Breast Muscle Percentage Research Articles

Effects of low crude protein content and glycine supplementation on broiler chicken performance, carcass traits, and litter quality.

• Low-protein diets decreased broiler chicken performance from 10 to 42 d of age. • The use of Gly in low protein diets did not improve broiler chicken performance. • The use of Gly in low protein diets increased broiler chicken meat quality. The objective of this experiment was to investigate the effects of crude protein (CP) content with or without Gly supplementation on performance, carcass traits, and litter quality of broiler chickens. One-day-old male broiler chickens were fed isoenergetic diets and were assigned to 5 treatments (12 replicates; 8 broiler chickens/replication). The CP content was different among treatments (starter diet from 22% to 19%, grower diet from 20% to 17%, finisher diet from 18% to 15%). The lowest CP concentration in diets has occurred in treatments 4 and 5, while the CP concentrations in diets in treatments 1, 2, and 3 were greater. Diet from treatment 5 was supplemented with Gly. During the starter period, there were no differences in performance among treatments. In the grower, finisher, and in whole periods, the reduction in CP concentration lowered the broiler chicken performance, regardless of supplementation of Gly in comparison to control treatment in which the protein content has not been decreased ( P < 0.05). The reduction in CP in diets also decreased breast muscles, however, the supplementation of Gly decreased fat deposition and increased carcass weight ( P < 0.05). The reduction in CP in diets affected improvement litter quality (litter dry matter and N content) ( P < 0.05) and also decreasing blood urea N content in litter ( P = 0.066). Results indicate that a decrease of CP in diets influenced negatively performance (body weight gain, feed intake, and feed conversion ratio) of broiler chickens (except starter period), percentage of breast muscles, and percentage of abdominal fat. The use of synthetic Gly did not improve broiler chicken performance, however increased carcass quality by reducing fatness.

Effect of yeast culture supplementation on blood characteristics, body development, intestinal morphology, and enzyme activities in geese.

The objective of this experiment is to evaluatethe effects of yeast culture (YC) supplementation on blood characteristics, body size, carcass characteristics, organ weights, intestinal morphology, and enzyme activities. Five groups of geese were randomly assigned to five dietary treatments: the basal diet (control) and basal diets plus 0.5%, 1.0%, 2.0%, or 4.0% YC. Compared with the controls, YC supplementation at 0.5% and 1.0% increased the serum total protein (TP), albumin (ALB), and globulin (GLO) and decreased the uric acidand creatine kinase (CK) contents (p < 0.05). YC supplementation at 2.0% and 4.0% increased the CK, growth hormone, catalase and glutathione reductase contents, and relative proventriculus weights, and decreased the TP, ALB, and GLO contents, relative liver, gizzard, jejunum, ileum, and thymus weights (p < 0.05). YC supplementation at 2.0% improved fossil bone length, breast muscle percentage, jejunal villus height, ileal and jejunal villus height/crypt depth ratios, pepsin, lipase, amylase and pancreatic trypsin activities, and decreased abdominal fat percentage (p < 0.05). Furthermore, YC inclusion increased the body slope length (linear, p = 0.002; quadratic, p = 0.02), breast width (quadratic, p = 0.02), ileal (linear, p = 0.04; quadratic, p = 0.01) and duodenal villus height (cubic, p = 0.04), and decreased the relative gizzard (quadratic, p = 0.04) and thymus (linear, p = 0.002; quadratic, p = 0.02; cubic, p = 0.02) weights, liver (linear, p = 0.002; quadratic, p = 0.02), and serum (linear, p = 0.006; quadratic, p = 0.03) malondialdehyde contents, and jejunal crypt depth (quadratic, p = 0.03). The findings indicated that the YC supplementation had a positive effect on the growth and development of geese, with 2% YC being the most effective.

