Effects of restricting body weight gain or limiting the photoperiod during rearing on sexual maturity,viability and semen production in large white Turkey males

1. Severe restriction of food from 6 to 54 weeks of age resulted in lower body weights and smaller testes weights in male turkeys.

2. As a proportion, mortality was 0.5 in turkeys fed ad libitum and 0.1 in those which were restricted. There were significantly fewer leg problems in the birds undergoing food restriction.

3. Sexual maturity was delayed 4 weeks by food restriction although semen quality was similar to that in ad libitum‐fed birds.

4. Individual semen production was lower after food restriction but, because mortality and food consumption were also lower, semen production per male housed and semen production per kg of food eaten were proportionally 0.30 and 0.32 greater in restricted‐compared with ad libitum‐fed turkeys.

5. Useable quantities of good quality semen were obtained from ad libitum‐fed turkeys at 23 weeks of age.

6. A short photoperiod (7L:17D) from 10 to 18 weeks of age in ad libitum‐fed turkeys produced more rapid development of normal semen production compared with turkeys given a longer photoperiod (14L:10D).     

Studies on the dilution of turkey semen.

1. A series of experiments were conducted to determine the effect of diluent, holding temperature and dilution rate on the viability of turkey semen. 2. No significant difference was observed in the fertility of the undiluted controls and semen diluted with Lake's solution to a final rate of 1:4 and maintained at 25 degrees C or 5 degrees C for 30 min. Under these conditions as few as 25 million sperm per weekly insemination were needed for optimum fertility. 3. Turkey semen exhibited the typical "dilution effect", increased respiration with a corresponding decline in fertilising capacity, when diluted at rates of 1 : 8 and 1 : 12.     

Effects of poult source on turkey production parameters

Flock records from a commercial turkey company were analyzed to determine if poult source affected flock performance. Comparisons were made between flocks supplied by two hatcheries (X and Y) reared on the same farms and among flocks reared on different farms. Flocks from hatchery X had significantly better livability and feed-conversion ratios than flocks from hatchery Y. Although not statistically significant, flocks from hatchery X tended to grade better at processing (percent grade A) and have lower condemnations than flocks from hatchery Y. Season significantly affected livability and feed conversion of all flocks regardless of hatchery source.     

Associations between body weight and rectal temperature in turkey poults

1. Associations between body weight and rectal temperature were observed in female turkeys.

2. Turkeys with lower weights between 13 and 30 d of age tended to have higher temperatures.

3. Turkeys with lower weights at 7 d exhibited depressed body temperatures.

4. Higher or lower body temperatures may be associated with poorer performance depending on the time of appearance.     

蜂花粉对公鸡体重和精液品质的影响

试验选用44只48周龄的新扬州公鸡，随机分成4组，每组11只，对照组饲喂基础日粮，试验I、Ⅱ、Ⅲ组分别在基础日粮中添加0.5、1.0、1.5%的蜂花粉。探讨蜂花粉对种公鸡体重和精液品质的影响，试验结果表明：日粮中添加1.0、1.5%的蜂花粉后，显著提高公鸡的精液量、精子活力和精子密度，显著降低精子畸形率，而对精液的PH值影响不明显；同时可以缓解高温应激造成的鸡体重下降的现象。     

Effects of dietary crude protein content and food intake on the production of semen in two lines of broiler breeder males

1. The effects of dietary crude protein (CP) concentration and feeding rate on semen production and quality from 21 to 66 weeks of age were assessed in a factorial experiment with 48 caged broiler breeder males from 2 strains.

2. The probability of obtaining semen and semen volume were lower in one of the two strains but the concentration and yield of spermatozoa were similar.

3. There was no evidence that males which were fed on an increasing quantity of food produced more semen or a greater concentration of spermatozoa than males on a fixed allocation of 120 g/d food.

4. The concentration of spermatozoa was lower in males fed on a diet containing 160 compared with 120 g CP/kg. On termination of the experiment, average testes size was small and testicular function was absent in a large proportion of the males on the high protein diet.     

澳洲白羊体质量与体尺指标的相关及回归分析

[目的]研究澳洲白羊体质量与体尺指标的相关及回归关系,为肉羊新品种选育提供参考.[方法]采用SPSS19.0软件对6月龄澳洲白羊体质量与体尺指标进行相关性分析、通径分析、逐步回归分析,并对其相关系数进行分解,得出了体质量与体尺指标之间的最优回归方程.[结果]体质量(y)与管围(x6)和胸围(x3)相关性极显著(P＜0....     

Effect of environment on the intake of food and water, body weight, egg production and plasma concentrations of corticosterone and prolactin in turkey hens

During the first 4 weeks of egg production, there were no differences in the plasma concentrations of prolactin and corticosterone, egg production, body weight and the consumption of food and water between turkey hens which were maintained in cages or in floor pens. The plasma concentration of prolactin increased to the same extent in both environments during the period of peak egg production. A further rise in concentration of prolactin occurred in association with the termination of oviposition in 15 of the 19 hens which stopped laying eggs. Prolactin appeared to be progonadal and then antigonadal, once a threshold concentration was exceeded. This threshold value was higher in caged turkey hens. After laying ended, high concentrations of prolactin in hens maintained in cages were not maintained in the absence of a stimulus or stimuli associated with the nests.     

