人工草地山羊集约化放牧技术体系的建立

本文在对国内外人工草地山羊生产系统相关研究基础上,针对南方山区人工草地养殖山羊的实践提出技术措施和指标体系。研究表明,三叶草与多年生禾本科牧草混播放牧草地,牧前草地现存量1800～2500kgDM(drymatter)/hm2(草层高15～18cm),牧后草地现存量1100～1200kgDM/hm2(草层高5cm),可有效地提高波尔山羊和杂交山羊的生产性能。划区围栏有效减少山羊的维持能需求,放牧草地豆禾比例的维持可以通过施肥技术、放牧小区的刈牧轮换计划和实行家畜组合放牧来进行调控。     

山羊草地放牧饲养的采食特性及草地放牧利用技术研究

本文论述了山羊草地放牧饲养时采食牧草的７个基本特性及其对广西１２个组草地的放牧利用与改良，其中以灌草丛组和稀树灌草丛组的放牧利用与改良为重点，并在实践和对石灰岩山区现状、自然资源系统分析的基础上，提出大力种植优良木本饲用植物和发展山羊生产，为广西石灰岩山区迅速脱贫致富和改善生态条件的主要途径之一。     

不同放牧压和放牧时期对山羊牧食行为的影响

在南方人工草地上,对云岭黑山羊在不同放牧压和放牧时期的牧食行为进行研究。结果表明:放牧压指数较小时,能减少采食时间和采食时行进步数,明显增加每步吃草口数、采食速度、口食量、日采食量、反刍时间,对其他牧食行为影响不大;9月份采食口数、行进步数最少,口食量、日采食量最大,6月份每步吃草口数明显小于其他月份。7,8,9月份采食速度相差不大,小于10月份采食速度;10月份反刍时间、每个食团咀嚼时间最长,反刍咀嚼速度、逆呕时间间隔在不同月份差别不大。     

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％。     

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％。     

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％。     

灌丛草地山羊放牧利用研究进展

综述了有关灌丛草地山羊放牧利用的研究现状,并提出了今后的研究方向.     

不同放牧强度对紫花苜蓿生理指标的影响

本试验于2006年5月至2007年10月,在宁夏盐池县四墩子行政村模仿天然草原,通过测定紫花苜蓿叶绿素、脯氨酸、POD活性、丙二醛含量来探讨荒漠草原中紫花苜蓿的抗逆性机制。结果表明,紫花苜蓿叶绿素含量在轻度放牧(LG)区出现了最大值,以后则随着放牧强度的增大而降低。脯氨酸含量、POD活性、丙二醛含量则随着放牧强度的增大而升高,在雨热条件较好的季节,缓解了放牧对苜蓿造成的伤害。     

浙江山羊放牧行为的研究

本文以山羊行为学及其对生态条件的反映为基础，观察测定不同品种的山羊在浙江丘陵低山缓坡生态环境下的放牧采食行为。结果表明，马萨本三元杂种山羊善行走登高，放牧采食能力强，适应放牧饲养；同品种山羊在不同类型植被放牧，行为差异显著；山羊放牧采食效果，阴天优于晴热天，下午优于上午，越近黄昏，山羊采食越专心。     

海南热带疏林草地山羊放牧试验初报

对海南热带疏林草地进行海南当地山羊的放牧试验,初步表明：人工草地上放牧海南山羊与天然草地相比有利于提高山羊对牧草的采食量和活增重。山羊的采食量与牧草蛋白质含量呈显著正相关,与粗纤维含量呈一定程度的负相关,与粗灰分、粗脂肪含量相关性不明显。无论人工草地还是天然草地在放牧山羊后禾本科草与豆科或其它杂类草、杂灌的比例明显提高。     

放牧和光照对林下栽培草地生产力的影响

研究了不同放牧强度G0(0只/hm2)、G1(22.2 只/hm2)、G2(44.4只/hm2)和不同光照条件(100%光强、68.83%光强和54.29%光强)对香樟(Cinnamomum camphora)林下混播草地生产力的影响.结果显示,在整个生长季,草地现存量、再生量和净初级生产力在同一放牧强度下均呈现随光照...     

Effects of stocking and nitrogen fertilization rates on steers grazing dallisgrass-dominated pasture

To compare the performance of steer calves managed under different stocking rates (SR; 3.7, 6.2, 8.6, and 11.1 steers/ha for 140 d; chi(I1)) and N fertilization rates (112, 224, and 336 kg of N/ha; chi(I2)) in May 1996, 1997, and 1998, 72 steer calves (BW = 231 +/- 2.5 kg) were assigned randomly to one of 12 0.81-ha dallisgrass (51%)/common bermudagrass (32%) pastures. One-third of the fertilizer was applied in the form of ammonium nitrate in May, June, and August to achieve the prescribed totals. Treatments were separated using a polynomial regression equation: gammai = beta0 + beta1chi(I1) + beta2chi(I2) + beta(11)chi2(I1) + beta(12)chi2(I2) + beta(12)chi(i1)chi(i2) + epsilonI, with years as replicates. Within the range of the data, ADG and BW gain per steer were greatest at a stocking rate of 3.7 steers/ha and 336 kg/ha of N. Body weight gain per hectare peaked at 701 kg when cattle were stocked at 8.9 steers/ha and the pasture was fertilized with 336 kg/ha of N. The least cost of production was at a stocking rate of 3.7 steers/ha, with 112 kg/ha of fertilizer N applied, and the greatest cost of production was at a stocking rate of 11.1 steers/ha with 336 kg/ha of fertilizer N applied. Fertilization at 336 kg/ha of N produced the most profitable stocking rate at 7.3 steers/ha and returned 355.64 dollars. The optimal stocking rate for net return was 79, 81, and 82% of that for maximum BW gain per hectare for 112, 224, and 336 kg/ha of N, respectively. Under the assumptions made in the financial analysis, these data show that the economically optimal carrying capacity of similar pastures can be increased with N fertilizer up to at least 336 kg/ha annually.     

