An economic evaluation of the differences between intensive and extensive beef production systems

A model to evaluate economic criteria involved when cattle are raised on high-forage diets prior to finishing or finished directly after weaning was developed using data from two experiments. In Exp. 1, each year for 3 yr, 136 Charolais-cross calves were weaned and allotted to either an intensive system, in which they were immediately finished on a high-grain diet, or an extensive system, in which they were wintered on crop residues, grazed on summer pasture and finished on a high-grain diet. In Exp. 2, 160 British breed steers were wintered, in one of eight different wintering systems utilizing crop residues, using supplemental protein and(or) alfalfa hay. After wintering, the steers grazed summer pasture and then were finished on a high-grain diet. Overall cost of gain and final "break-even" price were lower for cattle finished through the extensive system except when the price of corn was very low in relationship to other inputs. Interest costs were higher for cattle in the extensive system. Increasing the feeder calf purchase price had almost no effect on differences between the systems. Corn price and purchase price affected both systems similarly, whereas interest rate, wintering yardage and finishing yardage affected each system differently. Because of the additional weight produced through the extensive system, it yielded lower final "break-even" prices in most situations.     

莫能菌素对奶牛产奶性能的影响

本试验旨在研究莫能菌素对奶牛产奶性能的影响。将24头泌乳后期中国荷斯坦奶牛随机分为2组,试验组日粮中添加300g/d·头的莫能菌素。结果表明:在炎热的夏季,莫能菌素可提高奶牛的采食量,且奶牛产奶量比试验前提高了1.24%,比对照提高了15.91%,具有可观的经济效益;但对乳蛋白和乳糖的影响效果不显著。     

莫能菌泰对奶牛产奶性能的影响

本试验旨在研究莫能菌素对奶牛产奶性能的影响。将24头泌乳后期中国荷斯坦奶牛随机分为2组．试验组舀粮中添加300g/d·头的莫能菌素。结果表明：在炎热的夏季，莫能菌素可提高奶牛的采食量，且奶牛产奶量比试验前提高了1．24％，比对照提高了15．91％，具有可观的经济效益；但对乳蛋白和乳糖的影响效果不显著。     

Inbreeding effects on postweaning production traits, conformation, and calving performance in Irish beef cattle

The objective of this study was to quantify the effect of inbreeding on carcass quality, growth rate, live conformation measures, and calving performance in purebred populations of Charolais, Limousin, Simmental, Hereford, and Angus beef cattle using data from Irish commercial and pedigree herds. Variables analyzed are reflective of commercial farming practices. Inbreeding was included in a linear mixed model as either a class variable or a linear continuous variable. Nonlinear effects were nonsignificant across all traits. Inbred animals had decreased carcass weight and less carcass fat. The effects of inbreeding were more pronounced in the British beef breeds. Effects for carcass weight ranged from -0.87 kg (Charolais) to -1.90 kg (Hereford) per 1% increase in inbreeding. Inbred Charolais and Hereford animals were younger at slaughter by 3 and 5 d, respectively, per percentage of increase in inbreeding, whereas the effect of inbreeding on age at slaughter differed significantly with animal sex in the Limousin and Angus breeds. Inbred Limousin and Angus heifers were younger at slaughter by 5 and 7 d, respectively, per percentage of increase in inbreeding. Continental animals were more affected by inbreeding for live muscling and skeletal conformational measurements than the British breeds; inbred animals were smaller and narrower with poorer developed muscle. Calf inbreeding significantly affected perinatal mortality in Charolais, Simmental, and Hereford animals. The effects were dependent upon dam parity and calf sex; however, where significant, the association was always unfavorable. Dam inbreeding significantly affected perinatal mortality in Limousin and Hereford animals. Effects differed by parity in Limousins. Inbred first-parity Angus dams had a greater incidence of dystocia. Although the effects of inbreeding were some-times significant, they were small and are unlikely to make a large financial effect on commercial beef production in Ireland.     

硒对牛生产性能影响的研究进展

硒(Se)是动物必需的微量元素.缺硒会引起一系列疾病,硒过量则会导致硒中毒,而适量补硒则具有多方面的有益影响.硒在牛生产中的作用重大.日粮补硒不仅可以提高血液、牛奶及牛肉的硒含量,还能改善牛的繁殖性能、增强机体免疫力,同时改善牛肉品质.日粮补硒的效果受牛的生理状况、补硒前的硒状况、补饲硒的形态及补饲量的影响.目前,补硒...     