Assessment the effect of genomic selection and detection of selective signature in broilers

Due to high selection advances and shortened generation interval, genomic selection (GS) is now an effective animal breeding scheme. In broilers, many studies have compared the accuracy of different GS prediction methods, but few reports have demonstrated phenotypic or genetic changes using GS. In this study, the paternal chicken line B underwent continuous selection for 3 generations. The chicken 55 k SNP chip was used to estimate the genetic parameters and detect genomic response regions by selective sweep analysis. The heritability for body weight (BW), meat production, and abdominal fat traits were ranged from 0.12 to 0.38. A high genetic correlation was found between BW and meat production traits, while a low genetic correlation (<0.1) was found between meat production and abdominal fat traits. Selection resulted in an increase of about 516 g in BW and 140 g in breast muscle weight. Percentage of breast muscle and whole thigh were increased 0.8 to 1.5%. No change was observed in abdominal fat percentage. The genomic estimated breeding value advances was positive for BW and meat production (except whole thigh percentage), while negative for abdominal fat percentage. By selective sweep analysis, 39 common chromosomal regions and 102 protein coding genes were found to be influenced, including MYH1A, MYH1B, and MYH1D of the MYH gene family. Tight junction pathway as well as myosin complex related terms were enriched. This study demonstrates the effective use of GS for improvements in BW and meat production in chicken line B. Further, genomic regions, responsive to intensive genetic selection, were identified to contain genes of the MYH family.

Including dominance effects in the prediction model through locus-specific weights on heterozygous genotypes can greatly improve genomic predictive abilities

The dominance effect is considered to be a key factor affecting complex traits. However, previous studies have shown that the improvement of the model, including the dominance effect, is usually less than 1%. This study proposes a novel genomic prediction method called CADM, which combines additive and dominance genetic effects through locus-specific weights on heterozygous genotypes. To the best of our knowledge, this is the first study of weighting dominance effects for genomic prediction. This method was applied to the analysis of chicken (511 birds) and pig (3534 animals) datasets. A 5-fold cross-validation method was used to evaluate the genomic predictive ability. The CADM model was compared with typical models considering additive and dominance genetic effects (ADM) and the model considering only additive genetic effects (AM). Based on the chicken data, using the CADM model, the genomic predictive abilities were improved for all three traits (body weight at 12th week, eviscerating percentage, and breast muscle percentage), and the average improvement in prediction accuracy was 27.1% compared with the AM model, while the ADM model was not better than the AM model. Based on the pig data, the CADM model increased the genomic predictive ability for all the three pig traits (trait names are masked, here designated as T1, T2, and T3), with an average increase of 26.3%, and the ADM model did not improve, or even slightly decreased, compared with the AM model. The results indicate that dominant genetic variation is one of the important sources of phenotypic variation, and the novel prediction model significantly improves the accuracy of genomic prediction.

Effects of different intermittent illumination patterns on production performance of slow growing type Yellow chickens

Abstract The objective of this study was to investigate the effects of intermittent illumination around noontime on the F line of slow growing line of Yellow chickens. The chickens were randomly divided into three groups of 70 roosters and 100 hens kept under three different illumination patterns. Group I was the control group (16 h of illumination at 10 lux). After day 21, in group II the light was additionally turned off during noon from 12:00–13:00 and in group III from 12:00–14:00 based on the lighting schedule of group I. The results showed that there was no significant difference in body weight (BW) between the three groups during the first 21 days ( p> 0.05). On day 42, BW of roosters and hens in group II was 35.2 g/21.7 g and 39.7 g/27.3 g higher than that of those in groups I and III ( p< 0.05), but there were no significant differences between group I and III ( p> 0.05). Oblique body length and shank length of group II were significantly higher than in groups I and III (p<0.05). After day 43, feed conversion ratio of group II was significantly higher than in groups I and III (p < 0.05). Comb perimeter, area and vertical area of group I were significantly higher than in groups II and III, and in group II these parameters were significantly higher than in group III (p<0.05). Slaughtering weight and breast muscle percentage of group II were significantly higher than in groups I and III, leg muscle percentage was significantly lower in group III ( p< 0.05) compared with the other groups. On day 84, there were no significant differences in blood indices (IGF-1, growth hormone, testosterone) or meat quality indices (flesh colour, shear force, PH, and water-holding capacity) between the three groups ( p> 0.05), but some indicators in group II showed an increasing trend. Based on these results, the intermittent light pattern of group II not only saved electrical energy and diet resources but also improved some indices of production performance.

Effects of dietary oligosaccharides on serum biochemical index, intestinal morphology, and antioxidant status in broilers.

