Variations in parameters of liver function and plasma progesterone related to underfeeding and ketosis in a dairy herd

Twenty-eight Norwegian Red Cattle dairy cows were fed silage ad libitum and restricted amounts of concentrates. Blood samples were collected before morning feeding, once or twice weekly, from 2 weeks before to 12 weeks after calving. Parameters of liver function, carbohydrate status and fertility were recorded in order to assess their interrelationships. Eight cows were treated for clinical ketosis. Four of these had to be treated 2 or 3 times. Aspartate aminotransferase and bilirubin showed the highest within-animal coefficients of correlation with acetoacetate. Analysis of variance revealed a significant effect of carbohydrate status (indicated by plasma acetoacetate levels) on the levels of aspartate aminotransferase, glutamate dehydrogenase and sorbitol dehydrogenase, though only a small part of the total variation was explained by this factor. The estimated volume density of liver fat in the 4th week of lactation averaged 6.0 +/- 6.4% (+/- SD) ranging from 0.1-25.1%. Liver fat content at this stage of lactation was not significantly correlated with other indicators of liver function or carbohydrate status. Cows treated for clinical ketosis had significantly lower plasma progesterone values at the time of first ketosis treatment than untreated multiparous cows. The frequency of high progesterone values (greater than 3 ng/ml) being significantly lower in treated than in untreated cows during the period from 3-5 weeks post partum, though not at later stages. In conclusion, the results revealed a significant relationship between carbohydrate status and liver function, and also between clinical ketosis and luteal function.     

Studies on efficacy and stability of a vaccine bait containing ERA strain of rabies virus propagated in a BHK-21 cell line.

In a dose response study in foxes, the median protective dose of ERA BHK21 vaccine in a blister pack bait was 10(6.0) tissue culture infective doses (TCID)/mL, while artificially aged baits with titers of 10(6.3) TCID/mL induced seroconversion in 78% of foxes. There was no significant difference in the development of antibodies in foxes receiving 1, 2 or 3 mL volumes of vaccine in the bait. When baits were exposed to the elements and fed to foxes over a 21 day period, 85% of the animals seroconverted. Age, sex and the way in which the vaccine container was contacted did not appear to be factors in the responses of these animals. Juvenile foxes, approximately six months of age, were marked more readily with the tetracycline bait marker than older animals. Approximately 25% of foxes did not appear to respond well to vaccination and the titer of the vaccine was a critical factor in producing seroconversion in these animals.     

The effect of body condition, live weight, breed, age, calf performance, and calving date on reproductive performance of spring-calving beef cows.

Data from 321 spring-calving cows (mean calving date March 27) were used to assess the effects of body condition, live weight, cow age (from 4 to 13 yr), and breed (237 Hereford x Friesians and 84 Blue-Greys) and time of calving on the proportion of cows that became pregnant, the number of days from the start of mating to pregnancy, and calving interval. Mating started at turn-out to pasture in mid-May and lasted 9 to 10 wk. Body condition at calving and breed were the most significant animal factors affecting reproductive performance. Cows calving in higher body condition had shorter (P less than .001) calving intervals (11.2 d per unit of body condition at calving). Blue-Grey cows became pregnant in a higher proportion (90%) and calving interval was shorter (364 d) than in Hereford x Friesians (83%; 374 d). Body condition at the start of mating was less important and body condition at the end of mating had no effect. Live weight at calving and changes in live weight from calving to the start of mating and during the mating period had no significant effect. The proportion of cows becoming pregnant decreased significantly with age in Hereford x Friesian cows older than 7 yr. The variance in calving interval accounted for by calving date, body condition at calving, breed, and age was 42%.     

Behavioral and physiological effects of freeze or hot-iron branding on crossbred cattle.

Twenty-seven crossbred calves (1/2 Simmental, 1/4 Hereford, 1/4 Brahman) averaging 257 +/- 11 d of age were either hot-iron-branded (H), freeze-branded (F), or sham-branded (S). Calves were blocked for temperament, weight, and sex and were randomly assigned to day and order in which treatments were applied. To reduce stress from handling at treatment time, each calf was herded through the squeeze chute daily for 5 d before the experiment. Jugular cannulas were inserted in each calf 1 d before application of treatment. Blood samples and heart rate measures were obtained at -5, -3, 0, .5, 1, 3, 5, 10, 15, and 20 min after application of the treatments. Mean concentrations of plasma epinephrine (EPI) were higher for H calves at time .5 min than for either S or F calves (P = .10). To account for individual differences, prebranding heart rates and hormone concentrations were subtracted from subsequent samples and were also used to calculate a proportion for each subsequent sample. Analyses of subtracted values found that EPI concentrations were greater for H calves than for either S or F calves (P = .007) at .5 min postbranding. No other differences were found for the subtracted analyses. Analyses of proportion data also revealed that H calves had greater EPI than did either S or F calves (P = .027) at .5 min postbranding. Only three animals vocalized during branding, one H calf and two F calves. Despite the 5-d acclimation period, handling and restraint elevated plasma cortisol concentrations and heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of initial restraint, weaning, and transport stress on baseline and ACTH-stimulated cortisol responses in beef calves of different genotypes.

