The analysis of meat and bone traits of Plymouth Rock cockerels and capons (P55) at different age

Evaluation of coffee husks in pellet bedding, performance characteristics, footpad dermatitis scoring, and meat quality of broiler ducks

The study aimed to analyze the chemical composition of pellet bedding made of straw or coffee husks (10, 25, 50%) and the performance characteristics of broiler ducks and footpad dermatitis. During rearing, the properties of the bedding and utility features of ducks were analyzed, and the frequency of footpad dermatitis (FPD) in ducks was verified. There was a decrease in dry matter from the 28th day of rearing. The crude fiber, NDF, ADF, and nitrogen content decreased compared to fresh bedding, while phosphorus and potassium increased. The highest pH was found in the CH25 and CH50 groups in fresh bedding on day 42 and in CH50 on day 14. High adj. R2 was found due to rearing time and bedding material (0.817-0.985). The ducks' growth rate in the CH25 group was higher at week 6 than in the other groups. In CH10 and CH25 groups, higher carcass weight was found than in group C. In group CH10, a higher weight of pectoral muscles and lower wing proportion was found than in C. In CH25, a higher remains weight was shown than in C and CH50. In CH50, lower water-holding capacity in the pectoral muscles was found than in the other groups. Considering the bedding (the content of nitrogen, phosphorus, and potassium), carcass features, and meat quality (water-holding capacity, intramuscular fat, and water content), it is possible to use 10, 25 or 50% of coffee husks in straw pellets in the rearing of broiler ducks. Due to the FPD, the moisture should be lowered.

The effect of caponization on bone homeostasis of crossbred roosters. I. Analysis of tibia bone mineralization, densitometric, osteometric, geometric and biomechanical properties

The presented study focuses on assessing the effect of caponization on the densitometric, osteometric, geometric and biomechanical parameters of tibial bones in crossbred chickens. The study was carried out on 96 hybrids between Yellowleg Partridge hens (Ż-33) and Rhode Island Red cockerels (R-11) aged 16 weeks, 20 weeks and 24 weeks. Birds were randomly assigned to 2 groups-the control group (n = 48; which consisted of intact roosters) and the experimental group (n = 48, which consisted of individuals subjected to caponization at the age of 8 weeks). The caponization had no effect on the densitometric, osteometric and geometric parameters (except the horizontal internal diameter of 16-week-old individuals) of tibia bone, as well as the content of calcium (Ca), phosphorus (P) and the Ca/P ratio in the bone mineral fraction in all analyzed age groups of animals. However, it contributes to a lower percentage of ash in the bones of capons at 20 and 24 weeks of age compared to cockerels. On the contrary, some mechanical and material parameters show the negative effect of caponization. Ultimate load and bending moment decreased in capons in all of the analyzed age groups of animals and yield load, stiffness and ultimate stress also decreased but only in the group of 20-week-old and 24-week-old individuals. This can contribute to the weakening of the capon bones, and in the perspective of prolonged maintenance to their deformation and even fracture.

Growth of broiler chickens, and physical features of the digestive system, and leg bones after aluminosilicates used

The assessment of aluminosilicates' impact on the production of chickens, the physical features of the intestines, and leg bones was done. 500 Ross 308 chickens were used and divided into 5 groups. The control group was I. Groups II, III, IV, and V were fed with halloysite and zeolite (1:3 ratio) at 0,5% (1-35 days; starter, grower 1 and 2) and 1% (36-42 days; finisher) levels. Aluminosilicates were also used for the peat litter: II-500 g of halloysite/m²; III-250 g of halloysite/m² and 250 g of zeolite/m²; IV-500 g of zeolite/m²; V-130 g halloysite/m², 370 g zeolite/m². During 42 days, growth and feed indicators were recorded. 10 birds from each group were selected for slaughter. The digestive tract, femur, and tibia bones were sampled, and physical features were analyzed (weight, length, and strength). A lower feed conversion ratio on days 23-35 was found in the groups with the aluminosilicates addition. In group V a lower weight of the gizzard was found than in group I. A liver weight was higher in group V than in group III. A higher strength of the femurs was demonstrated in group IV. The tibia bones were characterized by higher strength than the femurs of broiler chickens. The aluminosilicates to feed and litter had no adverse effect.

