Journal of World's Poultry Research

124-132

Authors: Kongpechr S, Sohsuebngarm D and Sukon P.

Longitudinal bone growth is essential to support rapid body growth in commercial broiler chickens. The present study aimed to determine which simple mathematic model is best suitable for explaining the absolute and the relative bone growth in length (expressed as a ratio of bone length to body weight) as a function of age in male and female commercial broiler chickens over the first 35 days of age. A total of 1,800 broiler chickens (900 males and 900 females) of Cobb 500, Ross 308, and Arbor Acres raised in standard commercial broiler houses were randomly selected for this study. Body weight and the lengths of backbones, third toe, shank bone, and keel bone were individually measured in all chickens at 1, 7, 14, 21, 28, and 35 days of age. Regression analysis (with 4 simple mathematical models including linear, logarithmic, inverse, and exponential) was used to find a suitable model for estimating the absolute and the relative bone growth in length. In addition, an adjusted R2 was used to assess the model fitting. The results indicated that the absolute bone growth in length linearly increased with age. The adjusted R2 values for the linear model were 0.973, 0.937, 0.950, and 0.974 for the lengths of the backbones, third toe, shank bone, and keel bone, respectively. However, the relative bone growth in length logarithmically decreased with age. The adjusted R2 values of the logarithmic model were 0.971, 0.952, 0.957, and 0.905 for the relative length of the backbones, third toe, shank bone, and keel bone, respectively.The present investigation suggests thata linear model is a suitable model for estimating the absolute bone growth in length, but a logarithmic model is a proper model for estimating the relative bone growth in length of commercial broiler chickens.

139-146

Authors: Anggraini L, Marlida Y, Wizna W, Jamsari J and Mirzah M.

Nutrition is an essential factor for microorganisms to grow and survive. Carbon and nitrogen sources are used in producing primary and secondary metabolites. Gamma-Aminobutyric acid (GABA), a non-coded amino acid, is a secondary metabolite which acts as an inhibitory neurotransmitter of the central nervous system. Pediococcus acidilactici DS15 is a bacterium belonging to the order of Lactic Acid Bacteria. This study aimed to determine the effects of nutrients including glutamate, nitrogen and carbon sources on GABA production by Pediococcus acidilactici DS15. The tests were carried out using a range of 30 mM, 40 mM, 50 mM, 60 mM, and 70 mM glutamate as inducer and carbon sources in the form of peptone, yeast extract, skim milk, NH4NO3, KNO3, whey tofu and soy milk as nitrogen sources, and then glucose, lactose, maltosa, sucrose, palm, and cane sugar as carbon sources. The best sources of both will be tested with levels 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100% for nitrogen and 1, 3, 5, 7, 9, 11, 13 and 15% for carbon. The results of this investigation revealed that the addition of 60 mM glutamate caused the higher amount of GABA production and the best source of nitrogen and carbon for Pediococcus acidilactici DS15 were 100% whey tofu and 15% palm sugar, respectively. Production rate of GABA by Pediococcus acidilactici DS15 could reach up to 311,485 mg / L.

154-159

Authors: Maslami V, Mirnawati, Jamsari, Nur YSh and Marlida Y

Feed additives are ingredients that are added to the ration as growth promoters and enhancement of the immune system. Glutamate is a feed additive that improves performance by improving the quality of the small intestine and enhancing the immune system. The purpose of this study was to know the effect of including glutamate as a feed additive in improving broiler performance. The material used in this study was broiler strain MB 202 from PT Charoen Phokphand Indonesia as many as 240 birds. The design used was a Completely Randomized Design (CRD) trial design, with six treatments and four replications, so that there were 24 cage plots as experimental units. Each experimental unit consisted of 10 chickens. The Glutamate doses in groups were, A (0.4% commercial glutamate; B (0% glutamate); C (0.2% glutamate); D (0.4% glutamate); E (0.6% glutamate); F (0.8% glutamate). The results indicated that glutamate up to 0.8% had significant effects on feed intake body weight gain and feed conversion ratio (1.70%), but it did not affect the percentage of carcass. It is concluded that including the 0.8% glutamate in broiler disets can improve broiler performance with 35 days of maintenance.