海南州天然草地产草量地面监测报告

监测结果表明，海南州天然草地产草量１９９７年、１９９８年属正常年范畴。经草畜平衡分析，１９９８年全州草地理论载畜量为５０１．８６万羊单位，草地现有载畜量为５１４．７７万羊单位，草地牲畜的超载量为１２．９１万羊单位．超载率为２．５７％．草地生产基本实现了草畜平衡。     

简述放牧牦牛补饲精料的必要性

西部地区是生态保护和脱贫攻坚的重点区域。科学补饲精料可以有效促进放牧牦牛生长发育,提高母畜繁殖力,带动牧区牧民增产增收,推动西部地区打赢脱贫攻坚战。同时,科学补饲能够提高天然草地载畜量,化解草畜矛盾,促进草地畜牧业健康持续发展。     

同仁县天然草地产草量调查报告

为核定草地载畜量,合理保护草地资源,实行草畜平衡,根据农业部草地资源监测新标准,利用典型抽样的方法,2004年对同仁县草地资源进行了监测。结果表明:2004年草地可食鲜草产量为3 065.8kg/hm2,超载7.4万个羊单位,超载率24.1%,牲畜超载较严重。     

青海省海东、海北地区草地资源产量与草畜平衡现状研究

利用青海省海东、海北两地区地面实测产草量,经过GPS定位,与MODIS植被指数数据建立天然草地资源产量反演模型,以及天然草地理论载畜量计算模型;同时,利用粮食等饲料作物和林地面积等资料,估算农林副产品的载畜量,结合青海省各地区季节放牧的实际情况,建立天然草地以及考虑补饲后的地区草畜平衡监测模型,分析两地草畜平衡状况。结果表明,1)海东、海北两地草地资源产量分别为195.30×10⁴和4590.92×10⁴ t,采食牧草产量分别为98.41×10⁴和2306.07×10⁴ t,天然草地实际利用率为50.4%和50.23%;2)两地区天然草地所能承载的最大载畜量为90.97×10⁴和856.18×10⁴只标准羊单位;3)综合天然草地和农业补饲各种因素后,海东、海北地区超载率分别为97.9%和-32.2%,海东地区超载较严重,海北未超载。     

草原生态补奖政策下牧户草畜平衡调控行为研究

以内蒙古锡林郭勒盟东乌珠穆沁旗、锡林浩特市和苏尼特右旗三个旗(市)为例,分析了补奖政策实施前(2009年)、后(2014年)草畜平衡区牧户的生产决策行为,揭示牧户的草畜关系调控途径,解析不同牧户对草畜关系的调控策略,分析草畜平衡率变化以及补奖政策实前后牧户收入变化情况。结果表明:牧户通过调控牲畜数量、经营草地面积和饲草料购买量三个主要途径调增了载畜率,超载程度有所增重;牧户家庭收入有所增加,除了补奖资金对收入增加的直接作用外,牧户仍将过度利用草地的经营决策行为作为维持和提高其收入的主要手段。最后,剖析了生态补奖政策存在的问题,并有针对性地提出建议。     

鸭茅╋白三叶型混播放牧草地肉牛生产系统优化研究

在鸭茅（Dactylis glomerata）+白三叶（Triflium repens）草地型肉牛放牧系统内,实施全日制划区轮牧、载畜量季节性调控、维持肥施用、草地除杂、枯草期补饲等优化措施,对草地的土壤养分、牧草生长强度、现存量、组分、养分及肉牛体质量、日增体质量等指标进行了监测。结果表明,采用全日制放牧,在草地年平均载畜量1.4牛单位/hm2下,牧草的生长量超过8 077 kg/hm2,肉牛体况得到明显的改善,单位草地面积经济效益可达1 135元/hm2,草地实现可持续利用。同时,针对草地肉牛放牧系统中存在的问题,提出了有效改进的合理化建议。     

