Testing of the protective effect of cell-free lyophilized vaccine against Marek's disease in field trials]

The protective effect of a lyophilized vaccine against Marek's disease ("Keramvac"--Pfizer), prepared from a cell-free turkey's herpesvirus (strain FC 126), was compared in field trials with losses in the group of non-vaccinated chickens. Under the indicated conditions, the vaccine had only a 50.86% effectiveness. The possible causes of the reduced vaccination effect are discussed with regard to the pathomorphological and virological findings suggesting, among others, an increased incidence of the symptoms of the classical form of Marek's disease in the population investigated.     

Phage typing of strains of Staphylococcus aureus from staphylococcal mastitis of dairy cows]

Of 62 strains of Staphylococcus aureus, isolated from milk samples of dairy-cows with staphylococcic mastitis from five agricultural enterprises, 68 p. c. could be typified as bacteriophages. In 42 typified strains, altogether 17 different phage pictures were found, in which case, in the different agricultural enterprises, the number of phage picture fluctuated between 1 and 8. Phage picture 42 D was found and dominated in all the agricultural enterprises. Of the typified strains, 76% could be ranked only into one phage group and 24% in the "M" group (= miscellaneous). Of 32 typified strains, 56.3% belonged to phage group IV, 25% to group III, 12.5% to group I, and 6.2% to group II.     

Studies on pentagastrin-induced hypocalcaemia in lactating cows.

During recent years it has been evident that a number of gastrointestinal hormones are potent calcitonin secretagogues, and it has been suggested that a gastrointestinal-thyroid C cell system exists as a part of post prandial calcium homeostasis. In the present study the hypocalcaemic effect of pentagastrin, a synthetic peptide with gastrin effects, was studied in lactating cows. Intravenous infusion of pentagastrin caused marked hypocalcaemia and hypophosphataemia in the cows. Thyroidectomy completely abolished the hypocalcaemic and hypophosphataemic effects of the peptide. The results thus suggested that the effects of the peptide were due to release of endogenous calcitonin.     

"Dog pox": some clinical aspects of an eruptive condition of certain mucous surfaces in dogs.

An eruptive condition seen on certain mucous membranes of dogs occurs frequently but often asymptomatically. Lesions have been found to be present in over 60 percent of male dogs. The infection is probably due to a canine herpes virus and has been termed conveniently but inaccurately "dog pox". In many cases lesions are present without observable clinical signs but severe irritation, especially related to lesions in the lower bowel, can give rise to marked symptoms which may be confused with abnormality of the para-anal sacs, or to chronic diarrhoea of a type suggestive of colitis. The incidence, sites of infection and possible syndromes which may be ascribed to the condition are briefly discussed on a clinical basis only.     

Rapeseed Meal and egg taint

1. Certain rapeseed meals in the diet of hens laying brown eggs result in the production, from some birds, of eggs which have a “ fishy ” or “ crabby ” odour because of the presence of trimethylamine.

2. Such susceptible birds have been used to demonstrate that the activity can be extracted from rapeseed meal with appropriate solvents.     

The effect of heat treatment and enzyme supplementation on the nutritive value of barley for broiler chicks

1. The effect of heat treatment and enzyme supplementation on the nutritive value of barley was studied.

2. In only one experiment was weight gain significantly improved when the barley was heated.

3. Autoclaving barley at 120 °C for 30 min reduced dietary dry matter digestibility and treating the barley with dilute acid before heating had no effect on its nutritive value.

4. Supplementing diets containing commercial barley with a‐amylase produced slightly conflicting results in that there was an improved weight gain, food conversion efficiency and digestibility value in two of three experiments.

5. The digestibility and metabolisable energy values of a North American six‐row spring barley (Glacier) were significantly improved by enzyme supplementation.

6. The effect of the enzyme on diets containing a high amylose barley (Glacier Pentlandfield) was positive but not significant.     

The role of histamine and fish meal in the incidence of gizzard erosion and pro‐ventricular abnormalities in the fowl

1. The role of certain fish meals in the production of localised gizzard erosion is confirmed.

2. Lesions typical of gizzard erosion could be produced by the addition of histamine to the diet.

3. The amount of histamine occurring naturally in fish meal depends on the species of fish and the extent and nature of bacterial spoilage.

4. These variables may explain why histamine has not been implicated previously and also why there have not been consistent associations between the condition and geographical source or common factors in bulk consignments of the meal.     

Efficacy of two dichlorvos formulations against larval and adult Hyostrongylus rubidus in swine.

Coated (V-13) and uncoated (V-22) formulations of dichlorvos were used to treat experimentally established Hyostrongylus rubidus infections of pigs at intervals after exposure to infective larvae. Both dichlorvos formulations were efficacious against the adult stomach worm H rubidus, but showed little or no activity against 5- or 15-day-old worms. Neither formulation was as effective against H rubidus in sows as in barrows and gilts.     

Effect of diet composition and slaughter weight on animal performance, carcass and meat quality, and fatty acid composition in veal calves

The effect of true milk use in the diet of Spanish Brown Swiss male calves on animal performance, carcass and meat quality, and fatty acids composition was studied. In experiment 1, the effect of milk intake [ad libitum continuous (ADLIB) feed vs. restricted 0.7 during 75 days followed by ad libitum feed (RESTR)] and slaughter endpoint (225 kg vs. 5 month) were studied. In experiment 2, ad libitum concentrate feeding [grain-fed (GF)] was compared with milk supplementation until slaughter [milk-fed (MF)] in calves slaughtered at 345 kg. As regards to milk intake, carcass weight and degree of fatness were higher in the ADLIB group (P<0.05). The RESTR group revealed a higher percentage of saturated fatty acids (P<0.05). In experiment 2, the MF group exhibited a higher fat percentage (P<0.05), lower press and cooking losses (P<0.05), and higher scores for tenderness and juiciness (P<0.05) than the GF group. The percentage of saturated fatty acids was higher in the MF group (P<0.05). The results suggest that true milk use in veal production could be an advantageous alternative in terms on production costs, animal performance, and carcass and meat quality.