The increased relative weights of duodenum, jejunum, ileum, and spleen on coccidial challenged birds were lost on day 36. Correlation analysis also indicated that the jejunum weight was positively related to villus height, Eimeria acervulina, and Eimeria maxima on day 27 but was not on day 36. The loss of the positive relationships may be because of recovery of the birds from coccidiosis on day 36. Even though the coccidial challenge and riboflavin interactively affected feed conversion ratio and BW gain and supplementation of dietary B. subtilis reduced mortality from day 35 to 42 in the companion study, the same response of internal organs was not observed in the current study. Coccidial challenge compromised development of internal organs of Ross 708 male broilers at an early age, but the negative effects subsided with age of birds rather than supplementation of riboflavin and B. subtilis at current tested levels under our experimental set up.Genetic selection of quail for a low body weight for more than 80 generations established a low-weight (LW) Japanese quail line that has been previously characterized to have a muscle hypoplasia phenotype. The aim of this study is to investigate the relationship of temporal expression levels of myostatin (Mstn) and myogenic regulatory factors (MRFs) with hypoplastic muscle growth in the LW line. During embryonic day (E) 13 to 15, gain of embryo weight was 2-fold lower (P less then 0.001) in the LW line than that in the random bred control (CON). Gains in body weight and pectoralis muscle weight from hatch to posthatch day (P) 28 were also significantly lower (P less then 0.01) in the LW line but increased by 4-fold (P less then 0.05) during P42 to P75. PCR analysis showed that expression levels of Mstn were greater in the LW at embryonic stage (E12 to E14, P less then 0.05), but there was no difference after hatch. In addition, expression levels of Pax7 and myogenin (MyoG) at E12 were 23-fold (P less then 0.05) and 3.4-fold (P less then 0.05) lesser in the LW line, respectively. At E14, expression of Pax3, Pax7, and MyoG gene was 3.5-fold (P less then 0.05), 6.5-fold (P = 0.065), and 4.4-fold (P less then 0.01) less than that in the CON. Taken together, high expression levels of Mstn and low expression of MRFs during embryonic stages can be associated with development of muscle hypoplasia and delayed muscle growth in the LW quail line. These data provide evidence that genetic selection for a low body weight resulting in an avian model with muscle hypoplasia has altered the expression profiles of myogenic factors.The aim of this study was to determine the effect of addition of alfalfa protein concentrate (APC) at the dose of 15 g or 30 g per 1 kg on the chemical composition, fatty acid profile, dietary value, and antioxidant status in muscles and serum of Ross 308 chickens. The experiment involved 150 1-day-old Ross 308 broiler chickens allocated into 3 groups in 5 replications (10 birds per pen). A 1-way system with 2 levels of APC, 15 g or 30 g per 1 kg of a complete diet, was used. Group C receiving a standard feed mixture without APC was the control. The addition of 15 and 30 g APC increased the CP content in the breast muscle and in the thigh muscle, and reduction in the cholesterol and fat level was noted. Higher content of polyunsaturated fatty acids from the n-6 group was noted in the breast muscles of the 30-g APC-supplemented chickens. The thigh muscles with APC were characterized by more favorable values of the atherogenic index, thrombotic index, and hypocholesterol-to-hypercholesterol ratio.The supplementation with 30 g APC reduced the cholesterol and triacylglycerol levels, increased the high-density lipoprotein level, and decreased the low-density lipoprotein level and improved the antioxidant parameters in plasma (increase in superoxide dismutase and in glutathione peroxidase and reduction of malondialdehyde), compared with group C. The results of this study indicate that the supplementation with 30 g APC improved the metabolic functions of the organism, meat resistance to oxidative processes, and the composition and profile of fatty acids. Therefore, APC can be a potential alternative to synthetic feed additives and soya protein in production of healthier poultry meat.The objective of this study was to determine the ileal digestible energy (IDE), ME, and MEn of rice, broken rice, and rice bran. The birds were fed a standard starter diet from day 0 to 14 and experimental diets from day 15 to 21 after hatching. A total of 336 birds were grouped by BW and assigned to 7 diets, each diet comprised 8 replicates with 6 birds per replicate. The diets comprised a reference diet (RD) and 6 test diets (TD). The TD contained 2 levels of rice, broken rice or rice bran that partly replaced the energy sources in the RD at 120 or 240 g/kg (rice and broken rice) or 150 or 300 g/kg (rice bran). Addition of rice or broken rice to RD linearly increased (P less then 0.01) ileal digestibility of DM, energy, as well as total tract metabolizability of DM, energy, and N-corrected energy in the TD. The inclusion of rice bran in the TD linearly decreased (P less then 0.01) energy digestibility and utilization in the test diet. Regressions of rice-associated, broken rice-associated, or rice bran-associated IDE, ME, or MEn intake in kcal against rice, broken rice, or rice bran intake were as follows IDE = Y = 2 (6) + 3,185 (73) × Rice + 3,199 (72) × Broken Rice + 2,562 (61) × Rice Bran, r2 = 0.98; ME = Y = 8 (6) + 3,103 (72) × Rice + 3,190 (71) × Broken Rice + 2,709 (60) × Rice Bran, r2 = 0.98; MEn = Y = 4 (5) + 3,014 (68) × Rice + 3,092 (101) × Broken Rice + 2,624 (57) × Rice Bran, r2 = 0.98; Based on the regression equations, the IDE, ME, MEn values (kcal/kg of DM) of rice were 3,185, 3,103 and 3,014, respectively, while for broken rice, the values were 3,199, 3,190, and 3,092 and for rice bran, the values were 2,562, 2,709, and 2,624, respectively.Dysregulation of the preovulatory surge (PS) leads to lowered egg production. The hypothalamo-pituitary-thyroid (HPT) axis has been shown to influence plasma progesterone levels and follicle ovulation. The presence of thyroid hormone receptors (THR) in the reproductive axis suggests possible effects of thyroid hormone. selleckchem To further understand the potential role of thyroid hormone on the PS, HPT axis plasma hormone concentrations and gene expression were characterized surrounding the PS in average egg producing hens (AEPH), low egg producing hens (LEPH), and high egg producing hens (HEPH) (n = 3 hens/group). Data were analyzed using the mixed models procedure of SAS, with significance indicated at P less then 0.05. Average egg producing hens and HEPH displayed lower levels of triiodothyronine (T3) and higher levels of thyroxine (T4) inside of the PS, whereas LEPH showed inverse T3 and T4 levels relative to the PS. Expression of mRNA for hypothalamic thyrotropin-releasing hormone (TRH), pituitary thyrotropin (TSHB), and the main thyroid hormone metabolism enzyme (DIO2) were downregulated during the PS in AEPH and HEPH.