藏东南河谷型绵羊舍饲和放牧行为的观察

通过对藏东南河谷型绵羊放牧行为的观察发现,全天放牧时间450min,其中游走68min,占15.22%;采食328min,占75.1%,休息36min,占8.35%.对藏东南河谷绵羊舍饲行为观察结果表明,昼夜24h中,采食293.8min,占20.4%;反刍398.0min,占27.6%;站立290.9min,占20.2%,卧息453.6min,占31.5%,饮水4.3min,占0.3%.在放牧条件下,用计数法估测得绵羊的采食量为2.79kg,在舍饲条件下,日采食量为5.4kg,折算成风干物质分别为0.47和0.92kg,风干物质分别占活重的1.74%和3.41%.     

藏山羊舍饲和放牧行为的观察

对藏山羊放牧行为进行观察，发现全天放牧时间480分钟，其中游走82分钟，占16．15％；采食335分钟，占71．47％；休息42分钟，占9．14％。对藏山羊舍饲行为观察结果表明，昼夜24小时，采食290．1分钟，占27．09％；反刍487．60分钟，占33．86％；站立219．16分钟，占15．22％；卧息339．55分钟，占23．58％；饮水3．6分钟，占0．35％。在放牧条件下，用计数法测得绵羊的采食量为2．07kg，在舍饲条件下，日采食量为3．96kg，折算成风干物质分别为0．37kg和0．72kg,风干物质分别为活重的2．31％和4．50％。     

湘东黑山羊舍饲和放牧行为的观察

通过对湘东黑山羊放牧行为观察发现：全天放牧时间420分钟,其中游走81分钟,占19.29%;采食262分钟,占62.38%;休息77分钟,占18.33%.对湘东黑山羊舍饲行为观察结果表明：昼夜24小时中,采食353.8分钟,占24.57%;反刍236.7分钟,占16.44%;站立369.3分钟,占25.65%;卧息480.2分钟,占33.34%.在放牧条件下,用计数法估测得山羊的采食量为2.01 kg;在舍饲条件下,日采食量为3.85 kg,折算成风干物质分别为0.36和0.69 kg,风干物质采食量放牧与舍饲分别占活重的1.92%和3.70%.     

山羊舍饲和放牧行为的观察

通过对马头山羊放牧行为观察发现：全天放牧时间４２０ｍｉｎ，其中游走５５ｍｉｎ，占１３．１０％；采食２７６ｍｉｎ，占６５．７１％；休息８９ｍｉｎ，占２１．１９％。对马头山羊舍饲行为观察结果表明：昼夜２４ｈ中，采食３６２．６ｍｉｎ，占２５．１８％；反刍２４０．８ｍｉｎ，占１６．７２％；站立３６５．２ｍｉｎ，占２５．３６％，卧息４７１．４ｍｉｎ，占３２．７４％。在放牧条件下，用计数法估测得山羊的采食量为２．１３ｋｇ，在舍饲条件下，日采食量为４．０５ｋｇ，折算成风干物质分别为０．３８和０．７３ｋｇ，风干物质采食量分别占活重的１．９２％和３．７０％。     

藏绵羊后备母羊四季放牧采食量研究

为了探讨藏绵羊后备母羊四季放牧干物质采食情况,试验采用饱和烷烃法对藏绵羊后备母羊四季放牧采食量进行了测定。结果表明:藏绵羊后备母羊春、夏、秋、冬四季放牧干物质日采食量分别为1.27 kg±0.29 kg、1.09 kg±0.18 kg、1.24 kg±0.24 kg和0.20 kg±0.03 kg,相对放牧干物质采食量分别为4.13%、3.77%、3.41%和0.89%。其中,春季干物质采食量最高,显著高于夏季(P0.05),极显著高于冬季(P0.01),与秋季的采食量接近(P0.05);冬季干物质采食量最低,与春、夏、秋三季采食量比较,差异极显著(P0.01)。提示冬季应该对羊群进行有效补饲。     

山羊舍饲和放牧行为的观察

通过对马头山羊放牧行为观察发现，全天放牧时间４２０ｍｉｎ，其中游走５５ｍｉｎ，占１４．６１％；采食２７６ｍｉｎ，占７０．８３％；休息８６ｍｉｎ，占１４．５６％。对马头山羊舍饲行为观察结果表明，昼夜２４ｈ中，采食３６２．６ｍｉｎ，占２５．１８％；反刍２４０．８ｍｉｎ，占１６．７２％；站立３６５．２ｍｉｎ，占２５．３６％；卧息４７１．４ｍｉｎ，占３２．７％。在放牧条件下，用计数法估测得山羊的采食量为２．１３ｋｇ，在舍伺条件下，日来食量为４．０５ｋｇ，折算成风干物质分别为０．３８和０．７３ｋｇ，风干物质采食量分别占活重的１．９１％和３．６７％。     

