Prepration and Evaluation of Solar-Dried Fish By-Product Meal as a protein Supplement in Broiler Chick’s'diet.

Abstract

Abstract The present study was conducted to investigate the possibility of producing and usage of solar dried fish by—product meal (SPFBPM) as a replacement for an imported plant protein concentrate (IPPC) in both starter and finisher diets for broiler chicken. Slightly improved solar dryer tent (SDT) was tested to dry samples of fish by-products (FBPs). A questionnaire was carried out on the majority of fish processing shops (FPS) in Sana’a City Center, to collect information about marketed fishes, fish by-products, dressing out methods and consumer preferential customs. etc. Twenty seven Jahesh fishes (Lethrinidae.spp.] were selected and divided to three similar groups in weights, dressed out, in order to determine the components and percentages of FBPs according to three common dressing out methods. Samples of Jahesh FBPs were collected from FPS, processed and dried in SDT. Microbial tests for Salmonella, E.co1i and total bacterial count were carried out on samples SDFBPM, before and after 3 different heating treatments. Proximate chemical analysis was carried out on three replicate three times. Five starter and finisher experimental diets for broilers were formulated to meet NRC., 1994 recommendations. Diets were iso-caloric and iso-nitrogenous including 0.0, 2.5, 5.0, 7.5 and 10% of SDFBPM replacing equal percentages of IPPC. Two hundred and twenty five newly hatched Ross broiler chicken were randomly located in 5 groups of 45 birds three replicate each. Body weight gain, feed intake, feed conversion ratio and protein efficiency ratio were recorded and calculated for 7 weeks. At the end of the 49*‘ day, birds were fasted for 12 hours and 4birds from each pen were randomly selected and individually weighted, slaughtered, mechanically defeathered and carcass and non—carcass components were weighed. The obtained data showed that Jahesh fishes represent the most available and the most preferred fish type among the locally marketed fish species during the whole year. Percentages of fish by-products were (19-36-52%] of total body weight for gutted, sluiced and filleted dressing out methods, respectively. Moreover, the sliced dressing out method was the first preferred by consumers. Two days were enough to dry minced FBPs samples, which indicated that examined SDT was Well—improved by drying system of clean and cheap energy. Salmonella colonies were seen and the total bacterial count was 192x104 Cells / gm, but the bacterial colonies disappeared with samples autoclaved at 121C” for 21 minutes.

The chemical composition of SDFBPM was 95.02% DM, 48.5% CP, 21.5% EE, 0.0% fiber, 8% Ca, 4.26%P, 25.3% Ash, 4.74%NFE. However, the SDFBPM samples physically showed a good quality fish meal. The experimental chicks fed diets including up to 7.5% of SDFBPM showed satisfactory performance compared with the control birds, but depression in growth and protein efficiency resulted with broilers fed diets including 10% SDFBPM. On the other hand, there was no sign of salmonella infection in chicks during the 7 week experimental period also, meat color, flavor, tenderness or juiciness of their carcasses were not significantly affected. Generally, broilers fed diets wiuth 2.5% SDFBPM showed the performance numerically but not significantly different from those fed 5%, 7.5% and the control. ~'