Gossypol toxicity in preruminant calves

SUMMARY Twenty-four of 57 calves fed a diet containing 33% cotton seed meal (CSM) died between 7 and 15 weeks of age. Initial deaths were not accompanied by premonitory signs, but after CSM withdrawal most calves developed rough coats, anorexia, weakness, ascites and subcutaneous oedema. Those that died had large volumes of serous fluid in the body cavities, hard livers of ‘nutmeg’ appearance, and pulmonary congestion. Histopathologically the livers showed periacinar necrosis in acute cases and periacinar fibrosis in chronic cases. Lungs from several calves had oedema, haemosiderosis and fibrosis in some pulmonary vessels. Atrophy of myocardial fibres was present in most cases. The concentration of free gossypol in the diet was 100 to 220 mg/kg. Ante-mortem and post-mortem findings supported a diagnosis of gossypol poisoning. The deaths continued for 4 weeks after withdrawal of CSM from the diet.     

Apatite crystallites: effects of carbonate on morphology

Carbonate is a substituent in the apatite structure; when present, it limits the size of the growing apatite crystals and so influences their shape that they grow more equiaxed than needle-like. The tendency for carbonate apatites to be equiaxed is related to the nature of the chemical bonds formed in the crystal. The interference of carbonate with the good crystallization of apatite, and its weakening effect on the bonds in the structure, increase the dissolution rate and the solubility, thereby presumably contributing to the susceptibility to caries of dental apatites containing carbonate.     

Studies on the artificial propagation of Monopterus albus (Zuiew)

Artificial propagation of Monopterus albus (Zuiew) was conducted during their spawning season in the present study. Different doses of luteinizing-hormone-releasing-hormone analogue (LHRH-A) were tested for inducing the ovulation of brood females. No significant difference was found in the degree-hours and fertilization rates between three different doses (0.1, 0.2 and 0.3 μg LHRH-A g^-1 fish). A fertilization solution of 0.3% NaCl produced significantly higher fertilization rates than the other three solutions (0.5% NaCl, 0.65% NaCl and water). Fertilization times ranging from 5 to 2 0 min gave no significant difference in the fertilization rates. The embryonic and larval development of M. albus was observed and illustrated. The hatching time of eggs of M. albus was about 140 h in the 28-3 0^oC water temperature range. Using Tubifex spp. for the first food for the larval nursery gave higher growth rate than two other foods, zooplankton and artificial food.