基于MODIS植被指数的青海省玛多县草畜关系分析

为了研究青海玛多县草畜关系特征,对2008—2009年9个样地的实测地上生物量与MODIS(Moderate-resolution Imaging Spectroradiomete)归一化植被指数(NDVI)、增强型植被指数(EVI)分别基于线性、幂和指数函数建立回归模型,对理论地上生物量进行反演估算,并依据相关公式计算理论载畜量。结果表明:线性函数模型具有较好的模拟效果;2009年玛多县草地地上生物量显著高于2008年;玛多县基于NDVI的2008,2009年理论载畜量分别为40.93万、57.45万羊单位,基于EVI的理论载畜量分别为41.30万、59.03万羊单位;而玛多县2008,2009年年末的牲畜存栏数分别为33.11万、33.71万羊单位,可见玛多县这2年的理论载畜量尚有盈余。说明玛多县总体上正在由草畜关系极不平衡状态向逐渐草地恢复状态逐渐改变。     

西北牧区灌溉人工草地适宜发展规模分析

针对西北牧区水资源和草地资源已被超极限利用的现状,应用水草畜平衡原理,分析了西北牧区灌溉人工草地的发展规模,提出了西北牧区灌溉人工草地适宜发展规模为215.76～239.71万hm^2,载畜量控制在13833.18万羊单位之内即可实现草畜平衡,总体可达到人工种植冷季补饲水平。新增灌溉需水量约为71.85～83.55亿m^3,占2000年灌溉总用水量（777亿m^3）的9.25%～10.75%。解决这一灌溉需水量的可行途径是建设节水型社会,提高水资源利用效率。     

关于季节放牧地月适宜载畜量计算方法的探讨——以青海省荷日恒村为例

草地月适宜载畜量的计算,能够有效反映草地季节性草畜矛盾,帮助决策者及时调整放牧策略。本研究提出一种将基于遥感和地面调查建立的月牧草产量遥感经验模型与牧草产量月动态系数相结合的方法,用于估算月草地适宜载畜量,并在青海省河南县荷日恒村的季节牧场对该方法进行应用。结果表明,该方法能有效地反映各月适宜载畜量动态,使年内放牧地载畜平衡状况更明晰。荷日恒村放牧地在7月末草地产量达到最高,8月开始逐渐减少,除7月外,其他各月均有不同程度的超载。综合目前荷日恒村放牧地现实载畜情况和对补饲量的评估,本研究认为应以8月末适宜载畜量作为该村合理放牧量。本研究提出的月适宜载畜量计算方法,更有助于合理放牧数量的确定和草畜平衡状况的评估,为当地合理利用草地资源及可持续发展提供理论依据。     

海西州天然草地产草量地面监测报告

通过对草地产草量的调查和测定,海西州天然草地产草量2005年、2006年基本属于正常年范畴。经草畜平衡分析,2006年全州草地理论载畜量为265.45万羊单位,草地现有载畜量为280.162万羊单位,超载14.71万羊单位。     

Perinatal maternal feeding with an energy dense diet and/or micronutrient mixture drives offspring fat distribution depending on the sex and growth stage

Maternal nutrition during pregnancy and lactation influences offspring development and health. Novel studies have described the effects on next generation obesity‐related features depending on maternal macro‐ and micro‐nutrient perinatal feeding. We hypothesized that the maternal obesogenic diet during pregnancy and lactation programs an obese phenotype, while maternal micronutrient supplementation at these stages could partially prevent these features. Thus, the aim was to assess the influence of a perinatal maternal feeding with an obesogenic diet enriched in fat and sucrose and a micronutrient supplementation during pregnancy and lactation on offspring growth and obese phenotypical features during life course. Female Wistar rats were assigned to four dietary groups during pregnancy and lactation: control, control supplemented with micronutrients (choline, betaine, folic acid and vitamin B₁₂), high‐fat sucrose (HFS) and HFS supplemented. At weaning, the offspring were transferred to a chow diet, and weight and fat mass were measured at weeks 3, 12 and 20. At birth, both male and female offspring from mothers fed the obesogenic diet showed lower body weight (?5 and ?6%, respectively), while only female offspring weight decreased by maternal micronutrient supplementation (?5%). During lactation, maternal HFS diet was associated with increased body weight, while micronutrient supplementation protected against body weight gain. Whole body fat mass content increased at weeks 3, 12 and 20 (from 16 to 65%) due to maternal HFS diet. Maternal micronutrient supplementation decreased offspring fat mass content at week 3 (?8%). Male offspring showed higher adiposity than females at weeks 12 and 20. In conclusion, maternal HFS feeding during pregnancy and lactation was associated with a low offspring weight at birth and obese phenotypical features during adult life in a sex‐ and time‐dependent manner. Furthermore, maternal methyl donor supplementation protected against body weight gain in male offspring during lactation and in female offspring also during juvenile period.     

