Potentially hazardous sulfur conditions on beef cattle ranches in the United States

OBJECTIVE: To analyze the sulfur content of water and forage samples from a geographically diverse sample of beef cow-calf operations in the United States and to estimate frequency and distribution of premises where forage and water resources could result in consumption of hazardous amounts of sulfur by cattle. DESIGN: Cross-sectional study. SAMPLE POPULATION: 709 forage samples from 678 beef cow-calf operations and individual water samples from 498 operations in 23 states. PROCEDURE: Sulfur content of forage samples and sulfate concentration of water samples were measured. Total sulfur intake was estimated for pairs of forage and water samples. RESULTS: Total sulfur intake was estimated for 454 pairs of forage and water samples. In general, highest forage sulfur contents did not coincide with highest water sulfate concentrations. Overall, 52 of the 454 (11.5%) sample pairs were estimated to yield total sulfur intake (as a percentage of dry matter) > or = 0.4%, assuming water intake during conditions of high ambient temperature. Most of these premises were in north-central (n = 19) or western (19) states. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that on numerous beef cow-calf operations throughout the United States, consumption of forage and water could result in excessively high sulfur intake. All water sources and dietary components should be evaluated when assessing total sulfur intake. Knowledge of total sulfur intake may be useful in reducing the risk of sulfur-associated health and performance problems in beef cattle.     

The predictive value of pelvimetry in beef cattle.

To elucidate reasons for failure of pelvimetry to predict dystocia, we collected data from 1146 heifers and 210 cows in five beef cow herds in Saskatchewan. We assessed the reliability of pelvic area measurements, the generalizability of findings, various modifications of the technique, and the statistical association between pelvic area measurements and dystocia. The repeatability (kappa) of pelvic area measurements between and within veterinarians for the Rice and Krautmann pelvimeters were low to moderate, indicating pelvic area measurements were imprecise. The positive predictive values and sensitivities of pelvic area measurements were consistently poor across herds, years of study, breeds of heifers, times of measurement, various pelvic area cut-off points, and sires. Various modifications of the technique, including pelvic area/calf birth weight ratios, pelvic area/heifer weight ratios, and Ko's calving prediction equation were also poor on-farm tests for predicting dystocia. Although the mean pelvic area in heifers with dystocia was smaller than those without dystocia, there was a large overlap in the distribution of their measurements. Far too many heifers with a small pelvic area had no dystocia (false positives) and far too many heifers with a large pelvic area had dystocia (false negatives) for pelvimetry to be useful. We conclude there is little evidence to justify the continued use of pelvimetry as an on-farm test to reduce dystocia in beef cattle.     

Analysing quantitative parent-of-origin effects with examples from ultrasonic measures of body composition In Australian beef cattle

Parent-of-origin effects arise when an individual's genes are modified during gametogenesis. Commonly known as imprinting, affected genes may be completely, or partially, suppressed. Individual loci in mice, human and sheep are known to be imprinted, and the quantitative effects of imprinted loci have been found for many carcass traits in cattle and pigs. Differentiating between five types of loci - direct additive loci and partially and completely imprinted loci by sires and dams - is not possible as their effects are confounded such that only three of seven parameters can be estimated. An analysis of Australian Hereford and Angus heifers and bulls for four ultrasonic measures of body composition - eye muscle area, rib fat, rump fat and intramuscular fat per cent - found parent-of-origin effects for both parents in most trait-gender data sets and that they were an average of 28% of the total genetic variance. No parent-of-origin effects were found for Hereford bull intramuscular fat per cent and the maternal parent-of-origin effects were not significant for Angus Heifer eye muscle area.     

