Polyclonal rabbit antiserum to human T-cell CD3 was used to study its reactivity in lymphoid tissues (lymph nodes, spleen, aggregated lymphoid follicles [Peyer's patches], thymus) of several animal species (cattle, sheep, goats, rats, and mice). Using a peroxidase-antiperoxidase technique on formalin-fixed and paraffin-embedded tissues, immunoreactive cells were detected in T cell-dependent areas of the lymphoid tissues. Reactivity was high in all species tested, but mouse tissues had reduced reactivity, compared with the other species. To obtain a reaction, it was necessary to digest tissues with pronase before application of the immunocytochemical technique. Our results indicate that CD3 antiserum may specifically recognize T-lymphoid cells as it does in human lymphoid tissues and can be used as a marker to study physiologic and pathologic conditions of the lymphoid system of these species.

To compare the effects of milk stasis and milk flow on Brucella abortus infection of the mammary gland under the same systemic conditions, primiparous goats (n = 5) were inoculated IV with B abortus on the day of parturition, and suckling by their neonates was restricted to one mammary gland. Goats were euthanatized and necropsied at 3 weeks after inoculation, and milk, mammary glands, and supramammary lymph nodes were evaluated by bacteriologic, histologic, and immunoenzymatic staining techniques. Nonnursed mammary glands had high titers of brucellae in milk, moderate interstitial mastitis, and brucellar antigen in macrophages located primarily in alveolar and ductal lumina. Brucellae often filled the macrophage cytoplasm. In contrast, nursed mammary glands had fewer brucellae in milk, minimal inflammatory changes, and no detectable brucellar antigen in histologic sections. Hyperplastic changes were only seen in supramammary lymph nodes draining nonnursed mammary glands; these contained more brucellae than lymph nodes draining nursed mammary glands. These studies show that milk stasis may be the sole cause of increased susceptibility of nonnursed mammary glands to B abortus infection.

Bovine leukemia virus (BLV) was transmitted by horse flies, Tabanus fuscicostatus, from a cow with a lymphocyte count of 31,500/mm3 to goats and dairy calves. As few as 10 and 20 flies transmitted BLV to goats and calves respectively, but the minimal number of flies required to transmit the infection was not established. Groups of 150 and 100 T fuscicostatus transmitted BLV to beef calves from a cow with a lymphocyte count of 14,600/mm3. These results support a role for horse flies in the horizontal transmission of BLV.

Anthelmintic efficacy of levamisole against induced infections with 7- and 21-day-old Haemonchus contortus, Ostertagia circumcincta, Trichostrongylus axei, and T colubriformis was evaluated as an oral drench in goats. Group 1 (n = 8) was not treated, group 2 (n = 8) was given 3.96 mg of levamisole/kg of body weight, group 3 (n = 8) was given 7.92 mg of levamisole/kg, and group 3 (n = 7) was given 11.88 mg of levamisole/kg. Efficacy against all worms was low in goats given 3.96 mg of levamisole/kg, but was high against adult H contortus (99%) and adult T colubriformis (99.7%) in goats given 7.92 mg of levamisole/kg. Although efficacy against adults of all species was high in goats given 11.88 mg of levamisole/kg, some immature worms of all species remained in the abomasa of goats.

In healthy adult goats, closure of the esophageal groove was induced by thirst, IV administered vasopressin, and intracarotid administration of hypertonic NaCl solutions. The efficiency of stimulation was tested directly by visual inspection of the course taken by orally administered solutions through a ruminal or abomasal fistula, palpation of the lips of the esophageal groove through a ruminal fistula, and indirectly by following the glucose dynamics in the blood after oral administration of glucose solution. Esophageal groove closure was observed during drinking after a 48-hour period of water deprivation. Intracarotid administration of 1.5 ml of a saturated solution or 10.5 ml of a 1.5% solution of NaCl also stimulated groove closure; however, groove closure stimulated by administration of vasopressin is the most satisfactory procedure for passing compounds of therapeutic importance directly from the cardiac orifice to the abomasum.