活酶宝对泌乳奶牛产奶量及乳成分的影响

本试验选用60头中国荷斯坦奶牛,按照胎次、体况及产奶量随机分成对照组和试验组。对照组饲喂原有全混合日粮(TMR);试验组在此基础上,每天每头牛在精料中添加17g的活酶宝。结果表明,活酶宝可以提高奶牛的产奶量、乳脂肪率、乳蛋白率、乳糖率、干物质率和脂蛋比(P>0.05),并降低体细胞数(P>0.05)。与对照组相比较,试验组泌乳量、乳脂肪率、乳蛋白率、乳糖率、干物质率的值分别相对提高1.7kg、0.23、0.12、0.09和0.27;体细胞数相对下降26.16百万个。     

Performance of spring-calving beef suckler cows and their progeny to slaughter on intensive and extensive grassland management systems

The performance of rotationally grazed beef suckler cows and their progeny to slaughter on two lowland grassland management systems differing in stocking rate (SR) and fertiliser nitrogen (N) level was compared over eight years. The two Systems were 1) Intensive (INT): SR of 0.56 (bull production) or 0.71 (steer production) ha cow^? 1 unit, 211 kg fertiliser N ha^? 1, two silage harvests, and 2) Extensive (EXT): SR of 0.69 (bull production) or 0.88 (steer production) ha cow^? 1 unit, 97 kg fertiliser N ha^? 1 and one staggered silage harvest. A cow unit was defined as a cow plus progeny to slaughter. On the silage harvesting area, the mean application rate for fertiliser N was 110 and 80 kg ha^? 1 for first and second harvests, respectively. Herbage dry matter digestibility both pre- and post-grazing was similar (P > 0.05) for the two systems, whereas herbage crude protein concentrations were generally significantly lower for the EXT than the INT system. There was no difference (P > 0.05) between the Systems in cow live weight, body condition score or their changes or in calf live weight gain from birth to weaning. Post-weaning, live weight gain, slaughter weight, carcass weight, kill-out proportion, estimated carcass gain, carcass conformation score or carcass fat score did not differ (P > 0.05) between the systems for heifer, steer or bull progeny. It can be concluded that similar animal performance levels can be expected in an extensive grassland-based suckler calf-to-beef system compatible with the EU, Rural Environmental Protection Scheme as that attained in a more intensive System comprising of both a moderately high SR (~ 1.25 higher) and fertiliser N application (~ 2.1 higher).     

短期使用碘化酪蛋白对奶牛产量的影响

选择 2 0头泌乳期相近中国荷斯坦奶牛 ,随机分成 5组 ,每组 4头 ,对照组饲喂基础日粮 ,试验组在喂基础日粮的基础上添加 15 g/头·d碘化酪蛋白 ,为期 30d。结果表明 ,试验组牛产奶量比对照组平均升高 10 .73% (P <0 .0 5 ) ,牛奶密度变化不大。不论是逐渐撤去还是突然撤去饲料中的碘化酪蛋白 ,都不能有效地阻止奶产量的迅速下降     

丙三醇对肉牛生产性能和胴体品质的影响研究

选取杂交母牛(体重421.6kg±28.9)373头,饲喂含纯天然丙三醇的日粮,其中丙三醇含量分别为0、2%、4%、8%、12%、16%。牛的蒸汽压片玉米为主的日粮包括:6%的苜蓿干草、1.2%的尿素、300mg/kg的莫能霉素、90mg/kg的泰乐菌素、0.5mg/kg的醋酸美仑孕酮。每个牛栏中大约有6～7头牛,每组9个牛栏。从对照组饮食过渡到添加丙三醇的日粮持续10d,饲喂丙三醇的时间持续85d。结果显示,当丙三醇添加量从0增加至2%时,肉牛干物质采食量(DMI)也呈线性增加(P0.001)。肉牛饲喂含有0、2%、4%、8%、12%、16%的丙三醇,其平均日增重(ADG)分别增加1.19、1.34、1.29、1.25、1.17和1.03kg;料重比(F/G)呈显著二次方效应,且当丙三醇添加量为2%时,其料重比最高(P=0.046),当丙三醇增加至2%、4%和8%时,体重相应增加12.7、8.1和5.3kg;当丙三醇比例增加到12%和16%时,体重却分别减少1.9kg(一次线性,P=0.009)和14.3kg(二次方,P=0.006)。当丙三醇含量增加时,背最长肌面积也有所增加(P0.013),饲喂丙三醇也可降低牛肉皮下脂肪和大理石花纹评分等级(P=0.045)。当丙三醇含量不高于干物质含量8%时,肉牛日粮中添加丙三醇可以提高牛体重和饲料转化率。     

胡萝卜对奶牛产奶量及乳成分的影响

试验通过在产奶牛日粮中添加胡萝卜,研究胡萝卜不同饲喂量对舍饲奶牛的奶产量和乳成分的影响。试验牛选用中国荷斯坦奶牛,体重500~600 kg,胎次为头胎、泌乳100 d左右的健康荷斯坦奶牛30头,采用完全随机区组设计,分为3个处理组,试验1组为对照组(基础日粮),试验2组(基础日粮+5 kg胡萝卜)、试验3组(基础日粮+7.5 kg胡萝卜)为试验组,基础日粮由全株青贮玉米、羊草和精料组成。研究结果显示,奶牛在添加胡萝卜后能够显著提高产奶量,90 d后试验2组的产奶量比对照组提高了11.94%(P<0.05),试验3组的产奶量比对照组提高了16.17%(P<0.05),牛奶的风味也得到很大的改善。     

Factors affecting the calcium, magnesium and phosphorus content of beef cow milk.

