Breast Meat Yield Research Articles

Desempenho, qualidade da carne e lipidemia de codornas de corte alimentadas com rações contendo óleos essenciais

ABSTRACT: This study evaluated the effect of essential oil (ESOL) of Mentha piperita and Melaleuca alternifolia on meat-type quails. To examine performance, a completely randomized design was used, with four treatments and eight repetitions each, using seven birds per repetition. To assess lipidemia, a completely randomized design in a 4 × 2 factorial scheme was used, with four treatments and two collection conditions using eight repetitions and one bird per repetition. Weight gain, feed intake, feed conversion, carcass yield, cholesterol, high-density lipoporteins, triglycerides, pH, and brightness of quail breast meat were assessed. The data were analyzed for homoscedasticity and normality, and the means were subjected to analysis of variance. Adding M. piperita and M. alternifolia ESOL to the diets of meat-type quails can improve performance, carcass yield, and meat quality characteristics, comparable to the use of performance-enhancing antibiotics. The use of zinc bacitracin, M. piperita, and M. alternifolia under different collection conditions did not increase the serum levels of low-density and very low-density lipoproteins. The variation coefficients measured after 12 hours of fasting were 86% lower than without fasting.

Effect of supplementing limiting amino acids on growth performance and carcass traits of Gramasree male chicks fed with low protein diets

An experiment was conducted to study the effect of reduced dietary crude protein (CP) diet supplemented with limiting amino acids on growth performance and carcass traits of Gramasree male birds up to eight weeks of age. A total of 280 day-old chicks were allotted randomly under five dietary treatments each with four replicates of 14 chicks under completely randomized design. The different dietary treatments viz., control diet (T1) was formulated as per ICAR (2013) nutrient requirements for Indian improved native birds with 21 per cent CP and 2800 kcal/kg Metabolizable energy (ME) using corn, soya bean meal, wheat bran and de-oiled rice bran. Treatment diets T2, T3, T4 and T5 were formulated by reducing CP content to 20, 19, 18, and 17 per cent, respectively with isocaloric value of 2800 kcal/kg ME and supplemented with methionine, lysine, threonine and tryptophan to meet the daily requirements. Weekly body weight and feed consumption were recorded. For the carcass study, two birds from each replicate were randomly selected and slaughtered humanely at eighth week of age. The results showed that the final body weight and cumulative weight gain were comparable among the treatments. The lowest cumulative feed intake and feed conversion ratio (FCR) were observed in 17 per cent CP containing treatment (T5), which was not significantly different from rest of the groups. The mean per cent breast meat yield, giblet yield, dressing yield and ready-to-cook yield were comparable among the five dietary treatments. The mean abdominal fat content in birds fed with 18 and 17 per cent (T4 and T5) were significantly (p<0.05) higher than the other treatment groups.The overall results indicated that the dietary CP of Gramasree male chicks can be lowered up to 17 per cent with the supplementation of methionine, lysine, threonine and tryptophan without affecting the growth performance of birds.

Guanidinoacetic acid as a partial replacement to arginine with or without betaine in broilers offered moderately low crude protein diets

