Orapint Jintasataporn

Stability of Carotenoid Diets During Feed Processing and Under Different Storage Conditions

The stability of formulated carotenoid diets during feed processing and under different storage conditions were studied. All carotenoid diets were split into two groups with one group containing BHT (acting as an antioxidant) at 250 ppm and the other without BHT. The experiment was divided into two parts. First, all diets were evaluated in total carotenoid (TC) loss during feed processing, in dry mixed feeds after being processed and dried. In the final part, the completed dietary carotenoids were stored in an aluminum foil bag, the top of which was sealed with a bag sealer and kept under different storage conditions at 26–28 °C and 4 °C. The stability of the TC was observed during an 8-week trial period. The results showed that the diet pelleting process did not affect the carotenoid content of the diets, and the best storage temperature for the formulated carotenoid diet was at 4 °C. However, an antioxidant was added to assist in energy saving before feed processing. Thus, the addition of BHT at 250 ppm can be done at normal room temperature in order to reduce oxidation that might cause a loss of TC quantities in diets.

Effects of Exogenous Melatonin in Clarias Macrocephalus Male Broodstock First Puberty Stage

The purpose of this study was to investigate the exogenous melatonin feeding administration to the first puberty stage in male broodstock of the Walking catfish, Clarias macrocephalus. The melatonin level of 0 (Control), 50 (Mt0.05) and 250 (Mt0.25) mg/kg in the diet mixed in isonitrogenous and isocaloric of 37% crude protein and 9.3% crude lipid was applied. The male maturation analysis for this study comprised of gonad histology, testosterone assay, gonadosomatic index, sperm abnormality, live sperm rate, sperm concentration, and sperm kinetic parameters. Significant differences were found in maturation analysis (P<0.05) compared with the control treatment. In addition, the histological analysis found that the mature spermatozoa cells were highest in the melatonin-treated male catfish. The present results showed that exogenous melatonin is able to enhance the reproductive system of male C. macrocephalus. The suitable exogenous melatonin level to enhance the Clarias macrocephalus male broodstock first puberty is Mt0.25 (50 mg/kg melatonin in the diet).

The Use of Natural Carotenoids and Growth Performance, Skin Pigmentation, and Immune Response in Fancy Carp (Cyprinus carpio)

Fancy carp were fed seven dietary treatments with natural pigment sources (tea, mulberry, cassava) at a specific rate to achieve a total carotenoid (TC) concentration in the diet of 25 mg/kg. Growth performance among treatments was not significantly different (p ≥ 0.05). TC and skin redness (a*) of fish fed tea leaves was higher than the other treatments (p ≤ 0.05). Fish fed with tea extract and cassava leaves had higher serum astaxanthin concentrations than the other groups (p ≤ 0.05). This group also retained serum astaxanthin and red color better than other groups two weeks post treatment (p ≤ 0.05). Phagocytic activity was significantly greater in fish fed carotenoid supplements compared with the control group (P ≤ 0.05). Therefore, dietary supplementation with 25 mg/kg tea leaves is sufficient to obtain good coloration in fancy carp as well as enhance immunity.

Effects of Zinc Amino Acid in Walking Catfish (Clarias macrocephalus) Female Broodstock First Sexual Maturation

This study examines the effects of zinc amino acid (ZnAA) to the first sexual maturity stage in female broodstock of the Walking catfish, Clarias macrocephalus. The different ZnAA levels of Control (0 ppm ZnAA), ZnAA1 (100 ppm ZnAA) and ZnAA2 (200 ppm ZnAA) in the diet was applied to the first sexual maturation female catfish (Availa®Zn, Zinpro Corporation, Eden Prairie, MN USA). ZnAA accumulation, broodstock maturation analysis and breeding performance were evaluated. The ZnAA treatment has significant different in serum, meat and ovary ZnAA accumulation. The ZnAA treatment increased the fecundity, gonadosomatic index, egg diameter and development of oocytes at tertiary yolk stage. In comparison, the ZnAA treatment was insignificant in estradiol level. During artificial fertilization, the ZnAA treatment enhanced the fertilization rate and the larval survival rate. During recovery breeding, ZnAA treatment significantly increased the egg production and larval hatching rate. The optimum level to enhance the Clarias macrocephalus female broodstock first sexual maturation is ZnAA1.

