肉用犊牛早期断奶的饲养管理

<正>在现代肉牛生产中,为了提高生产效率,通常采取犊牛早期断奶,即犊牛哺乳45~60 d之后进行断奶。本文简述哺乳期为60 d早期断奶肉用犊牛的饲养管理。1肉用犊牛的饲养1.1哺乳1.1.1哺喂初乳(出生3日龄内)初乳营养丰富,含有免疫球蛋白、酶类等,新生犊牛依靠摄入初乳来获得被动免疫能力,抵抗病原微生物的侵袭,犊牛尽早适量摄入初乳,生产中尤为必要。     

用大豆蛋白做肉用犊牛代乳料的进一步研究

在美国,肉用犊牛饲料的生产专业化程度很高,绝大部分肉用犊牛饲料产于东北部和中西部各州。1991年Halone公司和Moore公司对肉用犊牛业进行了全面调查,他们估计全美向用犊牛饲料年产量约为25万吨。近年来,乳犊牛的屠宰数量急剧减少,导致这一现象的主要原因是奶牛存栏数下降和肉用乳牛生产上升。犊牛宰杀总数由1977年570万头降至1989年220万头。同时,行业资料表明,1977年向用犊牛宰杀数量为120万头、1990年降到85万头。专家们认为肉用犊牛的屠宰数量将维持在1990年的水平上。     

犊牛早期断乳的要点

过多的哺乳量和过长的哺乳期虽然可以取得较高的日增重及断奶重,但不利于犊牛消化器官的生长发育和机能锻炼,影响犊牛的健康、体型和以后的生产性能。早期断奶能显著缩短母牛的产后发情间隔时间,使母牛早发情、早配种、早产犊,缩短产犊间隔,提高母牛的终生生产力和降低生产成本。随着今后肉用母牛养殖规模化和专业化程度的提高,早期断乳技术在提高母牛生产效率方面将是最有效、最快捷的技术之一。     

肉用犊牛饲养管理技术探究

本文主要针对肉用犊牛饲养管理技术展开深入的研究,先阐述了肉用犊牛的饲养技术,如肉用犊牛初生期的饲养技术、肉用犊牛哺乳期的饲养技术、肉用犊牛断奶期的饲养技术等,然后又提出了几点切实可行的管理技术,主要包括犊牛的生理特征、管理技术、疾病防治,进而实现肉用犊牛饲养管理,防止存在病害的现象,保障犊牛饲养健康生长.     

肉用种母牛饲养管理技术要点

正要使肉用种母牛的效益高,必须做到每年从每头母牛获得一头犊牛,而母牛饲养管理科学与否,左右着母牛受配率和受胎率乃至产后犊牛的成活率,对能否达到饲养者的目的,起着决定性作用。一般情况下,母牛若营养不足,管理不当,会导致犊牛初生重小、生长慢、成活率低。可见,饲养管理对母牛的生产效率至关重要。为此,笔者根据自己多年的临床经验阐述肉用种母牛的饲养管理要点。一、妊娠母牛饲养管理     

母牛妊娠期和哺乳期的饲养技术

对于养殖场来说,繁殖母牛饲养管理的好坏,在一定程度上会影响到整个养殖场的整体经济效益。为了保障母牛拥有较高的繁殖性能,确保分泌的乳汁品质较高,拥有较强的哺乳犊牛的能力,确保犊牛断奶之后能够快速发情,快速排卵,就需要注重做好肉用母牛妊娠阶段和哺乳阶段的饲养管理工作,以此来提高母牛的生产效率和生产质量,为推动规模化养殖产业的健康发展奠定坚实基础。     

犊牛早期断乳的要点

<正>过多的哺乳量和过长的哺乳期虽然可以取得较高的日增重及断奶重,但不利于犊牛消化器官的生长发育和机能锻炼,影响犊牛的健康、体型和以后的生产性能。早期断奶能显著缩短母牛的产后发情间隔时间,使母牛早发情、早配种、早产犊,缩短产犊间隔,提高母牛的终生生产力和降低生产成本。随着今后肉用母牛养殖规模化和专业化程度的提高,早期断乳技术在提高母牛生产效率方面将是最有效、最快捷的技术之一。1优点节约商品乳及代乳料降低犊牛培育成本。减少     