Guanidinoacetic acid (GAA) is the direct precursor of creatine and can spare arginine (Arg) for creatine synthesis in low crude protein (CP) broiler diets. This study aimed to determine the extent GAA could spare Arg in broilers offered low CP diets and if supplemental betaine provides additional benefits. Seven hundred twenty-day-old Ross 308 male broilers were assigned into 9 dietary treatments with 8 replicates of 10 birds each. The treatments were; normal CP diet, a low CP (−15 g/kg) diet deficient in Arg, a low CP diet sufficient in Arg, and low CP diets with GAA, where 0.1% added L-Arg was spared by GAA at 50, 100, and 150% with and without 0.1% betaine. The treatments were offered during grower (d 10–24) and finisher (d 25–42) phases. The birds offered a low CP Arg deficient diet had 7.8% lower weight gain, 10 points higher FCR, 8.5% lower breast meat yield, 27.2% lower breast meat creatine concentration and 30.4% more abdominal fat pad compared to those offered a normal CP diet. When Arg was added back to the Arg deficient diet, growth performance, breast meat yield and creatine concentration loss were restored. When GAA spared Arg at 150%, feed intake, weight gain, FCR, breast and abdominal fat yields, breast meat moisture, drip loss, and breast meat creatine concentration became comparable to Arg sufficient low CP and normal CP treatments. When GAA spared Arg at 100 and 50%, FCR was 3 and 5 points lower than the normal CP treatment. Breast meat creatine concentration was positively correlated to feed efficiency (r = 0.70, P < 0.001) and breast meat moisture (r = 0.33, P < 0.01), and negatively correlated to relative weight of abdominal fat (r = −0.37, P < 0.01) and breast meat pH (r = −0.49, P < 0.001). There were no benefits of adding betaine with GAA on the parameters measured but the results with GAA were consistent in the presence or absence of betaine.

Meat yield characteristics of different upgraded dwarf chicken under intensive management condition

The study was conducted with attempts to determine the effects of autosomal dwarf (adw) gene introgression from Indigenous dwarf chicken (IDC) to White Leghorn (WLH) and Fayoumi (Fay) on growth and meat yield characteristics. Experiment was carried out at the Poultry Farm of Bangladesh Agricultural University (BAU), Mymensingh for a period of 28 months from March 2013 to June 2015 under intensive management condition. In this study, the di-allele crossing between WLH, Fay and IDC produced 4 up-graded chickens viz. IDC♂ × WLH♀, WLH♂ × IDC♀, IDC♂ × Fay♀ and Fay♂ × IDC♀. The up-graded F1 generations were mated intersex to access their productivity. The up-graded F1 generations were mated intersex to access their productivity. Pre-slaughter live weight of birds significantly (P&lt;0.001) varied by genotype, sex and genotype × sex interaction. Percentage of thigh meat, drumstick meat, dark and total meat weights was significantly influenced by genotype. Although meat yield parameters of male birds in relation to live weight were found higher than their female birds, some parameters like breast meat, liver, giblet and total meat yield were found higher in female birds than that of male birds of all genotypes. However, meat yield parameters like percentage of thigh, drumstick and total meat yield were the highest in IDC♂ × Fay♀ and Fay♂ × IDC♀ and the lowest in IDC♂ × WLH♀. From the above findings, Fayoumi mediated dwarf genotypes showed better meat yield characteristics than Leghorn mediated dwarf genotypes.

Performance, carcass yield and cuts of male broilers fed with canthaxanthin and 25-hydroxycholecalciferol in the diet

The objective of this study was to evaluate the effect of canthaxanthin (CTX) associated with 25-hydroxycholecalciferol (25-OH-D3) in the feed of male broilers. A total of 1500 one-day-old Cobb-500TM males were used, distributed in a completely randomized design, totaling two treatments with fifteen replicates of 50 birds each. The treatments were: CD - control diet and CTX+ 25-OH-D3 - control diet + canthaxanthin associated with 25-OH-D3 added to the diet up to 21 days of age. The experimental period was from 1 to 42 days of age. The performance parameters measured were body weight gain, feed intake, feed conversion. Carcass yield and cuts were analyzed (pH, color, water-retention capacity, shear force, weight loss in cooking and lipid oxidation of meat at different shelf times 0, 30, 60, and 90 days post mortem and feet pigmentation). To study bone characteristics, black bone syndrome, gait score, tibia rupture strength and percentage of calcium, phosphorus and ashes of the tibia were analyzed. The data were submitted to variance analysis using the statistical program SAS (2016). Male broilers fed with combination of CTX+ 25-OH-D3 in the diet had an increase (P < 0.05) in body weight gain and improvements in FCR (1–21 days of age), higher breast meat yield and better feet pigmentation, and increase in bone resistance (higher tibia rupture strength). Canthaxanthin associated with 25-OH-D3 in broiler diets improves bird performance and bone strength.

