Etlik Piliçlerde Odunsu Göğüs Eti Sendromu ve Etkileri

The aim of the study is to present a review about the "Wooden Breast Syndrome" (WBS) syndrome, which is a muscle disorder that has become increasingly important in recent years, and the etiology of the abnormalities caused by this myopathy, and its histological, macroscopic, and microscopic features. Besides, the effects on the visual, sensory, functional, mechanical quality and processing properties of the breast meat of broilers and their negative effects on the poultry industry were also discussed. Since this myopathy gives a hard structure to the pectolaris major muscle, it is called "Wooden Breast" in public. It is assumed that the leading direct and indirect causes of WB syndrome in broilers are pectoral muscle hypertrophy (volume increase in muscle cells), rapid growth rate, and high breast meat yield. Also, age, gender, diet, feed restriction, oxidative stress, genetics, etc. factors are also thought to be effective. However, the etiology of WB syndrome is still unclear in many aspects. As a result of the macroscopic examination of the wooden breast meat, a striking stiffness, swelling, viscous exudate (inflammatory fluid), petechial (purple-red bleeding spots) fluid, and a pale appearance in the pectoral major muscles are observed, and the lesions that occur can be detected by palpation. Due to these visual and sensory defects in breast meat, the consumability of meat decreases and this leads to significant economic losses for the poultry industry.

Dietary glycine equivalent and SID methionine+ cysteine levels for male broiler chickens fed low crude protein diets

This study was conducted to determine the optimum dietary glycine equivalent (Glyequi) level in low crude protein (LCP) diets of 181 g/kg containing varied concentrations of standardized ileal digestible (SID) methionine+cysteine (Met+Cys) for broiler chicks (1-21d old). A total of 1275, 1-d-old Cobb-Vantress® male broilers were distributed in a 5 × 3 factorial arrangement of completely randomized design of 15 treatments with five replicates of 17 birds each. Treatments consisted of 5 levels of dietary Glyequi (14.9, 16.4, 17.9, 19.4 and 20.6 g/kg) and three concentrations of SID Met+Cys (7.70, 9.0 and 10.3 g/kg). Interactions between Glyequi and SID Met+Cys levels were observed for feed:gain (P = 0.055) and breast meat yield (BMY) (P = 0.017). In 7.7 and 9.0 g SID Met+Cys/kg diets, optimal feed:gain and increased BMY were observed at the Glyequi level not lower than 17.9 g/kg. In 10.3 g SID Met+Cys/kg diet, a lower feed:gain was achieved at 19.4 g Glyequi/kg. Therefore, a minimum dietary level of 17.9 g Glyequi/kg is needed to increase growth of broilers fed diets containing 7.7 or 9.0 g/kg SID Met+Cys while 19.4 g/kg Glyequi is necessary in diets containing 10.3 g/kg SID Met+Cys for optimum growth.

Evaluation of a Product Derived from Porcine Plasma Protein and a Yeast Product with Similar Biological Activity in Diets of Growing Broilers

The post-hatch period of a broiler is an integral point in their development and for the programming of musculoskeletal and immune cells. Therefore, the efficacy of two bioactive protein products, betaGRO® (BG) and celluTEIN® (CT) to impact post-hatch and lifelong development was evaluated. Birds were grown under a low stress environment using clean wood shavings litter and a high stress environment with used litter from a commercial farm that had suffered high mortality. Each additive was fed at 300 g/ton from day 1–14 and 50 g/ton from day 15–42. Growing birds in the high stress environment had a negative impact on performance (p < 0.05); however, addition of either BG or CT successfully mitigated the detriments of the high stress environment (p < 0.05), and in many cases, the performance was equal to or better than the performance of birds on the control diet in the low stress environment. Birds fed BG and CT experienced improvements in 42-day feed conversion, and were more uniform than birds grown consuming the control diet (p < 0.05). Mortality of birds in the high stress environment was reduced by addition of BG or CT (p < 0.05). Addition of BG and CT resulted in improvements in carcass and breast meat yield (p < 0.05). Together, these data suggest that BG and CT can be used interchangeably to improve broiler health and performance.