In order to determine the effect of different oligosaccharides on growth performance, intestinal health, and antioxidant status of broilers, 240 1-day-old XiangHuang broilers were randomly distributed to 4 treatments with 6 replicates each. Birds were fed corn-soybean-based diets (CON), and birds in xylo-oligosaccharides (XOS), fructo-oligosaccharides (FOS), and iso-maltooligosaccharide (IMO) groups were given the basal diet supplemented with 200 mg/kg XOS, FOS, and IMO, respectively. Result showed that average daily gain (ADG) during the whole 5weeks in FOS group was greater than that in control group (p < 0.05). Both breast and thigh muscle percentages were higher for birds fed XOS versus CON (p < 0.05). Oligosaccharides supplementation increased jejunal villus height compared with control group (p < 0.05). Malondialdehyde (MDA) concentration in breast muscle was lower for birds fed diet containing FOS versus CON (p < 0.05). Activities of total superoxide dismutase (T-SOD) in serum and thigh muscle were higher in IMO than in control group (p < 0.05). Serum T-SOD and breast muscle's glutathione peroxidase (GSH-Px) activity was higher in XOS compared with control group (p < 0.05). Conclusion, dietary oligosaccharides such as XOS, FOS, and IMO could improve intestinal health and antioxidant ability of muscle without affect growth performance in broilers.

Effect of the Biologically Produced Nanoselenium Dietary Supplementation on Growth Performance, Carcass Characteristics, Blood Parameters, and Economic Efficiency in Broiler Chickens

This study evaluates the impacts of the produced nano selenium (SeNPs) products using lactic acid bacteria (LAB) as an alternative to the imported commercial organic selenium (Sel-Plex) as a source of Se dietary supplement on growth efficiency, carcass traits, blood parameters and economic efficiency in mixed‐sex Cobb500 broiler. A total of 480 one‐day‐old mixed‐sex Cobb500 broiler grown over a 35‐days period were allocated into three treatments with four replicates (n = 40). Chicks in the control group were fed commercial diets. The chicks of the second and third groups control diets supplemented with 0.3 mg/kg of either nano selenium (SeNPs) product or commercial organic selenium (Sel-Plex). Chicks fed a diet containing nano selenium diet (SeNPs) recorded significantly the highest final body weight, while those fed control diet recorded significantly the lowest final body weight (2132.2 vs. 1996.1 g, p &lt; 0.05). Chicks fed with diet of SeNPs showed the highest significantly breast muscle percentage, whereas there were no major variations between those fed the control and the Sel-Plex diets. Plasma total protein, albumin, globulin, A/G ratio and total lipids were not significant differences due to dietary selenium source. There were no substantial effects on all hematological parameters by nano or organic selenium in compared to control diet. In conclusion, the results confirmed that feeding broiler chicks on SeNPs form with the 0.3 Se mg/kg of feed enhanced growth performance and had no adverse effect on carcass markers and blood parameters.

The effect of light intensity on the body weight, keel bone quality, tibia bone strength, and mortality of brown and white feathered egg-strain pullets reared in perchery systems

The development of the musculoskeletal system is influenced by bird activity, which can be impacted by light intensity (L). The objective of this study was to determine the effect of L on the growth and bone health of Lohmann Brown-Lite (LB) and Lohmann LSL-Lite (LW) pullets. Three L treatments (10, 30 or 50 lux, provided by white LED lights) were used in a Randomized Complete Block Design in 2 repeated trials. LB and LW (n = 1,800 per strain [S]) were randomly assigned to floor pens (50 pullets per pen; 12 pen replicates per L × S) within 6 light-tight rooms from 0 to 16 wk. Each pen contained 4 parallel perches and a ramp. Data collected include cumulative mortality, BW at 0, 8, and 16 wk, and uniformity, keel bone damage (KBD; deviations, fractures), breast muscle weight, and tibiae bone strength at 16 wk. Tibiae bone resistance to mechanical stress was assessed using a three-point-bending test. The effect of L, S, and their interactions were analyzed using Proc Mixed (SAS 9.4) and differences were considered significant when P < 0.05. L did not affect BW, KBD, or mortality. An interaction between L and S was observed for bone stress (bone strength relative to bone size), however, in general, LW pullets had greater resistance to bone stress (peak noted at 30 lux) than LB (peak at 50 lux). LB pullets were heavier than LW at 8 and 16 wk. There were no S differences on KBD from palpated or dissected keel bones. LB pullets had higher breast muscle weight and heavier tibiae than LW, however relative to BW, LW had a higher percentage of breast muscle and a longer and thicker tibiae than LB. LW had higher mortality during the first wk but there was no relationship to L. Conclusively, the results suggest that L, within a range of 10 to 50 lux, does not affect pullet BW or KBD, however S may affect both parameters, as well as bone strength.