Accuracy of genomic selection for reducing susceptibility to pendulous crop in turkey (Meleagris gallopavo)

Pendulous crop (PC) in the turkey occurs when the crop distends from its normal position, thereby preventing the movement of feed and water from the crop down into the digestive system. This condition negatively impacts the turkey industry at both production and welfare levels. In this study, we estimated the genetic parameters for PC incidence and its genetic correlation with 5 production traits. Additionally, we evaluated the prediction accuracy and bias of breeding values for the selection candidates using pedigree (BLUP) or pedigree-genomic (ssGBLUP) relationships among the animals. A total of 245,783 turkey records were made available by Hybrid Turkeys, Kitchener, Canada. Of these, 6,545 were affected with PC. In addition, the data included 9,634 records for breast meat yield (BMY); 5,592 records for feed conversion ratio (FCR) and residual feed intake (RFI) in males; 170,844 records for body weight (BW) and walking score (WS) between 18 and 20 wk of age for males (71,012) and females (99,832), respectively. Among this population, 36,830 were genotyped using a 65K SNP Illumina Inc. chip. While all animals passed the quality control criteria, only 53,455 SNP markers were retained for subsequent analysis. Heritability for PC was estimated at 0.16 ± 0.00 and 0.17 ± 0.00 using BLUP and ssGBLUP, respectively. The incidence of PC was not genetically correlated with WS or FCR. Low unfavourable genetic correlations with BW (0.12 and 0.14), BMY (0.24 and 0.24) and RFI (−0.33 and −0.28) were obtained using BLUP and ssGBLUP, respectively. Using ssGBLUP showed higher prediction accuracy (0.51) for the breeding values for the selection candidates than the pedigree-based model (0.35). Whereas the bias of the prediction was slightly reduced with ssGBLUP (0.33 ± 0.05) than BLUP (0.30 ± 0.08), both models showed a regression coefficient lower than one, indicating inflation in the predictions. The results of this study suggest that PC is a heritable trait and selection for lower PC incidence rates is feasible. Although further investigation is necessary, selection for BW, BMY, and RFI may increase PC incidence. Incorporating genomic information would lead to higher accuracy in predicting the genetic merit for selection candidates.

Nutritional requirement of tryptophan for meat-type Japanese quails: Performance and carcass attributes

Tryptophan (Trp) as an essential amino acid for monogastric animals and preweaning ruminants plays crucial roles in physiological responses. An experiment was conducted to estimate the Trp requirements of quail chicks for optimum performance including body weight gain (BWG) and feed conversion ratio (FCR), and carcass attribute by different regression models. A total of 420, 21-day-old quail chicks were randomly allotted to one of seven experimental diets containing 2.12, 2.25, 2.38, 2.51, 2.64, 2.77, and 2.90 g Trp/kg from d 21 to 35. The treatments had 4 pen replicates and 15 birds each. Feed intake showed linear (P = 0.071) and quadratic (P = 0.078) increasing trend with increasing dietary levels of Trp during the whole of experiment. Feed conversion ratio, BWG, breast meat yield (BMY), thigh meat yield (TMY), edible section (ES) responded linearly or quadratically to graded levels of dietary Trp (P < 0.05). Regarding data structure in different regression models, the statistical evaluation of the models including one-slope broken line, two-slope broken line, and composite desirability function (D) as multi-criteria approach, was done by considering high R2, root mean square error (RMSE), and low standard deviation of residual (Sy.x) of the model. Based on statistical merit, the estimated Trp requirements of BWG, FCR, ES, BMY, and TMY were estimated as 2.68, 2.35, 2.69, 2.53, and 2.64 g Trp/kg of diet from 21 to 35 d. According to the D in order to get single value of Trp requirement for maximum BWG and minimum FCR, the optimized estimation of dietary Trp was 2.77 g/kg of diet. This study shows the importance of analysis methods used for requirement. The relative higher Trp needs of growing Japanese quails than that recommended by NRC (1994) call more attention while feed formulation for modern strains of Japanese quails.