中国美利奴初产母羊采食量与消化率的测定

为测定放牧条件下母羊在不同生理时期（妊娠、哺乳）的采食量和对日粮的消化率,采用了下述3种方法：①利用枯草期放牧绵羊干物质采食量高于合饲绵羊25％的关系,根据24只妊娠后期和20只哺乳前期母羊分别进行各12天的舍饲消化试验所测得的干物质采食量,得出在放牧条件下平均体重46．54kg的妊娠后期中国美利奴母羊每日来食干物质1．47kg,占体重的3．16％,占代谢你重W0.75的8．25％;平均体重39．4kg的哺乳前期母羊（哺单羔）每日采食1．93kg,占体重的4．90％,占W0.75的12．24％。②利用内源指示剂（不溶于4N─HCl灰分即AIA）和外源指示剂（Cr2O3）相结合的方法对6只妊娠前期和6只哺乳后期母羊分别进行了12天放牧条件下的消化试验,测得平均体重36．43kg妊娠前期中国美利奴母羊每日采食干物质1．38kg,占体重的3．79％,占W0.75的9．31％;平均体重43．57kg的哺乳后期母羊每日采食干物质1．74kg,占作重的3．99％,占W0.75的10．25％。在正常放牧条件下直接测得妊娠前期（11月份）母羊日粮干物质中（包括放牧采食和补饲草料）粗蛋白含量为9．87％时,日粮中粗蛋白和总能消化率分别是55．44％和66．84％;哺乳后期放牧母羊（4月份）日粮干物质中粗蛋白含量为11．57％时,日粮粗蛋白和总能消化率分别是     

放牧绵羊牧食行为及采食量研究

在锡林郭勒草原对三种放牧绵羊(蒙古羊、引种羊、杂种羊)进行不同月份的牧食行为观察及采食量测定,结果表明:放牧绵羊9月份的采食时间比例均高于8月份;沙质草地放牧绵羊的采食和游走时间比例低于高平原草地;蒙古羊、引种羊和杂种羊沙质草地的平均采食量分别为1.15kg/d、1.60kg/d和1.35kg/d,高平原草地为1.56kg/d、1.82kg/d和1.71kg/d,分别相差0.41kg/d、0.22kg/d和0.36kg/d。     

牧草枯黄末期放牧藏羊采食量的测定

放牧家畜采食量的测定远比舍饲条件下困难得多。但是测定高寒草场放牧家畜的采食量是确定其补饲补氮的重要依据，是制定其营养成分绝对需要量的基本技术。为了探讨家畜在枯草末期草场的营养获得，确保家畜在正常年景的安全过冬，我们于1999年4月在青海省祁连县多隆乡进行了藏系绵羊放牧采食量的测定工作。     

放牧绵羊行为生态学研究：Ⅳ.放牧绵羊白天主要牧食行为参数间的关系和变化

试验结果表明，在较低放牧率条件下，采食时间、进食速率和采食量相对稳定；采食口数和采食速度随放牧时期的推移而减少，每口采食量有所增大；采食口数、采食速度和每步采食口数均与每口采食量呈负相关；每步采食口数与采食速度呈高度正相关，其回归方程为ｙ∧＝６．１１８１＋４．５５２１ｘ（ｒ２＝０．８１＊＊）；各放牧时期基本上都有３个进食率峰值，且上午进食量只占全天采食量的１／３～１／２，所占比例随放牧时期推移而增大；不同放牧率的研究结果也有类似的关系。     

甘南藏羊高寒牧区冷季补饲育肥试验

高寒地区,生态环境恶劣,牧草生长缓慢、生长期短,草地过牧等因素是导致牧草缺乏,放牧藏羊生长缓慢,出栏率低的重要原因之一。在冷季分别对牧区、半农半牧区的架子羊开展不同方式的补饲育肥。结果表明,"放牧+精料"试验组比对照组体重少减少7.47 kg,"放牧+舔砖+干草"试验组比对照组体重少减少5.97 kg。"放牧+精料+暖棚"试验组比对照组体重少减少8.26kg;"放牧+舔砖+干草+暖棚"试验组比对照组体重少减少6.79 kg;"放牧+舔砖+干草+精料+暖棚"试验组比对照组体重少减少11.6 kg。五个试验组中以有暖棚设施补饲效果最好。说明甘南高寒牧区,暖棚对减少羊只死损具有很大的作用。     

