Author
MENGHE, LI - Mississippi State University | |
Bosworth, Brian | |
LUCAS, PENELOPE - Mississippi State University |
Submitted to: Journal of the World Aquaculture Society
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/13/2019 Publication Date: 8/1/2019 Citation: Menghe, L., Bosworth, B.G., Lucas, P. 2019. Effects of available lysine concentrations in 28 and 32% protein diets on growth, feed efficiency, processing yield, and fillet composition of pond-raised channel catfish, Ictalurus punctatus. Journal of the World Aquaculture Society. 51:235-243. Interpretive Summary: Lysine, is an essential amino acid, meaning that animals cannot synthesize it and it must be provided in the diet for normal growth and function. Ingredients used to make catfish diets (corn by-products, peanut meal, and cottonseed meal) are often low in lysine and supplemental lysine is added to catfish diets to ensure diets contain adequate lysine. This study was conducted to determine the effects of the level of lysine supplementation (1.22, 1.43 and 1.63% available lysine) on growth and meat yield of channel catfish fed diets containing either 28% or 32% crude protein, the protein levels commonly used in commercial catfish feed. The results showed that although there was no difference in growth among catfish fed the 3 levels of lysine, meat yield was improved in fish fed 1.43 and 1.63% available lysine. This is important information for catfish feed producers, farmers and processors as meat yield is an important trait in farm-riased catfish. Technical Abstract: A study was conducted in earthen ponds to investigate effects of available lysine (AL) concentrations in 28 and 32% protein diets on production and processing characteristics, proximate composition, and lysine concentrations in edible tissue of channel catfish, Ictalurus punctatus. Diets were formulated to contain 28% protein with 1.22 and 1.43% AL, and 32% protein with 1.43 and 1.63% AL, which were equivalent to 4.37, 5.1, 4.46, and 5.1% AL of protein, respectively. Fingerlings with a mean initial weight of 32 g/fish were stocked into 20 ponds (0.04 ha) at 19,760 fish/ha. Fish were fed once daily to apparent satiation for 181 d. No significant differences were observed for total diet fed, net yield, weight gain, survival, or fillet proximate composition among dietary treatments. However, the 28% protein, low AL diet (1.22% AL of diet or 4.37% AL of protein) resulted in significantly lower carcass and fillet yield and fillet lysine level compared with fish fed the 28% protein diet with 1.43% AL (5.1% AL of protein) and 32% protein diets with 1.43 and 1.63% AL (4.47 and 5.1% AL of protein). Results suggest 1.43% AL of diet is adequate for both 28 and 32% protein diets for optimum growth, processing yield, and lysine retention in fillets for pond-raised channel catfish. |