肉牛多杀性巴氏杆菌的分离鉴定及药敏分析

为调查多杀性巴氏杆菌在河北省部分地区肉牛群中的流行情况,本课题组从规模化肉牛养殖场中采集患有呼吸道综合征的病牛鼻腔拭子进行细菌分离鉴定、荚膜血清分型、毒力基因检测、动物攻毒试验及药物敏感性分析。结果显示,从105份鼻腔拭子中共分离了25株多杀性巴氏杆菌;菌株荚膜分型均为A型,携带ptfA、exbB和nanH等多种毒力基因,LD_(50)显示多数菌株毒力较强;分离菌株对大多数药物敏感性较高,但对复方新诺明、磺胺间甲氧嘧啶、磺胺二甲氧嘧啶和林可霉素药物耐药性较高,耐药率达到80%以上。     

Morphological assessment of beef cattle according to carcass value

In this paper we present an assessment function devised for bulls of a beef breed according to the specific market requirements of their carcasses. The procedure is completely repeatable since it is based on the measurements in centimeters of only 3 lengths of live animals plus an estimation of the curvature of the round profile. To derive this assessment, we used Artificial Intelligence tools based on Support Vector Machines (SVM). They allowed us to learn the estimations of the experts of the Association of Breeders (ASEAVA) about the value of carcasses of the animals in the sense that the score returned by the assessment function (on a scale 0–100) is higher for bulls with more valuable carcasses. Additionally, we studied the growth of bulls in order to adjust the assessments to a constant age of 365 days.     

从肉牛到牛肉的经济指标分析

【目的】为了解现阶段肉牛到牛肉之间的联系现状和产出能力,掌握主要经济指标,确定计算肉牛产值的依据。 【方法】以张掖市肉牛与牛肉之间的联系现状为例,从中选取１个能够代表现阶段生产水平的随机样本（n=11777）,利用统计分析方法进行分类和分组,列出次数分布表与分布图,研究宰前重、胴体重、净肉重、屠宰率和净肉率5个变量的频率分布,并根据平均数() 和标准差（S）及其分布规律推算出总体平均数u的概率置信区间代表群体生产水平,作为计算肉牛产值的依据。【结果】现阶段进行肉牛生产的主要品种为西门塔尔、安格斯和荷斯坦,公牛育肥产肉占84.54%。其中西门塔尔占74.61%居主导地位,安格斯占16.08%,荷斯坦占9.31%。西门塔尔牛以宰前重在500~700kg的小架子牛育肥产肉占56.12%居主导地位,依次为大架子育肥占39.28%、小牛肉占2.57%和成年牛占2.03%。肉牛宰前重、胴体重、净肉重和屠宰率、净肉率5个指标样本分组频率与正态分布理论概率相关度高、绝对差值小,概率相近。 【结论】现阶段生产牛肉的主要品种有西门塔尔、安格斯和荷斯坦,以公牛育肥为主。主导品种西门塔尔牛生产周期有缩短趋势,小牛肉生产起步。 西门塔尔牛群的宰前重、胴体重、净肉重和屠宰率、净肉率均值为：684.94kg、385.16kg、316.85kg和56.47%、45.71%时,区间为：581.33≦x≦788.55、321.9≦x≦448.40、266.09≦x≦367.61、53.85≦x≦59.09、42.57≦x≦48.85。 大群体宰前重、胴体重和屠宰率的均值为：678.13kg、379.54kg和55.81%%,区间为572.63≦x≦783.63 、311.42≦x≦447.66、52.34≦x≦59.28 。 反映肉牛生产水平的5个经济指标的概率分布为正态分布,平均值（）一倍标准差左右取值概率为0.6827,可用概率密度函数公式进行相应的计算。根据正态分布特点,平均值左右一倍标准差范围内取值的概率最大为,平均值即为群体盈亏平衡点,且主导品种的宰前重、胴体重和屠宰率较大群体分别高6.81kg、5.62kg和0.66%。 祁连牧歌实业有限公司为张掖市规模最大肉牛屠宰加工企业,屠宰牛源为周边规模养殖场育肥牛,该结果能够代表张掖市域内肉牛大群体生产水平,指标平均值（）可以作为计算肉牛产值的统计依据。 生产中可以此为标准对经营情况进行分析,当个体牛只或经营单位的宰前重、胴体重、净肉重和屠宰率、净肉率高于平均值时说明该牛只育肥状况较好或该经营单位经营状态良好,大概率保持盈利。     

DNA检测用于亲子鉴定的基本原理

目前国内外已经开展了动物的亲子鉴定工作。在公安、军队等专业部门(如保证工作犬血统纯正,建立警、军犬数据库等)和动物检疫检测(如检测动物疾病、鉴定性别等)等部门都开始得以应用。同时,由于社会经济的发展,不少有条件的百姓家中也养起了价格昂贵的犬种,为了确保犬的血统纯正,也寻求做亲子鉴定工作。让我们来了解一下这项高科技生物技术的基本原理。     

