤胃微生物多样性及丰富度最低。拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)及普雷沃氏菌属1(Prevotella_1)的相对丰度在3个物候期均较高;青草期厚壁菌门的相对丰度显著高于返青期和枯草期(P0.05);在种水平上,瘤胃微生物以纤维素降解菌为主。由此得出,不同物候期牧草常规营养成分含量存在差异,不同物候期牧草常规营养成分含量的变化引起了牦牛瘤胃内环境参数和瘤胃微生物多样性的变化;青草期瘤胃液氨态氮及总挥发性脂肪酸含量最高,在枯草期瘤胃液总挥发性性脂肪酸含量下降,能量源减少,因此在枯草期应对放牧牦牛进行补饲才能保证牦牛生长。     

三河牛成年乳牛放牧行为的研究

采取２４小时昼夜跟踪观测的方法，对６头身体健康，年龄在５￣８岁的成年乳牛，连续观测其在放牧条件下的采食、饮水、反刍、游走、休息、排粪、排尿等行为。结果表明，三河牛成年乳牛一昼夜（２４小时）的采食时间平均为８．４２小时，饮水时间０．１８小时，反刍时间８．３８小时，休息时间４．７２小时，游走时间２．０５小时，排粪、排尿１４次，挤奶时间０．２５小时。     

不同泌乳时期荷斯坦奶牛的行为观察

选用健康无病的奶牛12头（其中泌乳盛期4头,泌乳后期4头,干奶期4头）。按泌乳期分为3组。对各组奶牛逐头进行连续48h行为学观察。结果表明：牛夜间反刍时间（周期数）都比昼反刍时间（周期数）长（多）。泌乳盛期奶牛的总采食时间、反刍时间、采食咀嚼速度比泌乳后期和干奶期奶牛长（快）（P〉0．05）。饲后反刍开始时间泌乳后期最短,而干奶期最长。泌乳盛期奶牛饮水次数远比泌乳后期、干奶期多（P〈0．01）,排粪次数也多（P〈0．05）,排尿次数盛期牛与后期牛接近,但比干奶期牛多2次／d。干奶期牛的卧地时间最长,泌乳盛期牛次之,泌乳后期牛最短,但卧地次数泌乳盛期比后期、干奶期分别多4．13次和3、63次。这些行为的差异可为处于不同泌乳时期的荷斯坦奶牛提供适宜的饲养环境,制定科学的管理制度提供可靠的依据。     

不同物候期牧草对藏系绵羊血清生化指标、瘤胃内环境参数及瘤胃微生物功能菌群的影响

本试验旨在研究不同物候期牧草对藏系绵羊血清生化指标、瘤胃内环境参数及瘤胃微生物功能菌群的影响。分别于高寒草甸返青期、青草期和枯草期采集牧草样品,测定常规营养成分含量。选取体重为(34.08±2.94) kg的10只4岁全年放牧的藏系母绵羊,用耳标进行标记,分别于返青期、青草期和枯草期清晨放牧前空腹进行颈静脉采血及瘤胃液采集,用于分析血清生化指标、瘤胃内环境参数及瘤胃微生物功能菌群。结果表明:1)青草期牧草粗蛋白质和粗脂肪含量显著高于返青期和枯草期(P0.05),而枯草期牧草酸性洗涤纤维含量显著高于其他2个时期(P0.05),中性洗涤纤维含量显著高于返青期(P0.05)。2)血清中甘油三酯、低密度脂蛋白和生长激素含量随物候期推移无显著变化(P0.05)。枯草期血清总蛋白、白蛋白含量和谷丙转氨酶活性显著低于返青期和青草期(P0.05)。3)藏系绵羊瘤胃液氨态氮、乙酸、异丁酸、戊酸含量及丙酸比例均在青草期最高,乙酸比例在枯草期最高,乙酸/丙酸在枯草期显著高于返青期和青草期(P0.05)。4)宏基因组测序结果表明,放牧藏系绵羊瘤胃微生物相对丰度最高的是细菌,约占总微生物含量的70%,其次是真菌(20%),剩余是未注释到的微生物(10%)。其中,瘤胃液中主要纤维素分解菌为栖瘤胃普雷沃氏菌、白色瘤胃球菌和产琥珀酸丝状杆菌,其相对丰度均在枯草期显著高于返青期和青草期(P0.05),淀粉分解菌、反刍兽新月单胞杆菌的相对丰度在青草期显著高于其他物候期(P0.05)。由此得出,不同物候期牧草营养成分含量变化引起藏系绵羊血清生化指标、瘤胃内环境参数、瘤胃微生物功能菌群的变化;冷季(返青期和枯草期)因血清中总蛋白、白蛋白、球蛋白、葡萄糖及瘤胃挥发性脂肪酸含量低,导致藏系绵羊潜在的抵御疾病能力弱,可利用能量源少,因此在返青期和枯草期应对放牧藏系绵羊进行合理补饲提高藏系绵羊生长性能。     

