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  • Author: Michał Jankowski x
  • Veterinary Medicine x
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The Effect of Different Dietary Levels and Sources of Methionine on the Growth Performance of Turkeys, Carcass and Meat Quality

Abstract

The aim of this study was to determine the effect of different dietary levels and sources of methionine (Met) on the growth performance of turkeys, carcass and meat quality. A total of 816 Hybrid Converter turkeys in 6 groups and 8 replications were fed wheat-soybean meal-based diets supplemented with three sources of Met: DL-isomer, L-isomer and DL-hydroxy analog (DLM, LM and MHA, respectively). In four 4-week periods (from 1 to 16 weeks of age), the Met content of turkey diets corresponded to the level recommended by NRC (1994) or was increased by approximately 50% to match the intake recommended by some breeding companies. Increased dietary Met content resulted in a higher final body weight (BW) of turkeys (P=0.002) and a lower feed conversion ratio (FCR) (P=0.049), but had no effect on carcass dressing percentage and most parameters of carcass quality. The higher dietary Met level contributed to a decrease in meat pH, a lower contribution of redness and a smaller muscle fiber diameter (P=0.028, P=0.040 and P=0.004, respectively). The higher dietary Met level had no influence on the redox status of meat, but it reduced the incidence of lymphoid cell infiltration between muscle fibers threefold (P=0.003). Throughout the experiment, no significant differences were noted in the growth performance parameters of turkeys, irrespective of Met source. MHA contributed to higher abdominal fat content, lower dry matter (DM) content and lower catalase (CAT) activity in breast meat, compared with DLM and LM. Increased dietary Met content, approximately 50% higher than that recommended by NRC (1994), regardless of Met source, led to higher final BW of turkeys, but had no effect on carcass dressing percentage and most parameters of carcass quality.

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Performance and Small Intestine Morphology and Ultrastructure of Male Broilers Injected in Ovo with Bioactive Substances

Abstract

The objective of the present study was to determine the effect of prebiotic and synbiotic preparations injected in ovo on day 12 of embryogenesis on both development of intestinal villi and the number of neutral goblet cells in the small intestine of male broiler chickens on day 35 of rearing. Eggs containing live embryos were randomly separated into five experimental groups (1800 eggs per group), and treated with different bioactive compounds by in ovo injection. The control group (C) was injected with physiological saline. The prebiotic groups (PI and PB) were injected with a solution containing 1.76 mg of inulin or with a solution containing 0.528 mg of Bi2tos. The injection solution for both synbiotic groups (SI and SB) consisted of 1.76 mg Inulin + 1000 CFU of L. lactis spp. lactis 2955 (SL1) or 0.528 mg Bi2tos + 1000 CFU of L. lactis spp. cremoris 477 (SC1). Samples for histological analysis were taken from the three segments of the small intestine: the duodenum, jejunum and ileum. Broiler performance increased in the prebiotic group injected with Bi2tos when compared to both the control group and the prebiotic group injected with inulin. In relation to other groups, in the duodenum and ileum the highest intestinal villi were observed in chickens with the lowest body weight, i.e. groups C and PI. The smaller surface area of villi was found in the jejunum and ileum in group SB. As far as the jejunum and ileum are concerned, a significantly higher number of goblet cells was noted in groups PB and SB.

Open access