Effects of rearing system (floor vs. cage) and sex on performance, meat quality and enteric microorganism of yellow feather broilers

This study investigated the effects of floor and cage rearing systems on performance, meat quality, and enteric microorganisms of male and female yellow feather broilers. Two hundred Xueshan chickens (42 days old; 100 of each sex) were divided into four groups, according to sex and rearing system (stainless-steel cage or litter floor). Male and cage-reared broilers exhibited better (P<0.001) performance and higher (P≤0.001) eviscerated percentage than female and floor-reared broilers. The interaction between rearing system and sex had an effect (P<0.05) on the percentage of breast and thigh muscles. Female floor-reared broilers presented the highest (P<0.02) percentage of breast and thigh muscles among all the groups. In both sexes, the abdominal fat content in cage-reared broilers was higher (P<0.01) than that in floor-reared broilers. Female cage-reared broilers exhibited better (P<0.05) meat quality of breast muscle than other groups. An analysis of welfare observations indicated that the feather quality of floor-reared broilers was better (P<0.01) than that of cage-reared broilers, whereas the gait scores were not significantly affected (P>0.05) by rearing system. The enteric microbiota assessment by 16S rRNA amplicon-based sequencing showed that Firmicutes, Proteobacteria, and Bacteroidetes were the most prevalent phyla in both rearing systems, and that the cecum was relatively stable in terms of microbiome composition. Floor-reared broilers exhibited a richer diversity of bacteria in the intestinal tract than cage-reared broilers, while alpha diversity was not significantly different (P>0.05) among the groups. The ratio of Bacteroidetes to Firmicutes and the abundance of Helicobacter and Romboutsia could potentially affect the production of broilers. These findings indicate that cage rearing improved the production of male Xueshan broilers, which may be due to the difference in enteric microbiota between cage and floor rearing systems.

Effects of dietary fennel (Foeniculum vulgare Mill.) seed powder supplementation on growth performance, nutrient digestibility, small intestinal morphology, and carcass traits of broilers.

BackgroundWith the increasing demands in livestock and poultry breeding and the growing number of food-borne diseases, it is necessary to practice food safety and develop strategies to produce healthy livestock. Fennel (Foeniculum vulgare Mill.) has been used as an additive in poultry production by some researchers, but there are few studies on the systemic beneficial effects of dietary fennel seed powder supplementation on broilers. Therefore, this study aimed to investigate the effect of dietary fennel seed powder supplementation on feed intake, the apparent metabolic rate of nutrients, intestinal morphology, and carcass traits in Cobb broilers.MethodsA single-factor experimental design was used. In total, 160 1-day-old Cobb broiler chicks were randomly assigned to four treatments, with four replicates each (n = 10/replicate). Broilers in the control (CN) group were fed a basal diet without fennel seed powder, and broilers in the treatment groups were fed a basal diet supplemented with 0.15% (LF), 0.30% (MF), or 0.45% (HF) fennel seed powder, respectively. Feeding trials lasted for 42 days under the conditions of ad libitum access to feed and water, and 24-h illumination. During the third and sixth weeks, digestive and metabolic assays were carried out. When the broilers were 42 days old, one chicken with a weight close to the average was selected from each repetition, euthanized by an intravenous injection of 5% sodium pentobarbital, and carcass traits were measured and intestinal samples were collected for morphological assessment.ResultsThere was no significant difference in growth performance of broilers (P > 0.05). The breast muscle percentage, fat width and fat width index, breast muscle area, and breast muscle area index of broilers in the LF group were higher than those in other groups (P < 0.05). Jejunum weight and length were higher in MF than in CN and LF broilers (P < 0.05). Additionally, duodenal villi height, ileal villi height, and ileal wall thickness were higher in MF than in CN broilers (P < 0.05). There were no significant differences in nutrient utilization among all groups (P > 0.05), except that the ash apparent metabolic rate in MF broilers at 21 days of age was higher than that in LF broilers (P < 0.05). In conclusion, dietary supplementation with a moderate concentration of fennel affects carcass performance, and intestinal morphology, and promotes the growth and development of broilers.