This paper reports the calcium, magnesium and phosphorus content of milk from Shorthorn cattle during the five month calf nursing period as well as the effect of prepartum administration of a single intramuscular dose of vitamin D3 or of 25-hydroxyvitamin D3 on the milk mineral constituents. The colostrum of the group which received 25-hydroxyvitamin D3 was found to contain a higher percentage of calcium on the second and third day than the colostrum of control cows or those receiving D3. No differences occurred in colostrum magnesium or phosphorus contents due to prepartum treatment. Calcium, magnesium and phosphorus concentrations were all high in the first day of lactation, but declined until the third day after parturition. Milk calcium, magnesium and phosphorus content of individual cows was not uniform throughout the lactation and the variation was different for different cows.     

挤奶频率对奶牛生产性能的影响

文章介绍了挤奶频率对奶牛泌乳性能、繁殖性能、健康与福利等方面的影响。     

Effects of creep feeding, zeranol implants and breed type on beef production: I. Calf and cow performance

A 2-yr study was conducted to evaluate the effects of a high-energy creep feed, preweaning zeranol implants and breed type on calf and cow performance. Two hundred calves sired by Brahman and Romana Red bulls out of Angus and Angus x Brown Swiss reciprocal crossbred (F1) dams were stratified by breed type and sex to three creep treatments: no creep feed (NC); long-term creep (LC), creep-fed from 56 to 210 d of age (weaning); and short-term creep (SC), creep-fed from 146 to 210 d of age. Alternate calves within sex, breed type and creep treatment were implanted with 36 mg of zeranol at an average of 56 d and reimplanted 90 d later. The LC and SC calves had heavier (P less than .001) 210-d weights than NC calves (264 and 257 vs 231 kg, respectively), and the LC calves were heavier (P less than .001) at 146 d than NC calves. The LC calves had higher (P less than .001) ADG from 118 to 210 d of age and higher 146 and 210-d condition scores than did NC calves. Pregnancy rate was not affected (P greater than .46) by creep treatment of calf. Zeranol implants increased (P less than .01) 146- and 210-d weights (184 vs 175 kg and 259 vs 243 kg) and ADG during all periods to weaning. Brahman-sired calves had higher (P less than .005) 146- and 210-d weaning weights and frame scores than Romana Red-sired calves.(ABSTRACT TRUNCATED AT 250 WORDS)     

Breeding performance of beef bulls assigned to two-sire cow groups on pasture

Angus, Polled Hereford and Santa Gertrudis bulls from ages 1 through 5 and 7 yr were assigned to 26 two-sire breeding groups. Each year, straightbred and crossbred cows of these breeds were allotted at random within breed composition, age of dam and calving date to breeding groups on pasture. Sires within each breeding group or pair were the same age at breeding and were two of the three breeds of sires. Neither calving rate nor the proportion of calves born by one vs the other sire in the two-sire breeding groups was affected by sire age among breeding groups. For a given breed, there was no uniformity among the sires in the proportion of calves they sired in their two-sire breeding groups. The proportion of calves born for the 26 sire pairs averaged .64 vs .36 (SE = 0.4 for either high or low value) for one vs the other sire in a sire pair with no indication that calving rate was affected by unequal proportions of calves by sires within sire pairs. Cows calved significantly earlier in the calving period (b = -.775 +/- .127) as calving rate increased among sire pairs. The number of days from the start of the breeding period to calf birth was affected by differences between sires in sire pairs for 8 of the 26 pairs, but there were no significant differences due to sire pair or breed of sire because of interaction between these two variables.     

奶牛产奶性能与乳房性状的相关分析

本文对南京市栖霞区个体农户饲养的 40 0头荷斯坦奶牛的悬韧带、后乳房宽度、后乳房高度、乳头长与奶牛的产奶量和乳脂率进行了相关分析 ,数据应用MicrosoftExcel进行计算分析。结果表明 :后乳房宽度和悬韧带均与产奶量呈强正相关 ,与乳脂率呈中等强度的负相关 ;后乳房高度与产奶量呈中等强度的负相关 ,与乳脂率呈弱正相关 ;乳头长与产奶量呈弱正相关 ,与乳脂率呈弱负相关     

Contribution of breed, cow weight, and milk yield to the traits of heifers and cows in four beef breeding systems.