Effects of gonadectomy on clinical-hematological, metabolic and hormone conditions of cockerels

Gonadectomy (caponization) of cockerels is an important way of increasing their productivity, improving the quality and taste properties of the meat, and obtaining dietary products. The objective of the study was the influence of gonadectomy of cockerels on their clinical condition, morphological composition of blood, hemoglobin content and anabolism in the tissues, their productivity and chemical content of the muscles. In the experiment, we used 30 Adler silver cockerels aged 4 weeks, which were divided into two groups: control (intact) and experimental (gonadectomized) according to the analogue principle, with 15 individuals in each. The experiment lasted for 185 days, including the main period of 175 days. We determined that the body temperature of cockerels after gonadectomy increased as early as days one and three. In the blood of gonadectomized cockerels, the number of leukocytes decreased by 36.3%, thrombocytes – by 24.7%, while hemoglobin concentration, numbers of heterophils, eosinophils, basophils, monocytes and lymphocytes did not change compared with the intact individuals. On days 20 and 185 of the experiment, the concentration of testosterone in the blood plasma of gonadectomized cockerels was lower respectively by 57.1% and 53.1%, whereas no differences were found prior to gonadectomy and on the third day of the experiment. We determined increase in uric acid concentration and decrease in the level of ionizing calcium in blood plasma of gonadectomized cockerels compared with intact individuals, while the content of cortisol, glucose, total protein, triglycerides, cholesterol, total calcium and inorganic phosphorus, and also activities of alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase did not change. Live weight of gonadectomized cockerels in the period from 45 to 105 days of the raising did not change, and was higher by 10.4–17.0% from day 115 to 145, and further remained not different from the control. Thoracic muscles of gonadectomized cockerels contained 1.8 times more fat, while the levels of moisture, dry matter, protein and ash in thoracic and thigh muscles did not change. The conducted studies have revealed the effect of gonadectomy of roosters on clinical-hematological parameters, metabolic processes, productivity of birds and chemical composition of muscles and may be used to improve the production of chicken meat with high dietary and taste properties.

A Comparison of Morphometric Indices, Mineralization Level of Long Bones and Selected Blood Parameters in Hens of Three Breeds

The aim of the study was to compare morphometric indices and the mineralization level of humerus, femur and tibia in Leghorn (H-22), Sussex (S-66) and Rhode Island Red (R-11) hens at different age (weeks 6, 16, 45 and 64), as well as some blood parameters. The material for the experiment was one-day old chicks of breeds: Leghorn (H-22), Sussex (S-66) and Rhode Island Red – RIR (R-11), which were separated into three groups. At 6, 16, 45 and 64 weeks of the study, 10 birds selected from each group were weighed, slaughtered, and their right femurs, tibiae and humeri were dissected. After removing soft tissues, the bones were weighed and measured for length, diameter, and the Seedor index (SI) was calculated. The bones were analysed for the content of calcium (Ca), phosphorus (P) and crude ash (CA). At 64 weeks, blood was collected from the hens and analysed for the concentration of Ca, P, pyridinoline and deoxypyridinoline. The study showed that hen breed had an effect mostly on morphometric indices of the bones such as bone weight and diameter, and the Seedor index (SI), while the age of birds had an effect on the bone mineralization level up to 45 weeks of age. The bone mineralization did not decrease in the studied breeds of hens at the end of the laying period. It was also found that heavier birds (RIR) had greater diameter bones and a higher SI, but the content of ash and minerals in the bones of that breed was generally similar to the Leghorn and Sussex hens. RIR hens exhibited higher plasma phosphorus concentration compared to Sussex hens. This may suggest that RIR birds have a slightly stronger bone system compared to Leghorn and Sussex hens.

Ducks' Growth, Meat Quality, Bone Strength, and Jejunum Strength Depend on Zeolite in Feed and Long-Term Factors

Simple Summary

Natural agents ensuring the biosecurity of poultry production and the high quality of meat have again gained increasing interest. Natural zeolites absorb toxic gases and can also stimulate digestion and improve the physicochemical parameters of meat, which is important from the consumer’s point of view. The aim of the study was to assess the effect of a diet with a 4% inclusion of zeolite on the growth, the meat quality, and the strength of the bones and jejunum of Orvia and Cherry Valley ducks of different age and sex. The addition of zeolite was associated with reduced body weight gains and an increased feed conversion ratio, but with a higher water-holding capacity of breast muscles in seven-week-old ducks, and with a higher yellowness and water-holding capacity of leg muscles in six-week-old ducks. Interactions were found between long-term factors (age, sex, and origin) and the addition of zeolite. The results are inconclusive and indicate a need for further research, testing different doses of zeolite in different forms. Studies on the use of zeolite may help reduce the negative impact of poultry production on the environment, and ensure its safety and profitability.