肉用绵羊高效繁殖与饲养技术

随着我国人均收入水平的提高,羊肉消费量日渐增长,但肉羊的繁殖效率较低,使得肉羊产量在短期内难以实现大幅提高.本文从肉用绵羊的良种繁育、品种杂交筛选、繁殖调控、饲养管理、羔羊育肥、疫病监控和粪污处理利用技术等方面进行了介绍,以期为实现肉用绵羊良种繁育体系的规范化,营养供应和饲料生产的标准化和安全化,商品肉羊生产的模式化和程序化,大幅度提高肉用绵羊产品的附加值提供参考,从而促进肉用绵羊养殖业生产效率的提高.     

提高肉用犊牛存活率、健犊率的新措施

肉用犊牛的健康成长直接关系到我国肉牛养殖业的经济发展,但由于犊牛各身体器官发育不完善,对于环境的适应能力比较差,尤其在出生后的10～20d内,容易受到外界病菌和微生物的侵袭,进而产生疾病甚至是死亡,如何提高肉用犊牛存活率和健犊率成为当前肉牛养殖的关键.基于此,本文从笔者多年实践经验出发,加强犊牛管理,并最终提高犊牛的成...     

奶公牛的育肥(下)

奶公犊牛育肥肉用是绝大多数奶公犊牛的出路。用乳牛群来生产肉牛,饲料利用效率和经济效益都较高。乳用母牛除生产犊牛外,还生产大量的商品奶,母牛的饲料消耗     

温度对5个蓝莓品种花粉发芽率及坐果率的影响

本研究以5个蓝莓品种为试材,检测不同温度处理2 h后花粉发芽率及自交坐果率。结果表明：温度处理结束后,5个蓝莓品种花粉发芽率随培养时间的延长而增加,整体上呈现出随温度升高而降低的趋势。温度处理后花粉培养12 h的结果表明,蓝丰花粉在处理温度为25℃-37℃时发芽率最高,显著高于其余4个品种;在处理温度为41℃时,花粉发芽率最低,仅为0.67%。处理温度为39℃-41℃时,瑞卡为花粉发芽率最高的品种,显著高于其余4品种。高温降低了5个蓝莓品种的坐果率,布里吉塔坐果率在处理温度达到33℃时显著下降,较对照降低了22.96%。蓝丰、瑞卡和都克坐果率在处理温度为35℃时显著降低。处理温度为41℃时,五个品种中蓝丰坐果率最高。高温降低了5个蓝莓品种花粉发芽率和坐果率。处理温度相同时,花粉发芽率存在品种间差异。瑞卡是39℃-41℃处理后花粉发芽率最高的品种。处理温度为25℃-41℃时,5个蓝莓品种坐果率存在品种间差异。     

Comparison of heart rate and heart rate variability obtained by heart rate monitors and simultaneously recorded electrocardiogram signals in nonexercising horses

Heart rate (HR) and heart rate variability (HRV) are often determined with Polar heart rate monitors (HRMs; S810i; Polar, Kempele, Finland). The aims of this study were to compare data from horses obtained by Polar HRMs and a portable Televet electrocardiogram (ECG; 100 version 4.2.3; Kruuse, Marslev, Denmark) device and to determine appropriate recording times in horses (n = 14). Correlations were calculated and a Bland-Altman analysis was carried out to examine agreement between recording systems. For beat-to-beat (RR) interval, uncorrected and corrected data were highly correlated irrespective of the recording system and recording time (r > 0.99, P < 0.001). For HRV variables, standard deviation of RR interval and root mean square of successive RR intervals, correlations higher than 0.9 were obtained between uncorrected and corrected ECG but not Polar data. The RR interval, HR, and HRV from corrected Televet and Polar data at no time differed between the recording systems. However, with the increase in recording time, the RR interval decreased (P < 0.001). Thus, for comparisons, recording intervals of similar length should be chosen. Correlations among RR interval, HR, and HRV variables obtained by ECG and HRMs were highly significant at all recording times (r > 0.9, P < 0.001). Correlations increased with increasing recording time. Bland-Altman graphs showed a strong agreement between HRMs and ECG and mean RR intervals, HR, and HRV variables were close to identical. In conclusion, Polar HRMs are as adequate as ECG recordings in horses. Owing to a low HR in stationary horses, recording times below 2 minutes will underestimate changes in HR and HRV.     