Refining the Diagnosis of Growth-Related Muscle Abnormalities in Chickens Based on the Nomenclature Used to Characterise Human Myopathies.

Although worldwide poultry meat consumption is increasing, growth-related muscle abnormalities represent a limitation to the sustainability of chicken meat production due to their significant economic consequences and unfavourable impact on product quality and social acceptability (Kuttappan et al., 2012b). Several abnormalities have already been described in modern broiler strains, but there has been a notable increase in the prevalence of white striping (WS) and wooden breast (WB) syndromes over the past decade. Briefly, the WS defect corresponds to the appearance of white streaks mainly on the Pectoralis Major (PM) muscle of the fillet (Kuttappan et al., 2012b), while the WB defect corresponds to a hard, bulging PM muscle with a slimy appearance and petechiae in the most severe cases (Sihvo et al., 2014). Several studies have shown that rapid growth, high slaughter weight and breast meat yield as well as limited muscle glycogen store contribute to increase the incidence of such breast muscle abnormalities (Kuttappan et al., 2013a; Abasht et al., 2016; Alnahhas et al., 2016; Kawasaki et al., 2018. In recent years, many studies have been carried out to understand the molecular mechanisms underlying the development of breast muscle abnormalities in broiler. Muscle histological characterizations have allowed a detailed description of injuries associated with the abnormalities. Combined with high-throughput molecular studies, they have speed up the understanding of the biological processes involved in their establishment (for review, Soglia et al., 2021). In particular, these studies have shown that WS and WB muscle abnormalities share several histological features with human myopathies (Dubowitz et al., 2020) that could be used for their diagnosis (Praud et al., 2020). The purpose of this opinion paper is to highlight the importance of using current knowledge on human myopathies and existing nomenclature used by muscle pathologists to accurately interpret histological observations of chicken muscle abnormalities and thus improve their diagnosis.

Classic and Non-Classic Effects of the Duration of Supplementation of 25-Hydroxicholecalciferol in Broiler Chicken Diets.

Simple SummaryGenetic programs of modern commercial-type broiler chickens are based on growth performance parameters associated with muscular growth, feed efficiency, and meat and breast yield. Therefore, highly bioavailable vitamin D3 to sustain optimal muscle and bone development is necessary. In the present study the effect of different durations of supplementing of 25-hydroxycholecalciferol (25(OH)D3) in broiler chickens was evaluated. Growth performance response, carcass and cuts yield, bone resistance, plasma concentration of 25(OH)D3, and expression of the mTOR gene were evaluated. The use of 25(OH)D3 in the diets for broilers during different feeding periods did not influence growth performance but increased the plasma concentration of 25(OH)D3, and increased breast yield as the duration of the supplementation was extended. The supplementation of 25(OH)D3 increased breast yield and protein deposition in the breast muscle which may have been a result of the epigenetic changes caused by this vitamin D (Vit D) metabolite.The present study aimed to determine the effect of different times of supplementation of 25-hydroxycholecalciferol (25(OH)D3) in broiler chickens on the performance, carcass and cuts yield, bone resistance, plasma concentration of 25(OH)D3, and expression of the mTOR gene. The treatments were a control diet (CD) supplemented with 3000 IU vitamin D3/kg of feed from 1 to 46 d, or the CD + 2760 IU (69 mcg) of 25(OH)D3/kg of feed from 1 to 21 d, from 1 to 35 d, or from 1 to 46 d. The period of supplementation of 25(OH)D3 did not affect the growth performance of broilers, but the breast meat yield was linearly increased in response to increasing days of supplementation (p < 0.05). Birds supplemented with 25(OH)D3 at the time of the analysis showed an increase (p < 0.05) in the plasma concentration of 25(OH)D3 when compared to non-supplemented birds. The mTOR gene expression (p < 0.05), and breast protein deposition (p < 0.05) presented a quadratic response related to the supplementation period of 25(OH)D3. The fat content of the breast linearly decreased (p < 0.05) as the period of supplementation was extended. The results also showed a positive linear correlation between mTOR expression and 25(OH)D3 plasma levels (r = 0.593; p < 0.05).

