雄蚕小蚕“一日二回育”应注意的问题

在实际生产中,雏鸵鸟(尤其是45日龄内的雏鸵鸟)的饲养管理是鸵鸟整个生长周期中最重要、技术性最强的一个环节。雏鸵鸟生长发育的好坏直接关系到后备鸟的质量,进而影响到种鸟的生产性能。另外育雏率低将难于保证后备鸟的数量。我国鸵鸟饲养时间较短,有关     

鸸鹋卵人工孵化初探

鸸鹋(Dromaius novaehollandiae)，又名澳洲鸵，是一种产自澳洲的世界上仅次于鸵鸟的第2大型鸟类，高约180锄，体重可达55kg，具有很高的观赏价值和经济价值。目前，国内多家动物园、饲养场等都饲养繁殖鸸鹋。由于鸸鹋在圈养条件下自然孵化率和健雏率较低，鸸鹋的孵化主要采用人工孵化。现就影响鸸鹋人工孵化率和健雏率的主要因素加以分析，并对人工助产技术予以介绍。     

浅谈雏鸵鸟的饲养管理

雏鸵鸟是指三个月龄以内的小鸵鸟.雏鸵鸟的各项生理机能尚不健全,机体抵抗力差,对环境温、湿度的变化敏感,饲养管理不到位将影响雏鸵鸟的成活率和健雏率.鸵鸟是广西的外来品种,目前在广西发展迅速.但是在南方高温高湿气候下,雏鸵鸟的饲养管理一直面临多方面的问题.本文就本人工作经历谈谈提高雏鸵鸟成活率和健雏率的一些方法和体会,不足之处请指正.     

鸵鸟大肠杆菌病的诊治

我市某集团公司属下一大型非洲鸵鸟养殖场于2002年6月中旬至7月上旬期间，因为高温、多雨、潮湿气候而诱发种鸵鸟所产种蛋受精率、孵化率下降；雏鸵鸟从出壳到2月龄之间的健雏率明显下降。经我所组织兽医技术人员深入现场进行流行病学调查、临床剖检、实验室检验，最终确诊为鸵鸟大肠杆菌病。现将本次病例诊治情况报告如下。     

欧美兴起鸵鸟业

过去人们捕猎鸵鸟是为了获取有价值的鸵鸟羽毛,由于鸵鸟的肉质优良,皮可制革,因此现在已经人工饲养鸵鸟。鸵鸟的肉较瘦,与肉鸡和火鸡相比,鸵鸟肉的蛋白质含量高,而胆固醇含量低。鸵鸟的心、肝、胃及似牛尾的颈部都可制作美味佳肴。 中美洲的Costa Rica有一家大型商业鸵鸟场。这个场是最近4年内建立起来的,其中包括一个种鸵鸟场。种鸵鸟场里饲养着70只红颈鸵鸟和非洲黑鸵鸟。鸵鸟蛋是进行人工孵化,雏鸵鸟于3日龄以后出售。Costa Rica     

提高雏鸡健雏率的关键技术

人工孵化为养禽业的快速发展和规模化养殖提供了保证,同时孵化厂孵出雏鸡的健雏率直接影响孵化厂自身和养殖户的经济效益;因此,健雏率是每个孵化厂必须重视的一个指标。影响健雏率的因素很多,如种鸡的饲养管理、孵化技术等。笔者根据经验总结出提高雏鸡健雏率实用性较强的关键技术措施,     

非洲鸵鸟生长规律的研究

选择出壳非洲黑雏鸵鸟１５只,按商品化育肥方式进行饲养,观察其生长规律。结果表明,出壳至５月龄,生长速度不断上升;６月龄时日增重达高峰;７月龄以后生长速度不断下降;１０月龄后生长缓慢,体重接近屠宰体重。０－３、４－６和７－１０月龄料比分别为１．８３,３．１４和５．８８。根据非洲鸵鸟的生长规律,我国商品鸵鸟可采用三阶饲饲养模式：０－３月龄,适度限制饲养,争取最高健雏率;４－５月龄,充分饲养力求最大增重     

