Morbidity, mortality and body weight gain of surgically spayed, yearling Brahman heifers

Objective To determine morbidity and mortality rates in yearling heifers spayed by two methods under commercial conditions in northern Australia. Design In study 1,600 Brahman heifers were allocated to one of three treatments: physical restraint and ear-tagging (Control); physical restraint, ovariectomy by the Willis dropped ovary technique, ear-tagging and ear-marking (WDOT); or electroimmobilisation, ovariectomy via flank incision, ear-tagging and ear-marking (Flank). Heifers were monitored post spaying. Mortalities occurred at unanticipated times, so study 2 investigated their timing and cause in similar WDOT-spayed heifers (n = 574). Results In study 1, morbidity on the day of spaying was 6.0% in the Flank and 2.7% in the WDOT group (not statistically different). Spayed heifers showed behaviours indicative of acute pain/discomfort in the 6 h post spaying. Body weights and gains were significantly lower in the spayed compared with control heifers at days 21 and 42, and 5% of flank wounds were not healed at day 42. Mortalities were 0%, 1.5% and 2.5%, respectively, for Control, WDOT (3 estimated to have occurred on day 11) and Flank (2 on the day after spaying and 1 on each of days 5, 11 and 22). In study 2, the mortality was 0.5%, all within 4 days of spaying. Conclusions In yearling heifers, WDOT spaying resulted in lower morbidity and short-term mortality compared with flank spaying. Both methods compromised the health and welfare of some animals for up to 4 days and body weight gains were reduced during the 6 weeks post spaying.     

Comparison of carcass and meat characteristics of Brahman grade cattle (Bos indicus) and crossbred water buffalo (Bubalus bubalis)

This study was conducted to determine and compare the live traits, carcass yield and the physical, chemical, processing and sensory properties of meat from 20 Brahman grade cattle (crossbred cattle) and crossbred water buffalo (Philippine carabao × Murrah, Bulgarian or Indian) with an average age and weight of 29 months and 434 kg, respectively. The animals were fed a similar diet for 180 days before slaughter. A survey was performed to establish consumer meat preference between the two species. Live weights before slaughter of the two species were found to be different (P < 0.05) with the crossbred water buffalo showing higher bodyweight. However, the crossbred water buffalo had a lower (P < 0.05) dressing yield based on hot carcass weight and chilled carcass weight. The lower dressing yield of crossbred water buffalo can be attributed to its higher (P < 0.05) weights of edible and non‐edible slaughter by‐products. The chilled carcass yield of the forequarters and hindquarters from crossbred cattle and crossbred water buffalo were comparable when expressed as percent of live weight and chilled carcass weight. The estimated lean yield was higher in crossbred cattle than crossbred water buffalo. Crude protein, ash, fat, cholesterol, myofibrillar, sarcoplasmic and insoluble protein contents of the beef and carabao meat were all similar. Water holding capacity, pH, muscle fiber diameter, tenderness, firmness and marbling score in carabeef were all comparable to the beef. Redness was found to be higher (P < 0.05) in carabeef than the beef as measured with a color meter. The consumer meat preference survey showed that 55.9% selected the beef while 44.1% preferred carabeef. The color and amount of fat on the outside of the beef sample were primary in buyer selection.     

Comparison of carcass and meat characteristics of Brahman grade cattle (Bos indicus) and crossbred water buffalo (Bubalus bubalis) fed on high roughage diet

