Hepatic morphology and effects of intravenous injection of sodium propionate on plasma propionate and glucose in fed and fasted dairy cattle

Sodium propionate (3 mmol/kg) was injected IV into 8 nonlactating dairy cows before and after 6 days (144 hours) of fasting. During fasting, long-chain fatty acids in plasma increased from 0.30 +/- 0.05 (SE) mM to 1.09 +/- 0.15 mM (P less than 0.05). Liver fat increased from 0.5 +/- 0.3% to 9.3 +/- 1.7% (P less than 0.05). Half-life of injected sodium propionate increased significantly (P less than 0.05) from 7.6 +/- 0.5 minutes to 10.1 +/- 1.0 minutes during fasting. Sulfobromophthalein half-life did not change significantly (3.8 +/- 0.79 minutes to 5.3 +/- 1.3 minutes). Increases in plasma glucose concentrations after propionate loading were significantly less during fasting than during feeding. Thus, the change in glucose concentration served as an indicator of hepatic conversion of propionate to glucose. Increases in glucose concentration of less than 2 mM at 30 minutes after propionate loading indicated that liver function was altered in nonlactating dairy cows.     

Growth and reproductive performance of rabbits on a moderately low crude protein diet with or without methionine or urea supplementation

The reproductive and growth performances of New Zealand White rabbits on four dietary treatments were compared. The treatments were a 21.5% crude protein (CP) diet control, a 16% CP diet (LP), LP + .3% DL-methionine (LP + met) and LP + 2.1% urea (LP + urea). The CP in the LP diet was derived entirely from alfalfa meal and wheat mill run, with no protein supplement used. Data were collected over five parities. Preweaning and postweaning growth rates and reproductive performance as assessed by litter size, conception rate and litter interval, were comparable for the four treatments. Average daily postweaning gain was about 40 g per d. Litter size at weaning was seven kits per litter. This study indicates that a simple diet of forage and a grain-milling by-product, with no cereal grain or protein supplement, can support normal growth and reproduction of commercial meat rabbits.     

Primary isolation and identification of avian rotaviruses from turkeys exhibiting signs of clinical enteritis in a continuous MA 104 cell line

Avian rotaviruses were isolated from turkeys with enteritis using MA 104 cell line. MA 104 cells were suitable for primary isolation and propagation of avian rotaviruses. Trypsin appeared essential for the enhancement of infectivity and the occurrence of cytopathic effect (CPE). Serum neutralization (SN), electron microscopy (EM), and analysis of genomic RNA were done to identify and confirm the identity of rotaviruses. Electrophoretic migration patterns of genomic RNA from avian rotaviruses were examined, and they were compared with those from mammalian rotaviruses. The migration patterns differed between these groups.     

The cranial cervical ganglion and its branches in the White yak (Bos grunniens)

The heads of 12 White yaks (four castrated, four male and four female, 3-8 years old) were dissected to study the shape, location and branches of the cranial cervical ganglion macroscopically. The ganglion was a greyish arciform structure, with a mean length of 17.3 mm, a width of 8.0 mm and a thickness of 3.9 mm, located on the rostrolateral surface of m. longus capitis. Approximately 5% of the ganglion was covered laterally by the tympanic bulla and the rest by the m. stylohyoideus. The branches of the cranial cervical ganglion included the internal and external carotid nerves, the sympathetic trunk and communicating branches to the glossopharyngeal nerve, the pharyngeal branch of the vagus nerve and the hypoglossal nerve. In one specimen, the left cranial cervical ganglion was fusiform and only covered by the m. stylohyoideus. Gender differences of the cranial cervical ganglion in the White yak were not observed.     