Association analysis of ESR gene polymorphism and carcass traits in egg quails (Coturnix coturnix)

The polymorphism of estrogen receptor (ESR) gene was detected by PCR-RFLP in China yellow, Korean and Beijing white quails and the association between ESR gene polymorphism and carcass traits of egg quails was analyzed. The results showed that there were three genotypes including CC, CT and TT detected in exon 1 and exon 8 of ESR gene in egg quails. The frequencies of CC genotype in exon 1 of ESR gene were the highest in China yellow, Beijing white and Korean quail (0.515, 0.614, 0.723). The highest frequencies of TT genotype in exon 8 of ESR gene were detected in Beijing white and Korean quails (0.618 and 0.540), while the highest frequency of CT genotype was detected in China yellow quail (0.476). As demonstrated in this study, there were significant correlations between exon 1 of ESR gene and body weight, carcass weight, breast muscle weight, heart weight and percentage of leg muscles in egg quails (P&lt;0.05).

Influence of alfalfa meal, as a source of dietary fibre, on growth performance, development, pH of gastrointestinal tract, blood biochemical profile, and meat quality of broilers

ABSTRACT In this study, 192 female broilers (21 days old) were allocated to four dietary treatments: a control diet [CT], and three experimental diets containing 25 g/kg alfalfa meal [AM25], 50 g/kg alfalfa meal [AM50], and 75 g/kg alfalfa meal [AM75]. Final body weight and average daily feed intake of birds were significantly higher in alfalfa supplemented birds, with a linear response to alfalfa inclusion seen for average daily gain (P < 0.05). Serum triglycerides were comparatively lower in AM50 group than in CT group (P < 0.05). The total weight and gastrointestinal tract indices were higher in AM75 and AM50 and sequentially lower in AM25 and CT (P < 0.05). The AM75 and AM50 treatments resulted in significantly lower pH in the duodenum and caecum than in the CT (P < 0.05). The yield percentage of half-eviscerated AM75 chickens was significantly higher than that of CT (P < 0.05). However, breast muscle percentage was significantly lower in AM75 than in CT (P < 0.05). AM diets resulted in an increased yellowness of the muscles. It was concluded that AM improved the growth performance, development of the intestine, and meat yellowness, and reduced the pH of the intestine and serum triglycerides.

Effects of dietary supplementation with fermented Chenopodium album L. on growth, nutrient digestibility, immunity, carcase characteristics and meat quality of broilers

Here, we investigated the effects of fermented Chenopodium album L. (FCAL) on growth performance, apparent total tract nutrient digestibility, serum immunity, carcase characteristics and meat quality of broilers. Arbour Acres broilers (160, 1-d-old) were randomly allocated into four treatment groups with five replicates of eight birds each. The birds were fed a corn–soybean meal basal diet supplemented with 0 (control [CON]), 2, 4 and 8 g/kg FCAL. During the starter period (days 1–21), 4 and 8 g/kg FCAL significantly increased the average daily gain (ADG), apparent digestibility of dry matter (DM), crude protein (CP) and ether extract (EE), moreover; 8 g/kg FCAL significantly decreased the feed conversion ratio (FCR). During the finisher period (days 22–42), 2 g/kg FCAL significantly increased ADG and apparent digestibility of DM, CP and EE but significantly decreased FCR. During the whole period (days 1–42), dietary supplementation of 4 and 8 g/kg FCAL significantly increased ADG. Compared with the CON group, in the FCAL groups, the serum interleukin (IL)-1β and IL-8 levels were lower, while insulin-like growth factor-1, immunoglobulin (Ig) A (IgA) and IgM levels were higher. The serum IL-10 content was lower in the 2 and 4 g/kg FCAL groups. The breast muscle percentage significantly increased with 8 g/kg FCAL. FCAL significantly decreased muscle drip loss (breast), shear force (breast), water loss rate and lightness (leg). FCAL had positive effects on growth, nutrient digestibility, immunity, carcase characteristics and meat quality of broilers, thus it could be a reliable and phytogenic feed additive for promoting growth and maintaining health of broilers. Highlights Fermented Chenopodium album L. (FCAL) can improve growth performance and apparent nutrient digestibility of broilers. FCAL can promote immune responses and enhance carcase characteristics and meat quality of broilers. FCAL could be a reliable and potential phytogenic feed additive to promote growth and maintain the health of broilers.