The objective of this study was to compare the carcass and meat quality in crossbred cattle and crossbred water buffalo at the same younger age and fed with high roughage in the Philippines. Ten crossbred cattle and 10 crossbred water buffalo, with an average age of 22 months (18–24 months) were used in this experiment. The animals were fed a similar diet, which consisted of 85% Napier or Para grass and 15% concentrate mixture on a dry matter basis, for 180 days before slaughter. Slaughter weight of the crossbred water buffalo was higher (P < 0.05) than that of the cattle, although the dressing percentage was significantly (P < 0.01) lower for the former than for the latter. The estimated lean yield was higher (P < 0.05) in crossbred cattle than crossbred water buffalo. The muscle fiber diameter of loin in buffalo meat was smaller (P < 0.05) than that in cattle. In regard to carcass and meat quality, the crossbred water buffalo was comparable or slightly superior to the crossbred cattle in tenderness, sensory score of color (P < 0.01) and flavor (P < 0.05). These results clearly indicate that at a younger age and even under high roughage‐based fattening rations, crossbred water buffalo are able to produce good quality meat, which will be by no means inferior to that of crossbred cattle in the Philippines.     

Effect of the last diet on the selective feeding behavior of heifers

The present study examined and discussed the way the basal diet (BD) during the preliminary phase and the last diet (LD) before the food selection test affected the selective feeding behavior of heifers. For the BD and LD, oat hay and concentrate were used. Three different levels of roughage content (low, medium and high) were prepared by changing the mix ratios of oat hay and concentrate. Low and high roughage diets were used for the BD, and all three of the roughage levels were used for the LD. A mixture of orchard grass and white clover (MIX), and Japanese pampas grass leaf (JP) were used as testing foods. In the preliminary phase, all heifers were fed the BD three times per day. In the test phase, heifers were fed the LD for the first meal (06.00–12.00 hours), and food selection under different BD and LD was examined during the second meal (13.00–16.00 hours) of the day. The effects of the BD were significant for MIX dry matter intake (DMI), JP DMI and the rate of MIX DMI for total DMI. Under the high roughage BD condition, heifers ingested more MIX than under the low roughage BD condition. The effect of the LD was significant on JP DMI, whereas the rate of MIX DMI for total DMI was not significant. Selective feeding behavior was strongly affected by the BD and slightly by the LD.     

Differences in the behavior of the crossbred steers of different sire lines of Japanese Black cattle

We determined differences in the behavior of the progeny of two major sire lines of Japanese Black cattle by recording the behavior of 35 and 70 half-sib steers of sires from fast (FG) and slow (SG) growing lines, respectively. Two sire lines of steers were mixed and allocated to nine pens with 11–12 animals per pen. The proportion of steers lying was significantly (P < 0.001) higher in the SG line (43.4 ± 5.7% compared to 40.3 ± 6.0%). The proportion of time spent eating concentrate feed (FG: 12.1 ± 2.3%; SG: 11.4 ± 2.1%), drinking (FG: 0.8 ± 1.1%; SG: 0.4 ± 0.6%), licking the feed trough (FG: 0.4 ± 0.6%; SG: 0.2 ± 0.4%) and performing tongue-playing (FG: 3.1 ± 4.6%; SG: 1.0 ± 1.9%) was significantly higher in FG, whereas the proportion of time spent resting (FG: 41.5 ± 12.8%; SG: 43.7 ± 10.9%) and performing self-licking (FG: 1.7 ± 1.4%; SG: 2.1 ± 1.3%) was higher in SG (all P < 0.05). These results show progeny of the FG sire engaged in more active behaviors compared to the progeny of the SG sire line.     

Eating and rumination behaviour in Brahman grade cattle and crossbred water buffalo fed on high roughage diet

The purpose of this study is to compare feeding and other behavior and nutrient digestibility of tropical grade Brahman (body weight (BW) = 231 kg ± 12.4; n = 3) and crossbred water buffalo (BW = 300 kg ± 13.9; n = 3). This experiment on digestibility and measures of muscles of mastication utilized one‐way, and animal behavior two‐way, analysis of variance, respectively. Two video camcorders were installed in each pair of buffalo and Brahman for 24 h period programmed on the 107th, 109th and 111th days of the digestion trials. Frequency and duration of feeding, meal intake, rumination, bolus, chews, drinking, defecating, standing and lying were recorded daily. Muscle diameter of Digastricus, Masseter and Pterygoid and different regions of the tongue were sampled and measured under light microscope using a standard micrometer. Buffalo obtained significantly higher intake of dry matter, roughage, crude protein, total digestible nutrient and metabolized energy than Brahman. This was supported by longer meal duration (P ≤ 0.05), and shorter meal breaks (P ≤ 0.05) of buffalo than Brahman. The diameter of the muscles for mastication was bigger (P ≤ 0.05) in buffalo than in Brahman, which is indicative of stronger chewing ability. Briefly, lesser and slower chewing action; higher intake of roughage and crude protein; and longer resting behavior of crossbred water buffalo than Brahman are all indicative of better digestive and metabolic performance of the buffalo under high roughage feeding conditions.     

