Ovarian follicular characteristics, embryo recovery, and embryo viability in heifers fed high-fat diets and treated with follicle-stimulating hormone.

Postpubertal beef heifers (n = 55) were used to examine the effects of high-fat diets, independently of energy intake, on nonesterified fatty acid and lipoprotein metabolic patterns, ovarian follicular dynamics, and embryo recovery/viability after FSH superstimulation. High-lipid (HL) diets (5.4% added fat) increased (P < .01) serum concentrations of cholesterol, but not of nonesterified fatty acids, during the 35-d period before FSH treatment. Development of medium-sized (5 to 9.9 mm) follicles was enhanced (P < .05) during this period in heifers fed the HL diet. The HL diet increased total cholesterol (P < .05) and progesterone (P = .14) concentrations in follicular fluid obtained at ovariectomy (n = 10) 60 h after the onset of FSH treatment, but neither estradiol-17 beta nor androstenedione was affected. Granulosa cells recovered from FSH-induced, estrogen-active follicles in heifers fed the HL diet produced greater quantities of progesterone (P = .06) and less estradiol-17 beta (P < .05) in vitro than did granulosa cells from heifers fed the normal lipid diet. Dietary treatment did not influence FSH-stimulated recruitment of medium and large follicles, number of ovulations, embryo recovery, or embryo viability. Data suggest that increments in dietary fat intake can alter specific aspects of ovarian steroidogenic potential and can increase the population of medium-sized follicles theoretically available for maturation and harvest during the estrous cycle. However, conditions that limited the latter process in the current experiment are not understood and require further investigation.     

Increased litter size in Rambouillet sheep: I. Estimation of genetic parameters.

The variance and covariance components needed to estimate heritabilities of and genetic correlations among litter size, ovulation rate, scrotal circumference, and BW in a flock of Rambouillet sheep were estimated using REML via an expectation-maximization type algorithm. The heritability estimates from univariate analyses were .14, .21, .25, .36, and .15 for litter size, ovulation rate, scrotal circumference, 180-d BW of females, and 180-d BW of males, respectively, and average heritability estimates from bivariate analyses were .19, .20, .20, .34, and .10 for litter size, ovulation rate, scrotal circumference, 180-d BW of females, and 180-d BW of males, respectively. The genetic correlation between litter size and ovulation rate was near unity. Body weight in ewes had a moderate genetic correlation with both litter size (.22) and ovulation rate (.20) and a low residual correlation with both litter size (.03) and ovulation rate (.09). The genetic correlation between BW in rams and scrotal circumference was 0, whereas the residual correlation was .71. The genetic correlations of scrotal circumference with litter size and ovulation rate were -.25 and +.20, respectively.     

Kinetics of hydration and effect of liquid uptake on specific gravity of small hay and silage particles.

Kinetics of hydration of ground hay and silage particles (2-mm screen), determined by a pycnometric technique, was best described by a two- and one-pool exponential model, respectively. Fractional rates of hydration of the large pool, detected in hay particles only, and of the small pool present in both hay and silage particles averaged .135 and .021 min-1, respectively. When hydration was complete, liquid associated with particles averaged 1.16, 1.90, and .83 g/g of insoluble DM for bromegrass hay, alfalfa hay, and alfalfa silage, respectively. Functional specific gravity, which accounts for the effect of associated gas volume, averaged 1.54, 1.46, and 1.54, but unit specific gravity, calculated to include the effect of gases and liquid of hydration, averaged 1.22, 1.14, and 1.26 for bromegrass hay, alfalfa hay, and alfalfa silage, respectively. Preservation of forage as silage not only lowered gas volume, but also reduced water-holding capacity, both of which contribute to greater unit specific gravity and faster rate of escape from the rumen. In addition, estimates of unit specific gravity of approximately 1.2 indicate that even in the absence of associated gas, hydrated forage particles would tend to escape the rumen at a slower rate than that achieved by more dense particles.     

Function of neutrophils and chemoattractant properties of fetal placental tissue during the last month of pregnancy in cows.

Neutrophils were isolated from the blood of pregnant cows on days 255, 265, and 275 of pregnancy, and on the day of parturition (n = 5/group), and in addition, simultaneously from 4 ovariectomized healthy cows (control animals). Neutrophils were subjected to neutrophil function assays (chemotaxis against zymosan-activated serum, random migration, ingestion of 125I-iododeoxyuridine [IdUR]-labeled Staphylococcus aureus, iodination of proteins, cytochrome C reduction, antibody-independent and antibody-dependent cell-mediated cytotoxicity). Results were expressed as percentage of control animals. Fetal placental tissue (cotyledon), uterine wall tissue, and skeletal muscle were obtained from the principal animals on the aforementioned days via laparotomy, and tissue suspensions were prepared. Chemotaxis of neutrophils was tested against tissue supernatants. Compared with day 255, there was an increase in ingestion of 125I-IdUR-S aureus at parturition, whereas iodination of proteins and cytochrome C reduction were reduced on the day of calving. The other neutrophil functions tested did not change over time of gestation. Fetal placental and uterine wall tissue attracted neutrophils with uterine wall tissue having a tendency to be more potent than cotyledonary tissue. Skeletal muscle tissue did not attract neutrophils. There was no change in chemotaxis response of neutrophils evoked by intrauterine and uterine tissues over time of gestation. It was concluded that at parturition, neutrophil function is impaired with respect to their bactericidal effects, which may render the animal more susceptible to bacterial infections, and that the chemoattractant properties of fetal placental and uterine wall tissues are tissue-specific, at least when compared with skeletal muscle.(ABSTRACT TRUNCATED AT 250 WORDS)     