Abstract

The safety of production and the high quality of meat are important aspects of rearing poultry, especially when natural solutions are used. Because of the increasing popularity of duck meat, the aim of the present study was to assess the effect of a diet with an inclusion of zeolite on the growth performance, meat quality, and strength of the bones and jejunum in ducks of different origin, sex, and age at slaughter. The study was conducted on 320 Orvia and Cherry Valley ducks. Birds were allocated to eight groups, according to their sex and origin. Half of the birds received feed with a 4% inclusion of zeolite. Body weight gain, feed intake, and feed conversion ratio per kilogram of gain were calculated. After six or seven weeks, five birds from each group were selected and slaughtered. After dissection, meat quality (pH, water-holding capacity, colour) and the strength of the bones and gut were analysed. The analysis revealed that zeolite was associated with reduced body weight gains and increased feed conversion ratio, but with a higher water-holding capacity of breast muscles in seven-week-old ducks, and with a higher yellowness and water-holding capacity of leg muscles in six-week-old ducks. A positive effect of long-term factors (age, sex, origin) and the interaction with zeolite was found for most of the analysed traits. Findings on the effect of 4% inclusion of zeolite in duck diet were inconclusive. The study implies the need for further research, since zeolite has potential as a natural sanitizing agent and can improve the quality of produced duck meat.

Performance and Meat Quality of Dual-Purpose Cockerels of Dominant Genotype Reared on Pasture

Simple Summary

One-day-old laying cockerels are killed after hatching because they do not reach the growth rate of broiler chickens, and their fattening would be economically disadvantageous. A possible variant of the use of these cockerels could be organic or free-range farming, where it is desirable that the animals are fattened for a longer period of time, are more physically active, and graze pasture vegetation. Another possibility is dual-purpose genotype breeding, where hens are used for egg production and cockerels are fattened for meat. In the present study, three genotypes of dual-purpose cockerels Dominant were compared. All three genotypes showed the ability to graze with resulting improvements in meat quality. The Dominant 102 cockerels have the greatest prerequisites for use in extensive fattening, mainly due to higher performance, willingness to graze and vitamin E content, which protects the fat from becoming rancid.

Abstract

The culling of layer cockerels due to economic inefficiency is an ethical problem. Organic or free-range fattening of these cockerels or dual-purpose genotypes breeding is a possible solution to this problem. The aim of the study was to assess the differences in performance and meat quality characteristics in dual-purpose cockerels Dominant of three genotypes (Dominant Sussex D 104, Dominant Brown D 102 and Dominant Tinted D 723, 100 cockerels per genotype) with access to pasture. The cockerels were housed in mobile boxes on the pasture herbage from the 50th to 77th day of age (stocking density: 0.108 m²/bird). The highest body weight on the 77th day of age (p < 0.001) and the nonsignificantly lowest feed conversion was achieved by Dominant Brown D 102 cockerels (1842 g and 2.79, respectively). Non-significantly higher pasture herbage intake on the 70th day of age was recorded in genotype Dominant Brown D 102 (7.41 g dry matter (DM)/bird/day) and Dominant Tinted D 723 (7.52 g DM/bird/day). The pasture herbage contained 56.9 mg/kg DM α-tocopherol, 170.3 mg/kg DM zeaxanthin and 175.0 mg/kg DM lutein and had a favourable n6/n3 ratio (0.26). The boiled meat of cockerels Dominant Tinted D723 showed the highest tenderness based on both the sensory evaluation (p = 0.022) and the value of shear force (p = 0.049). This corresponds with a higher (p < 0.001) cross-sectional area and muscle fibre diameter in these chickens. The highest content of n3 fatty acids (eicosapentaenoic, clupanodonic and docosahexaenoic acids) in breast meat were found in Dominant Sussex D104 chickens (p < 0.001). In contrast, a significantly higher α-tocopherol content (p < 0.001) and higher oxidative stability (p = 0.012) were found in Dominant Brown D102 (4.52 mg/kg and 0.282 mg/kg) and Dominant Tinted D 723 chickens (4.64 mg/kg and 0.273 mg/kg) in comparison with the Dominant Sussex D104 genotype (3.44 mg/kg and 0.313 mg/kg). The values of the atherogenic and thrombogenic indexes were the lowest (p < 0.001) in meat from Dominant Brown D102 chickens. Moreover, a lower cholesterol content (p < 0.001) was recorded from the genotypes Dominant Brown D102 (396 mg/kg) and Dominant Tinted D723 (306 mg/kg) chickens, contrary to the Dominant Sussex D104 cockerels (441 mg/kg). It can be concluded that cockerels Dominant Brown D102 are a suitable genotype for free-range rearing due to higher performance and higher pasture herbage intake, which positively influences meat quality, whereas the meat of Dominant Sussex D104 cockerels shows higher amounts of n3 fatty acids and lower n6/n3 ratios.