不同物候期放牧牦牛采食量的研究

本试验以１．５岁及２．５岁阉牦牛各８头，首先在舍饲条件下，用称重法、校正称重法及４Ｎ－ＡＩＡ法测定的结果与实际采食量作对比，结果表明：校正称重法的测定结果与实际采食量差异不显著（Ｐ＞０．０５），４Ｎ－ＡＩＡ法有污染问题，但与实际采食量相关性很好，ｒ＝０．９０。然后在全放牧条件下（高山草甸草地），测定不同物候期放牧牦牛日消耗量（无效失重）、日采食量。结果表明：２岁、３岁牦牛日消耗量分别为２．３６７，３．２６２ｋｇ／ｄ·头，青草期、枯黄期、枯草末期、返青期的日采食量，２岁牦牛依次为３．９２，３．７２，５．５４，６．８２ｋｇ／ｄ·头；采用食道瘘管法采集牧草样品，使用粪尿袋收集粪尿，效果较好。     

播种比例,施氮量和刈割期对混播草地牧草产量和质量的影响

１９９８年４￣９月在华北农牧交错带的承德地区鱼儿山牧场进行了不同播量、施氮量和不同刈割期对燕麦＋箭舌豌豆混播人工草地牧草产量和品质影响的研究。结果表明,不同播种比例间的牧草产量除第三刈割期外差异显著（Ｐ〈０．０５）;不同播种比例间粗蛋白质、ＤＮＦ含量差异显著（Ｐ〈０．０５）,ＡＤＦ含量差异不显著（Ｐ〉０．０５）。     

冬春枯草期牦牛口服营养菌剂效果观察

用上５株活菌组成的营养菌剂口服牦牛后观察其增重效果。试验结果：冬春枯草季节，每隔半月口服菌剂１次，试验组平均增重－０．６２ｋｇ，对照组平均增重－５．４９ｋｇ，试验组比对照组少减重４．８７ｋｖ，差异显著，表明应用菌剂可减少冬春枯草季节放牧牦牛的体重下降。     

Monitoring cow comfort and rumen health indices in a cubicle-housed herd with an automatic milking system: a repeated measures approach

Background

Cow rumination and lying behaviour are potentially useful and interrelated indicators of cow health and welfare but there is conflicting evidence about how reliable these measures are. The objective of this study was to quantify the variation of indices of cow comfort and rumen health in a herd with an automatic milking system for which husbandry was relatively constant, in order to propose an alternative approach to optimising the use of these indices when continuous monitoring is not available. During a period of 28 days, standing index, cud chewing index and rumination index were observed.

Results

The daily mean standing index ranged between 9.0 and 18.0 per cent, cud chewing index between 43.5 and 74.0 per cent, and rumination index between 49.0 and 81.0 per cent. The point of lowest variation in the indices was determined as that with the lowest coefficient of variation. The coefficient of variation was lowest for data collected between 240 and 270 minutes after refreshing of the bedding material on the cubicles for both the standing index and rumination index, and for data collected between 120 and 150 minutes after refreshing of the bedding material on the cubicles for the cud chewing index.

Conclusions

In spite of relative constant husbandry practices in a herd with an automatic milking system, the variation in the standing index, cud chewing index and rumination index was still considerable. This suggests these measures should be repeated on several consecutive days, according to population size and wanted margin of error, to be representative and useful.     

Behavior of sheep fed babassu cake (Orbygnia speciosa) as a substitution for elephant grass silage

This study aimed to evaluate the behavior of sheep fed babassu cake as a substitution for elephant grass silage. The experiment was conducted at the Federal Rural University of Amazonia (Universidade Federal Rural da Amazônia ‐ UFRA), Brazil, using 45 sheep housed in individual stalls, with unlimited access to feed and distributed in a completely randomized design with five treatments (0, 12.5, 25, 37.5 and 50% inclusion of babassu cake) and nine replications. All of the treatments contained a roughage‐to‐concentrate ratio of 40:60. No differences were observed in the time spent feeding (P > 0.05), regardless of the source of roughage used. However, there was a reduction in the time spent in rumination (P < 0.05) and an increase in time spent idling (P < 0.05) when babassu cake was included in the diet. Although there was a reduction in the time spent chewing the ruminal bolus (P < 0.05), the total daily chewing time was the same for all animals (P > 0.05). However, the sheep fed babassu cake showed higher feeding and rumination efficiency (P < 0.05). Therefore, the substitution of elephant grass silage with babassu cake can be performed at up to 50% without compromising the total time spent eating and chewing, which allows increased feeding and rumination efficiency.     