Effects of defaunation and dietary coconut oil distillate on fermentation,digesta kinetics and methane production of Brahman heifers

A 2 × 2 factorial experiment was conducted to assess the effects of presence or absence of rumen protozoa and of dietary coconut oil distillate (COD) supplementation on rumen fermentation characteristics, digesta kinetics and methane production in Brahman heifers. Twelve Brahman heifers were selected to defaunate, with 6 being subsequently refaunated. After defaunation and refaunation, heifers were randomly allocated to COD supplement or no supplement treatments while fed an oaten chaff‐based diet. Methane production (MP; 94.17 v 104.72 g CH₄/d) and methane yield [MY; 19.45 v 21.64 g CH₄/kg dry matter intake (DMI)] were reduced in defaunated heifers compared with refaunated heifers when measured at 5 weeks after refaunation treatment (p < 0.01). Supplement of COD similarly reduced MP and MY (89.36 v 109.53 g/d and 18.46 v 22.63 g/kg DMI, respectively; p < 0.01), and there were no significant interactions of defaunation and COD effects on rumen fermentation or methane emissions. Concentration of total volatile fatty acid (VFA) and molar proportions of acetate, propionate and butyrate was not affected by defaunation or by COD. Microbial crude protein (MCP; g/d) outflow was increased by defaunation (p < 0.01) in the absence of COD but was unaffected by defaunation in COD‐supplemented heifers. There was a tendency towards a greater average daily gain (ADG) in defaunated heifers (p = 0.09), but COD did not increase ADG (p > 0.05). The results confirmed that defaunation and COD independently reduced enteric MP even though the reduced emissions were achieved without altering rumen fermentation VFA levels or gut digesta kinetics.     

不同杂交品种肉牛背最长肌LPL基因表达的发育性变化及其对IMF的影响

选择西杂、利杂、利草杂交肉牛共42头为研究对象,以品种为单位,随机分为3组,饲喂相同营养水平的日粮,在饲养的第90、180、270天按比例屠宰,研究不同杂交品种肉牛背最长肌和半腱肌IMF含量随时间的变化规律;采用荧光RT-PCR技术,检测不同杂交品种肉牛背最长肌LPL mRNA表达量的变化规律。结果表明:IMF含量品种间存在差异,利杂牛含量最高;屠宰部位间存在差异,背最长肌IMF含量高于半腱含量。背最长肌LPL表达量对肌内脂肪沉积有显著的影响,并且存在品种的特异性,利杂牛和利草杂牛LPL表达量和IMF含量存在显著的正相关。     

全株玉米青贮与湿玉米芯饲喂肉牛效果对比

[目的]试验旨在研究全株玉米青贮与湿玉米芯饲喂肉牛效果对比,[方法]选择体重450 kg左右的西门塔尔杂交牛30头,随机分为2组,保证精饲料不变,分别饲喂全株玉米青贮与湿玉米芯,试验期70 d。[结果]结果表明,(1)全株玉米青贮组的日增重显著高于玉米芯组(P<0.01),比玉米芯组高出20.92%,全株玉米青贮组的料重比较玉米芯组低21.16%;(2)每头牛全株玉米青贮组的养殖效益为15.38元/d,比玉米芯组高出52.37%。[结论]综上所述,全株玉米青贮组的饲喂效果优于湿玉米芯组。     