pH Characterization of Digestive Enzyme and In vitro Digestibility of Red Bee Shrimp Caridina cantonensis (Decapoda: Atyidae)

The characteristics of digestive enzyme from red bee shrimp (Caridina Cantonensis), a tiny ornamental shrimp, were investigated under various pH ranging from 2 to 12. The aim of this study was to find out the specific activities of protease, amylase, lipase, cellulose, trypsin and chymotrypsin and in vitro raw materials by shrimp enzyme digestibility. Fifteen and sixty-day old shrimp were obtained from private farms in Bangkok, Thailand. Protease, lipase, amylase, cellulase, trypsin and chymotrypsin specific activity were determined. The results showed that protease activity had its optimal activity at pH ranging from 8 to 10 and showed the highest activity at pH 10 in both age groups. The alkaline amylase activities were found to be significantly higher than acidic amylase in both age groups. Both acidic and alkaline amylase activity of the 15-day old shrimp was significantly lower than the larger shrimp. The Lipase activity in the 60-day old shrimp showed the highest activity at pH 12, pH 10 and 11, respectively. In the 15-day old shrimp, the lipase activity was stable over a broad pH ranging from 2-12. In the 60-day old shrimp, the cellulase activity showed the highest activity at assay condition pH 7 and decreased when pH levels increased. In the 15-day old shrimp, cellulase activity showed optimal pH at pH 8 and 11. The trypsin and chymotrypsin activity at neutral to weak alkaline condition was greater under acidic condition in both age groups. The activity of 15-day old shrimp was significantly lower than the older shrimp. Regarding in vitro digestibility, the study on protein digestion showed that fish meal was suitable to be a protein source for red bee shrimp. The carbohydrate digestibility showed that wheat flour and maltodextrin were more appropriate as a carbohydrate source for red bee shrimp than cassava, rice bran and Na-alginate. Therefore, it can be concluded that red bee shrimp had diet digestibility in neutral to mid alkaline condition. The animal protein materials are appropriate to be red bee shrimp feed ingredients with low fiber and carbohydrate source.

Comparative pharmacokinetics after feeding fancy carp (Cyprinus carpio) with diets containing carotenoids from natural sources [tea (Camellia sinensis) , mulberry (Morus alba) , and cassava (Manihot esculenta) leaf]

The carotenoid composition of tea, mulberry, and cassava leaf has been determined by TLC on silica gel 60 with 75:15:10 (v/v) petroleum ether-diethyl ether-acetone as mobile phase. Spectrodensitometric detection was performed at 450 nm. The results showed lutein and β-carotene were the main carotenoids in all the leaves. Tannin was found in tea leaves at a level of 4.60 ± 0.07 g kg−1. The amount of cyanide in cassava leaf was equivalent to 918.31 ± 11.37 mg hydrocyanic acid kg−1. A pharmacokinetic study of total carotenoids was designed with three experimental fancy carp diets based on tea, mulberry, and cassava leaves as raw materials. The results showed that the maximum concentrations of serum total carotenoids in fish fed with tea, mulberry, and cassava leaves were 0.0022, 0.0016, and 0.0018 µg mL−1 48, 72, and 48 h after feeding, respectively (Tmax). The volumes of distribution were 23.40, 22.28, and 23.39 mL kg−1, total body clearance was 0.24, 0.30, and 0.41 mL h−1 kg−1, and the area under the concentration-time curve was 108.23, 79.74, and 60.58 µg h mL−1, respectively. It is concluded that when fish were fed a tea leaf diet carotenoids were absorbed more readily than from other diets. Similar serum astaxanthin levels were observed for fancy carp on all diets 48 h after feeding, and astaxanthin concentration in blood serum continued to increase with time. These studies indicated that irrespective of the lutein and β-carotene content of the three plant leaves in the diet, the fancy carp can convert them to astaxanthin in serum.