Pigment deposition and in vitro screening of natural pigment sources for enhancing pigmentation in male Siamese fighting fish (Betta splendens Regan, 1910)

Distribution in pigment deposition was studied in male Siamese fighting fish (Betta splendens Regan, 1910) of solid Blue and solid Red phenotypes. Growths were similar, and also indicated by similar activity ratio of trypsin to chymotrypsin. Growth strategy was different at maturing stage, whereas trypsin expression decreased in solid Blue while chymotrypsin expression decreased in solid Red (P ≤ 0.05). Ranking of total pigment contents was muscle > skin > caudal fin > anal fin > dorsal fin > pelvic fin > pectoral fin. Immature fish had similar total contents and concentrations of pigments, except solid Blue had higher total contents in dorsal fin than solid Red. At maturing stage, solid Blue showed higher total pigment contents than solid Red due to higher contents in the fins. Solid blue had higher concentration in pelvic fin, while solid Red had higher in pectoral and dorsal fins. Age, phenotype and their interaction influenced pigment deposition. Determinations of pigment levels, high temperature tolerant of pigments and in vitro digestibilities of pigments, protein and carbohydrate from twenty natural sources indicated that fermented red rice was the most suitable pigment source, following with Chlorococcum sp.     

Growth and Survival of Juvenile Freshwater Mussel,Chamberlainia hainesiana (Lea, 1856), at Three Densities in the Natural Reservoir and River Environments,Thailand

The effects of location and density on the growth and survival of juvenile freshwater pearl mussel, Chamberlainia hainesiana, 150–360 d after metamorphosis were investigated to determine the optimal ranges for commercial farming in Thailand. Juveniles were reared outdoors in two locations (the Mae Klong Reservoir and the Khwae Yai River, Kanchanaburi Province). Three density levels (25, 50, and 100 mussels/basket) were established at each location, with three replicates per density level. Phytoplankton from the water column in the natural habitats served as feed; no supplemental feed was provided. The mussels cultured in the reservoir had significantly higher growth rates than those cultured in the river (P < 0.01). The density level of 25 mussels/basket exhibited the highest average growth rates (in weight, length, height, and width per day). The density levels of 25 and 50 mussels/basket did not show significant differences in growth from each other (P > 0.05), but both showed significant differences in growth from the density level of 100 mussels/basket (P < 0.01).     

Screening of in vitro nutrient digestibility coefficients of selected insect meals in broiler chickens,black-meat chickens and quails

The objective of this study is to identify potential insect species comparing with commonly used protein sources based on efficiency of the in vitro digestibility on dry matter (DMd), organic matter (OMd) and crude protein (CPd) in broiler chickens, black-meat chickens (Native breed) and quails. Each of gastric mucosa, pancreas and duodenal mucosa were obtained from proventriculus, pancreas and duodenum, respectively. Crude digestive enzyme extracts (CTE) were extracted from these organs to perform in vitro digestibility. Eighteen insect samples and six commonly used protein sources were served as substrates which were evaluated on DMd, OMd and CPd in triplicate for each substrate. The CTE from gastric mucosa was used to simulate proventriculus, whereas small intestine was simulation by adding the CTE from pancreas and duodenum. The large variation of chemical composition between insect meals was presented. For commonly used protein sources, animal proteins were higher on digestibility than plant proteins (p < .001). Quails represented a great potential to digest insect meals comparing other animals. Based on CPd results, there were potential insect species for broiler chickens (Achroia grisella: AG, Tenebrio molitor: TM and Musca domestica), black-meat chickens (Patanga succincta, TM and AG) and quails (Hermetia illucens, Acheta domesticus and Locusta migratoria; p < .001). The evidences from this study suggest that these insect species contain a great potential to use as alternative protein sources promoting an animal production with sustainability. However, the in vivo experimentation must be performed to confirm in further study.     

Morphometric relationship of weight and size of cultured freshwater pearl mussel, Hyriopsis (Limnoscapha) myersiana, under laboratory conditions and earthen pond phases

The freshwater pearl mussel, Hyriopsis (Limnoscapha) myersiana (Lea, 1856), was cultured in the laboratory (0–120 days old), in an earthen pond in acrylic containers (120–270 days old) and in pocket nets with frames (270–360 days old). Measurements were taken of the length–height and the total body weight–size (shell length, shell height and shell width). It was found that the length–height in each period of culture showed a linear relationship and that the shell height increased as the shell length increased, along with the same linear relationship. When statistical analyses were performed, this linear regression line consisted of three distinct lines (P < 0.01). The general morphometric relationships between the length and height of mussels grown in the laboratory, in acrylic containers and in pocket nets were Log H = −0.147 + 0.828Log L, Log H = −0.211 + 0.909Log L and Log H = −0.264 + 0.951Log L, respectively. The relationship between the total body weight–size in different culture phases was a positive allometric equation and the two curved lines were not the same (P < 0.01). The general morphometric relationships between the length and the total body weight of the mussels cultured in acrylic containers and pocket nets were Log W = −3.747 + 2.674Log L and Log W = −4.149 + 2.976Log L, respectively. Such measurements are useful in the management of different culture phases of H. (L.) myersiana.     

