Experimental reproduction of ovine vulvitis with bacteria of the haemophilus/histophilus group

Ovine vulvitis was experimentally reproduced by intravaginal inoculation of a mixture of bacterial strains of the histophilus/haemophilus group isolated from field cases. Grossly, the experimental vulvitis was identical to the field condition, and bacteria indistinguishable from the inoculated strains were reisolated.     

Efficacy of the immunoblot assay for cysticercosis in pigs and modulated expression of distinct IgM/IgG activities to Taenia solium antigens in experimental infections

A recently invented immunoblot assay for human cysticercosis was evaluated for efficacy in pigs. The test population consists of 45 pigs with parasitologically confirmed cysticercosis, 47 with heterologous infections, 45 SPF or concrete raised control animals. With this group of 137 animals the test performance was 100% sensitive and 100% specific. The antigen-specific responses of immunoglobulin A (IgA), IgG and IgM in four pigs infected with Taenia solium eggs derived from a human were quantified by immunoblot. Antigen-specific activities were observed as early as 1 week postinfection. The first antigen-specific isotypic response was IgM antibodies directed against a glycoprotein at 97 KD (GP97). This activity generally disappeared between the sixth and ninth week postinfection. Between Weeks 5 and 8, IgG activity rose as IgM activity fell. The IgG activity, however, was directed mostly towards GP50 and GP42 antigens. If the same response occurs in people with cysticercosis, identifying specific isotype activity may help to distinguish new infection from old.     

Sexual performance of rams as determined by maturation and sexual experience

The purpose of this study was to compare the sexual performance of rams that differed in age (maturation) and sexual experience. Twenty-four ram lambs (8 mo of age) and 21 rams (20 mo of age) were individually exposed to four females in hormonally induced estrus for 30 min on five occasions, 7 d apart. Half (12) the ram lambs and nine of the yearlings were sexually naive at the start of testing (had been denied access to females since weaning); the remaining males were sexually experienced. The sexual performance of the virgin rams was poorer during the initial exposure to females than in subsequent tests, whereas the sexual behavior of the sexually experienced males did not change over the days of testing. Sexually naive ram lambs and rams exhibited an improvement in sexual performance between Tests 1 and 2; during Test 3 to 5 the sexual performance (ejaculations per test) of sexually naive and experienced rams was similar. The only effects of age (maturation) on sexual performance during the last three test days were a higher frequency of mounts without ejaculation plus mount attempts (P less than .03) and a greater number of mount interactions per ejaculation (P less than .02) by ram lambs. In conclusion, one or two relatively brief exposures to estrous females can bring the sexual performance of virgin rams up to levels comparable to that of experienced males. Also, ram lambs in good condition exhibit acceptable levels of sexual performance.     

Development of sexual and aggressive behaviors in Hereford bulls

The purpose of this study was to describe maturation-related changes in the sexual and aggressive behaviors of Hereford bulls. Two groups of 13 and 14 bulls, respectively, were tested for sexual and aggressive behaviors every 3 mo from 3 to 24 mo of age. At 3 and 6 mo of age, the bulls were exposed, as groups, to two estrous females, whereas at 9, 12, 15, 18, 21, and 24 mo these bulls were tested under each of the following several treatment conditions: 1) individual tests (single males were exposed to single females), 2) small-group tests (three or four bulls:three females), 3) large-group tests (13 or 14 bulls:3 females), and 4) male-only tests (13 or 14 bulls were placed in the test arena in the absence of females). Most bulls consistently mounted females by 9 mo of age. Twenty-one of the 27 bulls (78%) attained their first ejaculation at either 12 or 15 mo of age. The frequency of mounting without ejaculation was greatest in large-group tests at 12 mo of age, and ejaculation frequency peaked at 18 mo. The incidence of male-male mounting in large-group tests (with females) did not appreciably change from 3 to 24 mo, whereas male-male mounting in male-only tests was greatest at 9 and 24 mo. We conclude that sexual performance data obtained in serving capacity tests administered to yearling bulls before 18 mo of age may underestimate the mating potential of certain individuals.(ABSTRACT TRUNCATED AT 250 WORDS)     

