Morphological Study of the Surface Structure of the Omasal Laminae in Cattle, Sheep and Goats

The mucosal relief of the omasum in cattle, sheep and goats was examined by the naked eye, stereoscopic microscope and scanning electron microscope. The mucosal relief of the omasum showed wide variations both between and within these species. Omasal papillae on the laminae varied highly in shape, i. e. conical, rounded, claw-like, wart-like, finger-like etc. They decreased gradually in size from the oral to the aboral region of the omasal lamina. Ridge-like structures and linear arrangements of the papillae were also seen on the omasal laminae of cattle and sheep. Many grooves and folds were found on the lateral surface of the omasal papillae in adult cattle and on the inter-papillar surface of the laminae of all three species. The mucosal relief of the omasum in cattle seemed to be more well-developed than those of sheep and goats. Dietary effects on the omasal mucosa were also discussed.     

Experimental poisoning of pheasant chicks with nitrates and nitrites in drinking water

The effect was studied of nitrates and nitrites in drinking water on the methemoglobin level in blood and pathomorphological changes in fourteen-day-old pheasant chickens. The concentrations of 500 ppm of NO3- and 15 ppm NO2- in the drinking water were not lethal, they caused only the increase in the methemoglobin in blood to 7.1% (NO3-) and 16.5% (NO2-). The pheasants exposed to NO3- suffered from hyperaemia of liver, kidneys and mucosa of the small intestine and from the multiplication of the eosinophilic granulocytes in the villus stroma. The exposition to NO2- resulted in the non-specific dystrophic changes in liver and kidneys and in the villus edema of the small intestine. Lethal levels of nitrates and nitrites in drinking water were estimated in relation to the age of pheasants.     

Effects of growth curve parameters on cow efficiency.

Weight-age data from 50 Retinta beef cows from 8 to 97 mo of age located in southwestern Spain were fitted to von Bertalanffy, Brody, and Richards functions to determine the relationship between growth curve parameters and cow efficiency. Only cows having at least 31 weights were included in the analysis. Von Bertalanffy, Brody, and Richards functions were fitted to weights of each cow. Relevant parameters of the three functions are A and K, associated with the asymptotic mature weight and rate of maturing, respectively. Criteria for comparisons among the three functions were computing difficulty, goodness of fit, and lack of bias of A. Productivity indicators were number of calves weaned during the first five calving seasons (NC), average birth weight (BWT), average weaning weight (WW), and average weaning weight per cow per year (WWY). The von Bertalanffy function was selected as the most appropriate. Least squares means for A and K were 650 +/- 8.17 kg and .038 +/- .001 mo-1, respectively. The values of NC, BWT, WW, and WWY were 4.0 +/- .11 calves, 38.2 +/- .4 kg, 218 +/- 5 kg, and 172 +/- 5 kg, respectively. Regression analysis for A indicated a decrease in NC when mature weight increased (P less than .05). There was a nonsignificant trend for heavier cows (higher A) to have calves with heavier BWT or WW. The value of WWY increased (P less than .05) with increased maturing rate (K) of cows. No significant associations were found between K and BWT or WW.(ABSTRACT TRUNCATED AT 250 WORDS)     

Demonstration of Clostridium septicum infection in a goose flock.

Clostridium septicum infection causing 5.0 to 5.2% mortality is reported for the first time in the literature from six-week-old growing geese in three flocks comprising 5,200, 5,500 and 5,900 geese, respectively. The affected birds exhibited weakness, uncoordinated movement, ataxia and, frequently, oblique position of the head and neck (torticollis) as well as signs indicative of dysequilibrium. The affected birds died within 18-24 h. Gross pathological examination revealed anaemia, hepatitis with map-like necroses of irregular outline (Fig. 1), acute enteritis, pulmonary oedema and cardiac dilatation. Light and electron-microscopic examination showed that the sinusoids of the liver were markedly dilated (Fig. 2) and filled with serous exudate and gas (Figs 2 and 3), and the hepatocytes surrounding them exhibited severe oedema (Fig. 4). Among the hepatocytes, ciliated bacteria 7-10 mu in length and 1-3 mu in width, bounded by a well-defined cell wall and often showing signs of spore formation were observed (Figs 5 and 6). By bacteriological examination the pathogen was isolated, its properties were studied, and the clinical entity of malignant oedema was experimentally reproduced by intramuscular injection of guinea-pigs and rabbits. The applied antibiotic (oxytetracycline) and furazolidone therapy proved effective.     

Application of a cluster-bootstrapping method for identifying the dietary patterns of fish populations

Dietary data usually exhibit considerable statistical awkwardness and the analytical techniques commonly used in the study of fish diet suffer from various problems (especially at the intraspecific and intrapopulation levels) resulting from difficulties in group definition and pooling of data. Considering that, we advocate the use of a combination of cluster analysis and bootstrapping to identify statistically significant groups of individual predators. Both basic and extended versions of the procedure (yielding slightly different results) are outlined. We also suggest the use of detrended correspondence analysis (DCA) for further interpretation of significant clusters. When applied to dietary data from a brown trout population, the method successfully finds different feeding patterns, even though possible sources (geographical and temporal) of dietary variation were very limited. Dietary patterns appear to be related to the seasonal dynamics of the prey community coupled with seasonal shifts in microhabitat use by the predator; and, in a finer time-scale, to diel macroinvertebrate drift periodicity or interindividual, size-related differences in preyhandling capabilities.     

Ovarian Activity at Naturally Attained Oestrus in the Sow. An Ultrasonographic and LH Study

In 6 multiparous crossbred sows (2nd to 4th parity, Swedish Landrace x Swedish Yorkshire), 15 proosestrous-oestrous periods during 2 oestrous cycles were studied after weaning. The animals were controlled for oestrus, and the follicular growth and ovulation in their ovaries were followed by transrectal ultrasonography. Blood was sampled through indwelling catheters for analyses of LH and progesterone (P₄).The duration of oestrus (standing reflex) was 47 ± 12.4 h, and the interval from onset of standing reflex until the end of ovulation was 39 ± 12.4 h (range 20-64 h). The LH peak concentration was 3.7 ± 0.8 μg/1, and the interval from LH peak level until ovulation was 23 ± 8.4 h (range 8-32 h). The onset of standing reflex occurred in average 13 h before the LH peak level (range -4 - +36 h).The peripheral plasma concentration of P₄ showed a normal cyclic pattern in all animals. Low levels (mean levels, 1.1-1.3 nmol/1) were seen during prooestrus and oestrus, high mean levels were found on days 10-16 (45-75 nmol/1) in the oestrous cycle. It was concluded that for an accurate determination of ovulation, each animal has to be examined repeatedly. Ultrasonography is a most valuable tool for this purpose.