Culinary preparation and processing of meat with wooden breast myopathy

Recently, poultry meat production and consumption has become increased worldwide. Decades of intensive selection in poultry breeding resulted in fast-growing broilers, improved food conversion, low production costs, and high yield of breast meat, as the most valuable part of the carcass. Some side-effects of intensive production and rapid growth of broilers include the appearance of myopathies in breast muscle. Increasing attention has been paid to the defect known as "wooden breast" (WB) due its incidence and severity of anomaly. WB is characterized by the hardness and pale colour of the fillet. These changes lower the consumer acceptance of the meat, and a pronounced WB is unsuitable for culinary and industrial processing. Different procedures can be used to tenderize the meat and include physical and chemical procedures, often combined in industry. Physical procedures comprise the application of heating, mechanical force, ultrasound, electric stimulation, hydrodynamic shock wave-pressure technology, high pressure processing, and pulsed electric field. Chemical procedures include marinating, exposure to the endogenous enzymes, and the use of exoenzymes. In the future, it is necessary to develop optimal tenderizing techniques or combinations of different tenderizing techniques to achieve better sensory quality and improved nutritional value of WB.

Effects of Pantothenic Acid Supplementation on Growth Performance, Carcass Traits, Plasma Parameters of Starter White Pekin Ducks Fed a Corn-Soybean Meal Diet.

Simple SummaryThe yield of meat duck has increased over the past decade. Precise nutrition of ducks would contribute to improve growth performance and feed efficiency. As one of the important B-vitamins, pantothenic acid is essential for animals, and the deficiency of this vitamin could lead to growth depression, high mortality, and abnormal glucose metabolism. Similarly, pantothenic acid is also needed for ducks. The objectives of this study were to evaluate the effects of dietary pantothenic acid levels on growth performance, carcass traits, and plasma biochemical parameters of ducks, as well as the pantothenic acid requirement of ducks based on conventional corn–soybean meal diets. The results showed that among all ducks, the birds fed the basal diet without pantothenic acid supplementation had the lowest growth performance, breast meat yield, and plasma pantothenic acid and glucose contents. In addition, all these parameters increased linearly or quadratically as the dietary pantothenic acid level increased. The pantothenic acid requirements of starter male white Pekin ducks were 13.29–15.0 mg/kg. The data potentially provides theoretical support for the utilization of pantothenic acid in duck production.This study aimed to evaluate the effects of different dietary pantothenic acid levels on growth performance, carcass traits, and plasma biochemical parameters of starter Pekin ducks from 1 to 21 days of age, as well as the pantothenic acid requirement of starter ducks. A total of 384 one-day-old male white Pekin ducklings were assigned randomly into 6 dietary treatments, each with 8 replicate pens of 8 ducks. Ducks were fed conventional basal corn–soybean diets containing 8.5, 10.5, 12.5, 14.5, 16.5, and 18.5 mg/kg pantothenic acid for 21 days. Growth depression, poor pantothenic acid status, fasting hypoglycemia, and elevated plasma uric acid (UA) content were observed in the ducks fed the pantothenic acid-deficient basal diet (p < 0.05), and these adverse effects were ameliorated by pantothenic acid supplementation. Among all ducks, the birds fed the basal diet with no supplementation of pantothenic acid had the lowest body weight, average daily weight gain (ADG), average daily feed intake (ADFI), breast meat yield, and plasma pantothenic acid and glucose contents (p < 0.05), and the greatest plasma UA content (p < 0.05). In addition, all these parameters showed a linear or quadratic response as dietary pantothenic acid levels increased (p < 0.05). According to broken-line regression, the pantothenic acid requirements of starter male white Pekin ducks for body weight, ADG, and plasma pantothenic acid content were 13.36, 13.29, and 15.0 mg/kg, respectively. The data potentially provides theoretical support for the utilization of pantothenic acid in duck production.

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.