Simplified calculation of the NRC estimates for net energy for maintenance in beef cattle diets

Calculation of dietary intake for beef cattle using the equation outlined by the NRC (1984) is confounded by the need to know the net energy for maintenance content of the diet (NEmkg). Intake cannot be calculated until NEmkg is specified, but intake must be indicated before performance can be predicted. To calculate NEmkg, dietary intake must be known or estimated, or it can be calculated using a complicated quartic equation. This quartic equation, when solved, gives the percentages of selected feedstuffs necessary to balance a diet. Placing the resulting percentages of feedstuffs necessary back into the generalized net energy equation solves for NEmkg. The quartic equation may be simplified by inserting imaginary nutrient values that optimize the equation for simplicity. It remains a quartic equation, but the coefficients for the first three factors of the equation are fixed, with only the unary X term and the coefficient containing variables. A modified version of Newton's method of approximating roots of equations estimates the percentage of feed necessary and when incorporated into the generalized net energy equation solves for NEmkg. The final reduced form results in simplified equations for NEmkg for each of the classes of beef cattle that are easily solved by the hand-held calculator.     

Disruption of the caudal component of the reciprocal apparatus in two horses

Two horses became acutely lame following a fall during strenuous exercise and were diagnosed as having disruption of the caudal component of the reciprocal apparatus. Clinical signs consisted of lameness of the right pelvic limb, characterized by flexion of the hock and simultaneous extension of the stifle. Radiography revealed an avulsion fracture from the supracondylar tuberosity and fossa of the distal portion of the femur in one horse. Clinical and radiographic findings indicated avulsion of the lateral origin of the gastrocnemius and superficial digital flexor muscles. Treatment consisted of stall rest, limb immobilization, and phenylbutazone administration. One horse recovered to soundness and the other deteriorated and was euthanatized.     

Mass selection for increased 200-day weight in a closed line of Landrace pigs

Mass selection for increased weight at 200 d of age was conducted for six generations in a line of Landrace pigs. In the select line, the heaviest nine boars and 18 gilts were selected from each generation to produce the subsequent generation. A contemporaneous control line was maintained by randomly selecting a son from each sire and a daughter from each dam to attain a line size of five boars and 10 gilts. Inbreeding coefficients averaged .182 and .191 for the select- and control-line pigs and .150 and .162 for the select- and control-line dams, respectively, in the sixth generation. The 200-d weights and ultrasound backfat thickness data were collected from 1,022 pigs of 2,181 pigs farrowed. These pigs were sired by 92 boars and out of 210 sows. The generation interval was 13 mo. Twelve traits were studied: weights at birth and at 21, 35, 70, 154, and 200 d of age; daily gains from birth to 35 d, 35 to 70 d, 70 to 154 d, and 154 to 200 d; ultrasound backfat thickness at 200 d; and ultrasound backfat thickness adjusted for 200-d weight. Total weighted cumulative selection differential for 200-d weight was 88.7 kg. Realized heritability for 200-d weight was .26 +/- .08 with an average response of 4.2 +/- 1.3 kg/generation. Correlated responses resulted in increases for all weights and daily gains evaluated. Although ultrasound backfat thickness at 200 d increased in the select line compared to the control line, it was not altered by selection for 200-d weight when adjusted for 200-d weight.     

Inflammatory middle ear disease of the dog: the clinical and pathological features of cholesteatoma, a complication of otitis media

During a study of inflammatory middle ear disease in the dog cholesteatoma was found to accompany otitis media in seven of the 62 ears examined (11 per cent). The clinical, radiological and pathological findings in these animals imply that cholesteatoma in the dog is an aggressive lesion which must be differentiated from uncomplicated otitis media.