Digestive enzymes and in-vitro digestibility of different species of phytoplankton for culture of the freshwater pearl mussel, <Emphasis Type="Italic">Hyriopsis</Emphasis> (<Emphasis Type="Italic">Hyriopsis</Emphasis>) <Emphasis Type="Italic">bialatus</Emphasis>

Hyriopsis (Hyriopsis) bialatus has been cultured during the mussel life cycle from glochidia to the adult stage with a low total survival of 6% up to 130-day-old juveniles. The main digestive enzymes (amylase and proteinases) were not detectable in one-day-old juveniles, and increased during development. The stomach, including digestive glands, was the major digestive organ for both carbohydrate and protein. The optimum conditions for amylase activity were 40°C and pH 7; for acidic proteinases they were 60°C and pH 5. Two main alkaline proteinases were found in the intestine, with optimum conditions of 30°C and pH 8 and 60°C and pH 8. To improve mussel survival by finding suitable phytoplankton species and age as food for juveniles and adults, an in-vitro digestibility test was performed on ten algal species three and seven days old using amylase and proteinases in crude enzyme extracts from different mussel life stages. Among the phytoplankton selected, the three most efficiently digested by juveniles were seven-day-old Chlorella sp.2, seven-day-old Chlorococcum sp. and seven-day-old Kirchneriella incurvata, in the ratio 1:1:3 for 30-day-old juveniles and 3:1:1 for 130-day-old juveniles. For the adult mussel, three-day-old Chlorella sp.2, seven-day-old Coccomyxa sp., and seven-day-old Monoraphidium sp., in the ratio 3:1:1, were the most digestible phytoplankton. Levels of in-vitro digestibility were related to the quality (not the concentrations) of carbohydrate and protein in the phytoplankton mixtures, and protein digestibility seemed to be the key factor determining food quality for the mussel.     

Microwave irradiation and pelleting method affected feed chemical composition and growth performance and feed utilization of sex‐reversed Nile tilapia,Oreochromis niloticus (L.)

Microwave processing and pelleting methods were assessed to improve aquafeed quality for sex‐reversed Nile tilapia. The 2 × 3 experimental feeds were prepared with and without microwave irradiation of ingredients prior to pelleting with either a meat mincer, extruder or steam conditioner followed by a meat mincer. Five feedstuff ingredients, including fish meal, meat and bone meal, soybean meal, broken rice and rice bran, were irradiated separately at optimal times, according to the third‐order polynomial regression analysis between in vitro digestibility and microwave irradiation times (r = 0.681–0.942, P < 0.001, n = 42). The prepared feeds were studied for chemical compositions and responses in fish growth performance and feed utilization efficiency. The fish (1.57 ± 0.01 g initial weight) were fed ad libitum for 4 months. All proximate chemical compositions of experimental feeds, except protein, were influenced by microwave processing, pelleting methods or their interaction (P < 0.05). There were no significant effects from either parameter on water quality during the fish trial. Fish fed steamed microwave‐irradiated feed, mechanically pelleted with a meat mincer, showed the highest growth performance (weight gain 18.91 ± 0.73 g and specific growth rate 2.15 ± 0.26% day^?1) and feed utilization efficiency (feed conversion ratio 1.31 ± 0.05 g feed g gain^?1 and protein efficiency ratio 2.27 ± 0.08 g gain g protein^?1) compared with the other dietary groups. These findings indicate that microwave irradiation of feed ingredients prior to steam conditioning followed by mincing can improve aquafeed production quality.     

Effect of salts and plasticizers on stability of shellac film

The aim of this study was to increase the stability of shellac because of the polymerization. A few approaches have been applied in this study. Shellac film was prepared in two salt forms, that is, ammonium and 2-methyl-2-amino 1-propanol salts, and a comparison was made with shellac film in free acid form. The other approach was by the application of plasticizers. These plasticizers were diethyl phathalate, triacetin, and polyethylene glycol 400 (PEG 400). Plasticized shellac and unplasticized shellac films in free acid form were then compared. All shellac films were kept in stability chamber at 40 degrees C, 75% RH for a period of 3 months. The studied parameters such as insoluble solid, acid value, mechanical properties, and water vapor permeability were detected every month. Analysis of variance (ANOVA) technique was used to analyze data. The applications of salt forms proved statistically significant (p < 0.01) to reduce the polymerization process whereas certain plasticizers could enhance the stability. PEG 400 was the only plasticizer that could show the increase in stability. The improvement of stability might be a result of the interference of a larger molecule of PEG 400 causing the difficulty in interaction among carboxyl or hydroxyl groups of shellac and the effect of lower loss of plasticizer.