Early Growth and Protein-Energy Metabolism in Chicken Lines Divergently Selected on Ultimate pH

In chickens, a divergent selection on the Pectoralis major pHu allowed the creation of the pHu+ and pHu− lines, which represent a unique model for studying the biological control of carbohydrate storage in muscle. The present study aimed to describe the early mechanisms involved in the establishment of pHu+ and pHu− phenotypes. At hatching, pHu+ chicks were slightly heavier but exhibited lower plasma glucose and triglyceride and higher uric acid. After 5 days, pHu+ chicks exhibited higher breast meat yield compared to pHu− while their body weight was no different. At both ages, in vivo muscle glycogen content was lower in pHu+ than in pHu− muscles. The lower ability of pHu+ chicks to store carbohydrate in their muscle was associated with the increased expression of SLC2A1 and SLC2A3 genes coding glucose transporters 1 and 3, and of CS and LDHα coding key enzymes of oxidative and glycolytic pathways, respectively. Reduced muscle glycogen content at hatching of the pHu+ was concomitant with higher activation by phosphorylation of S6 kinase 1/ribosomal protein S6 pathway, known to activate protein synthesis in chicken muscle. In conclusion, differences observed in muscle at slaughter age in the pHu+ and pHu− lines are already present at hatching. They are associated with several changes related to both carbohydrate and protein metabolism, which are likely to affect their ability to use eggs or exogenous nutrients for muscle growth or energy storage.

In pursuit of a better broiler: carcass traits and muscle myopathies in conventional and slower-growing strains of broiler chickens.

Selection for accelerated growth rate and high breast yield in broiler chickens have been associated with an increase in myopathies, including wooden breast (WB) and white striping (WS). To investigate effects of growth rate on carcass traits and incidence of myopathies, 14 strains were evaluated, encompassing 2 conventional (CONV; strains B and C: ADG0-48>60 g/d) and 12 slower-growing (SL) strains. The latter were categorized based on growth rate: FAST (strains F, G, I and M; ADG0-62=53-55 g/d), MOD (strains E, H, O and S; ADG0-62=50-51 g/d), and SLOW (strains D, J, K and N; ADG0-62<50 g/d). In a randomized incomplete block design, 7,216 mixed-sex birds were equally allocated into 164 pens (44 birds/pen; 30 kg/m2), with each strain represented in 8-12 pens over 2-3 production cycles. From each pen, 4 males and 4 females were processed at 2 Target Weights (TW) based on their expected time to reach 2.1 kg BW (TW 1: 34 d for CONV; 48 d for SL strains) and 3.2 kg BW (TW 2: 48 d for CONV; 62 d for SL strains). Weights and yields for the carcass, breast, drumsticks, thighs and wings were obtained; breast fillets were assessed to determine the presence and severity of WB and WS. At both TWs, breast yield was higher as growth rate increased (P<0.001), with CONV having greater breast yield than other categories. Strain F had the greatest breast yield at both TWs (P<0.001) within the FAST category. At TW 2, CONV had the greatest incidence of WB and WS (P<0.001). However, within FAST, strain F had the greatest incidence of myopathies (P<0.001) at both TWs, exhibiting values as high or greater than CONV birds. The incidence of WB and WS in strains with differing growth rates but high breast meat yield suggests that the latter may play a major role in the occurrence of these myopathies.

Dietary branched-chain amino acid assessment in broilers from 22 to 35 days of age

Background Valine and isoleucine are similar in chemical structure and their limitation in broiler chicken diets. To evaluate their limitation and interactive effects, multivariate assessment nutrition studies for the branched-chain amino acids (BCAA) are needed. A three level (− 1, 0, + 1), three-factor Box-Behnken design study was conducted to assess dietary BCAA ratios to lysine of 65, 75, and 85 for valine, 58, 66, and 74 for isoleucine, and 110, 130, and 150 for leucine in male and female Lohman Indian River broilers from 22 to 35 d of age. Results Live performance of male broilers was not affected by BCAA level. However, male broilers fed increasing isoleucine had improved (P = 0.07) carcass yield as leucine and valine were reduced. Female broilers had improved body weight gain (P = 0.05) and feed conversion (P = 0.003) when leucine and isoleucine were at their lowest levels, independent of valine, but increasing leucine impaired live performance and warranted concomitant increases in isoleucine to restore responses. Increasing dietary isoleucine and valine in female broilers increased breast meat yield (P = 0.05), but increasing leucine tended to diminish the response. Conclusion The female Lohman Indian River broiler is more sensitive to BCAA diet manipulation than males. Specifically, as dietary leucine is increased in female broilers, dietary isoleucine increases were needed to offset the negative effects. Both increases in dietary valine and isoleucine improved breast meat yield in female broilers, but only when birds were fed the lowest dietary leucine.