蓝孔雀种蛋人工孵化技术

潮州市红山林场粤东孔雀园自1997年开始至今共入孵种孔雀蛋22000多个，平均受精率为78％，入孵5日照受精蛋的出雏率为90％，健雏率为95%，种蛋破损率为0．2％。现将经多年实践总结出的一套蓝孔雀的人工孵化经验简单介绍如下。     

鸵鸟种蛋人工孵化出雏期助产的时机和技巧

鸵鸟种蛋人工孵化出雏期助产的时机和技巧王宗焕（东北林业大学野生动物资源学院黑龙江哈尔滨１５００４０）鸵鸟属大型走禽。野生环境中，种蛋自然孵化率为５～１０％；人工养殖条件下，鸵鸟受精蛋孵化率可达８０～９０％以上，其余１０～２０％死胚中，出雏期死亡占一定...     

提高雏鸡健雏率的关键技术

<正>人工孵化为养禽业的快速发展和规模化养殖提供了保证,同时孵化厂孵出雏鸡的健雏率直接影响孵化厂自身和养殖户的经济效益;因此,健雏率是每个孵化厂必须重视的一个指标。影响健雏率的因素很多,如种鸡的饲养管理、孵化技术等。笔者根据经验总结出提高雏鸡健雏率实用性较强的关键技术措施,     

生长速度

在测量生长速度时,利用国际标准度量单位(g/d)优于盎司/d或磅/周等英制单位,因为英制的测量单位不是非常精确,尤其是对小猪而言. 在实际生产中,平均日增重(Average Daily Gain,ADG)或每日活体增重(Daily Liveweight Gain,DLWG)是评估猪生长速度的首选词,但在营养学与遗传学研究论文中也常遇到"瘦肉组织增重率(Lean Tissue Growth Rate,LTGR)"这一名词.     

Pregnancy rate and first-service conception rate in Angus heifers

The objective of this project was to determine the genetic control of conception rate, or pregnancy percentage in Angus beef heifers. Producers from 6 herds in 5 states provided 3,144 heifer records that included breeding dates, breeding contemporary groups, service sires, and pregnancy check information. Two hundred fourteen sires of the heifers were represented; with 104 sires having less than 5 progeny, and 14 sires having greater than 50 progeny. These data were combined with performance and pedigree information, including actual and adjusted birth weights, weaning weights, and yearling weights, from the American Angus Association database. Heifer pregnancy rate varied from 75 to 95% between herds, and from 65 to 100% between sires, with an overall pregnancy rate of 93%, measured as the percentage of heifers pregnant at pregnancy check after the breeding season. Pregnancy was analyzed as a threshold trait with an underlying continuous distribution. A generalized linear animal model, using a relationship matrix, was fitted. This model included the fixed effects of contemporary group, age of dam, and first AI service sire, and the covariates of heifer age at the beginning of breeding, adjusted birth weight, adjusted weaning weight, and adjusted yearling weight. The relationship matrix included 4 generations of pedigree. The heritability of pregnancy and first-service conception rates on the underlying scale was 0.13 +/- 0.07 and 0.03 +/- 0.03, respectively. Estimated breeding values for pregnancy rate on the observed scale ranged from -0.02 to 0.05 for sires of heifers. Including growth traits with pregnancy rate as 2-trait analyses did not change the heritability of pregnancy rate. As expected for a reproductive trait, the heritability of pregnancy rate was low. Because of its low heritability, genetic improvement in fertility by selection on heifer pregnancy rate would be expected to be slow.     

Ovulation rate and twinning rate in cattle: heritabilities and genetic correlation