Effect of restricted and ad libitum feeding on semen production and fertility in broiler breeder males

1. The effect of food restriction on the quality of semen production and fertility in broiler breeder males was studied.

2. Seventy‐two Ross broiler breeder males, from 20 to 54 weeks of age, were divided into 4 groups and fed as follows: group 1 = 110 g/bird/d; group 2 = 120 g/ bird/d; group 3 = 130 g/bird/d; group 4 = ad libitum.

3. Body weight, sperm quality (volume, concentration, % motility and % live cells) and fertility were measured. The birds were slaughtered at 55 weeks of age; the abdominal fat pad and testicles were weighed.

4. Groups 2 and 3 produced the highest volume of semen. The quality of semen was very similar in all the restricted groups.

5. Males fed ad libitum produced semen with the best motility and percentage of live cells. Groups 3 and 4 showed the best fertility percentage (79%) against group 1 and 2 (59 and 72% respectively).     

Current role of semen storage and artificial insemination in the turkey industry

The turkey industry is moving towards the development of stud farms, but an essential condition is the existence of efficient methods to store semen. Much research has been done recently to determine the number of viable spermatozoa in an insemination dose needed for maintaining optimum fertility. Practical methods to determine the number of intact spermatozoa in semen, both before and after storage, are under development. It is now possible to store turkey semen for 6 to 24 h without appreciable loss in fertility and hatchability. Ideal experimental conditions for 48 h storage have not yet been fully determined. Development of new storage media, allowing the insemination of very low numbers of spermatozoa, may provide interesting possibilities regarding the use of elite sires.     

猪显性白毛调控基因KIT不同基因型对仔猪初生重影响的研究

为了研究白毛调控基因KIT不同基因型对仔猪初生重的影响,试验采用限制性内切酶片段长度多态性分析(RFLP)的方法,分析基因KIT不同基因型(III、ii、i)对仔猪初生重的影响。结果表明:携带隐性基因i的猪初生重比携带显性基因I的猪重,且差异显著(P<0.05);不同基因型间断奶重差异不显著(P>0.05)。     

Effect of age and body weight on plasma concentrations of luteinizing hormone in turkey hens before and after photostimulation

The independent effects of age and body weight (BW) on photostimulatory response in turkey breeder hens were studied by measuring changes in plasma luteinizing hormone (LH; ng/mL) before and 3 d after photostimulation. The study was conducted with hens from two BW groups at 24–25, 27–28, and 31–32 wk of age. There was approximately a 1-kg difference in BW between groups within an age. Six hens per BW and age group were cannulated (jugular vein) and serially sampled during each of two 6-hr periods. Samples were collected at 10-min intervals. The two sampling periods were the last 6 hr of the short-day photoperiod (SD) and the same period during the third long day after photostimulation (LD). The photostimulatory response (PR) or difference between the SD and LD baseline LH concentrations was greatest in the 24–25-wk-old hens. The PR was unaffected by hen BW at any age. The baseline LH concentration during the SD photoperiod declined as hens aged. After photostimulation, baseline LH and LH peak amplitude concentrations were higher in 24–25-wk-old hens compared with the older ages. The number of LH peaks increased after photostimulation, but there were no significant effects attributable to age or BW within an age. In conclusion, the PR was affected by hen age but not hen BW or BW within a particular age.     

Influence of feeding level on live body weight and semen characteristics of Sardinian rams reared under intensive conditions

The aim of the present study was to assess the effects feeding level on body weight changes and semen parameters in adult Sardinian rams reared under intensive conditions in a semi-arid area of southern Italy. During an experimental period of 90 days, 24 healthy Sardinian rams were divided into three equal groups that differed in their feeding level, in terms of concentrate amount. The control-concentrate (CC; n = 8) group received 1.0 times their maintenance requirements, the medium-concentrate (MC; n = 8) group received a diet that supplied 1.2 times their maintenance requirements, and high-concentrate (HC, n = 8) group received a diet that supplied 1.5 times their maintenance requirements. Mixed vetch–oat hay was offered ad libitum to ram groups and water and mineral licks were freely available. Body weight and feed intake was recorded weekly, and semen characteristics were determined every 2 weeks. Dietary treatment affected final body weight (P < 0.01) as feeding level increased. Total dry matter and protein intake changed significantly (P < 0.05 and P < 0.01, respectively) among experimental groups. Semen volume and concentration were positively influenced by feeding level for HC group, whereas no differences were observed in sperm viability and scrotal circumference of rams. It was concluded that dietary level with higher concentrate supplementation resulted in improved body weight gain, feed intake, sperm production, and semen quality in Sardinian rams.