The effects of stocking density on slaughter performance and some meat quality parameters of Pekin ducks.

The effects of stocking density on slaughter performance and meat quality were primarily investigated in this research. A total of 240 Pekin ducks were used, and they were reared until slaughter age (42 d) in three different stocking density groups (three, five and seven ducklings m - 2 ). To compare the slaughter performance of the ducklings' live weight, carcass weight, carcass yield, thigh and breast meat weight and yield, and edible giblet weight (heart, liver and gizzard) were investigated. The meat quality was compared between the treatment groups based on dry matter ratio, cooking loss, water-holding capacity, pH values, and colour parameters ( L , a , b , c , h and Δ E values). Carcass weight, carcass yield, thigh and breast meat weight were found to decrease in parallel to the increasing stocking density, resulting in a reduction in thigh and breast meat weights and ratios ( P < 0.05 ). Increasing the stocking density decreased the heart weight and positively improved the liver and gizzard ratio ( P < 0.05 ). However, it did not affect the meat quality parameters investigated in this research ( P < 0.05 ). The breast meat of the ducks reared under higher stocking density had higher L , h and Δ E values, lower a value ( P < 0.05 ), and similar b and c values ( P < 0.05 ). Evaluating the overall research findings, it was concluded that increased stocking density when rearing ducks negatively affects the slaughter performance, affecting only breast meat colour and weight of thigh meat with skin in investigated meat quality parameters.

Effects of incubator oxygen and carbon dioxide concentrations on hatchability of fertile eggs, some blood parameters, and histopathological changes of broilers with different parental stock ages in high altitude.

The effects of incubator carbon dioxide (CO2) and oxygen (O2) concentrations with parental stock age (PSA) on embryonic deaths (ED), hatchability of fertile eggs (HFE), some blood parameters, and the tissue development of broilers were investigated. Four consecutive repetitions following the similar materials and methods were carried. From 3 different aged ROSS 308 broiler parental flocks 7,680 hatching eggs were obtained and classified as young (Y; 29 wk), middle (M; 37 wk) and old (O; 55 wk) as regards PSA, and randomly distributed. Four different incubator ventilation programs (IVP) as control (C; 0.67% CO2 and 20.33% O2), high CO2 (HC; 1.57% CO2 and 20.26% O2), high O2 (HO; 0.50% CO2 and 21.16% O2), and high CO2 + O2 (HCO; 1.17% CO2 21.03% O2) were applied with oxygen concentrator, and ED and HFE were investigated. Lung and heart tissues, hemoglobin value, packed cell volume, and red blood cell count, triiodothyronine, thyroxine, adrenocorticotropic hormone (ACTH) values of the chicks were analyzed. It was found that IVP affected ED and HFE. Higher rate of early ED (EED) was obtained from the HC than HCO, and higher middle+late stage+pipped but unhatched ED (MLPED) with a lower rate of HFE was observed in the C group than HO and HCO (P < 0.05). Association was found between PSA and IVP (P < 0.05), being more evident in EED for young PSA, in MLPED with HFE for Y and O PSA. From hematological values, no statistical difference in RBC, PCV, and Hb values were found among the treatment groups, ACTH concentration known as a response to stress was found to be higher than C in all groups, triiodothyronine concentration was higher in the HO group than C. In the histopathological examination, used IVPs were found to have negative effects on the lung and heart such as vacuolization, hemorrhage in all PSA groups except for C. Conclusively, PSA and IVP affected some hatching, blood and tissue development parameters of the broiler chicks.

The effects of plastic slatted floor and a deep- litter system on the growth performance of hybrid Pekin ducks.

This research was conducted to evaluate the effects of plastic slatted floors and a deep-litter system using wood shavings on the growth performance of current commercial hybrid Pekin ducks. A total of 96 Pekin ducks (Star 53) were reared for 42 d. Live weight, live-weight gain, feed consumption, feed conversion ratio, water consumption, and water  /  feed consumption ratio were investigated as the performance criteria. With the use of plastic slatted floors, the feed conversion rate dropped and the water  /  feed consumption ratio showed an incline ( p < 0.05 ). This is a very favourable result for the poultry industry and growers. The remaining parameters did not change by altering the ground system ( p > 0.05 ). Generally, it can be stated that plastic slatted floor use has advantages concerning the performance criteria of the feed consumption ratio and the water  /  feed consumption ratio in comparison to the deep-litter system. Furthermore, improvement in the feed conversion ratio is known to benefit the overall performance of poultry as well as having a positive economic impact. It should also be noted that as the birds grew, they were visually less stained, which is another important factor determining feather quality. However, this should be further investigated in future research.