Effect of frequent ejaculation on semen characteristics in rams.

Sixteen Suffolk rams were ejaculated repeatedly for a period of eight hours during the month of November. Ejaculates were examined for semen characteristics. Volume density and number of sperm per ejaculate declined significantly in successive ejaculates. Motility and percentage abnormal sperm were not affected by frequent collection. It is concluded that the number of sperm per ejaculate, after the eighth ejaculate, could fall below that required for fertilisation to occur, particularly in progestagen treated ewes.     

Effect of Trypanosoma vivax infection on semen characteristics of Yankasa rams.

Twelve Yankasa rams aged between 2 1/2 and 3 years with good semen characteristics were used in this 15-week study. Six rams were infected with Trypanosoma vivax, while six served as controls. The infected rams developed chronic trypanosomosis accompanied by fluctuating pyrexia, lethargy, anaemia, scrotal oedema and cachexia. There was a drastic and progressive deterioration in semen quality in all infected rams manifested by a decrease in volume or cessation of semen production, oligozoospermia, a sharp decrease in progressively motile sperm, elevated numbers of dead (eosinophilic) sperm and 100% morphological abnormalities of sperm in most animals. The rams were all deemed unfit for breeding by 3 weeks post-infection. Uninfected rams were healthy and had good semen characteristics throughout the investigation. The results show that rams infected with T. vivax may become infertile within a short interval due to rapid deterioration of semen characteristics and this trypanosome species may be an important causative agent of infertility in endemic areas.     

限时饲喂对鸡体重及性成熟的影响

用自来航鸡研究了在育成期采用限制饲喂时间的效果。试验鸡在0～4周龄之内自由采食，4～24周龄饲养在25℃的恒温室内，每日12h照明并采用限制饲喂。限制饲喂的时间分成3h(18周龄以后为2．5h)、6h(10周龄以后不限时)、12h。结果限时饲喂使鸡生长变慢、体重变小，12h组与其它2组差异明显。4～24周龄公雏的3h组采食量是12h组的80％、母雏为84％：而4～24周龄各组间的饲料转化率差异不显著。3h、12h组母雏的初产日龄分别为153d、137d，解除限时饲喂后4周时的3h组蛋重54g、12h组为50g，解除限时饲喂后10周时3h组产蛋率为70％、12h组为67％。     

Photoperiodic control of growth hormone secretion and body weight in rams

This study was undertaken to assess the influence of photoperiod on growth hormone (GH) secretion in rams and its possible influence on body weight. Twenty young adult rams were divided into two groups. One was subjected to an annual (AR) and the other to a semestral (SR) light regime during the same 18-month period. In both groups, daylength (DL) varied gradually between 8 to 17 hr. Plasma prolactin (PRL) and GH profiles consisting of 6 hr samples were determined and animals were weighed throughout the course of the experiment. Maximal PRL secretion was observed with largest DL. In contrast, GH secretion increased during increasing DL but it began to decrease before maximal DL was reached in both light regimes. Mean GH secretion was maximal when the DL was about 11 hr in SR and between 8 to 12 hr in AR. Similarly, body weight increased when DL increased and plateaued during decreasing DL in both AR and SR animal groups. Significant (P less than 0.05) differences were observed throughout the course of the experiment according to the effects of decreasing or increasing DL in each group. Analysis of variance showed that the effect of DL on plasma PRL and GH levels and weight velocity (WV) was significant (P less than 0.05) in both light regimes. This suggests that in SR, plasma PRL and GH levels and WV vary according to a six month period.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of chemotherapy on semen characteristics of Balami rams infected with Anaplasma ovis

Six intact Balami rams were experimentally infected with Anaplasma ovis. Another six were infected one month after splenectomy and six others served as controls. Clinical manifestations of the disease, first observed between 5 to 7 days post-infection, were more severe and prolonged in the splenectomised-infected than in the intact-infected group. There was progressive deterioration in semen quality, which was also significantly more severe and prolonged in the splenectomised than in the intact-infected rams. Following treatment with long-acting terramycine, clinical recovery occurred earlier in the intact-infected (1–4 weeks) than in the splenectomised-infected group (5–7 weeks). A similar pattern was observed in post-treatment improvement in the spermiogram. However, although the infected animals recovered clinically by 1–7 weeks post-treatment, restoration of the reproductive potential did not occur for 20 to 25 weeks. It appears that stress factors may aggravate the deliterious effects of anaplasmosis.     