The effect of relaxing massage on heart rate and heart rate variability in purebred Arabian racehorses

The objective of this study was to assess the effect of relaxing massage on the heart rate (HR) and heart rate variability (HRV) in young racehorses during their first racing season. In the study, 72 Purebred Arabian racehorses were included. The study was implemented during the full race season. The horses from control and experimental groups were included in regular race training 6 days a week. The horses from the experimental group were additionally subject to the relaxing massage 3 days a week during the whole study. HR and HRV were assumed as indicators of the emotional state of the horses. The measurements were taken six times, every 4‐5 weeks. The HRV parameters were measured at rest, during grooming and saddling the horse and during warm‐up walking under a rider. The changes of the parameters throughout the season suggest that the relaxing massage may be effectively used to make the racehorses more relaxed and calm. Moreover, the horses from the experimental group had better race performance records.     

三种草坪草净光合速率和蒸腾速率的日变化特点研究

研究了在晴天的条件下，假俭草、细叶结缕草和地毯草净光合速率和蒸腾整编的日变化特点。结果表明：（1）假俭草和细叶绍缕草的净光合速率的日变化曲线均为双峰型，而地毯草为三峰型，3种草出现峰值的时间不同，均有明显的“午睡”现象，日平均净光全速率的大小顺序为俭草＞地毯草＞细叶结缕草；（2）假俭草和细叶结缕草的蒸腾速率的日变化曲线均为双峰型,而地毯草为单峰型，3种草出现峰值的时间有所判差别，“午睡”现象均不明显，日平均蒸腾速率的大小顺序为细叶绍缕草＞地毯草＞假俭草；（3）不同生态因子与3种草坪草净光合速率、蒸腾速率的相关程度均不相等。同种态因子与不同草坪草的净光合速率、蒸腾速率的相关程度也不一样。     

播种量与施氮量对夏播苏丹草生产性能的影响

本研究以新苏2号苏丹草(Sorghum sudanense ‘Xinsu No.2’)为研究对象,研究播种量与施氮量对夏播新苏2号苏丹草生产性能的影响。结果表明,当磷肥的施用量一定时,B1(播种量为22.5 kg·hm-2)和N3(施氮量为550 kg·hm-2)处理对株高的增长最有利;B1处理对主茎直径的增粗和单株分蘖数的增加最有利;B2(播种量为45 kg·hm-2)和N2(施氮量为415 kg·hm-2)处理对干草产量最有利,总干草产量分别达到19 200.0和19 744.5 kg·hm-2;B3(播种量为67.5 kg·hm-2)和N2处理的粗蛋白增产效果最佳,总粗蛋白产量分别达到1 607.03和1 572.00 kg·hm-2。从干草和粗蛋白产量来综合考虑,B3(播种量为67.5 kg·hm-2)+ N2(施氮量为415 kg·hm-2)是提高夏播苏丹草生产性能的最佳处理组合。     