Enhancing immunity to nematode parasites in single-bearing Merino ewes through nutrition and genetic selection

The effectiveness of protein supplementation and genetic selection to enhance the resistance of periparturient Merino ewes to infection from gastrointestinal parasites was tested in a replicated grazing experiment. One hundred and twenty ewes from lines selected for increased resistance (R) to Haemonchus contortus or at random (C) were subjected to one of the three supplement groups that provided 0 or 250 g per day cottonseed meal for 5 weeks prior to, or for 6 weeks after the start of lambing. Faecal egg counts (FEC) of R ewes were consistently lower than those of C ewes but both groups exhibited a periparturient rise in FEC. Supplementation during the pre-partum period reduced FEC and increased ewe body weight gain. The benefits of pre-partum supplementation in reducing FEC continued to be apparent up to 10 weeks after supplementation ceased. There was a strong suggestion that the benefits to parasite resistance from protein supplementation were greatest in C ewes. Wool growth rates (15%) and birth weights (5%) were greater for C ewes but differences between the lines for lamb body weight had disappeared by day 97. The greatest benefit to resistance from protein supplementation was observed when ewes were experiencing a loss of maternal body weight. Conversely, no benefits to resistance were observed when ewes had moderate (78-107 g per day) rates of maternal weight gain. These results suggest that increased resistance as a result of protein supplementation is dependent on the prevailing supply and demand for scarce nutrients such as metabolisable protein (MP). Both genetic selection and protein nutrition are effective strategies to enhance host resistance to nematode infection during the periparturient period.     

The effect of supplementary feeds on the bodyweight of yaks in cold season

The present study was conducted to determine the effects of supplementary feeds, oat hay (OH), highland barley straw (HBS) and multi-nutrient blocks supplementation (UMMB) on reducing liveweight losses of both yak cows and calves grazed on low quality pastures during cold season. The trials of OH and HBS supplementation were conducted by using completely random design on 104 yak cows between 6 and 12 years of age as the following treatments: pure grazing (41 animals, body weight 230±67 kg) as control (CK); grazing+1.5 kg DM of OH per head daily (30 animals, body weight 216±28 kg); grazing+1.5 kg DM of HBS per head daily (33 animals, body weight 221±34 kg). The trial of UMMB was conducted on three types of yaks, 1-year calves (8-12 months old, body weight 61.1±6.9 kg), 2-year calves (18-24 months old, 98.0±11.3 kg) and yak cows (164.5±27.1 (S.D.) kg) with 20 animals in control group (CK) and 20 animals in supplement group for each type by using completely random design as the following treatments: pure grazing for CK group; grazing+150, 250 and 500 g UMMB per day averagely for 1-year calf, 2-year calf and cow at night. The results indicate that the animals supplemented with oat hay received body weight gain (32±20.7 g day⁻¹), while those supplemented with highland barley straw still suffered from body weight loss (−56.7±39.3 g day⁻¹); UMMB supplementation can decrease the body weight loss by 109.7%, 86.6% and 63.4% for the 1-year calves, 2-year calves and yak cows, respectively, as compared with pure grazing. Around US$1.60 output can be achieved on the basis of US$1 input for UMMB supplementation in the farming systems of the 1-year calves, 2-year calves and yak cows, while US$1 input can produce US$1.55 and 1.14 output for OH and HBS supplementations, respectively, in yak cows' farming system. It can be preliminary concluded that UMMB supplementation was the most economic way to alleviate body weight loss of grazing yaks over cold season, and the higher productive returns were obtained from OH supplementation for grazing yak cows during winter/spring months.     