Supplementation of guanidinoacetic acid and betaine improve growth performance and meat quality of ducks by accelerating energy metabolism

This study was conducted to investigate the effects of guanidinoacetic acid (GAA) and betaine on growth performance, meat quality and metabolism of ducks. A total of 384-one-day-old Cherry Valley meat ducks (55.75 ± 0.55 g) were randomly assigned to four treatments with 6 replicates of 16 ducks. Ducks were fed a basal diet (control) or a test diet supplemented with 0.6 g GAA/kg, 2.0 g betaine/kg, or 0.6 g GAA/kg + 2.0 g betaine/kg. The results showed that compared with the control group, GAA and betaine improved feed conversation ratio from day 1 to 14 and 1 to 35 and body weight at 35 days of age (p < .05). GAA and betaine increased breast muscle percentage while reduced abdominal fat percentage, and drip loss and shear force of breast muscle (p < .05). GAA and betaine lowered free serine, methionine, tryptophan and total amino acid contents in muscles, increased free serine, aspartic acid, phenylalanine and tryptophan contents in plasma (p < .05). There was a synergistic effect on non-esterified fatty acid, lactic acid and uric acid between GAA and betaine. GAA and betaine increased the creatine kinase activity in plasma and creatine and ATP content in breast muscle, decreased the lactate dehydrogenase and L-arginine: glycine amidino transferase activities (p < .05). In conclusion, supplementation of GAA and betaine improved the growth performance and meat quality of ducks by accelerating energy metabolism. There was a synergistic effect on NEFA, LA and UA concentrations in plasma of ducks between GAA and betaine. Highlights Supplementing GAA and betaine improved the growth performance and meat quality of ducks. Adding GAA and betaine accelerated the energy metabolism of ducks. There was a synergistic effect on non-esterified fatty acid, lactic acid and uric acid concentrations in the plasma of ducks between GAA and betaine.

Quercetin Improving Lipid Metabolism by Regulating Lipid Metabolism Pathway of Ileum Mucosa in Broilers.

This study is aimed at evaluating the regulatory mechanism of quercetin on lipid metabolism in the ileum of broilers to better understand these pathways decreasing abdominal fat. 480 chickens were randomly divided into 4 groups (control, 0.02% quercetin, 0.04% quercetin, and 0.06% quercetin). Breast muscle, thigh muscle, and abdominal fat pad were removed and weighed at 42 d of age. Serum was obtained by centrifuging blood samples from the jugular vein (10 ml) to determine high-density lipoprotein (HDL), total cholesterol (TC), low-density lipoprotein (LDL), triglyceride (TG), leptin, and adiponectin using ELISA. About 5 g of the ileum was harvested and immediately frozen in liquid nitrogen for RNA-seq. Then, the confirmation of RNA-seq results by the Real-Time Quantitative PCR (RT-qPCR) method was evaluated using Pearson's correlation. Compared with control, abdominal fat percentage was significantly decreased with increasing quercetin supplementation, and the best result was obtained at 0.06% dietary quercetin supplementation (P < 0.01). Breast muscle percentage was significantly decreased at 0.02% quercetin (P < 0.01), and thigh muscle percentage tended to increase (P = 0.078). Meanwhile, 0.04% and 0.06% quercetin significantly decreased TG (P < 0.01), TC (P < 0.01), and LDL content (P < 0.05) in serum. Serum leptin and adiponectin contents were significantly increased by 0.04% and 0.06% dietary quercetin supplementation, compared with the control (P < 0.01). Analyses of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) database were used to identify differently expressed genes and lipid metabolism pathways. Quercetin decreased abdominal fat percentage through regulating fat digestion and absorption, glycerophospholipid metabolism, AMPK signaling pathway, fatty acid degradation, and cholesterol metabolism.