Repeated measures of ovulation rate on puberal heifers should be an effective way to select for increased twinning rate. A reliable estimate of the genetic correlation between ovulation and twinning rates is needed to implement such selection and to predict its efficiency. Restricted maximum likelihood was used to estimate genetic correlations from subsets of data collected from the twinning project at the Roman L. Hruska U.S. Meat Animal Research Center. The animal model included numerator relationships among the animals and fixed effects of year-season of measurement, age at measurement, and birth group. Genetic correlations between averages of ovulation rates for three, four, five, six, seven, and eight estrous cycles and the occurrence of twins were, respectively, .62, .76, 1.00, 1.00, 1.00, and .98 based on observations on 200 to 325 puberal heifers. Corresponding phenotypic correlations ranged from .06 to .26. Genetic correlations between ovulation rate in a single estrous cycle and occurrence of twins were .38, .98, and .98, respectively, for 323, 430, and 283 cows with ovulation rate measured after measurement of twinning, in the same season as measurement of twinning, and more than 1 yr before measurement of twinning. Phenotypic correlations were .00, .07, and .00. Genetic and phenotypic correlations among ovulation rates at six consecutive estrous cycles averaged, respectively, .66 and .12 for 610 heifers. Heritabilities for ovulation rates in individual cycles averaged .16. No evidence of negative environmental covariance between ovulation rates in adjacent cycles was found. These results support the approach of indirectly selecting for twinning rate by measuring ovulation rates in estrous cycles of puberal heifers.     

提高肉用犊牛存活率、健犊率的新措施

提高肉用犊牛生产效率和生产水平已经成为我国肉牛养殖业关键环节,文章根据已有研究结论结合笔者多年实践经验,总结出了一套从肉用犊牛出生处理、科学吃到初乳、正确哺乳补料到循序渐进断奶操作提高犊牛存活率和健犊率的新措施,以期为提高肉用犊牛生产效率和生产水平带来帮助。     

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.     

Ovulation rate, lambing rate, litter size and embryo survival of Rambouillet sheep selected for high and low reproductive rate

Ewes from lines selected for high and low reproductive rate and a control line bred and selected randomly were endoscopically examined 3 to 5 d after breeding to determine ovulation rates in the fall of 1985, 1986 and 1987. Fertility (ewes lambing per ewe exposed), lambing rate (lambs born per ewe exposed) and litter size (lambs born per ewe lambing) were evaluated at lambing in the spring of each year. Embryonic survival was estimated as the number of lambs born per corpora lutea. Ovulation rates were 1.28, 1.73 and 1.46 for low, high and control lines, respectively. More (P less than .01) single ovulations occurred in low-line ewes than in the other two lines; high-line ewes had more (P less than .01) twin ovulations than did low- or control-line ewes. Fertility did not differ among lines. Selection line affected (P less than .01) lambing rate at first and all services. Control-line ewes had mean lambing rates at first and all services that were intermediate between those of the low and high lines, which were different from each other. Line x age of ewe interactions existed (P less than .01) for lambing rate at all services and litter size at first and all services. High-line ewes had lower lambing rates and litter sizes as 2-yr-olds than other lines, but their performance increased steadily to 6-yr-olds, whereas the low and control lines remained relatively constant. Embryo survival differed (P less than .10) between lines, being 74%, 63% and 67% for low, high and control lines, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Heart rate and heart rate variability in the pregnant mare and its foetus

Abortion and preterm birth of foals are major reasons for reproductive losses in the horse. Risk pregnancies require close supervision so that adequate treatment can be initiated in time. The aim of this study was to determine normal values in heart rate (HR) and heart rate variability (HRV) of the pregnant mare compared to her foetus and to detect physiological changes during ongoing gestation. In mares, the RR interval decreased from 1480±29 ms on day 270 of pregnancy to 1190±58 ms on day 330 of pregnancy (p<0.05). In contrast, foetal RR interval increased during the same time period from 611±23 ms on day 270 of gestation to 756±25 ms on day 330 of gestation (p<0.05). Concomitantly, maternal HR increased and foetal HR decreased. No further changes in RR interval occurred during the last 10 days before foaling, neither in the mare nor the foetus. In the last hours preceding parturition, maternal RR interval was lower than at all times earlier in pregnancy (average of 1037±13 ms) but did not change during this time. Maternal HRV did not change during gestation. Marked changes in HRV occurred only during the last minutes of foaling. Then, all HRV variables increased significantly (standard deviation of beat-to-beat interval: p=0.01, root mean square of successive beat-to-beat differences: p<0.01). The cardiovascular system of pregnant mares adapted to the demands of ongoing pregnancy with an increase in HR. We have no evidence that in healthy mares, pregnancy is a major stressor.