Effects of feed restriction on the occurrence of white striping and wooden breast myopathies, performance, carcass characteristics and some blood parameters in broiler chickens

This study was planned to determine the effects of feed restriction applied at different times and levels on the occurrence of white striping and wooden breast myopathies, performance, carcass characteristics and some blood parameters in broilers. In total, 600 male broilers were randomly placed to 5 groups with eight replicates. Control group was fed ad libitum throughout experimental period. T1 and T2 groups received feed as 80% and 70% of control group from 11 to 24 days of age, respectively. T3 and T4 groups received feed as 80% and 70% of control group from 25 to 39 days of age, respectively. T2, T3 and T4 groups had the lower mean values for feed intake and body weight gain from 0 to 49 days of age, final body weight, carcass weight, serum alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) levels, compared to control group. T3 and T4 groups had lower dressing percentage, breast meat yield, serum aspartate aminotransferase (AST) and creatine kinase (CK) levels than control. T2, T3 and T4 groups had lower incidence for white striping and wooden breast myopathies than control. T3 and T4 groups had also the lower incidence for severe degree white striping and wooden breast myopathies than control. In conclusion, feed restriction to 70% of ad libitum intake between 11 and 24 days of age and feed restriction to 80% and 70% of ad libitum intake between 25 and 39 days of age may reduce the incidence and severeness of white striping and wooden breast myopathies, although there is some loss in performance traits. Feed restrictions to 80% and 70% levels of ad libitum intake between 25 and 39 days of age may be more effective in reducing these myopathies on pectoralis major muscle of broilers.

Effect of methionine chelated Zn and Mn and corn particle size on Large White male turkey live performance and carcass yields

Most turkey research has been conducted with a regular corn particle size set through phase-feeding programs. This study's first objective was to determine the effect of increasing corn particle size through the feed phases on performance, processing yield, and feed milling energy usage in Large White commercial male turkey production. Zinc (Zn) and manganese (Mn) are essential microminerals for animals' healthy growth. The source in which these elements are supplied to the bird will determine their bioavailability, effect on bird growth, and subsequent environmental impact. This study's second objective was to measure both inorganic and chelated Zn and Mn sources on turkey performance, turkey carcass processing yields, and subsequent litter residues. Twelve hundred Nicolas Select male poults were randomly assigned to 48 concrete; litter-covered floor pens. The experimental design was a completely randomized block design with a 2 × 2 factorial arrangement of 2 sources of minerals (organic blend vs. inorganic) formulated to match breeder recommendations and 2 types of corn mean particle size (coarse corn [1,000–3,500 µm] vs. fine corn [276 µm]). The ASABE S319.4 standard was used to measure corn mean particle size. Bird performance, carcass processing yield, litter content of Zn and Mn, and pellet mill energy consumption were analyzed in SAS 9.4 in a mixed model. There was a reduction of pellet mill energy usage of 36% when coarse corn was added post-pelleting. Birds fed increasing coarse corn mean particle size were 250 g lighter on average in body weight (BW) than birds fed a constant control mean particle size. No difference was found in feed intake (FI) or feed conversion ratio (FCR). Birds fed methionine chelated Zn and Mn blended with inorganic mineral sources were 250 g heavier on average than birds fed only an inorganic source of minerals. In addition, feeding an organic blend of Zn and Mn resulted in greater breast meat yield. Litter from birds fed the control corn mean particle size, and inorganic minerals had a higher concentration of Zn in the litter but were not different when the chelated Zn/Mn were fed. In conclusion, increasing the corn mean particle size and adding it post pellet could save money during feed milling; however, birds might have a slightly lower BW. A combination of inorganic and chelated Zn and Mn may improve performance and increase total breast meat yields.

