Growth of gram-positive mastogenic bacteria in normal, simulated bulk tank, and mastitic milk held at simulated fluctuating temperatures of farm bulk tank.

Growth of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus bovis, and Streptococcus uberis was studied in normal milk, simulated bulk tank milk, and aseptic mastitic milk held at simulated fluctuating temperatures of farm bulk tank for 48 h. With the exception of S. bovis, growth rates of the other five bacteria were similar in both normal and simulated bulk tank milk. Mastitic milk inhibited growth of all bacteria studied. A 24-h adjustment period occurred before most of the bacteria started growing. The mastitis level in a dairy herd may be monitored by cultures of bulk tank milk samples and by calculations as discussed in this study.

Observations on the use of prostaglandin F(2alpha) as an abortifacient and effect of gonadotrophin-releasing hormone on ovarian activity after induced abortion during the breeding season in goats.

Results of two experiments are described. In the first experiment, forty-one mixed-breed goats (does) with unknown gestation lengths were given 10 mg prostaglandin F(2alpha) (PGF(2alpha)) (2 doses of 5 mg each, 24 h apart) i.m. Blood samples were obtained before each treatment with PGF(2alpha) by jugular venipuncture, and plasma progesterone (P(4)) concentrations were determined by a nonextraction solid-phase radioimmunoassay. P(4) concentrations (ng/ml) were significantly decreased (15.47 vs 1.55, P<0.005) 24 h after the first injection of PGF(2alpha). A total of 63 fetuses was collected within 46.5 h following the first injection. Mean (+/- SE) crownrump lengths and body weights of 62 fetuses were 21.46 +/- 0.29 centimeters (cm) and 575.00 +/- 20.60 g, respectively. Based on these findings, the mean gestation length of these does was estimated to be 86.96 +/- 0.74 d. Thirty-one does retained their placenta for 12 to 72 h and were treated with a single injection of 5 mg PGF(2alpha) and 800 mg oxytetracycline i.m. Placental expulsion in all does occurred within 24 h posttreatment. The results of this study suggest that two doses of 5 mg PGF(2alpha) intramuscularly (i.m.) 24 h apart is an effective abortifacient at about 3 mo of pregnancy in does. In the second experiment, 38 does from the first experiment were divided in two groups of 19 each on Day 13 postabortion. Group A (treated) was given 50 ug GnRH i.m. while Group B (control) received 1 ml 0.9% saline i.m. Blood samples were obtained prior to treatment and on Day 23 postabortion and assayed for P(4) concentrations. There was no significant difference (P>0.10) in P(4) concentrations of samples obtained pre- and post-GnRH treatment. However, 14 of 19 and 12 of 19 in Groups A and B, respectively, exhibited estrus within 52 days following abortion. Twenty-six does were bred naturally and 17 became pregnant.

Cerebellar disease in an adult cow.

This is the report of clinical signs and lesions of a cerebellar disorder in an adult four year old Limousin cow grazing perennial ryegrass (Lolium perenne). The most striking histopathological lesion was a marked paucity of Purkinje cells throughout the cerebellum.

Follicular cysts in sheep.

A flock of 188 sheep was surveyed for cutaneous lesions that were noticed 3 days after shearing. On the basis of histologic features of the cyst wall, ie, association with sebaceous glands and lack of follicular structures or rete pegs, the cysts were classified as follicular cysts.

Epidermal inclusion cysts in a cow.

A 6-year-old Hereford-cross cow had multiple 2-cm diameter, well-circumscribed, firm, nonulcerated cutaneous nodules along the ventral midline. Biopsy of several nodules revealed epidermal inclusion cysts. Such cysts may be of economic importance because they affect hide quality in beef and dairy cattle.