绵山羊双羔素提高美利奴羊繁殖率的研究

为了提高美利奴羊的繁殖率,增加美利奴羊产区养殖者的经济效益,运用绵山羊双羔素(睾酮-3-羧甲基肟·牛血清白蛋白)对新疆维吾尔自治区巩乃斯种羊场、新疆生产兵团76团兴牧公司、齐齐哈尔种畜场和甘肃省绵羊繁育技术推广站的美利奴羊进行免疫试验。结果显示:4个试验点试验组发情率和受胎率与对照组相比,差异均不显著(P>0. 05);与相应对照组相比,巩乃斯种羊场和76团兴牧公司产羔率和双羔率极显著升高(P<0. 01),齐齐哈尔种畜场和甘肃省绵羊繁育技术推广站显著提高(P<0. 05);单羔和双羔初生重与对照组相比,齐齐哈尔种畜场试验组显著降低(P<0. 05),其他羊场无显著差异(P>0. 05);对76团兴牧公司2～6岁母羊双羔率进行统计,发现2岁母羊产双羔率最低,5岁母羊产双羔率最高;齐齐哈尔种畜场试验组双羔的断奶重与对照组相比,降低2. 10 kg。结果提示:通过对不同地方美利奴羊应用绵山羊双羔素可以提高美利奴羊的繁殖率,提高养殖者的经济效益。     

太子参光合速率变化特征初探

为探明太子参Radix pseudostellariae光合速率变化特征,采用Li 6400光合测定系统,在晴朗的天气测定了太子参倒二叶的光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gc)的日变化和不同生长期的变化。研究结果表明：太子参的光合作用日变化呈单峰型,不存在“光合午休”现象,光合速率和蒸腾速率都在很大程度上决定于气孔导度,气孔导度与光合速率和蒸腾速率均表现为极显著（P<0.01）的正相关关系。太子参光合速率和蒸腾速率都随着整个生长期的推进,先缓慢升高后在倒苗期间急剧降低。     

Cortisol release,heart rate,and heart rate variability in transport-naive horses during repeated road transport

Domestic animals are often repeatedly exposed to the same anthropogenic stressors. Based on cortisol secretion and heart rate, it has been demonstrated that transport is stressful for horses, but so far, changes in this stress response with repeated road transport have not been reported. We determined salivary cortisol concentrations, fecal cortisol metabolites, cardiac beat-to-beat (RR) interval, and heart rate variability (HRV) in transport-naive horses (N = 8) transported 4 times over a standardized course of 200 km. Immunoreactive salivary cortisol concentrations always increased in response to transport (P < 0.001), but cortisol release decreased stepwise with each transport (P < 0.05). Concentrations of fecal cortisol metabolites increased from 55.1 ± 4.6 ng/g before the first transport to 161 ± 17 ng/g the morning after (P < 0.001). Subsequent transport did not cause further increases in fecal cortisol metabolites. In response to the first transport, mean RR interval decreased with loading of the horses and further with the onset of transport (1551 ± 23, 1304 ± 166, and 1101 ± 123 msec 1 d before, immediately preceeding, and after 60–90 min of transport, respectively; P < 0.05). Decreases in RR interval during subsequent transports became less pronounced (P < 0.001). Transport was associated with a short rise in the HRV variable standard deviation 2 (P < 0.001 except transport 1), indicating sympathetic activation. No consistent changes were found for other HRV variables. In conclusion, a transport-induced stress response in horses decreased with repeated transport, indicating that animals habituated to the situation, but an increased cortisol secretion remained detectable.     

Selection for ovulation rate in rabbits

An experiment of selection for ovulation rate was carried out. Animals were derived from a synthetic line first selected 12 generations for litter size, then 10 generations for uterine capacity. Selection was relaxed for 6 generations. Selection was based on the phenotypic value of ovulation rate with a selection pressure on does of 30%. Males were selected from litters of does with the highest ovulation rate. Males were selected within sire families in order to reduce inbreeding. Ovulation rate was measured in the second gestation by a laparoscopy, 12 days after mating. Each generation had about 80 females and 20 males. Results of three generations of selection were analyzed using Bayesian methods. Marginal posterior distributions of all unknowns were estimated by Gibbs sampling. Heritabilities of ovulation rate (OR), number of implanted embryos (IE), litter size (LS), embryo survival (ES), fetal survival (FS), and prenatal survival (PS) were 0.44, 0.32, 0.11, 0.26, 0.35, and 0.14, respectively. Genetic correlation between OR and LS was 0.56, indicating that selection for ovulation rate can augment litter size. Response to selection for OR was 1.80 ova. Correlated responses in IE and LS were 1.44 and 0.49, respectively. Selection for ovulation rate may be an alternative to improve litter size.