模拟放牧强度下割草地鸭茅可溶性糖含量的季节性变化

通过在新疆昭苏马场设置不同模拟放牧强度,研究了不同放牧强度下割草地鸭茅Dactylis glomerata叶片和根部可溶性糖含量的季节变化,结果显示:鸭茅叶片可溶性糖在打草前呈上升趋势,返青后叶片可溶性糖含量较高,进入抽穗期后其含量降低。生长季前期根的可溶性糖含量差异不大(P0.05),打草后其含量迅速变低,而后逐渐上升,9月下旬其含量减少。时间和放牧强度共同作用对鸭茅叶片和根部可溶性糖含量影响显著(P0.01)。结果表明不同放牧强度对鸭茅叶片和根部可溶性糖含量有一定的影响,由于时间和气候变化的原因,其变化没有呈现一定的规律。     

Effects of pasture applied biosolids on performance and mineral status of grazing beef heifers

Angus x Hereford heifers (n = 50) were randomly assigned to bahiagrass pastures treated with biosolids varying in mineral content and evaluated for mineral status, with special attention to Cu. Biosolids and NH4NO3 were all applied at the rate of either 179 kg N/ha (X) or twice this (2X). Fertilizer was applied to .81-ha pastures for the following treatments: 1) Baltimore biosolids (1X = 179 kg N/ha); 2) Baltimore biosolids (2X = 358 kg N/ha); 3) Tampa biosolids (1X = 179 kg N/ha); 4) Tampa biosolids (2X = 358 kg N/ha); or 5) control NH4NO3 (1X = 179 kg N/ha) applied at two times. Pastures were divided into five blocks with each treatment represented once in each block. Copper loads varied from 8.8 to 42.2 kg/ha, and Mo loads varied from .27 to 1.11 kg/ha. Heifers (two per pasture) grazed their assigned pastures exclusively for 176 d. Liver biopsies were taken from all animals at d 1, 99, and 176, and blood samples on d 1, 50, 99, 135, and 176. Liver and plasma were analyzed for selected mineral contents, and blood was analyzed for hemoglobin and hematocrit. Experimental animals were generally low in mineral status when assigned to pastures and deficient in Se and P. By d 50, plasma Ca, Mg, Se, P, and Zn were adequate for all treatments. Plasma Cu declined (P < .03) for all treatments from d 50 to 176. Plasma Cu reflected depleted liver Cu storage, with the two Tampa and highest Baltimore treatment means lower in plasma Cu than the control at 176 d. Liver Fe concentrations were adequate for all treatments, and Mo concentrations (< 2.18 mg/kg) did not approach levels indicative of toxicity. Liver Cu declined (P < .05) with time for all treatments. By d 99, animals receiving the two Baltimore treatments and the lowest Tampa application rate had lower (P < .05) liver Cu than the control, and all treatments were lower at 176 d. The decline of animal Cu status (liver and plasma) reflects the low Cu status of bahiagrass and the possibility of high forage S (.30 to .47%) interfering with Cu metabolism. Forage Mo was low but was slightly higher in biosolids-treated pastures. High levels of biosolids applications to bahiagrass pastures were not detrimental to mineral status except Cu, which had a tendency to decline in plasma and for all biosolids treatments declined in liver.     

放牧强度对晋北盐碱化草地植物经济类群的影响

通过在晋北盐碱化草地设置不放牧（CK）、轻度放牧(LG)、中度放牧(MG)、重度放牧(HG)和极度放牧(EG)5个放牧强度研究该草地群落物种类群的变化,为确定草地合理的载畜量和放牧利用奠定基础。研究表明,随着放牧强度的增大,禾本科类群比例减小,CK与其他4个放牧强度之间差异显著（P＜0.05）;豆科类群比例呈增大的趋势,但各放牧强度之间差异不显著（P＞0.05）;菊科类群比例减小,EG与其他4个放牧强度之间差异显著（P＜0.05）;委陵菜属比例增大,CK和LG之间差异显著（P＜0.05）;杂草类群减小,CK与LG、HG、EG之间差异显著（P＜0.05）。随着放牧强度的增大,草地中禾本科类群、豆科类群和菊科类群的质量指数减小,委陵菜属和杂草类的质量指数增大。     

应用牧草生长-消费模型分析牧民的放牧行为--作为对政府管理行为的建议

利用牧草生长与消费模型,从理论和实际两个方面,对实施"双权一制"后牧民放牧行为的选择进行了分析.结果显示,由于牧民对草场使用权的预期不高,所以当前牧民采取的放牧策略不但对于其自身收益不是最优的,而且对生态环境的破坏也是最严重的,出现了草牧场使用的"非理性"现象.预期不高的主要原因是政策不稳定、不连续,因此保持政策的连续性、稳定性和协调性至关重要,且政府应该提前一段时间与牧民续签草场承包合同,而不是等到承包期限到期时再续签.同时,不断明晰产权,用允许牧民转让与买卖草场的方法来防止牧民破坏草场是可行的,而且也是畜牧业的规模化和产业化经营所必须的.因此,尽快明晰产权,建立健全草牧场流转市场是解决草牧场使用"非理性"的根本途径.