九龙牦牛冷季补饲试验

[目的]为了提高冷季补饲效果.[方法]本试验选择1～15岁的60头九龙牦牛作为试验组,同龄50头牦牛作为对照组,试验组采用白天放牧+晚上补饲配制精料的方式开展补饲试验,对照组只开展放牧,不补饲.试验开始时及开始后30 d和90 d分别测量体尺和体重.[结果]表明:在试验不同阶段,同龄牦牛身高、体斜长和胸围等体尺指标在补...     

Effect of cooking and methionine supplementation on nutritional value of bitter vetch seed as a feed ingredient for broilers

The present study was conducted to evaluate the adequacy of applying heat treatment and methionine (Met) supplementation to improve the use of bitter vetch (BV) as a feed ingredient in the growth diet of broilers. A total of 540 Ross-308 chicks were fed various BV-supplemented diets between the ages of 35 and 49 days. The chicks were assigned randomly to one of nine experimental treatments, including raw and cooked bitter vetch seeds at two levels (100 and 200 g/kg) with or without Met (210 mg/kg) supplement and a corn–soybean-based diet as control. Results showed that feeding the 200-g/kg raw BV decreased feed intake by 52% in relation to the control diet (P < 0.05). Cooking the BV did not improve the feed intake. Met supplementation of 100 g/kg raw or cooked BV and 200 g/kg cooked BV resulted to a similar feed intake in the control group. Chicks fed with the 200 g/kg raw BV had an average depressed body weight gain of 90% in comparison to the birds fed with the control diet. The combination of cooking and Met supplementation of this diet resulted to a similar body weight gain to the control diet. Feeding 100 g/kg of raw or cooked BV also reduced (P < 0.05) body weight gain, and Met supplementation of these diets resulted in a body weight gain similar to the control group. Chicks fed with 100 g/kg of raw or cooked BV supplemented with Met or 200 g/kg of cooked BV plus Met has similar feed conversion ratio to the control group. In conclusion, heating BV seeds is not sufficient to overcome the limiting effects of BV seeds on feed intake and weight gain, and that Met supplementation does provide some improvement. The combination of cooking and Met supplementation was more efficient.     

"NPN"补充料对肉牛增重效果试验

[目的]为了验证"NPN"补充料时肉牛增重效果,进行本试验.[方法]试验将西杂牛20头随机分为试验组和对照组,每组10头,试验组在精料中添加"NPN补充料",对照组饲喂常规饲料,不添加"NPN补充料".经过80 d的试验.[结果]表明:试验组肉牛总体重5 116.8 kg,比对照组的4 806.1 kg,多增重310....     

EFFECT OF SELENIUM ON WOOL PRODUCTION, BODY WEIGHT AND MORTALITY OF YOUNG SHEEP IN WESTERN AUSTRALIA

The effect of regular selenium supplementation on the body weight, wool production and mortality of young Merino sheep was investigated. Groups of Se-treated and control sheep involving from 260–500 on each of 15 farms were observed from six weeks to 19 months of age. Ten mg Se as sodium hydrogen selenite was administered orally to the treated sheep at two-monthly intervals. Treated and control sheep grazed together throughout the trial period. Statistically significant responses to selenium were recorded in body weight gains on four farms, in decreased mortality on five farms and as an increase in fleece weight on eight farms. The response in fleece weight varied from 2.9-7.6% and could not be explained as a result of increased body weight. The increase in fleece weight was not due to an increase of grease in the wool but appeared to be due to an increase in fibre diameter and to a lesser extent an increase in staple length. A statistically significant decrease in the incidence of tender fleeces as a result of selenium supplementation was also recorded. All farms on which responses to selenium were obtained were in areas with average annual rainfall more than 20 inches. On two farms selenium caused statistically significant depressions in the parameters measured. Both farms were in areas with less than 20 inches average annual rainfall.     