Dominance and mating behavior of rams under paddock conditions

Contents A total of 30 ewes in three-sire or four-sire breeding pens were observed continously during daylight for four consecutive days of a synchronised estrus period. A linear dominance hierarchy was observed between the rams which was consistent and stable for each observation period. The highest ranking ram had more mounting encounters and was more aggressive than the subordinate rams. This activity disturbed his ejaculatory mechanism and sometimes resulted in the absence of ejaculation or energetic ejaculation. In the four-sire breeding pens the dominant ram often found it impossible to completely curtail the sexual activity of the subordinate rams. He made 70.9% and 49.0% of the total number of mounts in the three-sire and our-sire breeding pens, respectively. At the beginning of each observation period the highest ranking ram claimed most estrous ewes for his “harem”. The subordinate rams only had an opportunity to mate when several ewes were simultaneously in estrus. The average number of mounts per first copulation per ram was 2.2 (range 1.3–3.1). The time spent from first contact with the ewes until completion of the copulatory act in first copulation varied from 0.2–16.2 min. with an average of 4.0 min., whereas this interval was increased during the second copulation (average = 5.8 min.). Furthermore, the mating behavior of single rams was also observed. Inhalt: Rangordnung und Paarungsverhalten von Schafbocken unter Stallhaltungsbedingungen Es wurden insgesamt 30 Mutterschafe in Zehnergruppen mit 3 bzw. 4 Böcken gleichzeitig in einer Buchte gehalten und wahrend einer Östrusperiode tagsüber beobachtet. Fur die Böcke konnte eine klare Rangordnung erkannt werden, die über alle Beobachtungsperioden unverändert blieb. Der an höchster Stelle stehende Bock vollzog mehr Aufsprungsversuche und war aggressiver als die untergeordneten Böcke. Diese Aktivitäten störten bei ihm wiederholt den Ejakulatonsmechanismus, so daß ein unvollständiger Deckakt bei fehlender Ejakulation die Folge war. Bei gleichzeitiger Anwesenheit von 4 Böcken in einer Gruppe way es für den dominanten Bock häufig unmöglich, die Sexualaktivität der untergeordneten Böcke vollständig zu unterbinden. Auf den dominanten Bock entfielen bei Anwesenheit von 3 Böcken 70,9% aller Auf sprünge, bei der Anwesenheit von 4 Böcken waren dies 49,0%. Zu Beginn einer jeden Beobachtungs-periode versuchte der an höchster Stelle rangierende Bock, die meisten östrischen Mutterschafe für seinen “Harem” zu beanspruchen. Die untergeordneten Böcke hatten nur dann Gelegenheit zu decken, wenn mehrere Mutterschafe gleichzeitig im Östrus waren. Im Durchschnitt betrug die Anzahl der Auf sprünge bei der ersten Belegung pro Bock 2,2 (Schwankungsbreite 1,3 -3, 1). Die erforderliche Zeit fur die erste Paarung uariierte bei einem Mittelwert uon 4,0 Alin. zwischen 0,2 und 16,2 Min.; diese Zeitspanne erhöhte sich allerdings für die zweite Belegung auf durchschnittlich 5,8 Min. Darüber hinaus wurde das Paarungsuerhalten einzelner Böcke ohne die Anwesenheit anderer beobachtet.     

Sex differences in the effect of intermittent compared with continuous light on growth rate, testes and body weight of broilers reared under commercial conditions

The effect of intermittent light (IL) on the growth of broilers was tested under commercial conditions. One-d-old chickens were subjected to continuous light (CL) until 7 d of age and then received either CL or 7.5L:4.5D:7.5L:4.5D until 53 d. Body and testes weights were measured. At 53 d of age, the mean body weight of males was greater on IL than on CL; for females there was no difference. The testes of males on IL weighed more than those on CL. Growth of broilers was greater (P less than 0.05) at 35, 49 and 53 days of age if light was provided continuously from hatch to 7 d of age and then switched to IL than those remaining on CL during the entire periods.     

Growth related traits in body weight selected lines and their crosses reared under different nutritional regimens

1. Four populations—two that had undergone 37 generations of selection for high (HH) and low (LL) body weight, and reciprocal crosses between them (HL and LH) were fed two diets differing in protein and energy. Diet A, under which selection had been made, contained 200 g protein and 11.23 MJ/kg. Diet E contained 240 g protein and 13.16 MJ/kg.