The value of using DNA markers for beef bull selection in the seedstock sector

The objective of this study was to estimate the value derived from using DNA information to increase the accuracy of beef sire selection in a closed seedstock herd. Breeding objectives for commercial production systems targeting 2 diverse markets were examined using multiple-trait selection indexes developed for the Australian cattle industry. Indexes included those for both maternal (self-replacing) and terminal herds targeting either a domestic market, where steers are finished on pasture, or the export market, where steers are finished on concentrate rations in feedlots and marbling has a large value. Selection index theory was used to predict the response to conventional selection based on phenotypic performance records, and this was compared with including information from 2 hypothetical marker panels. In 1 case the marker panel explained a percentage of additive genetic variance equal to the heritability for all traits in the breeding objective and selection criteria, and in the other case to one-half of this amount. Discounted gene flow methodology was used to calculate the value derived from the use of superior bulls selected using DNA test information and performance recording over that derived from conventional selection using performance recording alone. Results were ultimately calculated as discounted returns per DNA test purchased by the seedstock operator. The DNA testing using these hypothetical marker panels increased the selection response between 29 to 158%. The value of this improvement above that obtained using traditional performance recording ranged from $89 to 565 per commercial bull, and $5,332 to 27,910 per stud bull. Assuming that the entire bull calf crop was tested to achieve these gains, the value of the genetic gain derived from DNA testing ranged from $204 to 1,119 per test. All values assumed that the benefits derived from using superior bulls were efficiently transferred along the production chain to the seedstock producer incurring the costs of genotyping. These results suggest that the development of greater-accuracy DNA tests for beef cattle selection could be beneficial from an industry-wide perspective, but the commercial viability will strongly depend on price signaling throughout the production chain.     

肉牛百日肥育方法

所谓肉牛百日肥育,是指把350kg以上的改良架子牛,分3个期段(适应期、正常育肥期、强化育肥期),经过3个多月的肥育,使牛的体重达到500~550kg,膘度达到不露肋骨、不露腰角、不露坐骨结节、不露脊骨的4不露标准,而且食肚要小,屠宰率达到56%左右。具体肥育方法是:1选购架子牛架子牛的优劣与肥育速度及肉牛品质关系甚大,是确保高效饲养的首要环节,应注意以下几个方面。1.1品种:应选购肉用牛的杂交后代,如西门塔尔牛、利木赞牛、德国黄牛、夏洛来牛与本地牛附:肉牛肥育日粮配方(表1)、添加剂配方(表2)表1肉牛肥育日粮配方g阶段精料粗料合计玉米高…     

肉牛养殖中饮水管理注意事项

随着肉牛养殖业的不断发展,养殖户越来越注重精粗饲料的高效利用以及饲养管理水平的提升,往往容易忽视养殖过程中最基础同时也是非常重要的环节——饮水管理。适宜的饮水条件不仅可以降低肉牛疾病的发生,还可提高饲料消化率及生产性能,从而提高经济效益。     

Dwarfism in beef cattle: Diagnosis and control

Abstract

Extract

In a previous publication dealing with the active immunity of mice to Salmonella typhimurium, it was shown that, by varying the interval of time between vaccination and challenge, two phases of increased resistance were observed (Jonas, 1967a Jonas, W. E. 1967a. Studies on the immunological aspects of salmonellosis of mice. Active immunity. N.Z. vet. J., 15: 27–30. [Taylor &; Francis Online] , [Google Scholar]). Phase I resistance occurred from 3 to 11 days after vaccination and phase II from 15 to 21 days.     