草地放牧的牛羊需要吃饱也需要吃好

草地放牧的牛羊需要吃饱,也需要吃好,以快速增重,达到缩短出栏期、增加牲畜生产、减少对草原资源的消耗、保护草原的目的。在放牧的基础上,自由放牧羊的日粮中增加20％-25％豆科牧草,使日粮粗蛋白含量全年平均维持在11％-12％的水平,当年生羔羊体重可以增加57％-71％,达到55-60 kg水平,对于家畜生产和草地管理具有重要的推广价值。     

Effect of monensin on the performance of cattle on pasture or fed harvested forages in confinement

Three series of trials were conducted to evaluate the effect of monensin on the growth performance of cattle. Twenty-four trials were conducted to evaluate the addition of monensin at 200 mg/d to limited quantities of supplemental concentrate for growing cattle grazing pastures. The pastures ranged from dormant end-of-the-season grasses and crop residues to lush green pastures, and were located in several different states. Pasture plus supplement supported gains of control cattle (without monensin) of .24 to .96 kg, with an average of .56 kg/d. The addition of 200 mg monensin to the supplement increased daily gain in all 24 trials by an average of .09 kg daily (+16.3%). Eleven trials were conducted with monensin and energy supplements fed at .907 kg.- head-1 X d-1 to growing cattle grazing growing, nondormant pastures for an average period of 117 d. Each trial was designed to compare the performance of unsupplemented cattle, cattle fed a supplement and cattle fed a supplement with monensin. Cattle on pasture gained .50 kg daily. Supplement feeding increased average daily gain by .09 kg and the addition of monensin to the supplement further increased gain by .09 kg, for a total increase of .18 kg (34.2%). The efficiencies with which supplemental feed was converted to extra gain (kg supplement/kg gain) for the supplement-only and the monensin treatment groups were 10.1:1 and 5.0:1, respectively. In a series of 12 trials, monensin was added at a level of 33 mg/kg air-dry diet to limited quantities of supplemental feed for cattle fed harvested forages in confinement. All trials compared monensin feeding with a nonmedicated control treatment. Hay was fed in 8 of the 12 trials, fresh-cut green-chop in two trials and ensiled corn stover and ensiled milo stover in one trial each. Monensin reduced feed intake by -3.1%, improved average daily gain by .09 kg (+14.4%) and improved feed efficiency by 15.3%.     

不同饲养方式对江城牛肉品质的影响

试验旨在研究不同饲养方式对江城牛肉品质的影响,获得江城牛最优肉品质的饲养方式。选取年龄在2.5岁左右、健康状况良好的24头江城牛,其中公牛9头、母牛15头,根据性别随机分成3组,每组8头（公牛3头、母牛5头）,第1、2组舍饲,在自由采食全株玉米青贮的基础上,每头牛每天分别补饲肉牛精料补充料2 kg（精料补充料组）和浓缩料1 kg（浓缩料组）,第3组在人工草地上放牧饲养（放牧组）,饲养90 d后从精料补充料组和浓缩料组分别选4头,从放牧组选6头,公母各半,共14头进行屠宰试验,测定江城牛的肉品质。结果表明,不同饲养方式对江城牛肉品质有一定影响,补饲精料补充料和浓缩料后,江城牛在失水率、剪切力、粗脂肪、粗蛋白质方面与放牧组存在显著差异（P<0.05）,其他成分各组间差异均不显著（P>0.05）,但眼肌面积、背膘厚度、大理石花纹等表现为补饲了精料补充料和浓缩料的牛肉品质优于放牧组。不同饲养方式对江城牛肉品质有一定的影响,补充精料补充料和浓缩料后,在肉品质方面,精料补充料组和浓缩料组优于放牧组。说明在饲养过程中可以通过补充精料补充料和浓缩料改善江城牛的肉品质。本研究结果为江城牛的合理饲养和提高肉品质提供了理论依据。     

Digestion criteria in nursing beef calves supplemented with limited levels of protein and energy.