The productivity and well-being of animals can be substantially affected by stress. This is particularly true in the case of beef calves that are subjected to a multitude of stressors over a short period during the first year of life. Perhaps the most often studied stress-responsive variable has been blood corticosteroid concentrations. Factors such as age, gender, genetics, and degree of prior experience, can influence how an animal perceives and responds to a given stressor. Few studies have tried to control these variables, and accordingly, many conflicting results have been published regarding the impact of various stressors on cortisol response. We measured baseline plasma cortisol concentration over a 44-day study in Bos indicus and Bos taurus calves. Plasma cortisol values in Bos indicus calves were higher (32.60 +/- 0.66 ng/ml) than values in calves of Bos taurus (25.81 +/- 0.76) breeding. A precipitous decrease in cortisol concentration was observed 7 days after transport stress in all calves. Baseline cortisol concentration did not provide any indication of the intensity of the various stressors. However, significant differences were readily observed after ACTH administration. On the basis of cortisol secretion, stresses of transport and weaning were similar and were the most stressful to calves, regardless of genotype.     

Actinomycin D for Reinduction of Remission in Dogs With Resistant Lymphoma

Twenty-five dogs with malignant lymphoma refractory to chemotherapy were treated with actinomycin D at a median dose of 0.7 mg/m² (range, 0.5 to 0.9 mg/m²) every 3 weeks. The dogs treated had received between 2 and 8 chemotherapeutic agents (median 7), for a median of 266 days before being treated with actinomycin D. For 23 of the 25 dogs, previous chemotherapy included doxorubicin. No dog responded to actinomycin D chemotherapy.     

Use of a shrub (Medicago arborea) to control water erosion on steep slopes

Abstract. The effect of Medicago arborea on erosion on a burnt area was studied in experimental plots near Valencia, Spain, between 1989 and 1992. Its growth and development was studied, and its effect was compared with the natural vegetation (matorral) and bare soil. Medicago decreased soil loss by 41.7% and runoff by 25.7% compared with bare soil. However, under natural vegetation soil loss was 27.5% less than under Medicago.     

Cardiopathological observation on a case of persistent ventricular tachycardia in a pony mare.

A 20-year-old pony mare with persistent ventricular tachycardia (VT) was examined cardiopathologically. At necropsy, the heart was enlarged and rounded with both ventricular dilatation. In a longitudinal section of the ventricular septum, a large grayish white patchy lesion (5 x 25 mm) was detected in the relatively higher portion. Microscopically, the lesion was extensive myocardial fibrosis located in the vicinity of the proximal part of the left bundle branch. Partially the fibrotic lesion was in contact with the branch. Such a lesion might play an important role in creating a suitable background for the development of VT via automaticity or reentry mechanism.     

Spring Barley Responses to Row Spacing and Fungicide Triadimefon in Regions with a Short Crop-growing Season

Aspects of intensive management practices such as high-yielding cultivars, narrow-row spacings and fungicide treatments could potentially increase cereal yields in regions with a short crop-growing season and occasionally dry and hot weather. A field experiment was carried out at McGill University, Canada for three years (1987 to 1989) to test the effects of triadimefon (1-[4-chlorophenoxy]-3,3-dimethyl-1-[1H-1,2,4-triazol-1-yl]-2-butanone, or Bayleton, a trade name) fungicide (0 vs. 140 g a.i. ha⁻¹) and row spacing (10 vs. 20 cm) on the yield components, yield and other agronomic traits (spike emergence, days to maturity, leaf disease and plant height) of spring barley ( Hordeum vulgare L.) cv. Cadette, Laurier and Leger. A cultivar by row spacing interaction resulted in a 11 to 13.5 % increase in grain yield due to narrow rows for Laurier in two out of the three years and up to 16 % for Leger in one year. Over the three years grain yields were on average increased 6 to 12 % due to use of the narrower row spacing. Fungicide application to barley at the early heading stage effectively controlled leaf diseases without influence on yield components or grain yield. Our results indicate that some components of intensive management such as narrow row spacing can be applicable in regions with a short crop-growing season.     

Thermal injury by in vitro incision of equine skin with electrosurgery, radiosurgery, and a carbon dioxide laser.

Freshly harvested equine skin incised with an electrosurgical unit, a radiosurgical device, or a carbon dioxide (CO2) laser was examined by light microscopy to determine the extent of thermal injury caused by each instrument. There was no significant difference between the thermal injury caused by the electrosurgical unit in the pure-cut mode and the CO2 laser in the superpulse mode, or between the electrosurgical unit and the radiosurgical device in the fully filtered cut mode. However, thermal injury caused by the CO2 laser was significantly less than that caused by the radiosurgical device. The amount of thermal injury in this in vitro study was similar to that found in vivo with other species.