BREED DIFFERENCES IN THE RESPONSE OF YOUNG BEEF BULLS TO ELECTRO-EJACULATION

SUMMARY A total of 702 electro-ejaculation attempts are recorded on young (16 to 31 months) beef bulls of 3 breeds and 3 breed crosses (Brahman cross 100, Africander cross 93, Shorthorn cross 109, Brahman 81, Africander 89, and Hereford 230. Four hundred and forty of these attempts were conducted on bulls of the first 5 of these breeds which had been reared under similar conditions on the same property. The machine employed was a Watson Transtimulator, powered by a 12-volt automobile battery, and connected to a 6.25 cm diameter bipolar ring electrode probe, 37.5 cm in length. The voltages at which the sperm free (sample A) and sperm rich (sample B) samples were initiated were 4.8 ± .2 and 7.7 ± .2 volts respectively. No breed differences occurred. Breed differences occurred in the proportion of bulls showing a severe reaction to the electricity (P < 0.001) with the Africander (32.6% P < 0.001) and Ax (28.0% P < 0.01) having the highest proportions of severe reactions. These 2 breed groups also had the highest proportions of electro-ejaculation failures (respectively, 23.6% P < 0.05 and 19.4% n.s.). Overall, bulls of Bos indicus derivation did not differ from those of Bos taurus derivation in electro-ejaculation failures. During stimulation, erection was achieved by 19.8% of bulls and failure to collect an assessable ejaculate occurred in 15%. No breed differences occurred in either category. Collapse during stimulation occurred in 5.3% of electro-ejaculation attempts (overall P < 0.05) with the SH breed group having highest representation (12.8% P < 0.001).     

REPRODUCTIVE PERFORMANCE OF BEEF CATTLE IN NORTHWESTERN QUEENSLAND

The reproductive performance of beef cattle in 5 herds mated all year round in north-west Queensland was examined from 1970 to 1973. Conception rates, conception patterns and branding rates were used to assess annual reproductive performance. The level of loss between the times of confirmed pregnancy and branding was defined. The mean annual conception rate was 83.1% with individual property means ranging from 75.4 to 90.9%. Conception rates for heifers, first calf cows and mature cows were 83.9%, 80.6% and 84.7% respectively. Conception patterns were influenced by seasonal conditions, 68.1% of conceptions occurring in the wet season, between December and May. In this region, conception patterns were highly correlated with rainfall during the previous month. Losses between the times of confirmed pregnancy and branding ranged from 5.9 to 27.7%. Body condition of animals varied and was dependent upon lactation, seasonal and parity effects.     

ANTHELMINTIC TREATMENT OF YOUNG BEEF CATTLE IN THE WALLUM REGION OF SOUTH-EASTERN QUEENSLAND

An anthelmintic treatment trial on 125 Brahman-British crossbred 2 to 4 month old calves was undertaken on Wallum country in south eastern Queesland. The calves were divided into 5 experimental groups, grazed together and treated as follows for 17 months: Group 1--Untreated controls; Group 2--Monthly levamisole--niclosamide on 4 occasions; Group 3--Monthly levamisole until 1 month after weaning; Group 4--Levamisole 3 to 6 weeks after saturating rains; Group 5--No levamisole--niclosamide as for Group 2. The mean body weight gains for cattle in Groups 1 to 5 were 95, 124, 105, 121 and 97 kg respectively. Four cattle were lost from each of Groups 1 and 3 and five from Group 5. Most of these losses occurred towards the end of the second summer rainfall season. Faecal egg count maxima were recorded around weaning in untreated groups and during the summer rainfall period of both the first and second summer in all groups. The most prevalent nematode species encountered were H. placei, Cooperia spp and O. ostertagi. It is recommended that in this region cattle under 2 years of age should receive anthelmintic treatment at least in autumn and spring.     

THE RELATIONSHIP BETWEEN A SERVING CAPACITY TEST AND FERTILITY OF BEEF BULLS

SUMMARY In a trial using Bos indicus and Bos taurus bulls in a tropical environment the serving capacity, defined as the number of complete services achieved during a 40-minute yard test, failed to predict the fertility of the bulls after 3 or after 7 weeks of mating. The numbers of services achieved during the yard test were much lower than those reported from a temperate region using Bos taurus bulls.     

ANTHELMINTIC TREATMENT OF YOUNG BEEF CATTLE IN CENTRAL QUEENSLAND

The value of regular anthelmintic treatment of beef calves was assessed in two herds in central Queensland. In each herd groups of 31 suckling calves were observed. Control groups received no treatment, and treated groups received injectable trichlorphon either after rainfall exceeding 2 inches or monthly. Regular faecal egg counts revealed moderate infestations with Haemonchus placei, Oesopha-gostomum radiation, Cooperia spp, and Tricha-strongylus spp. In one herd, the groups received 0, 7, and 14 treatments over a period of 15 months, and showed mean weight gains of 356, 355, and 365 lb respectively. In the second herd after 0, 6, and 12 treatments, the corresponding gains were 407, 415, and 419 lb. It was concluded that, in these circumstances, the anthelmintic treatment had no economic value.     

CONGENITAL ABNORMALITIES OF THE VERTEBRAL COLUMN IN FERRETS

Vertebral column pathologies requiring surgical intervention have been described in pet ferrets, however little information is available on the normal vertebral formula and congenital variants in this species. The purpose of this retrospective study was to describe vertebral formulas and prevalence of congenital vertebral anomalies in a sample of pet ferrets. Radiographs of 172 pet ferrets (96 males and 76 females) were included in this retrospective study. In 143 ferrets (83.14%), five different formulas of the vertebral column were recorded with normal morphology of vertebrae (rib attachment included) but with a variable number of thoracic (Th), lumbar (L), and sacral (S) vertebrae. The number of cervical (C) vertebrae was constant in all examined animals. Observed vertebral formulas were C7/Th14/L6/S3 (51.74%), C7/Th14/L6/S4 (22.10%), C7/Th14/L7/S3 (6.98%), C7/Th15/L6/S3 (1.74%), and C7/Th15/L6/S4 (0.58%). Formula C7/Th14/L6/S4 was significantly more common in males than in females (P < 0.05). Congenital spinal abnormalities were found in 29 ferrets (16.86%), mostly localized in the thoracolumbar and lumbosacral regions. The cervical region was affected in only one case. Transitional vertebrae represented the most common congenital abnormalities (26 ferrets) in the thoracolumbar (13 ferrets) and lumbosacral regions (10 ferrets) or simultaneously in both regions (three ferrets). Other vertebral anomalies included block (two ferrets) and wedge vertebra (one ferret). Spina bifida was not detected. Findings from the current study indicated that vertebral formulas may vary in ferrets and congenital abnormalities are common. This should be taken into consideration for surgical planning.     

香猪生殖器官的发育及血浆雌二醇和睾酮含量变化

测试验定了初生、10、20、30、90、150和210日龄香猪公母猪的生殖器官及其血浆雌二醇和睾酮浓度。结果表明,香猪公猪的生殖器官发育较早,母猪生殖器官发育较迟。90日龄时,公猪睾酮水平达3273±1455pg/ml,母猪雌二醇水平也开始上升。发现公猪血浆中查得较母猪高的雌二醇水平。