Measurements were taken on 216 cows with 469 calvings for weight at weaning, condition at weaning, milk yield, milk fat percentage, milk lactose percentage, milk protein percentage, dry period feed intake, lactation period feed intake, total feed intake, first-service pregnancy rate, pregnancy rate, and days to pregnancy. Measurements were also taken on 183 heifers for first-service pregnancy rate, days to pregnancy, and age at first calving. The data spanned the years 1980 to 1988; animals belonged to one of four breeding systems: Hereford, small rotation (Angus, Gelbvieh, Pinzgauer, Tarentaise), large rotation (Charolais, Maine Anjou, Simmental), and Angus-large rotation (cows with Angus sires and large-rotation dams). Maine Anjou-sired cows had lower annual feed intake and Charolais-sired heifers lower first-service pregnancy rate than the other large-rotation breeds. Gelbvieh-sired cows had lower milk lactose and protein percentages than the other small-rotation breeds. Within breeding system neither cow weight nor milk yield were significantly associated with reproductive traits of cows. No differences among breeding systems in associations between feed intakes and weights or milk yields were detected.     

喀斯特地区奶牛小区泌乳盛期能量需要量研究

选用处于泌乳盛期中国荷斯坦奶牛12头,采用随机分组设计,根据产奶量、胎次、泌乳期、体重等因素,将试验牛分为试验1组(对照组,采用当地惯用日粮饲喂)、2组和3组。其中试验2组和3组进行2×2因子交叉饲养试验。试验牛的日粮由苜蓿、野草、稻草和精料组成,其中一组能量的供给量按饲养标准的推荐量供给,另一组的供给量是饲养标准推荐量的120%。饲养试验共进行2期,每期正式期15d,预试期7d。通过试验得到喀斯特地区奶牛小区饲养能量、蛋白质与钙、磷供应平衡模式:NER盛期(KJ)=1.2097(356W0.75×k) M×(0.4 15×Fat)×3138 △W×6.56×3138。     

共轭亚油酸对奶牛产奶量和乳脂率的影响

共轭亚油酸 (ｃｏｎｊｕｇａｔｅｄｌｉｎｏｌｅｉｃａｃｉｄ ,ＣＬＡ)是指与亚油酸的不饱和双键位置和空间构型不同的一类脂肪酸同分异构体的混合物 ,是最新提出的具有抗癌和抗动脉粥样硬化 ,并且可加强人类免疫功能 ,可以重新分配体脂 ,建造骨骼 ,防止高血糖和糖尿病 ,促进生长发育等作用的天然脂肪酸。有报道表明 :共轭亚油酸能改善猪的饲料转化率 ,降低背膘厚 ,增大眼肌面积 ,提高胴体瘦肉率及脂肪硬度 ,且不影响日增重 (Ｄｕｇａｎ等 ,1 987;Ｐａｒｋ等 ,1 997;Ｌｉ等 ,1 998)。ＪｏｈｎＥｇｇｅｒｔ( 1 999)报道 ,饲喂共轭亚油酸能改…     

添加混合油料籽实对奶牛生产性能及CLA的影响

选取年龄、体重、胎次、泌乳期及泌乳量基本一致的荷斯坦奶牛8头,随机分为2组,每组4头牛,进行为期45d的饲养试验。本试验预试期为15d,正试期为30d。试验组为添加整粒胡麻籽与整粒棉籽的混合物,胡麻的添加量为972g/(d·头),棉籽的添加量为2169g/(d·头);对照组不添加任何油料籽实。胡麻与棉籽的添加用以研究添加油料籽实对奶牛生产性能及乳脂脂肪酸组成的影响。研究结果表明:本试验条件下,加入胡麻籽与棉籽的混合物能提高奶牛产奶量,其中非校正产奶量比对照组提高4.7%,4?M产奶量比对照组提高7.3%,但与对照组差异均不显著(P>0.05);乳脂率提高了3.5%,乳脂产量提高了7.4%,与对照组之间差异也不显著(P>0.05);对于乳蛋白率,试验组比对照组提高了2.7%,乳蛋白产量提高了9.0%,但差异不显著(P>0.05);对于乳糖率,试验组比对照组下降了3.7%,乳糖产量比对照组提高了3.6%,差异不显著(P>0.05);乳中总干物质率比对照组提高了0.17%,无脂干物质率比对照组降低了0.96%,但与对照组差异不显著(P>0.05);试验组总的短链脂肪酸比对照组减少了16.8%,总的中链脂肪酸比对照组减少了11.6%,而长链脂肪酸比对照组增加了17.5%。其中试验组短链脂肪酸中的C14比对照组降低了21.5%,与对照组差异显著(P<0.05),其它短链及中链脂肪酸均与对照组差异不显著(P>0.05),长链脂肪酸中的CLA含量比对照!组提高了14.3%,但差异也不显著(P>0.05)。