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The objective of this research was to evaluate the e ects of dietary supplementation of blood meal (BM) on carnosine (L-Car) and anserine (L-Ans) content in the chicken breast muscle (CBM). In Experiment , Ross broiler chicks of d old were assigned to dietary treatments: basal diet (BM-), basal diet BM (BM-), and basal diet BM (BM-). In Experiment , Ross broiler chicks of d old were fed BM-treated diets, including BM (BMI-), BM (BMI-), and BM (BMI-), with isocalorie and isonitrogen adjustment. Broilers were reared in

An experiment was conducted to evaluate the effect of dietary supplementation of histidine, β-alanine, blood meal (BM), magnesium oxide (MgO), and their combination on carnosine and anserine concentrations of broiler breast meat. A total of 210 1-d-old broiler chicks were randomly allotted to 3 replicates of 7 dietary treatments: (1) Control diet (C), (2) C＋histidine (His), (3) C＋β-alanine (β-Ala), (4) C＋histidine＋β-alanine (His＋β-Ala ); (5) C ＋histidine＋β-alanine＋MgO (His＋β-Ala＋MgO), (6) C＋5% BM (BM), and (7) C＋5% BM＋MgO (BM＋ MgO). Histidine, β-alanine, and MgO were supplemented to diets at 2.9, 3.7, and 4.0 g/kg diet, respectively. The broilers were fed experimental diets for 32 d and the concentrations of carnosine and anserine in breast meat were measured weekly and at 32 d of the age. Results indicated that the concentrations of carnosine, anserine, and their sum in breast meat were increased (linear, P＜0.01) with age in all treatments. There were significant differences in carnosine concentrations among treatments in all weeks. At 32 d, all 3 histidine-supplemented treatments (His, His＋ β-Ala, and His＋β-Ala＋MgO) and BM＋MgO treatment had greater (P＜0.05) carnosine concentrations than the control. The anserine concentrations differed (P＜0.01) among treatments at 7, 14, and 21 d. The sum of carnosine and anserine concentrations was the greatest for His＋β-Ala＋MgO treatment, but the least for β-Ala treatment at 21 d. In conclusion, dietary supplementation of histidine alone or with β-alanine may increase carnosine concentrations, but not anserine concentrations of broiler breast meat. Dietary supplementation of additional MgO in diets containing His, β-Ala, and/or BM has little effect on carnosine and anserine concentrations in broiler breast meat.

The objective of this research was to evaluate the effects of dietary supplementation of blood meal (BM) as a source of histidine, and magnesium oxide (MgO) as a catalyst of carnosine synthetase, on carnosine (L-Car) content in the chicken breast muscle (CBM), laying performance, and egg quality of spent old hens. Four hundred eighty laying hens (Hy-Line ® Brown), 95wk old, were allotted randomly into five replicates of six dietary treatments: T1; 100% basal diet, T2; 100% basal diet+MgO, T3; 97.5% basal diet+ 2.5% BM, T4; 97.5% basal diet+2.5% BM+MgO, T5; 95% basal diet+5% BM, T6; 95% basal diet+5% BM+MgO. Magnesium oxide was added at 0.3% of diets. The layers were fed experimental diets for 5wk. There were no significant differences in the weekly L-Car content in CBM among all treatments during the total experimental period, but some of the contrast comparisions showed higher L-Car in CBM of T6. The L-Car contents linearly decreased (p<0.01 or p<0.05) as the layers got older except in T4 (p>0.05). There were significant differences in egg weight (p<0.01) and soft and broken egg ratio (p<0.05). The control (T1) was highest in egg weight and T6 was lowest in soft and broken egg ratio. Among the parameters of egg quality, there were significant differences in eggshell strength (p<0.01) and egg yolk color (p<0.05). Magnesium oxide supplementation increased the eggshell strength and BM tended to decrease egg yolk color. Eggshell color, eggshell thickness, and Haugh unit were not influenced by BM and MgO. In conclusion, BM and MgO did not significantly influence the L-Car in CBM of spent layers. The L-Car content rapidly decreased as the layers became senescent. Eggshell strength was increased by MgO supplementation.

The effects of dietary supplementation of feather meal (FM) and pyridoxine (B 6 ) on the taurine content of egg yolk and performance of laying hens were investigated. A feeding trial was conducted in nine hundred 31-wk-old Hy-Line ® Brown layers over 4 wk. The hens received 6 dietary treatments: Control, FM 3% supplemented diet (FM 3%), FM 3%+B 6 supplemented diet (FM 3%+B 6 ), FM 6% supplemented diet (FM 6%), FM 6%+B 6 supplemented diet (FM 6%+B 6 ), and synthetic taurine 0.25% supplemented diet (Taurine). Parameters of production were significantly (p<0.05) affected by treatments. The egg production of hens fed FM 3% was the highest and hens fed FM diets were more productive than the Taurine and Control groups. The egg weights of the Taurine group were significantly lower than those of the FM 3% and FM 6% groups, but not significantly different from those of other treatments. The feed intake of the Control group was highest among all groups. The feed conversion ratio of the Control group was higher than in groups receiving other treatments of which FM 6% was the lowest. The broken egg production of the Taurine group was highest, while that of the Control group was lowest among treatments. The taurine content of egg yolk was significantly (p<0.01) increased by supplementation of taurine (64.7%), FM 6%+B 6 (57%), FM 3%+B 6 (32.1%), and FM 6% (16.6%) over a 4 wk average. Sensory evaluation data of the Taurine group showed the highest score in all of the sensory attributes and those of other treatments were not significantly (p<0.05) different. In conclusion, taurine can be enriched in egg yolk by supplementation of 6% FM and B 6 , as well as 0.25% synthetic taurine.