Effects of feeding level on efficiency of high- and low-residual feed intake beef steers

Comparing heat production after ad libitum (ADLIB) and restricted (RESTRICT) feeding periods may offer insight into how residual feed intake (RFI) groups change their energy requirements based on previous feeding levels. In this study, the authors sought to explain the efficiency changes of high- and low-RFI steers after feed restriction. To determine RFI classification, 56 Angus-cross steers with initial body weight (BW) of 350 ± 28.7 kg were individually housed, offered ad libitum access to a total mixed ration, and daily intakes were recorded for 56 d. RFI was defined as the residual of the regression of dry matter intake on mid-test BW^0.75 and average daily gain. High- and low-RFI groups were defined as >0.5 SD above or below the mean of zero, respectively. Fourteen steers from each high and low groups (n = 28) were selected for the subsequent 56-d RESTRICT period. During the RESTRICT period, intake was restricted to 75% of previous ad libitum intake on a BW^0.75 basis, and all other conditions remained constant. After the RESTRICT period, both RFI groups had decreased maintenance energy requirements. However, the low-RFI group decreased maintenance energy requirements by 32% on a BW^0.75 basis, more (P < 0.05) than the high-RFI group decreased maintenance requirements (18%). Thus, the low-RFI steers remained more efficient after a period of feed restriction. We conclude that feed restriction decreases maintenance energy requirement in both high- and low-RFI groups that are restricted to the same degree.     

Effect of Pre- and Post-Partum Feed Supplementation on the Productive and Reproductive Performance of Grazing Primiparous Brahman Cows

This experiment studied the combined effect of pre- and post-calving feed supplementation on the productive and reproductive performance of primiparous Brahman cows. The animals were 4 years old (420 kg live weight) and pregnant, and grazed rotationally on Stargrass (Cynodon nlemfuensis) pastures. Supplementation was given before and after (T1, n = 15), only before (T2, n = 15) or only after (T3, n = 16) calving, and there was an unsupplemented control (T4, n = 16). The supplement (1.5 kg/animal per day, 13.4 MJ digestible energy/kg dry matter and 20% crude protein) was given for 45 days before and/or after calving. Changes in body weight and body condition score and the productive behaviour of the calves were similar (p>0.05) among treatments. The concentration of urea in the plasma was low in the control group (T4) before and after calving. The animals in all the groups had a poor reproductive performance. The percentage of cows in oestrus was higher (p<0.05) in T1 (73.3%) than in T3 (37.5%). The interval from calving to conception (148.7±53.7 days) and the pregnancy rate (48.5%) were similar (p>0.05) among the treatments. The level of supplementation offered before and/or after calving did not improve the pregnancy rate.     

Ingestive behavior of supplemented Nellore heifers grazing palisadegrass pastures managed with different sward heights

Three sward heights (15, 25 and 35 cm) and three supplement types (energy, energy‐protein, and a mineral mix supplement) were evaluated in a 3 × 3 factorial arrangement distributed in a completely randomized design to study changes in forage search patterns in Nellore heifers in a continuous grazing system. Pasture data were collected using two replicates (paddocks) per treatment over four periods during the rainy season. The behavior assessments were made in the first and fourth grazing seasons. It was hypothesized that supplements and pasture management would modify ingestive behavior, considering that animals would require less time grazing if they had energy requirements met through higher digestibility of better managed paddocks, or use of supplements high in energy. Total and green forage masses along with green : dead material ratio were greater in treatments managed with higher sward heights. Sward managed with 35 cm height resulted in lower leaf : stem ratio compared with 15 cm sward height treatments. The animals on the 15 cm pastures spent more time grazing overall and during each meal, but there were no differences observed in meal numbers in comparison to 35 cm treatments. Heifers fed protein and/or energy supplements spent less time grazing in the early afternoon, but overall grazing time was the same for all animals.     

