Effect of dietary protein levels on the performance and carcass characteristics of cockerel finishers

A study was carried out to investigate the effect of dietary crude protein (CP) levels in diets of 2600kcal kg metabolisable energy content on the performance and carcass characteristics of cockerel finishers. The experimental diets A, B, C, D and E contained CP levels of 140, 160, 180, 200 and 200g kg and they were produced by modified diet dilution technique. Response criteria such as weight gain and feed conversion ratio, among others, and carcass characteristics were measured. Results on performance and carcass characteristics, with the exception of the neck, intestinal weights and other visceral offals, revealed that these response criteria were optimized in the birds fed on 180g kg dietary CP level. Beyond this level, it was nor beneficial to feed higher CP levels. It is therefore, concluded that the CP requirement of finisher cockerels is 18% on the bases of their Performance and carcass characteristics.

Digestible threonine requirement in diets for tambatinga (♀Colossoma macropomum x ♂Piaractus brachypomus) fingerlings

ABSTRACT Cross breeding of native fish species is a technique to produce hybrids that can express higher weight gain and feed efficiency compared to the parental species. The digestible threonine requirement in diets for tambatinga fingerlings (Colossoma macropomum ♀ x Piaractus brachypomus ♂) was determined in this study. For this, 700 fingerlings with an average initial weight of 2.39 ±0.02 g and average final weight of 35.96 ±2.03 g were distributed in a completely randomized design consisting of six treatments (0.600, 0.800, 1.000, 1.200, 1.400, and 1.600% digestible threonine) and five replicates per treatment, with 20 fish per experimental unit. Diets were formulated by the “diet dilution” technique using the ideal protein concept. Performance, feed efficiency, body depositions of protein, ash and fat, and nitrogen retention efficiency of the fish were evaluated. The digestible threonine levels that optimized weight gain, specific growth rate, and feed conversion ratio were 1.40, 1.27 and 1.10%, respectively. Body deposition of fat was reduced in a quadratic manner (p<0.01), and the body depositions of protein and ash, together with the efficiency of nitrogen retention, were optimized by the digestible threonine level of 1.20; 1.33, and 0.82%, respectively. The recommended digestible threonine level in the diet for tambatinga fingerlings is 1.20 to 1.40% (0.40 and 0.47% Mcal DE-1) to obtain higher body deposition of protein and weight gain, respectively.

Pengaruh pembatasan Pakan pada Awal Umur yang Berbeda terhadap Performa dan Profil Lipid pada Broiler Umur Empat Dua Hari

ABSTRAKPenelitian ini dilakukan untuk mengevaluasi pengaruh umur awal pembatasan pakan terhadap performa, profil lipid dan komposisi gizi dalam hati, daging dada dan paha pada ayam broiler. Berat badan dan pertambahan berat badan pada broiler dengan diet dilution dan physical restriction lebih rendah (P<0,01) daripada kontrol, kecuali pada broiler dengan physical restriction dimulai umur 4 hari. Meal feeding menghasilkan berat badan dan pertambahan berat badan yang berbeda tidak nyata (P>0,05) jika dibandingkan dengan kontrol. Konsumsi pakan dan FCR pada broiler secara nyata (P<0,05) lebih rendah daripada kontrol. Pembatasan pakan berpengaruh tidak nyata (P>0,05) terhadap fatty liver score, lemak abdominal dan konsentrasi kolesterol dalam serum, tetapi berpengaruh secara nyata (P<0,05) terhadap konsentrasi trigliserida dalam serum. Pembatasan pakan berpengaruh tidak nyata terhadap kadar lemak, protein, air dan abu dalam hati (P>0,05), kadar air, protein dan abu dalam daging dada dan paha, tetapi berpengaruh secara nyata (P<0,05) terhadap kadar lemak dalam daging dada dan paha. Dapat disimpulkan bahwa meal feeding menghasilkan performa yang lebih baik dengan profil lipid yang tidak menurun pada broiler umur 42 hari.Kata kunci: Pembatasan pakan, umur awal pembatasan, broiler, performa, profil lipid