Slaughter value and meat quality in two strains of polish crested cockerels

With increasing consumer awareness of animal welfare, and also on humanitarian grounds, the search is on to find the possibility of using slow-growing cockerels, which are becoming an alternative for conventional broilers. Therefore, the aim of this study was to evaluate slaughter value and meat quality in two new strains of Polish Crested cockerels: CP-11 (40 birds) and CP-22 (40 birds) which were raised for 25 weeks on a finishing diet based on whole wheat and oat grain. Carcase quality parameters (carcase weight, dressing percentage, leg and breast muscle percentage) were evaluated. Moreover, breast meat parameters (pH24, cooking loss, colour, muscle fibre diameter, sensory traits, chemical composition, fatty acid profile) were determined. The results showed that CP-22 cockerels were characterised by significantly lower carcase weight (p < .05) and significantly higher dressing percentage (p < .05) compared to CP-11 cockerels. Genotype had no significant effect on breast meat quality parameters such as acidity, cooking loss, colour, as well as chemical composition of raw meat, tenderness, texture parameters, and muscle fibre size. On the other hand, breast meat from CP-22 cockerels was characterised by higher aroma desirability (p < .05) as well as higher content of nutritionally desirable fatty acids such as CLA (p < .01), GDLA (p < .01), AA (p < .01), EPA (p < .05), DPA (p < .05) and DHA (p < .01). Summarising, the obtained results indicated that the application of a similar model for the farming and feeding of surplus Polish Crested cockerels will provide a relatively large amount of meat, which can be used in traditional or alternative farming. Highlights The cockerels of both strains exhibited high dressing percentage, their meat had a beneficial chemical composition and delicate texture. Breast meat from CP-22 cockerels was characterised by higher aroma desirability as well as higher content of nutritionally desirable fatty acids. The use of post-production cockerels of the CP-11 and CP-22 strains of Polish crested chickens may be a good choice for organic farming or free range.

Evaluation of Achyranthes japonica Nakai extract on growth performance, nutrient utilization, cecal microbiota, excreta noxious gas emission, and meat quality in broilers fed corn–wheat–soybean meal diet

This study was conducted to investigate the effects of dietary supplementation of Achyranthes japonica Nakai (AJN) extract as a natural feed additive on growth performance, nutrient utilization, cecal microbiota, excreta noxious gas emission, and meat quality in broilers fed corn–wheat–soybean meal diet. In total, seven hundred twenty 1-day-old male Ross 308 broilers with an average body weight (BW) of 43.36 ± 1.42 g were used in a 35-d feeding trial. Broilers were randomly assigned to 1 of the 4 treatments. Each treatment had 10 replication pens with 18 birds per replication. Dietary treatments composed of corn–wheat–soybean meal–based diets along with the addition of 0, 0.025, 0.05, and 0.1% of AJN extract. The BW gain and feed conversion rate were linearly influenced (P < 0.05) by the supplementation of AJN extract during days 8 to 21, 22 to 35, and the overall experiment. At the end of the experiment, the digestibility of dry matter and nitrogen and the population of cecal lactic acid bacteria were linearly improved (P < 0.05) in response to increasing AJN extract supplementation. Excreta emission of ammonia showed a linear decrease (P < 0.05) with the increasing levels of AJN extract. The breast muscle percentage linearly increased (P < 0.05) in birds fed AJN extract contained diets. In summary, the inclusion of AJN extract in corn–wheat–soybean meal diet improved growth performance, nutrient utilization, intestinal microbiota balance, and breast meat production and decreased excreta ammonia emission, which confirmed the applicability of AJN extract as a natural feed additive in broilers.

Carcass Characteristics, Physicochemical Properties, and Texture and Microstructure of the Meat and Internal Organs of Carrier and King Pigeons.