婆罗门牛及其改良云南黄牛的效果研究

通过婆罗门牛(种牛或冻精)与云南黄牛杂交改良比较,其F1代的初生重、6月龄断奶重、12月龄和18月龄体重分别比云南黄牛高64.53%、13.37%、24.87%、37.91%。24月龄F1代牛市场价每头比云南黄牛高出1500元。     

饲养模式对科尔沁肉牛育肥性能的影响

[目的]为研究饲养模式对科尔沁肉牛育肥性能的影响,特开展本试验研究,以期为农牧民提供饲养育肥牛的技术指导。[方法]选取体重体型均等的科尔沁肉牛架子牛120头,随机分为试验组1、试验组2与对照组,每组各40头。试验组1根据资料与经验制定为期185 d的饲养方案1,试验组2对养殖户自有饲养模式的饲料量与精粗配比优化后制定为期245 d的饲养方案2,对照组按照养殖户以往模式进行饲养,育肥期结束后称量体重,计算各组日增重数据。[结果]结果显示,试验组2的增重比试验组1与对照组分别提高37.2%与6.4%;试验组2与对照组的饲料利用率显著低于试验组1;经济效益方面试验组2的效益高于试验组1与对照组。结果表明试验组2为较合适的育肥牛饲养模式。[结论]试验证明,制定科学、系统的饲养模式,以合理的育肥时长、饲料摄入及精心的饲养管理,能够提高科尔沁肉牛育肥牛的育肥性能并获得更高的经济效益。     

日粮精粗比对思南杂交肉牛体尺性状和血液常规指标的影响

为研究日粮不同精粗比对思南杂交肉牛体尺性状与血液生化指标的影响,试验选择体重相近的12头思南杂交肉牛随机分为A、B、C、D共4个组,每组3个重复,每个重复1头牛,A、B、C、D组精粗比分别为3:7、4:6、5:5、6:4.结果表明:(1)提高思南杂交肉牛日粮精粗比可以促进体高、体斜长、胸围和管围的增长,并且各组后60天...     

科尔沁肉牛早期补饲饲养模式试验研究

[目的]通过试验探究科尔沁肉牛犊牛最佳的饲养模式,为后续科尔沁肉牛早期补饲的推广和普及提供理论支持。[方法]选取体型相近,初生体重在34～50 kg之间健康的科尔沁肉牛犊牛60头,分为对照组、补饲组1、补饲组2,每组20头,补饲组按试验方案进行早期补饲,对照组按传统饲养模式饲养,对比6月龄各项数据及试验牛母牛产后发情情况,进行分析总结。[结果]补饲组与对照组相比,犊牛生长发育效果差异显著,试验母牛产后恢复明显加快,产后90 d内发情母牛占比显著提高。[结论]科尔沁肉牛犊牛早期补饲更利于犊牛后期生长发育,促进母牛早发情提高繁殖能力,结合数据分析得出早期补饲至6月龄是更为适合科尔沁肉牛犊牛的饲养模式。     

复合添加剂对肉牛生长性能和代谢参数的影响

由于复合添加剂具有控制代谢问题和提高动物生长性能的能力,最近已被用于动物饲料中。本研究评估了复合添加剂摄入量是否会改变肉牛瘤胃发酵参数或动物生长性能。试验共分为两个部分,生长试验和代谢试验,其中生长试验分为生长期(42 d)和育肥期(84 d),共48头肉牛(12个平行),而代谢试验共4种日粮。结果显示:在生长试验中,复合添加剂提高了肉牛干物质摄入量和反刍时间(P <0.05)。在育肥期中,日粮添加复合添加剂较对照组显著提高了干物质摄入量(P <0.05),各处理对瘤胃发酵指标无显著影响(P> 0.05)。综上所述,在肉牛生长期日粮中添加复合添加剂(氨基酸+维生素+有机矿物质+益生菌+必需脂肪酸)可以提高干物质摄入量和反刍时间。     

Effect of pre- and postweaning management system on the performance on Brahman crossbred feeder calves

