C- AND G- BANDING PATTERNS AND CHROMOSOMAL MORPHOLOGY OF SOME BREEDS OF AUSTRALIAN CATTLE

A cytogenetical study using metaphase chromosomes from cultured lymphocytes, was made of 2 Banteng (Bibos banteng) steers and 218 bulls representing 13 purebreeds (Bos taurus type, Bos indicus type and Sanga) and 7 cross-breeds. Studies were made of photographic karyotypes of Giemsa stained and C-banded chromosomes of bulls of each breed and of B-banded chromosomes from 3 breeds of Bos indicus and one cross-breed Australian Friesian Sahiwal) cattle. The relative lengths of chromosomes of Bos taurus and Bos indicus bulls were compared and significant difference in relative lengths of the X chromosomes were noted between these two species. There was a differences in morphology of the Y chromosomes; Sanga, Banteng and Bos taurus type breeds had a small submetacentric Y chromosome, except for the Jersey which had a metacentric Y chromosome. All Bos indicus type bulls had an acrocentric Y chromosome but the Droughtmaster breed had two forms of the Y chromosome (submetacentric and acrocentric). The C-banding patterns of the autosomes and X chromosomes were similar for all breeds while those of the Y chromosomes of Bos indicus type cattle allowed their accurate identification. G-banding patterns of Bos indicus resembled those of Bos taurus and enabled pairing of homologous chromosomes. Centromeres of the autosomes were unstained but those of the sex chromosomes were darkly stained.     

INFERTILITY IN THE HORSE ASSOCIATED WITH CHROMOSOMAL ABNORMALITIES

SUMMARY Reproductive failure was studied in 12 phenotypically normal mares (9 Arabian, 3 Quarter horses, 1 Appaloosa and 1 pony). Karyotyping was performed using lymphocytes isolated from peripheral blood by density gradient procedures, followed by standard culture methods for karyotyping. Nine mares had karyotypes of 63,XO; 1 had 63,XO/64,XX; 1 had 63,XO/64,XY and 1 had 64,XY. All mares had small, firm ovaries that when removed and examined from 4 mares, lacked germ cells and consisted of undifferentiated ovarian stroma.     

蓖麻蚕和栗蚕的性染色体研究

根据在蓖麻蚕（ｐｈｉｌｏｓａｍｉａｃｙｎｔｈｉａｒｉｃｉｎｉ）（♀）和栗蚕（Ｄｉｃｔｙｏｐｌｏｃａｊａｐｏｎｉｃａ）（♀）减数分裂前期所观察到的ｘ（Ｚ）染色体的长度和在全套染色体中的序号以及栗蚕Ｘ染色体的异染色质区域等特征，认为蓖麻蚕的ＸＯ型可能是由ＸＹ型中的Ｙ染色体缺失所致，而栗蚕的Ｘ染色体则可能是由Ｘ和Ｙ染色体融d合为一条而成。     

应用性诱剂测报与防治桑蛀虫的研究

性诱剂防治桑蛀虫试验结果表明，诱杀防治区的株受害率下降60.90％，枝受害率下降66.83％；迷向防治区的株受害率下降54.67％，枝受害率下降62.15％。性诱剂引诱蛾量高峰日可以代表发蛾高峰日,作出虫情预报。     

桑蛀虫性信息素研究

采用大田性诱测定及触角电位测定技术,从八种合成样品中筛选出反3,顺13-十八碳双烯醇-1乙酸酯,对桑蛀虫雄蛾具有明显的生物活性和触角电位响应,这一结构通过雌成虫性腺体漂洗液的气相层析而得到确证。触角毛测定结果表明,雄成虫对性信息素的感受主要是通过其触角上的毛形感器接受并作出的反应,通常在0.01μg就能引起敏感反应,且这种反应是专一的。性诱测报试验结果表明,性诱蛾量高峰日与全代发蛾50％高峰期之间的差异不显著。因此,性诱蛾量高峰日可作为蛾高峰期的指标发布虫情预报。     

不同授精时间对仔猪性比影响的研究

有研究报道认为，在母牛排卵前授精易得雌性后代，在接近排卵时授精易得雄性后代，在授精当时预测的犊牛性别与实产犊牛性别的符合率达到约７０％。为了检验这一现象是否也存在于猪的繁殖活动，特别安排在同一发情母猪的排卵前和后，分别用不同毛色的公猪配种，观察在不同排卵期授精是否也影响仔猪的性比。为了探讨不同排卵期授精当时的内分泌活动，在二次配种当时分别在尾动脉采血，测定血清中雌二醇和促黄体素含量。２２窝母猪的试验结果表明，排卵前授精得母仔５５．６％（６９／１２４），排卵后授精得公仔５７．３％（７５／１２４），Ｐ＜０．０５。其中有１窝只在排卵前授精（母仔占６９．２％，９／１３）和５窝只在排卵后授精（公仔占６７．４％，２９／４３），更加显著地（Ｐ＜０．０２５）表现出对仔猪性比的影响。激素测定表明，排卵前授精时血清中雌二醇和促黄体素水平分别比排卵后授精高２．３和６．３倍，对测定结果的进一步分析表明，母猪在授精当时血清中雌二醇含量较高时，后代母仔的比例较高。     