This study was conducted with grazing nursing calves (197 kg) to determine the effects of 1) limiting creep feed intake and 2) increasing the concentration of ruminal escape CP in creep feed at a limited level of creep feed intake on fescue and milk intake, ruminal NDF digestion, and total tract digestibility in calves fed high-quality, freshly harvested fescue. The treatments were 1) control (no creep feed), 2) limited intake of creep feed (.60 kg/d) having a moderate concentration of CP (13%), 3) limited intake of creep feed (.60 kg/d) having a high concentration of CP (35%), and 4) unlimited (high) intake (1.62 kg/d) of the same creep feed fed in Treatment 2. Forage OM intake was negatively correlated (r = -.995, P less than .05) with level of creep feed OM intake, whereas milk OM intake was not affected by level of creep feed intake. Decreases in ruminal fiber digestion and total tract NDF digestion caused by unlimited creep feeding were partially avoided by limiting creep feed intake. Digestible OM intake increased by .47 kg per kilogram of creep feed OM intake.     

Effects of pre-feeding of a corn silage-based supplement on the feed intake, milk production and nitrogen utilization of grazing dairy cows

Four Holstein cows were used to determine the effect of timing of the feeding of a corn silage (CS)‐based supplement on the feed intake, milk production and nitrogen utilization of grazing dairy cows. The cows were fed the supplement 2 h before grazing (pre‐grazing) or immediately after grazing (post‐grazing). Cows were grazed for 5 h per day under a rotational grazing system. There was no difference in the herbage and total feed intake between treatments. The milk protein yield for pre‐grazing tended to be higher than that for post‐grazing, whereas the milk yield did not differ between treatments. The total nitrogen intake for pre‐grazing tended to be higher than that for post‐grazing (P = 0.06). There was no difference in the urinary nitrogen output between treatments, whereas the proportion of urinary nitrogen output : total nitrogen intake for pre‐grazing tended to be lower than that for post‐grazing (P = 0.06). The milk nitrogen output and nitrogen retention for pre‐grazing tended to be higher than that for post‐grazing (milk nitrogen, P = 0.06; nitrogen retention, P = 0.05). Nitrogen utilization of grazing dairy cows was improved by feeding a CS‐based supplement before grazing.     

不同饲养方式对涪陵水牛生长性能的影响

为了提高涪陵水牛的产肉性能，探索适合涪陵水牛的科学饲养模式，本试验研究了不同饲养方式对涪陵水牛生长性能的影响。挑选3Q头体重接近的涪陵水牛，随机分为A、B、C三组，A组采用栓系舍饲方式、B组则用半天放牧加补饲的方式、C组采取全天放牧加补饲，试验时间为3个月，通过每月末定期测定牛的体斜长、体高、胸围和管围四项指标反映生长发育情况。结果表明，半天放牧组的生长性能明显优于全天放牧组，而舍饲组优于放牧组。     

饲养方式对滩羊羔羊肌肉及脂肪组织中脂肪酸组成的影响

为探究饲养方式对滩羊羔羊肌肉和脂肪组织中脂肪酸组成的影响,试验选择24只健康且体重相近（14.16 kg±0.58 kg）的2月龄滩羊羔羊随机分成舍饲组和放牧组,每组12只,于4月龄屠宰取其背最长肌、股二头肌、膈肌、皮下脂肪、肾周脂肪、尾部脂肪,用气相色谱仪测定脂肪酸含量。结果表明：①在肌肉组织饱和脂肪酸中,与放牧组相比,舍饲组滩羊羔羊股二头肌丁酸、棕榈酸含量显著提高（P<0.05）,膈肌辛酸、月桂酸、肉豆蔻酸含量显著降低（P<0.05）。在肌肉组织不饱和脂肪酸中,与放牧组比较,舍饲组滩羊羔羊背最长肌棕榈油酸、花生四烯酸含量显著降低（P<0.05）,γ-亚麻酸、α-亚麻酸含量显著提高（P<0.05）,二十碳五烯酸（EPA）、n-3多不饱和脂肪酸（n-3 PUFA）极显著提高（P<0.01）;股二头肌花生四烯酸含量显著降低（P<0.05）,十七碳一烯酸、α-亚麻酸、EPA、n-3 PUFA含量极显著提高（P<0.01）;膈肌棕榈油酸含量显著降低（P<0.05）。②在脂肪组织饱和脂肪酸中,与放牧组比较,舍饲滩羊羔羊皮下脂肪十一碳酸、十五碳酸含量显著降低（P<0.05）,十三碳酸含量极显著降低（P<0.01）;肾周脂肪葵酸、肉豆蔻酸含量显著降低（P<0.05）,丁酸、硬脂酸含量极显著提高（P<0.01）;尾脂十一碳酸含量显著降低（P<0.05）。在脂肪组织不饱和脂肪酸中,与放牧组比较,舍饲滩羊羔羊皮下脂肪十八碳二烯酸含量极显著提高（P<0.01）,肉豆蔻油酸、棕榈油酸、γ-亚麻酸含量极显著降低（P<0.01）;肾周脂肪十八碳一烯酸、α-亚麻酸、n-3PUFA含量显著提高（P<0.05）,肉豆蔻油酸含量显著降低（P<0.05）,十七碳一烯酸、二十碳二烯酸、十八碳二烯酸含量极显著提高（P<0.01）;尾脂肉豆蔻油酸、棕榈油酸含量显著降低（P<0.05）,十八碳二烯酸含量极显著提高（P<0.01）。综上,不同饲养方式对滩羊羔羊肌肉和脂肪组织脂肪酸含量存在一定影响,舍饲滩羊羔羊股二头肌中饱和脂肪酸含量及肾周脂肪中不饱和脂肪酸含量显著高于放牧滩羊羔羊。     