Effects of the in ovo injection of vitamin D3 and 25-hydroxyvitamin D3 in Ross 708 broilers subsequently challenged with coccidiosis. I. performance, meat yield and intestinal lesion incidence1,2,3

Effects of the in ovo administration of vitamin D3 (D3) and 25-hydroxyvitamin D3 (25OHD3) on broiler intestinal lesion incidence, performance and breast meat yield after a coccidiosis challenge were investigated. On each of 10 incubator tray levels, 10 Ross 708 broiler hatching eggs were randomly assigned to each of the following 5 in ovo injection treatments administrated at 18 d of incubation (doi): 1) noninjected; 2) diluent; diluent containing either 3) 2.4 μg D3 (D3), 4) 2.4 μg 25OHD3 (25OHD3), or 5) 2.4 μg D3 + 2.4 μg 25OHD3 (D3+25OHD3). A 50 μL solution volume was injected into each egg using an Inovoject multi-egg injector. Four male chicks were randomly assigned to each of 80 battery cages in each of 2 rooms. Half of the treatment-replicate cages (8) in each room were challenged with a 20× live coccidial vaccine at 14 d of age (doa). One randomly selected bird from each of 4 treatment-replicate cages was scored for coccidiosis lesions before and 2 wk after challenge. Mean BW, BW gain (BWG), feed intake, and feed conversion ratio were determined for all birds from 0 to 14, 15 to 28, and 29 to 41 doa. Carcass weight, and the absolute and relative (% of carcass weight) weights of carcass parts were determined in 3 birds per treatment-replicate cage at 42 doa. Hatchability of live embryonated injected eggs and hatch residue were not affected by treatment. Across challenge treatment, birds in the 25OHD3 treatment group experienced an increase in BWG between 29 and 41 doa when compared to the D3 or diluent-injected birds. Furthermore, pectoralis major muscle percentage tended (P = 0.059) to increase in birds belonging to the 25OHD3 treatment in comparison to birds in the D3 or diluent-injected treatments. These results indicate that regardless of challenge treatment, 2.4 μg of 25OHD3 may increase the BWG and breast meat yield of birds relative to those that only received an injection of commercial diluent.

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

Effect of Incorporating Early Feather Restriction Gene (KS) From Native Chicken to Purebred Chicken

Fast growing chicken suffers more in a hot humid condition than a slow growing one. The slow feathering affects the insulation mechanism of the chicken, thus enhance birds ability to dissipate heat during heat stress to a greater extent. As a consequence, slow feathered birds are more adaptive to hot humid environmental conditions. This study was undertaken to investigate the effect of incorporating early feather restriction gene (KS) in exotic population. A total of 34 slow feathered (SF) native chicks with KS gene of 28-day-old were collected from different villages and markets and were reared up to sexual maturity. After attaining sexual maturity, 2 males and 8 females of SF native chicken were randomly chosen to make a di-allelic cross with rapid feathered (RF) Rhode Island Red (RIR) and Fayoumi (FY). The crossbred progeny of each cross were reared up to 105 days to assess growth, survivability, heat tolerance and carcass yield under hot humid Bangladeshi condition. The collected data were arranged in a 3(genotype)×2(feather pattern)×9(age) factorial experiment in a Completely Randomized Design (CRD) and analyzed by SAS. Among genotypes, the highest survivability was obtained in Desi×Fayoumi (96.7%) and in SF chicks (96.1%) and the lowest in Desi×RIR (91.5%) and in RF chicks (90.5%). The SF chicks exhibited an average 8% heavier live weight than that of their RF counterparts. The cloacal temperature varied among genotypes and between feathering patterns (FP); being highest in Desi×RIR (430C) and in RF chicks (41.60C) and lowest in RIR×Desi (400C) and in SF chicks (41.40C). In case of Desi×RIR, RIR×Desi and Desi×Fayoumi, cloacal temperature increased linearly by 0.047, 0.044 and 0.0320C for each gram of live weight increase. Further, the cloacal temperature increased linearly by 0.036 and 0.0440C for the increase of each gram of live weight gain in case of RF and SF chicks, respectively. There was no significant (P&gt;0.05) difference of dressing percentage for the effect of either genotype or FP (55.4% for SF vs. 46.6% for RF birds). Genotype and FP had significant effects (P&lt;0.05; P&lt;0.01) on total meat yield; being highest in Desi×RIR (24.6%) and in SF birds (26.2%) and lowest in Desi×Fayoumi (21.4%) and in RF birds (20.6%). Breast meat yield of SF birds (9.2%) was significantly (P&lt;0.01) higher than that of RF birds (7.1%). The highest thigh meat yield was obtained in Desi×RIR (7.6%) and in SF birds (8.3%) and the lowest in Desi×Fayoumi (6.7%) and in RF counterparts (6.0%). The highest drumstick meat yield was obtained in RIR×Desi (5.6%) and in SF birds (5.9%) and the lowest in Desi×Fayoumi (5.0%) and in RF birds (4.8%). Genotype and FP had significant interaction effect on total meat yield as well as fractional meat yields. The study revealed that incorporation of ‘Ks’ gene in the exotic one by crossing with native chicken and rearing under hot humid environment may be a means of improving growth, survivability, heat tolerance and carcass yield.

