Superovulation after administration of PMSG in cows of various breeds

Superovulation response was studied to i. m. administration of 2500 and 3000 i. u. of PMSG (special product Folligon, Intervet Co.) in 67 breeding cows of the Black-Pied Lowland. Slovak Pied and Slovak Pinzgau breeds within the 9th to 12th days of their sexual cycles. The time which had elapsed from these cows' last calving ranged from 50 to 150 days and the number of their prior calvings ranged from one to ten. The best superovulation effect was obtained after the administration of 2500 i. u. PMSG in the Pinzgau breed: these cows had, on the average, 13.20 +/- 2.36 corpora lutea without non-ovulated follicles. At the PMSG dose increased to 3000 i. u., the number of yellow bodies rose to 18.11 +/- 1.12 and that of non-ovulated follicles to 3.46 +/- 0.46. In the Slovak Pied breed the average number of yellow bodies obtained after administration of 2500 i. u. PMSG was 11.74 +/- 1.27 and that of non-ovulated follicles was 0.44 +/- 0.02. At the PMSG dose of 3000 i. u., the number of yellow bodies increased to 15.49 +/- 1.62 and that of non-ovulated follicles increased up to 5.12 +/- 0.81. In the Black-Pied Lowland breed the lowest response was obtained: the i. m. administration of 2500 i. u. PMSG resulted in the formation of 9.5 +/- 0.84 yellow bodies and 1.16 +/- 0.26 non-ovulated follicles, and at the dose of 3000 i. u. the respective numbers were 13.41 +/- 0.89 and 3.07 +/- 0.39. Comparing the superovulation effect in dependence on age, the response of the cows of the Black-Pied Lowland and Slovak Pinzgau breeds to PMSG administration increases until the age of nine years (from 9.79 and 13.6 yellow bodies, respectively, on the average for the first five years to 12.71 and 17.99, respectively, in the ninth year); in the Slovak Pinzgau breed it decreases from 15.83, recorded in the first five years, to 8.28 +/- 1.68 in the ninth year. The number of non-ovulated follicles grows with age in the Slovak Pinzgau breed from 3.46 +/- 0.46 in the first five years to 3.64 between five and nine years of age and up to 4.44 +/- 0.52 after the ninth year, in the Slovak Pied breed from 0.79 to 4.21 +/- 0.38, and in the Black-Pied Lowland breed from 2.69 to 3.20 +/- 0.22 between the fifth and ninth year.     

Incidence of mastitis in beef cows after intramuscular administration of oxytetracycline

There is limited information on the value of antibiotic therapy for mastitis in beef cows. Effects of antibiotic treatment at weaning and the subsequent calving on calf weaning weight, milk somatic cell counts, milk components, and intramammary infection were studied in beef cows. Additionally, effects of number of infected mammary quarters, number of dry mammary quarters, type of intramammary pathogen, and parity on response variables were determined. Cows (n = 192) were randomly assigned to treatments in a 2 x 2 factorial arrangement; factors were time of treatment (weaning and after calving) and treatment (vehicle and vehicle plus antibiotic). Oxytetracycline (LA-200) or vehicle was administered intramuscularly following collection of quarter milk samples at weaning and calving. Percentage of infected cows and quarters averaged 43.4 and 16.4%, respectively, at calving and increased (P < 0.05) to 53.7 and 29.7% at weaning. Calves from cows with one or two dry quarters weighed 12.7 kg less (P < 0.05) at 90 d after calving and 18.7% less (P < 0.05) at 212 d after calving than calves from cows with no dry quarters. Calves from cows with three or four infected quarters weighed 17.5 kg less (P < 0.05) at 90 d and 25.5 kg less (P < 0.05) at weaning than calves from cows with two or fewer infected quarters. Infections by Staphylococcus aureus and coagulase-negative staphylococci were the most common and accounted for 67 and 78% of the infections. Percentages of infected cows and quarters, infections caused by S. aureus, and dry quarters increased (P < 0.05) with parity. No differences were found among antibiotic treatments for any of the response variables studied. Intramuscular oxytetracycline was not effective in the control of mastitis in beef cows under the conditions of the study.     

Dexamethasone and mastitis in cows

Abstract

Extract

Sir, — The use of corticosteroids to induce early parturition to obtain a concentrated calving period has been widely accepted in New Zealand. Retention of the placenta following treatment with corticosteroids has been described by Adams (1969 Adams, W. M. 1969. The elective induction of laborand parturition in cattle. J. Am. vet. Med. Ass., 154: 261–265.  [Google Scholar]), Lauderdale (1972 Lauderdale, J. W. 1972. Effects of corticoid administration on bovine pregnancy. J. Am. vet. med. Ass., 160: 867–871.  [Google Scholar]) and Jochle et al. (1972 Tochle, W., Esparza, H., Gimenez, T. and Hidalgo, M. A. 1972. Inhibition or corticoid-induced parturition by progesterone in cattle: Effect on delivery and calf viability. J. Reprod. Fert., 28: 407–412.  [Google Scholar]). Welch et al. (1973 Welch, R. A. S., Newling, P. and Anderson, D. 1973. Induction of parturition in cattle with corticosteroids: An analysis of field trials. N.Z. vet J., 21: 103–108. [Taylor &; Francis Online] , [Google Scholar]), using dexamethasone trimethylacetate* *Opticortenol: Ciba-Geigy. in the Huntly and Bay of Plenty areas, reported that calf mortality was disturbingly high — 31.3% and 17.1% for the respective areas. Despite having no apparent effect on milk production or subsequent fertility it is possible pre-existing infections may be exacerbated by the use of corticosteroids.     

奶牛乳房炎的治疗方法

奶牛乳房炎是乳腺受到物理、化学、微生物刺激所发生的一种炎性变化.本病以乳汁的理化性改变为主,由多种非特定的病原微生物引起,不仅影响产奶量、牛乳质量、延长产后发情和妊娠时间,严重时还能使奶牛泌乳机能丧失而被淘汰,是世界奶牛业的主要危害因素之一[1-3].笔者根据多年的治疗经验,总结如下.