Simple SummaryThe tradition of pigeon meat consumption dates back to ancient civilizations. Today, pigeons are a popular meat in the cuisines of China, North America, North Africa, and some European countries. The aim of this study was to compare carrier pigeons and pigeons of the King breed after three reproductive seasons for carcass weight and measurements, carcass composition, physicochemical characteristics, the texture, rheological properties and microstructure of meat, and some biometric characteristics of the digestive system. Significant differences (p < 0.05) were observed between the pigeon groups in terms of the carcass weight and measurements, carcass composition (except for breast muscle percentage), physicochemical (except for pH24 and redness of breast muscles) textural (except for cohesiveness and shear force), rheological, and microstructural characteristics, and more digestive system characteristics. These differences result primarily from the type of use. King pigeons are raised for meat, and carrier pigeons are used for flying.Pigeons have been the subject of research in the past, but the knowledge gained is incomplete and must be extended. The aim of the study was to provide information about differences in carcass weight and measurements, carcass composition, proximate chemical composition, acidity, electrical conductivity, color attributes, the texture, rheological properties and microstructure of the meat, and some biometric characteristics of the digestive system in carrier and King pigeons, and also to determine if the two compared breeds meet the expectations of pigeon meat consumers to the same extent. The study involved 40 carcasses from carrier pigeons and King pigeons after three reproductive seasons. The chemical composition was determined by near-infrared transmission (NIT) spectroscopy, color coordinates according to CIELab, the texture according to Texture Profile Analysis (TPA) and Warner–Bratzler (WB) tests, and the rheological properties of meat according to the relaxation test. The compared pigeon groups differed significantly (p < 0.05) in carcass weight and measurements, carcass composition (except breast muscle percentage), chemical composition (except leg muscle collagen content) and electrical conductivity, lightness (L*), yellowness (b*), chroma (C*) and hue angle (h*), textural characteristics (except cohesiveness and Warner‒Bratzler shear force), rheological properties, microstructure of the pectoralis major muscle, as well as the total length of intestine and its segments, duodenal diameter, weight of proventriculus, gizzard, liver, heart, and spleen. The sex of the birds had a significant (p < 0.05) effect on the carcass weight, chest circumference, carcass neck percentage, breast muscle collagen content, and caeca length. The genotype by sex interaction was significant (p < 0.05) for fat content, collagen content, hardness, sum of elastic moduli and sum of viscous moduli of the pectoralis major muscle, protein and collagen content of leg muscles, duodenal and caecal length, jejunal and ileal diameter, and spleen weight. The obtained results show a significant effect of genetic origin and sex on the nutritive and technological value of the meat, and on the digestive system development of the pigeons.

Effect of Age and Genotype of Native Breed Cockerels on Carcass and Meat Quality

Abstract The aim of the study was to determine meat quality in cockerels of two multipurpose breeds reared to different ages. The study involved 30 cockerels each of two native breeds: Yellowleg Partridge (Ż-33) and Rhode Island Red (R-11). The results showed that cockerels of the native breeds Rhode Island Red (R-11) and Yellowleg Partridge (Ż-33) represent a good starting material for niche production of poultry meat R-11 cockerels exhibited a better rate of weight gain and their carcasses had higher yellowness and redness values compared to Ż-33 birds. The carcasses of both cockerel breeds had lower breast and higher leg muscle percentage, and their meat contained more collagen and protein and less fat. As birds aged, body weight and abdominal fat percentage increased, and giblets percentage decreased in the cockerels of both breeds, whereas in the R-11 breed dressing percentage increased, leg bone percentage decreased, yellowness (a*) increased and redness (b*) decreased. Neither genotype nor slaughter age had a significant effect on chemical composition of the breast and leg muscles. In both breeds, the breast and leg muscle quality traits were more affected by age than genotype.

Effect of betaine, a methyl group donor, on broiler chicken growth performance, breast muscle quality characteristics, oxidative status and amino acid content

This study was aimed to investigate the effect of feed supplemented with betaine on broiler chickens’ growth and slaughter performance, breast muscle histomorphometric and physicochemical properties, oxidative status and amino acid content. A total of 1000 1-day-old Ross 308 broiler chickens were divided into four treatments. Control group chickens were fed with standard compound diet (SCD), the chickens from experimental groups B1, B2 and B3 receiving SCD supplemented with 1 g/kg (B1), 2 g/kg (B2) and 3 g/kg (B3) betaine anhydrous, respectively. Each treatment had five replicate pens. Feeding test results showed that betaine reduced broilers’ mortality but increased feed conversion ratio (p < .05). Forty broiler chickens (5 weeks old) were slaughtered and slaughter performance showed that 2 g/kg betaine inclusion improved breast muscle percentage and yield (p < .05). Betaine dosage of 1 g/kg into feed increased breast muscle fibre areas (p < .05). Betaine affected some physicochemical properties: higher a* and the highest drip loss in B2; the highest cooking losses in B1, B2; the highest shear force and fat content in SCD; the highest amounts of ashes in B1, B2 (p < .05). Lower malondialdehyde levels were observed in all betaine-treated groups (p < .05), except B1 fresh meat samples. The highest total amino acid content and a greater amount of essential amino acids were obtained in SCD breast muscles (p < .05), except equally highest amounts of methionine were found in both SCD and B3 samples (p < .05). However, according to our study results, betaine, as a methyl group donor, in broiler chicken diets cannot replace methionine as an essential amino acid. Highlights Betaine is known as functional nutrient in poultry nutrition, which can fulfil the function of a methyl donor. Betaine in animal feed is saving feed costs by replacing choline chloride and methionine.