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

Simple SummaryA 42-day feeding trial was carried out in a commercial research institution to determine the efficacy of two bioactive protein products, betaGRO® (BG) and celluTEIN® (CT). The birds were grown under two different environments. One was a low stress environment using clean wood shavings, while the other was a high stress environment where used wood shavings were obtained from a commercial farm that had suffered high mortality to simulate a commercial environment. Growing birds in the high stress environment had a negative impact upon overall bird performance; however, the addition of either BG or CT successfully mitigated these detriments. Improvements in 42-day body weight and feed conversion were observed in chicks grown in both environments in response to the addition of either BG or CT. Birds fed BG and CT were more uniform than birds grown on control diets. Mortality of birds in the high stress environment was significantly reduced by the addition of BG or CT. Addition of BG and CT resulted in improvements in total carcass yield and breast meat yield. This was observed under both environmental conditions, and in a similar magnitude for both products.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.

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 to 12 pens over 2 to 3 production cycles. From each pen, 4 males and 4 females were processed at 2 Target Weights (TWs) 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 as 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.

Determination of the optimum digestible isoleucine to lysine ratios for male Yield Plus × Ross 708 broilers between 1.0 and 4.0 kg body weight utilizing growth performance and carcass characteristics

Three experiments (Exp) were conducted to determine optimal digestible Ile to Lys ratios for male Yield Plus × Ross 708 broilers from approximately 1.0 to 4.0 kg BW. Broilers were fed dose-response diets with inclusions of blood cells that were formulated to contain a gradient of digestible Ile to Lys ratios (0.46 to 0.83). Treatments for Exp 1 to 3 were fed from 21 to 35, 28 to 42, and 35 to 49 d of age, respectively, to target market weights from 2.5 to 4.0 kg. Experiments utilized positive control (PC) diets that did not contain blood cells and were formulated to the same Ile ratios as Treatment 5. Birds and feed were weighed by pen on the first and last days of the experimental period to determine growth performance. Selected broilers were processed and deboned to determine carcass characteristics. For all Exp, quadratic effects (P ≤ 0.001) were observed with BW gain, feed conversion ratio (FCR), breast meat weight, and breast meat yield (BMY) as digestible Ile to Lys ratios increased. Contrasts between PC and Treatment 5 for each Exp displayed no effect of blood cell inclusion with the exception of FCR in Exp 1 (P = 0.001) and BMY in Exp 3 (P = 0.017). Optimum digestible Ile to Lys ratios for Exp 1 were determined to range from 0.640 to 0.725 for growth from 1.0 to 2.5 kg BW (P ≤ 0.001) and breast meat characteristics. In Exp 2, optimum ratios ranged from 0.664 to 0.682 for growth and breast meat characteristics from 1.6 to 3.1 kg BW (P ≤ 0.001). For growth and breast meat characteristics of broilers in Exp 3, optimum ratios ranged from 0.625 to 0.730, from 2.6 to 3.9 kg BW (P ≤ 0.001). Based on these findings, optimum digestible Ile to Lys ratios were determined to range from 0.63 to 0.73 for broilers from 1.0 to 4.0 kg BW.