2. Body weight and feed efficiency were measured weekly from hatch to 56 d of age at which time oesophagus, abdominal fat pad, heart, liver and lungs were removed and weighed. At 35 d of age chicks were inoculated with sheep erythrocytes (SRBC) and antibody titre was measured 6 d later.

3. Chicks fed diet E were heavier than those fed diet A. HH chicks were heavier dian LL chicks wim HL and LH chicks intermediate to the parental lines. LH chicks were heavier than HL ones reflecting large maternal effects.

4. Food efficiencies among stocks and diets were consistent with those for body weight, with HH > LH > HL > LL and E > A. Relative differences between diets were similar across ages and heterosis for food efficiency was about 15%.

5. Relative to body weight, oesophagus and liver weights were heavier in chickens fed diet A than fed diet E. The pattern reversed for abdominal fat pad.

6. Antibody to SRBC antigen was greater in the crosses than in line HH and in cross HL than line LL, with heterosis of 70%.     

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。     

Effect of body condition score on the testicular biometrical measures,semen characteristics and testosterone level in jackass

This study was undertaken to evaluate the effect of body condition score (BCS) on testicle and epididymis biometrics, semen characteristics and testosterone level in Egyptian Jack. This study was conducted on 50 mature Jacks divided according to their body condition score into four groups: Poor (G1), moderate (G2), good (G3) and fat (G4). The complete testis was collected immediately after execution in the Giza Zoo abattoir; then, the epididymis was carefully dissected at the testicular junction. Biometrical measures including length, weight and volume were determined for the right and left testis and epididymis. Also, epididymal sperm was collected from all examined animas and evaluated for sperm concentration, progressive motility, viability and sperm abnormalities. Serum samples were collected for determination of total testosterone level. Results showed that the body condition score of the examined animal affects their biometrical measure of testicles and epididymis. There is a significant decrease (p < .05) in biometrical measures for the testicles and epididymis, sperm concentration, motility, viability and testosterone level in poor BCS animals (G1). The highest values were recorded in Good BCS (G3) Jacks. Conclusion: Jacks with good BCS (G3) should be selected for breeding activity in donkey.     

Adult body weight of indigenous and crossbred ewes under semi-arid conditions in India

Data on adult body weight of ewes belonging to Nali, Chokla breeds and their crosses (F1) with Rambouillet and Soviet Merino raised under semi-arid conditions in India were analysed. The ewes belonged to 5 distinct age groups ranging from 16.5 to 64 months. Nali and Chokla were significant lighter than all the 4 crossbred groups. There were no significant differences in body weight between crossbred groups except in the case of Soviet Merino x Chokla group which was the lightest and differed significantly from all other groups. Rambouillet crosses were heavier than Merino crosses but the difference was statistically significant only on Rambouillet x Chokla and Merino x Chokla. The improvement in body weight in crossbreds over native sheep ranged between 9.3 and 21.88%. The increase in live weight was significant only up to 49 months.     

Fattening performance and carcass traits of Chios male lambs fed under traditional and intensive feeding conditions

This study was carried out to compare the fattening performance and carcass traits of Chios male lambs fed under traditional and intensive feeding conditions. In the study, a total of 34 lambs were randomly separated into traditional (T) and intensive (I) groups in equal numbers. Lambs in group T were fed on ration prepared in local style and grazed in olive grove for 8 h/day. On the other hand, lambs in group I were fed on 255 g alfalfa hay animal⁻¹ day⁻¹ and ad libitum mixed feed. After a period of 8 weeks, lambs were transported to the slaughterhouse. The results showed that Chios lambs fed under intensive conditions has better performance and produced heavier carcass compared to those fed under traditional conditions. However, consumption of concentrate feed mixture was about twice as much in group I as in group T. Total feed consumption and feed conversion ratio was similar in each group. The values of carcass traits of lambs in group I were found to be significantly higher than those of group T. On the other hand, carcass fat thickness was slightly lower in group T. Traditional condition is considered to respond to better to consumer demands for lean lamb carcass.     

舍饲辽宁绒山羊种公羊冷冻精液生产期间的饲养管理

在生产冷冻精液过程中,由于采精频率高,辽宁绒山羊种公羊的营养消耗较大,相互争斗行为加剧。因此,加强种公羊的饲养管理显得尤为重要。