Dietary L-carnitine increases plasma insulin-like growth factor-I concentration in chicks fed a diet with adequate dietary protein level

1. The effect of L-carnitine supplemented into experimental diets with varying dietary protein concentrations (50, 200 and 400 g/kg) on body weight gain and plasma insulin-like growth factor-I (IGF-I) concentration in chicks was examined. 2. Dietary L-carnitine supplementation provided 0, 200, 500 and 1000 mg/kg. Chicks were given the diet ad libitum for 10 d. 3. When L-carnitine was provided as 500 or 1000 mg/kg, body weight gain was significantly improved in birds receiving the 200 and 400 g protein/kg diets. 4. There was an interaction between dietary L-carnitine and protein content on plasma IGF-I concentration. L-carnitine supplementation had little influence on plasma IGF-I concentrations in birds receiving the low protein (50 g/kg) diet. When dietary L-carnitine concentrations were increased from 0 to 1000 mg/kg in the adequate protein (200 g/kg) diet, plasma IGF-I concentrations were also increased. However, when dietary L-carnitine content was more than 500 mg/kg in the 400 g/kg protein group, plasma IGF-I concentration decreased with increasing dietary L-carnitine content. 5. Body weight change correlated significantly with the alteration in plasma IGF-I concentrations in chicks given diets with adequate dietary protein. 6. In conclusion, the improvement in body weight gain caused by dietary L-carnitine supplementation was achieved when chicks were given their dietary protein requirement, which may be partially explained by an increase in plasma IGF-I concentration.     

饲粮中添加α-亚麻酸对产蛋鸡生产性能和肝脏AMPK的影响

本试验旨在探讨日粮中添加α-亚麻酸对海兰褐商品蛋鸡生产性能和肝脏AMPK的影响。采用单因素试验设计方法,在日粮中分别添加α-亚麻酸0.0%(对照组)、0.5%、1.0%、2.0%、3.0%和4.0%6个处理,每个处理组设5个重复,每个重复3只30周龄海兰褐商品蛋鸡。试验期28d。结果表明:添加α-亚麻酸使平均蛋重增加,添加α-亚麻酸3.0%组增加最大(P<0.05);料蛋比降低,第4周添加α-亚麻酸4.0%组降低最大(P<0.01);肝脏重、肝脏/体重、卵巢重、卵巢/体重、腹脂重和腹脂率减少,均以添加α-亚麻酸3.0%组最低(P>0.05)。AMPK酶活增加,添加α-亚麻酸1.0%组达极显著(P<0.01)。结论:添加α-亚麻酸可提高蛋鸡生产性能,增加AMPK酶活。     

蚯蚓提取液对彭县黄鸡生产性能、血清免疫指标和抗氧化指标的影响

为比较添加不同浓度蚯蚓提取液对彭县黄鸡生产性能、血清免疫指标和抗氧化指标的影响,选取健康且体重相近的100日龄彭县黄鸡(母鸡)288只,随机分成4个组,每组4个重复,每个重复18只。4个组均饲喂基础日粮,蚯蚓提取液饮水添加的稀释倍数分别为0、300、600、900倍。预饲期5 d,正试期47 d。每周记录采食量,记录生产性能。分别在105日龄和152日龄时全群称重,152日龄时检测血清免疫性能和抗氧化性能指标。结果显示:饮水添加300倍蚯蚓提取液时,能提高彭县黄鸡活重、105~152日龄阶段重、日增重、日采食量(P<0.05),血清C3、IgA、IgG、IgM和IL-6水平显著升高(P<0.05);添加300倍和600倍时,料重比显著降低(P<0.05);添加600倍时,C3、IgA和IgG水平显著升高(P<0.05),T-AOC水平显著降低(P<0.05);添加900倍时,IgA和IgG水平显著升高(P<0.05)。研究表明,本试验条件下饮水添加蚯蚓提取液的适宜稀释倍数为300倍。