草颗粒饲料在牛瘤胃内的降解与饲养价值

用3头瘘管牛，以尼龙袋法（in situ)测定草颗粒，牧草与秸秆在瘤胃培养24hDM、CP、NDF和ADF的消失率，结果表明，草颗粒中营养物质的消失率均高于秸秆和羊草及秋白草，用颗粒饲料喂育肥牛，牛的日增重和饲料转化率均显著高于对照组，颗粒饲料的密度增加，牛的采食速度加快30%-50%。     

肉牛胚胎移植操作技术

肉牛胚胎移植技术分为手术法和非手术法。从实际操作和生产应用的角度看 ,目前重点推广非手术法。1　供体牛的选择和超数排卵1 1　供体牛供体牛 (Ｄｏｎｅｒ)必须具备本品种的典型体征和优秀的生产性能 ,牛体健康 ,年龄一般在 3岁以上 ,青年牛可宽至 1 8月龄左右 ,繁殖机能正常 ,黄体发育良好 ,具备超数排卵的基本条件。1 2　超数排卵供体牛的超数排卵 (Ｍｕｌｔｉｐｌｅｏｖｕｌａｔｉｏｎ ,ＭＯ)在自然发情或诱导发情的第 9～ 1 3天实施。常用超排方法有 3种。1 2 1　促卵泡素 (ＦＳＨ)和促黄体素 (ＬＨ)联合处理法 :供体牛在发情后的…     

Utilization of beef from different cattle phenotypes to produce a guaranteed tender beef product

Cattle (n = 303) were visually selected from four feed yards to represent six phenotypes (English [EN; n = 50], 3/4 English-1/4 Brahman [ENB; n = 52], 1/2 English-1/2 Exotic [ENEX; n = 56], 1/2 English-1/4 Exotic-1/4 Brahman [ENEXB; n = 47], 3/4 Exotic-1/4 Brahman [EXB; n = 49], and 1/2 Exotic-1/4 English-1/4 Brahman [EXENB; n = 49]). Carcasses were processed at a commercial beef packing facility, and strip loins were collected after 48-h chilling. Strip loins were aged for 14 d at 2 degrees C and frozen at -20 degrees C for 3 to 5 d before three 2.5-cm-thick steaks were cut for Warner-Bratzler shear force (WBSF) determinations and sensory evaluations. Phenotype EN had the highest (P < 0.05) adjusted fat thickness, and EXB had adjusted fat thickness that was lower (P < 0.05) than all other phenotypes except EXENB. Carcasses of EN and ENB had smaller (P < 0.05) longissimus muscle areas than phenotypes ENEX, EXB, and EXENB. Phenotype EN produced carcasses with the highest (P < 0.05) numerical yield grade, whereas carcasses originating from phenotype EXB had lower (P < 0.05) numerical yield grades than all other phenotypes except ENEX. No differences (P > 0.05) were found among phenotypes for mean WBSF values or sensory panel ratings for initial and sustained tenderness, initial and sustained juiciness, beef flavor characteristics, and overall mouthfeel. More than 90% of steaks from carcasses of all phenotypes had WBSF values less than 3.6 kg when cooked to an internal cooked temperature of 70 degrees C. Results from this study indicated that all phenotypes represented in this study could be managed to produce tender beef.     

Prediction of enteric methane emission from beef cattle in Southeast Asia

We conducted a meta‐data analysis to develop prediction equations to estimate enteric methane (CH₄) emission from beef cattle in Southeast Asia. The dataset was obtained from 25 studies, which included 332 individual observations on nutrient intakes, digestibilities, and CH₄ emissions. Cattle were provided tropical forage or rice straw, with or without concentrates in individual pens equipped with indirect open‐circuit head hood apparatus. The simplest and best equation to predict daily CH₄ emission was CH₄ (g/day) = 22.71 (±1.008) × dry matter intake (DMI, kg/day) + 8.91 (±10.896) [R² = 0.77; root mean square error (RMSE) = 19.363 g/day]. The best equation to predict CH₄ energy as a proportion of gross energy intake (CH₄‐E/GEI, J/100 J) was obtained using DMI per body weight (DMIBW, kg/100 kg), content (g/100 g DM) of ether extract (EE) and crude protein (CP), and DM digestibility (DMD, g/100 g); CH₄‐E/GEI = ?0.782 (±0.2526) DMIBW ? 0.436 (±0.0548) EE ? 0.073 (±0.0218) CP + 0.049 (±0.0097) DMD + 8.654 (±0.6517) (R² = 0.39; RMSE = 1.3479 J/100 J GEI). It was indicated that CH₄ emissions from beef cattle in Southeast Asia are predictable using present developed models including simple indices.