Proliferative response of mammary gland mononuclear cells to recombinant bovine interleukin-2.

Methods of augmenting bovine mononuclear cell responsiveness during physiological transitions of the udder may enhance resistance of the mammary gland to intramammary infections. Interleukin-2 is required for proliferation of T-lymphocytes and may contribute to B-lymphocyte proliferation. Recombinant bovine interleukin-2 (rBoIL-2) was evaluated as a potential immunoenhancer of bovine mammary gland mononuclear cells. Bovine mononuclear cells were isolated from five primiparous Holstein cows at 14-18 and 28-32 days of involution and at 7-13 days prior to parturition. Bovine blood and mammary gland mononuclear cells were highly responsive to rBoIL-2. Response of mammary gland mononuclear cells to rBoIL-2 was comparable with response of blood mononuclear cells. These data suggest that rBoIL-2 may be an effective immunoenhancer of bovine mononuclear cells during the non-lactating and prepartum periods.     

Use of netting and whitewash spray to protect papaya plants against Nivun Haamir (NH)-dieback disease

A disease causing the decline of papaya (Carica papaya) plants was noticed in the Jordan Valley in 1982. The disease caused severe yellowing of the upper leaves and dieback of the apex. The disease was not transmissible mechanically and continued efforts to associate viruses and viroids have so far been unsuccessful. Epidemiological observations suggested that the disease is airborne and probably caused by a mollicute. In order to test this hypothesis, plots were covered by an insect-proof net and with white nets providing 15, 30 and 50% shade. The 30%, 50% and insect-proof nettings provided complete protection, and the 15% netting reduced disease incidence to <2%, compared with>37% in the uncovered control plot. Spraying plants at weekly intervals with a commercial whitewash solution was also found to be effective in reducing disease incidence. The advantages of using a range of netting field treatments as a simple means for obtaining information on the epidemiological nature of a new disease are described.     

Large granular lymphoma in an FIV-positive and FeLV-negative cat

The clinical course of a feline leukaemia virus (FeLV)-negative and feline immunodeficiency virus (FIV)-positive cat affected with a large granular lymphocyte lymphoma is presented. Cyto-logical examination showed neoplastic cells in the pleural effusion and in two abdominal masses. Bone marrow and peripheral blood were moderately involved and chemotherapy was used to control the tumour. Cytochemistry, immunohis-tochemistry and ultrastructural studies were applied to define the cellular lineage; cytochemistry suggested a T-cell lineage.     

Immunocytochemical Study of the Ultimobranchial Tubule in Wistar Rats

A systematic immunohistochemical study of the ultimobranchial tubule (UBT) has been carried out in 45 Wistar rats of different ages (0, 5, 10, 15, 20, 25, 30, 60 and 120 days). The existence of calcitonin immunoreactive cells in the UBT wall has been demonstrated in a 5-days old rat. In addition, immunohistochemical studies for thyroglobulin revealed positive staining in follicular cells connected to the UBT and, occasionally, in isolated cells lying within solid clusters from the UBT. These last results together with the continued and repeated existence of numerous mitosis and PAS (+) microfollicles, apparently rising from the UBT, support the hypothesis that the ultimobranchial body (UBB) may contribute partially to the formation of a part of the follicular component.     

The effect of porcine somatotropin supplementation in pigs on the lipid profile of subcutaneous and intermuscular adipose tissue and longissimus muscle.

The effect of porcine somatotropin (pST) on the lipid profiles of adipose tissue and muscle was investigated. Sixteen crossbred barrows were injected daily with either 3 mg of pST or a placebo. After slaughter, total lipid and fatty acid composition of raw subcutaneous (SC) adipose and intermuscular (IM) adipose tissue and longissimus muscle were determined. The SC adipose tissue from pST-treated pigs had a 7.5% decrease in total lipid content; specific fatty acids 16:0, 18:0, and 18:1(n-9)c decreased most. The IM fat from pST-treated pigs had lower levels of 16:0 and 20:0. There was no effect of pST treatment on the lipid profile of the longissimus muscle. The data suggest that pST treatment produces small but significant changes in the saturated fatty acid content of adipose tissue in pigs.