The effects of concentrate added to pineapple (<Emphasis Type="Italic">Ananas Comosus linn. Mer.</Emphasis>) waste silage in differing ratios to form complete diets,on digestion,excretion of urinary purine derivatives and blood metabolites in growing,male, Thai swamp buffaloes

Four, male, growing Thai swamp buffaloes (197 ± 5.3 kg and all 1 year old) were used to evaluate the effects of concentrate added to pineapple waste silage in differing ratios, to form a complete diet, studying in vivo digestion, the rate of passage, microbial protein synthesis and blood metabolites. Animals were fed ad libitum with 4 diets, using four combinations of pineapple waste silage (P) and concentrate (C), in the proportions (on a dry matter basis) of 0.8:0.2 (P80:C20), 0.6:0.4 (P60:C40), 0.4:0.6 (P40:C60) and 0.2:0.8 (P20:C80). The results showed that the intakes of dry matter (DM), organic matter (OM), nitrogen (N), the N-balance, urinary purine derivatives (PD) excretion, the ratios of allantoin to creatinine (CR), PD to CR, the plasma urea-N (PUN) and insulin increased in the animals, but the intake of neutral detergent fiber (NDF), the coefficient of whole tract, apparent digestibility of NDF, the transit time (TT) and the mean retention time (TMRT) decreased, when the proportion of concentrate in the diet increased. This study indicated that the proportion of P40:C60 in the diet produced the best efficiency of urinary PD excretion (mmol) per digestible OM intake (kg DOMI).     

Identification of progesterone and 17α-hydroxyprogesterone in polychaetes (Perinereis sp.) and the effects of hormone extracts on penaeid oocyte development in vitro

A possible factor behind the successful use of polychaetes for prawn broodstock diet was investigated. Some steroid hormones in polychaetes have been suspected as being a potential component for prawn reproductive system development. Progesterone (P4) and 17-alpha hydroxyprogesterone (17α-OHP4) were extracted from polychaetes (Perinereis sp.) and female Penaeus monodon broodstock at various maturation stages. Concentration of both hormones was determined using RIA or HPLC. Immature natural polychaetes (2 months old) displayed the highest level of P4 and 17α-OHP4 compared to more mature ones (4, 6 and 8 months old polychaetes) (47.48 ± 6.70 ng P4/mg Protein and 143.74 ± 28.70 ng 17α-OHP4/mg Protein) whereas opposite results were received with cultured polychaetes in which a reverse relationship between P4 and its derivative with polychaete maturation was obtained. Diverse concentrations of both hormones may be linked with other factors such as types of polychaetes, habitats, seasons, and feed intakes. Twenty-four hours in vitro incubation of prawn previtellogenic oocytes with P4 or 17α-OHP4 extracted from polychaetes or with synthetic hormones, significantly increased percentages of vitellogenic oocytes and oocytes with cortical rod compared to the control with no hormones. P4 was more effective in enhancing the final maturation of oocytes while 17α-OHP4 had more effects on vitellogenic oocytes. Synthetic steroid hormones at equal hormone concentrations produced similar results to steroid hormones extracted from natural polychaetes.