18 March 2009 diets indicated that Diets 1 Diet 2 (18 percent protein) were deficient in one or more essential amino acids having a EAAI value of 0.72, whereas the 28 percent protein showed to be sufficient in satisfying the essential amino acid requirement of red claw having an EAAI value of 1.15-1.49. Webster et al. (1994) stated that formulation of diets for intensive culture requires an understanding of nutritional requirements and the lack of such information may impede red claw aquaculture in the United States. Thompson et al. (2005) stated that in the absence of a commercially available diet formulated specifically for red claw, producers may feed expensive high quality, commercial shrimp diets; a decision that may be a financial and nutritional waste. Another approach would be the use of low-quality diets that do not completely meet the nutrient requirements of the species, but may reduce growth, health and survival. Processing yield data were evaluated to compare the overall meat yields between male and female crayfish. Data in the present study indicate that males grow larger, have a higher percentage of their body weight comprised of claw (chelae), higher tail (outer shell) weight, and slightly higher tail muscle weight compared to that of females. In conclusion, the results of the present study indicate that red claw grown in ponds can be fed a diet with 28 percent crude protein with no fishmeal if a combination of plant-protein ingredients is added; however, it appears that 18 percent crude protein with or without fishmeal is not adequate for optimal growth. Reducing protein and fishmeal levels in red claw diets may help reduce operating costs, and, thereby increase producers’ profits. Notes 1Aquaculture Research Center, Kentucky State University, Frankfort, Kentucky, 40601, USA. e-mail: cwebster@dcr.net; phone: (502)-597-8109; fax: (502)-597-8118 2Central Queensland Crayfish, Queensland, Australia 3Farmers Feed, Lexington, Kentucky 4Unpublished data from C. D. Webster, Aquaculture Research Center, Kentucky State University, Frankfort, Kentucky, 40601, USA References Thompson, K.R., L.A. Muzinic, L.S. Engler, S. Morton and C.D. Webster. 2004. Effects of feeding practical diets containing various protein levels on growth, survival, body composition, and processing traits of Australian red claw crayfish Cherax quadricarinatus, and on pond water quality. Aquaculture Research 35: 659-668. Thompson, K.R., L.A. Muzinic, L.S. Engler and C.D. Webster. 2005. Evaluation of practical diets containing different protein levels, with or without fish meal, for juvenile Australian red claw crayfish (Cherax quadricarinatus). Aquaculture 244: 241-249. Webster, C.D., L.S.Goodgame-Tiu, J.H. Tidwell and D.B.Rouse. 1994. Evaluation of practical feed formulations with different protein levels for juvenile red claw crayfish, Cherax quadricarinatus. Transaction of the Kentucky Academy of Science 55:108-112. Fig. 1. Final weight (g) and weight gain (%) of red claw fed each of the four treatments. Means with the same letter are not significantly different (P>0.05). Fig. 2. Processing trait weights (g) of male red claw fed each of the four diets. Means with the same letter are not significantly different (P>0.05). Fig. 3. Processing trait weights (g) of male red claw fed each of the four diets. Means with the same letter are not significantly different (P>0.05).
RkJQdWJsaXNoZXIy MjExNDY=