Nutritive value of selected grasses in North Sumatra, Indonesia

The nutritive values of seven native grass species collected in North Sumatra, Indonesia, during dry and rainy seasons were evaluated. The chemical composition, in vitro dry matter digestibility (IVDMD), in vitro organic matter digestibility (IVOMD), in vitro crude protein digestibility (IVCPD), macro mineral concentrations of calcium, phosphorus and magnesium, in vitro gas production profile and metabolizable energy (ME) content of the grasses varied greatly among species and seasons. The crude protein content ranged from 6.6 (Andropogon gayanus) to 16.2% dry matter (Cynodon plectostachyus) in the rainy season, with a significant (P < 0.05) reduction in the dry season. Data on the fiber fraction showed that the grasses contained more neutral detergent fiber (NDF) and acid detergent fiber (ADF) in the dry season and it significantly (P < 0.05) decreased in the rainy season, except for Panicum maximum and Pennisetum purpureum for NDF content and C. plectostachyus, P. maximum and Brachiaria decumbens for ADF content. Data on the mineral concentration showed that C. plectostachyus in the dry and rainy seasons had a higher calcium content than those of other species. The overall means of the seven grasses for IVDMD, IVOMD and IVCPD were significantly higher (P < 0.05) in the rainy season than in the dry season. The in vitro gas production and ME concentration were numerically higher in the rainy season than in the dry season. In conclusion, the nutritive value of the observed grasses in North Sumatra was relatively higher during the rainy season compared with the dry season. Among the species of grass, P. purpureum and C. plectostachyus had a higher nutritive value in both the dry and rainy seasons.     

乌骨山羊生活习性与行为的初步研究

在自由放牧条件下对乌骨山羊的生活习性与行为进行观察记录。结果表明,在放牧时间内,乌骨山羊每天平均采食时间212 min,游走时间58 min,反刍时间113 min,每次反刍的咀嚼次数54.21次、每次时长56.39s,排粪次数6.25次、每次8.69s,排尿次数8.75次、每次9.77s。表明乌骨山羊对南方山区的适应性强、食性广、采食能力强,适于山区放牧饲养。     

The assessment of the frequency of chews during rumination enables an estimation of rumination activity in hay-fed sheep

The objective was to assess rumination behaviour and, more specifically, the intra-individual and inter-individual variation of the frequency of chews during rumination (per min) in five Blackhead sheep fed hay at a level of 100% maintenance (experimental period [EP] I), 50% maintenance (EP II) and ad libitum (EP III). Animals ruminated in EP II less (416 min/day) than in EP I and III (558 and 592 min/day, respectively). Mean inter-individual coefficents of variation (CV) of frequency (defined as number of chews/duration of chewing per cycle) were 12.5%, mean intra-individual CV were 2.5%. The respective CVs for the duration of rumination per day were 8.1 and 9.7%, respectively. The level of intake influenced the frequency of chews significantly. It is concluded that the frequency of chews has to be considered in studies investigating chewing behaviour of ruminants. Under the experimental conditions investigated, number of chews during rumination per day could be estimated by the frequency of chewing with nearly the same precision as by using the duration of rumination per day.     

Effect of Soaking on Nitrate Concentrations in Teff Hay

Soaking can affect respirable dust particles and the concentrations of some nutrients in alfalfa and cool season grass hays. However, the effect of soaking on nitrates in hay has not been reported. The aim of this study was to evaluate the effects of soaking on teff hay, a warm season annual grass, that contained high concentrations of nitrate (>2.0%). Six bales of teff hay were used for the study. Six 0.5 kg samples were taken from each bale and assigned to one of six soaking treatments: no soaking (control), cold water immersion for 10 seconds, warm water immersion for 10 seconds, cold water soaking for 1 hour, warm water soaking for 1 hour, and cold water soaking for 8 hours. After soaking, hay was dried, ground, and submitted to a commercial laboratory for analysis. Data were analyzed by analysis of variance as a block design. When the main effect of treatment was significant (P < .05), means were separated by Tukey's honest significant difference test. Soaking for 1 or 8 hours decreased water-soluble carbohydrate (P < .0001). Phosphorus, potassium, sodium, and zinc concentrations were reduced by soaking for 1 hour or longer (P, K, Na: P < .0001; Zn: P = .003). Nitrate concentrations were reduced (P < 0.05) to safe levels for horses (≤0.5%) by soaking hay for 1 hour or longer but soaking also reduced the concentrations of some nutrients in the hay. Minimal differences were observed between cold and warm soaking temperatures.     