During a 3-yr period (1986 through 1988), 117 calves (57 steers and 60 heifers) from the same genetic base and reared under four distinct preweaning management systems were weaned in the fall and transported from Uvalde, TX to El Reno, OK (800 km). Weaning weight and transportation shrink varied more from year to year than among preweaning treatments. Postweaning performance was not affected by preweaning treatment. After a 28- to 32-d receiving period the calves were blocked by sex and previous preweaning treatment, then randomly assigned within block to graze winter wheat forage (WHEAT) or dormant tall-grass native range (GRASS). The WHEAT group gained more (P less than .01) weight than the GRASS group during the winter (November to March), but when both groups were allowed to graze spring wheat pasture (March to June) the GRASS group gained more (P less than .01) weight than the WHEAT calves. During the subsequent finishing phase the GRASS calves were more (P less than .01) efficient than the WHEAT calves in converting DM to gain. Because cattle were slaughtered at the same degree of finish, no differences were noted in carcass characteristics among the pre- or postweaning treatments. Feeder calves exposed to a restrictive period of growth during the postweaning period gained weight more rapidly in a subsequent forage-based stockering system and were more efficient in a grain-based finishing system than nonrestricted calves.     

BMY牛与婆罗门牛的毛色遗传

为了解BMY牛和婆罗门牛的毛色遗传,本文分析了BMY牛和婆罗门牛的生产资料,以期在BMY牛新品系的经济性状达到稳定遗传的同时,也达到毛色的相对固定。BMY牛和婆罗门牛的红色、黑色和灰色所占比例分别为31.55%、16.04%、14.98%和44.03%、0、11.19%。BMY牛3个毛色个体的比例占群体的62.57%,这暗示着还存在很大的选择潜力。基于毛色的遗传基础,推测BMY牛红毛和灰毛两个品系将快于黑毛品系育成。另外,我们也认为尽管毛色标志着品种的基本特征,但也不能一味强调对毛色的选种选配,而应更注重于经济性状的选择与提高。     

Dystocia in beef heifers: A review of genetic and nutritional influences

Breeding beef heifers for the first time at 15 months of age has potential to increase the efficiency of the beef breeding-cow herd. An increased incidence of dystocia in heifers calving at 2 years of age, compared to mature cows, is a major reason many farmers in New Zealand have not adopted the practice. The predominant type of dystocia affecting 2-year-old heifers is feto-maternal disproportion, a condition in which the fetus is too large relative to the size of the heifer's pelvis. Reducing birthweight of the calf is a means of reducing the incidence of dystocia. Birthweight and length of gestation are determined by genotype of the calf, maternal genetic effects and environmental effects.

Bulls with low estimated breeding values for birthweight have been selected for mating heifers; however, the positive genetic correlation between birthweight and mature weight meant that the progeny of these bulls tended to be lighter at finishing, making them less desirable in the beef industry. The genotype of the dam also plays a role in determining the risk of dystocia; the maternal ability of the dam to nurture the fetus influences birth- weight, and the dam's genetic potential for growth influences the size of her pelvic area. Heavy heifers tend to produce high- birthweight calves, counteracting the reduction in the incidence of dystocia resulting from the larger pelvis in larger heifers.

Manipulating feeding level during pregnancy offers an alternative method for manipulating the birthweight of calves. Little is known about the effects of nutrition in early gestation on placental development or birthweight of calves. No differences in the birthweight of calves have been observed in response to variation in feeding in mid-pregnancy, and variable responses in birthweight and the incidence of dystocia to feeding in the third trimester of pregnancy have been reported. Differences in birthweight have not always resulted in differences in the incidence of dystocia, primarily due to differences in liveweight of the heifer also induced by feeding regimens. Variability in the incidence of dystocia in response to feeding level in the third trimester of pregnancy makes it difficult to make recommendations for the feeding of heifers at this stage of gestation. More research is needed into the effects of nutrition in early gestation on fetal and placental development in cattle.