One hundred eight milking goats from a dairy that had been using a modified caprine arthritis-encephalitis virus (CAEV) eradication program were tested for CAEV antibodies by serologic methods and for proviral CAEV DNA by use of polymerase chain reaction (PCR) technology. All goats were free of clinical symptoms of CAEV infection. Twenty-seven of the 108 goats were considered seropositive, on the basis of ELISA results. Proviral CAEV DNA was detected, using PCR techniques, in mononuclear leukocytes in blood samples obtained from 25 of the these 27 seropositive goats. Twenty of the 81 seronegative goats also had positive PCR test results. Ten of these goats seroconverted by 8 months later, and virus was readily isolated from mononuclear leukocytes in venous blood samples after the goats had seroconverted. Virus was also isolated from mononuclear leukocytes in blood samples collected from 4 of 11 goats that were seronegative, but had positive PCR test results. These results indicated that seroconversion can be delayed for many months following natural infection with CAEV. Delayed seroconversion appears to be a feature of CAEV infection, which may have direct implications for CAEV eradication programs and epidemiologic studies that rely on serologic methods to detect infected goats.

Plasma luteinizing hormone and progesterone concentrations, time to onset of estrus, and pregnancy rates were determined in nonlactating anestrous does given 1 of 4 treatments: subcutaneous ear implants containing 3 mg of norgestomet for 9 days (NOR; n = 6); subcutaneous administration, using osmotic minipumps, of 250 ng of gonadotropin-releasing hormone (GnRH)/h for 48 hours (GnRH; n = 6); 3 mg of NOR for 9 days, followed immediately by 250 ng of GnRH/h for 48 hours (NOR + GnRH; n = 6); or no treatment (control; n = 6). During the 72-hour period after removal of NOR or insertion of GnRH pumps, 6 of 6, 0 of 6, 6 of 6, and 3 of 6 does were observed in estrus at a mean (+/- SE) of 49 (+/- 3.0), 0(+/- 0), 32 (+/- 2.0), and 35 (+/- 13.8) hours in groups NOR, GnRH, NOR + GnRH, and control, respectively. Time from end of treatment to peak concentrations of luteinizing hormone were 56 +/-4.0, 28 +/- 4.7, 34 +/- 4.3, and 41 +/- 9.7 hours (mean +/- SE) for NOR, GnRH, Nor +/- GnRH, and control, respectively. Peak concentrations of luteinizing hormone were significantly greater and occurred significantly later in does given NOR. Progesterone concentrations in does that became pregnant increased to concentrations greater than or equal to 1.0 ng/ml 3 to 5 days after breeding and remained high. Functional corpora lutea (CL) was found in 6 does that did not become pregnant, 1 CL was associated with pseudopregnancy and 1 CL was associated with ovulation prior to placement of the GnRH pumps. Functional CL failed to form in 10 of the 12 does in groups GnRH and control. Does had either continual low concentrations of progesterone (3 does) or short-term increases in concentrations of progesterone (7 does). Conception rates for does in groups NOR, GnRH, NOR + GnRH, and control were 83%, 0%, 50% and 0%, respectively. Four does given GnRH and 3 control does were observed in estrus and were bred during the subsequent 2-week period. All of these does, except 1 control became pregnant subsequent to these breedings. The treatments NOR and NOR + GnRH were effective in inducing a synchronized estrus in dairy goats. However, the use of bucks to detect estrus may have introduced the buck effect and enhanced the performance of NOR alone, which has not been this effective in other studies with small ruminants.

A method of inducing Pasteurella haemolytica serotype 1 (Ph1) lung infection in goats, using low numbers of bacteria and without impairing host immunity, was developed. Two trials were conducted. Results of trial 1, using 10 principals (Ph1 agar beads) and 6 controls (agar beads alone), indicated that Ph1 organisms imbedded in agar beads could survive host lung defenses for 32 days. Results of trial 2 indicated that lung immunity in the inoculated goats (principals) was high and they were more protected than controls against a transthoracic challenge of Ph1 (1.18 X 10(7) colony-forming units) injected into lung of each goat on posttreatment day 35. When comparing challenge-exposed principals with controls, the controls developed rectal temperatures above normal for a longer time, duration of anorexia was longer, and sign of depression were seen. The controls developed large are of consolidated lung tissue, more Ph1 isolates were recovered from nasal turbinates and lung tissue, and higher Ph1 concentrations were found in the lungs. The serum Ph1 indirect hemagglutination antibody titers in the principals of both trials increased, compared with titer in controls. Principal goats in trial 2 had higher Ph1 indirect hemagglutination antibody titers after injection of Ph1-impregnated agar beads and less severe lung lesion after challenge exposure than did controls. The small pneumonic consolidated lesions in the principals, compared with extensive lesions in controls after Ph1 challenge exposure, indicated a high degree of immunity after exposure to Ph1 organisms imbedded in agar beads.