Classification of abomasal displacement in cows according to histopathology of the liver and clinical chemistry

Histopathological features of livers and blood chemical values in cows with abomasal displacement were investigated. Liver biopsy samples were collected during redressment operations in 92 cows with abomasal displacement, and the samples were stained with haematoxylin and eosin or periodic acid Schiff (PAS). Blood was collected for chemical tests. Livers were histopathologically divided into the following four types: normal histology cases (21%), fatty degeneration cases (36%), cloudy swelling cases (19%) and fatty degeneration cases with cloudy swelling (24%). The number of PAS-positive samples was significantly higher in the normal histology group and significantly lower in the severe fatty degeneration group and severe cloudy swelling group. Cows with fatty degeneration had significantly higher levels of serum 3-hydroxybutyric acid, non-esterified fatty acid and aspartate aminotransferase than did those with cloudy swelling or normal histology. The results indicate that the morbid conditions of cows with abomasal displacement can be classified into four types.     

Genetic correlation between serum insulin-like growth factor-1 concentration and performance and meat quality traits in Duroc pigs

This study was intended to examine whether serum IGF-I concentration is appropriate for use as a physiological predictor for genetic improvement of meat production and meat quality traits in pigs. Heritabilities and genetic correlations were estimated for these traits. The Duroc breed used in this study was selected for seven generations for average daily BW gain (DG) from 30 to 105 kg of BW, loin-eye muscle area (EM), backfat thickness (BF), and intramuscular fat (IMF) content. Serum IGF-I concentration of boars and gilts at the fourth generation of selection and that of boars, gilts, and barrows from the fifth to seventh generations of selection were measured at 8 wk (IGFI-8W) for 832 animals and again at the time they reached 105 kg of BW (IGFI-105KG) for 834 animals. A multivariate REML procedure was used to estimate genetic parameters with a model incorporating generation of selection, sex, common environmental effect of litter, and individual additive genetic effects. Heritability estimates for IGFI-8W and IGFI-105KG were 0.23 +/- 0.02 and 0.26 +/- 0.03, respectively. The estimates of common environmental effect for IGFI-8W and IGFI-105KG were 0.20 +/- 0.02 and 0.03 +/- 0.01, respectively. Positive genetic correlations were estimated between IGFI-8W and DG (0.26 +/- 0.08), EM (0.22 +/- 0.10), and IMF (0.32 +/- 0.10). Moreover, the positive genetic correlation between IGFI-105KG and EM was 0.42 +/- 0.08. These results indicate that serum IGF-I concentration at an early stage of growth was effective for prediction of IMF, but it was not a reliable physiological predictor of genetic merit of meat production traits.     

Feeding-unrelated factors influencing the plasma leptin level in ruminants

The triglyceride content of lipid depots associated with the current feeding level is the primary determinant of leptin gene expression and the circulating leptin level. In laboratory rodents and primates the plasma leptin is influenced also by the age, gender and physiological status (puberty, pregnancy, lactation, postpartum period), and by the health condition such as sepsis due to Gram-negative (GN) bacteria. Some pathologic conditions with intensive cytokine release evoke an increase in plasma leptin, which is thought to depress the subsequent feed intake. However, the effect of these secondary factors may be species-dependent, with still unknown clinical relevance in ruminants. In our ovine and bovine models plasma leptin increased after castration and dexamethasone treatment, decreased after experimental administration of synthetic androgens in castrated rams, but remained unchanged throughout the ovarian cycle and after ovariectomy. The circulating leptin level increased temporarily during synthetic progestin (fluorogestone) treatment in ewes, but similar changes were not seen in progesterone-supplemented ewes and norgestomet-treated cows. In a second trial on dairy cows we wanted to study whether elevated plasma leptin levels are induced by experimental endotoxin mastitis, or by natural outbreak of GN mastitis and puerperal metritis. Experimental endotoxin mastitis resulted in some-hour elevation in cortisol and insulin, with a simultaneous decrease in IGF-I and thyroid hormones. In the first 14 days of lactation GN mastitis induced the same endocrine alterations as the experimental endotoxin challenge, but in natural cases these changes varied within a wider range, and were more protracted and robust. Cows with puerperal metritis had more obvious catabolic changes in the early weeks of lactation, than their healthy counterparts. However, both mastitis and puerperal metritis failed to increase the circulating leptin level, showing that in cows the plasma leptin is not responsible for the anorexia associated with these inflammatory diseases.