Intake of direct cut or wilted grass silage as related to chewing behavior, ruminal characteristics and site and extent of digestion by heifers

Six nonpregnant Friesian heifers (516 kg avg BW) with ruminal and duodenal cannulas were used to examine intake of direct cut (DC) or wilted (W) grass silage in relation to chewing behavior, ruminal characteristics and site and extent of digestion. Dry matter content of the silages was 20.3% and 40.3%, and feed intake averaged 1.88% and 2.17% of BW (P less than .01), respectively. Mean ruminal osmolality was 291 mosm/liter for the DC and 318 mosm/liter for the W silage (P less than .05), with extreme values exceeding 350 mosm/liter for the W silage at 1 h to 2 h postfeeding. There was a shift from eating to ruminating on W silage associated with a longer duration of the average rumination bolus cycle (P less than .01). Duration of chewing time per kilogram of DM intake was 103.5 min and 91.7 min (P less than .05) for the DC and W silages, respectively. Fecal mean particle length was 2.2 times greater (P less than .01), accompanied by higher spread coefficients (P less than .001), for the W silage. No differences occurred between silages in ruminal digestibility of OM and NDF. In the total digestive tract, apparent digestibilities of OM and NDF were depressed after wilting grass prior to ensiling (P less than .01), but the proportion of digestible OM apparently digested in the rumen was .74 for both silages.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dietary grain source and oil supplement: Feeding behavior and lactational performance of Holstein cows

Effects of grain source and dietary oil supplement on dry matter intake (DMI), feeding, chewing behavior, and production performance of lactating dairy cows were evaluated using eight multiparous Holstein cows (77±22.1 days in milk; mean±SD) in a duplicated 4×4 Latin square design with a 2×2 factorial arrangement of treatments. Experimental diets contained either ground barley or ground corn supplemented with either fish oil or soybean oil at 2% of dietary dry matter (DM). Geometric mean particle size of dietary treatments was 4.1 mm. Dry matter intake tended (P=0.09) to be greater for barley- vs. corn-based diets (23.2 vs. 22.3 kg/d), but was reduced for the fish oil compared to soybean oil supplemented diets (21.1 vs. 24.3 kg/d; P<0.001). This reduction in DMI was attributed to smaller meal size (1.24 vs. 1.55 kg of DM; P=0.004) and slower eating rate (0.082 vs. 0.098 kg of DM/min; P<0.001) for fish oil compared to soybean oil supplemented diets. Main treatment effects interacted (P=0.005) for DMI of particles retained on 19 mm sieve but not for sorting index. Eating rate (0.090 kg of DM/min) was similar between barley- and corn-based diets, however, rumination time was greater for barley- compared to corn-based diets as result of longer rumination bout duration (32.5 vs. 28.5 min/bout; P=0.01). Barley- compared to corn-based diets increased total chewing time by 71 min (709 vs. 638 min) for cows fed fish oil, but not for cows fed soybean oil. Grain source did not affect milk yield or milk composition. Compared to soybean oil, fish oil negatively affected milk yield (40.4 vs. 43.4 kg/d; P=0.01), and thereby, both milk fat (0.91 vs. 1.26 kg/d; P<0.001) and protein (1.23 vs. 1.33 kg/d; P=0.007) production. However, feed efficiency (milk yield/DMI) was greater in fish oil compared to soybean oil supplemented diets (1.94 vs. 1.80; P=0.003). Results indicated that grain source and oil supplement can interact to affect feeding and chewing behavior, but not lactational performance of lactating cows.     

Results of chewing and ruminant activity of cows fed rations of cereal straw of various physical forms and after chemical treatment with sodium lye]

3 trials were conducted with adult cows. The animals received different types of coarse fodder (straw, lucerne) which was subjected to chemical treatment (liquid NaOH) and mechanical treatment (pelleting, wafering); then, the chewing and ruminating activity of the cows was measured. Different criteria were used, i.e. movements of the jaws during food intake and rumination and number of regurgitated bits of food. On the average, one movement of jaws lasted 0.94 sec. and swallowing and regurgitation took 5.5 sec. From this, the duration of the rumination process was determined. No differences in ruminating activity were found between lucerne and chopped/chaffed food while the the case of wheat straw about 30% of additional ruminating activity was performed in comparison with pelleted lucerne and chaffed food. This structural effect was even a bit more pro nounced when the straw was first ground and then wafered. Preceding chemical treatment of the straw with liquid NaOH reduced the ruminating activity in the case of chopped food by 53%, with pellets by 40% and with straw pressed into blocks by 62%. The finess of the feed was in no case found to be related to rumination activities, while hardness of the food particles as well as physical and chemical treatment of the food had an importent influence on the rumination activity.