Breast meat yield, muscle linear measurements and meat composition of turkeys fed 2 diet containing wheat or sorghum as sole cereal source

Breast meat yield, chemical composition, mineral profile and linear measurement of the resultant breast meat Supracoracoides and Pectoralis thoracicus of one hundred and eighty (28 days old BUT) male turkeys fed diet containing wheat or sorghum as sole cereal source were studied. One hundred and eighty 28-days old male turkeys (British United Turkeys, BUT) were randomly allotted into 18 pens with 10 poults housed in each pen (of dimension 3.0× 2.0 m). Three experimental diets were formulated for the starter (29-56 days), grower (57-84) and finisher phase (85-112 days) such that ground maize (control), wheat or sorghum (light brown coat variety) was used as the only cereal source. The turkeys were randomly allotted to 18 pens (each housing 10 turkeys) with each pen allocated to one of the experimental diets. Growth response, breast meat yield, chemical composition, mineral profile and linear measurement of the resultant breast meat yield were measured at the end of finishing phase. Turkeys fed with wheat and sorghum had similar dressing percentage values. Turkeys fed with sorghum recorded lower (P<0.05) final live weight (10,002.10 g), weight gain (9084.90 g), feed intake (19,942.67 g), dressed weight (8099.94 g), breast meat yield (2691g) and higher relative BMY (269.05 g/kg LWT) than those fed with wheat. However, turkeys fed with wheat had higher (P<0.05) Supracoccoides weight (672.15 g) and length (26.9 g) than those fed with sorghum which recorded higher relative Supracoccoides weight (58.81 g) than those fed with sole wheat (53.76 19 g). Crude protein, ether extract, ash content, gross energy and mineral content of the BMY were not affected by dietary inclusion of wheat or sorghum as sole cereal source. However, the breast meat of turkeys fed with sorghum had lower (P<0.05) moisture (60.12%), cholesterol (19.05 mg/100g) and LDL (2.01 mg/100g) values than other corresponding values obtained for turkeys fed with wheat or control diet

41 Estimating the heritability of meat quality traits in turkeys

Genetic selection for improved meat quality traits has been successfully implemented in many livestock species. The objective of this study was to estimate the heritability of several meat quality traits to assess their selection potential in turkeys. Pedigree toms (n = 1,033) were processed at a commercial facility and live weight, breast meat yield (as a percentage of live weight), ultimate pH, color (CIELAB values), drip loss, cooking loss, and shear force were recorded on M. pectoralis superficialis (fillet). White striping was also rated on a 1–4 scale. Heritabilities were estimated using univariate animal models in ASReml version 4.1. Hatch week and age at slaughter were included as fixed effects in the mode,l and 32 generations of pedigree records were used. Breast meat yield (h2 = 0.62; SE = 0.090) showed the highest heritability and was higher compared to previous estimates, probably due to the smaller sample size. Live weight (h2 = 0.31; SE = 0.078), ultimate pH (h2 = 0.36; SE = 0.087), lightness (h2 = 0.28; SE = 0.086), redness (h2 = 0.22; SE = 0.075), and white striping score (h2 = 0.27; SE = 0.085) all had moderate heritabilities. The estimate for ultimate pH was similar to previous studies in broilers but was high compared to previous studies in turkeys. Estimates for color were similar to those found in previous studies involving turkeys. Drip loss and cooking loss had similar heritability estimates of 0.13 (SE = 0.071) and 0.10 (SE = 0.064), respectively, which were akin to previous estimates in pork. Shear force (h2 = 0.02; SE = 0.056) was found to have a very low heritability. In conclusion, the heritability estimates provided in this study show great potential for the inclusion of meat quality traits in selection programs of turkeys. This study is part of a larger project working towards the implementation of genomic information in the selection of turkeys for improved meat quality.

Dietary branched-chain amino acid assessment in broilers from 22 to 35 days of age

Background: Valine and isoleucine are similar in chemical structure and their limitation in broiler chicken diets. To evaluate their limitation and interactive effects, multivariate assessment nutrition studies for the branched-chain amino acids (BCAA) are needed. A three level (-1, 0, +1), three-factor Box-Behnken design study was conducted to assess dietary BCAA ratios to lysine of 65, 75, and 85 for valine, 58, 66, and 74 for isoleucine, and 110, 130, and 150 for leucine in male and female Lohman Indian River broilers from 22 to 35 d of age.Results: Live performance of male broilers was not affected by BCAA level. However, male broilers fed increasing isoleucine had improved (P = 0.07) carcass yield as leucine and valine were reduced. Female broilers had improved body weight gain (P = 0.05) and feed conversion (P = 0.003) when leucine and isoleucine were at their lowest levels, independent of valine, but increasing leucine impaired live performance and warranted concomitant increases in isoleucine to restore responses. Increasing dietary isoleucine and valine in female broilers increased breast meat yield (P = 0.05), but increasing leucine tended to diminish the response.Conclusion: The female Lohman Indian River broiler is more sensitive to BCAA diet manipulation than males. Specifically, as dietary leucine is increased in female broilers, dietary isoleucine increases were needed to offset the negative effects. Both increases in dietary valine and isoleucine improved breast meat yield in female broilers, but only when birds were fed the lowest dietary leucine.