High-fiber diets in pregnant sows: digestive utilization and effects on the behavior of the animals

Twelve pregnant, multiparous sows were assigned during gestation to three dietary treatments in a 3 x 3 Latin square design to evaluate the effect of increasing levels of crude fiber (CF): a conventional diet low in CF (L, 15.8 MJ DE/kg of DM, 3.3% CF), a diet with a medium level of CF (M, 14.4 MJ DE/kg of DM, 10.6% CF), and a high-fiber diet (H, 12.9 MJ DE/kg of DM, 18.1% CF). The daily feed supply was adjusted to provide the same 33.4 MJ of daily digestible energy (2.4, 2.7, and 3.0 kg/d for diets L, M, and H, respectively). Over the day, a shorter time standing was spent when sows received the H diet (291 min/d) compared with the L (363 min/d) and M diets (324 min/d). Duration of feeding was longer with the high-fiber diet. Mastication represented the main part of the feeding activity in sows fed the H diet (56%) and was reduced with the M and L diets (40% and 25%, respectively). Feeding rate increased when fiber level decreased (67, 120, and 152 g/min for the H, M, and L diets, respectively). Feeding the fibrous diet reduced the incidence of nonfeeding oral behaviors. These results show that high-fiber diets can reduce apparent feeding motivation of pregnant sows and, thus, improve the welfare of sows subjected to feed restriction.     

Performance and Economics of Dairy Cows Fed a Corn Silage-Based Total Mixed Ration or Grazing Annual Ryegrass During Mid to Late Lactation

Economic and performance characteristics of a low cost grazing system based on annual ryegrass vs a total mixed ration (TMR) for cows during mid through late lactation were evaluated. Cattle used in the trial (28 Holstein and 12 Jersey cows) were blocked by parity, lactation number, days in milk, projected mature equivalent milk yield, and current milk yield, and cows were assigned to two treatments in a randomized complete block design. For 10 wk (March through May 1998), cows either received a corn silage-based TMR or grazed annual ryegrass and received no supplemental concentrates. Changes in feed composition, milk yield, milk composition, BW, condition score, and income over feed costs were examined. Cows on Treatment 1 were fed the TMR twice daily and were housed together in a free-stall barn. Cows assigned to grazing were allowed ad libitum access to annual ryegrass in a rotational 12-paddock system. Loose mineral was provided for ad libitum consumption, but no supplemental concentrate was offered. Daily milk production by the TMR cows was consistent, ranging between 22.5 and 27.2 kg per cow throughout the study. By contrast, daily milk production of the grazing cows declined from 26.6 to 15.9 kg per cow as lactation progressed. Ryegrass grazing reduced milk fat content during wk 4 and 8 of the study and increased MUN content during wk 2 but had no effect on milk protein content or somatic cell count. The BW, body condition score, and estimated DMI of grazing cows were less than they were for TMR cows. Milk income for the grazing cows was less than that for the TMR cows throughout the study. However, feed cost for grazing cows was substantially lower than that for the TMR cows. Hence, income over feed cost (IOFC) was greater for grazing cows than for TMR cows in all but the last 2 wk of the study. These results indicated that annual ryegrass grazing was more profitable than feeding a TMR to cows in mid to late lactation. However, grazing cows did lose body condition, which could have a negative effect on milk production in the subsequent lactation.