桑尺蠖性信息素研究

桑尺蠖雌成虫性腺体漂洗液通过气相层析与触角电位联用（GC－EAD），测定出6种环氧类化合物具有明显的触角电位响应，大田生物测定结果表明，其中3Z，6Z－9S，10R环氧十八碳烃（SR－2）和6Z－9S，10R环氧十八碳烃（SR－1）为桑尺蠖的性信息素组分，这是一种新的性信息素结构。SR－2与SR－1的10：1混合物对桑尺蠖雄成虫具有最强的生物活性，可望用于桑尺蠖的性诱测报和防治试验。     

A STUDY OF THE ACCESSORY SEX GLANDS OF BULLS EN ABATTOIRS IN NORTHERN AUSTRALIA

The accessory sex glands of 521 slaughtered bulls were examined for lesions; normal anatomical observations were also made.
The average weights and measurements (length and width) of the seminal vesicles and bulbourethral glands of 110 bulls were 34.1 g and 9.1 × 2.5 cm, and 4.6 g and 2.9 × 1.9 cm, respectively. Weights of both glands were correlated to age, but bulbourethral gland weight was more closely correlated to bodyweight than age. The average length and diameter of the ampulla was 11.1 and 1.0 cm, respectively.
Seminal vesiculitis and ampullitis were found in 9.0% and 3.8% of bulls respectively. The incidence of both conditions was highest in old bulls. Mesonephric duct anomalies (observed in 1.7% of bulls) and other congenital and inflammatory lesions of the accessory sex glands were also recorded.
Macroscopically normal accessory sex glands of 86 bulls were studied histologically and a high percentage of all glands showed inflammatory changes.
Attempts to isolate viral agents, Mycoplasma, and Chlamydia from accessory sex glands were unsuccessful. Corynebacterium pyogenes was isolated from two cases of seminal vesiculitis. IBR-IPV virus, Campylobacter fetus subsp. venerealis and Tritrichomonas foetus were frequently isolated from the prepuce of bulls, many of which also had positive serological titres to Leptospira pomona and Leptospira hardjo.
No one factor capable of causing bull infertility was consistently identified, and the incidence figures for observed conditions of the accessory sex glands were generally comparable to those found in bull populations elsewhere.     

低温诱发嵌合体蚕的真皮细胞的性染色质小体

研究调查了低温处理受精卵诱发的斑纹嵌合体蚕的真皮细胞的性染色质小体（ＳＢ）。（１）限性淡灰色斑蚕品种的斑纹嵌合体幼虫的淡灰色斑部位的真皮细胞均存在ＳＢ，而素斑或普通斑部位的真皮细胞都不存在ＳＢ，表现为体细胞雌雄嵌合体。同一个体内，ＳＢ仅存在于持有Ｗ染色体的细胞中，不受嵌合体幼虫生殖腺性别的影响。（２）非限性斑蚕嵌合体幼虫有两种：正常受精部分与单性生殖部分组成的嵌合体，其雌核发生部位真皮细胞的ＳＢ存在状况与受精核发生部位相当一致；雄核发生部位则不存在ＳＢ。由两个正常受精部分组成的嵌合体，其各斑纹部位真皮细胞的ＳＢ的存在状况几乎完全一致。（３）认为第二极体是嵌合体蚕形成时雌核发生部分的主要参与者。     

蛋鸡育成后期日粮添加脂肪对脂肪代谢及产蛋期生产性能的影响

用京白蛋鸡研究了开产前饲喂高脂日粮对血浆极低密度脂蛋白含量的影响,及对开产后产蛋性能的影响。结果表明蛋鸡开产前饲喂高脂日粮可使试验鸡血浆极低密度脂蛋白水平显著增加。在蛋鸡开产后对其生产性能有良好的影响,使产蛋量（克／只日）和蛋重显著增加（Ｐ＜０．０１）,产蛋率也有增加的趋势,但不显著（Ｐ＞０．０５）。     

THIAMBUTENE AND ACEPROMAZINE AS ANALGESIC AND PREANESTHETIC AGENTS IN HORSES AND SHEEP

Investigations into the analgesic effect of thiambutene and its value as a pre-anaesthetic agent were carried out in the horse and the sheep. Special emphasis was placed on the post-anaesthetic recovery period.
Thiambutene produced analgesia in both species. Toxic effects such as muscle tremor and hyperkinesia occurred with high doses. Prior administration of acepromazine increased the tolerated doses of thiambutene, and satisfactory neuroleptanalgesic states were produced.
Combined use of thiambutene and acepromazine in pre-anaesthetic medication reduced the dose of thiopentone required for anaesthesia in both species and significantly improved post-anaesthetic recovery.
Administration of nalorphine in both species reduced the duration of the recovery period. In the horse, even after prolonged thiopentone anaesthesia, nalorphine produced a shorter, quieter recovery.
It was concluded that pre-anaesthetic medication with thiambutene and acepromazine facilitated thiopentone anaesthesia and greatly reduced the problems of post-anaesthetic recovery in horses.     

现代科学技术与草业现代化

简要阐述了科学技术与草业的兴起及其相互关系，并首次提出了草业现代化及其基本内涵，通过论证，表明实现现代化是草业科学技术发展的必然。