Czech Journal of Animal Science - In Press
Comparison of carcass traits between mallard ducks (Anas platyrhynchos) and domestic ducks (Anas platyrhynchos domesticus)Original Paper
Eva Straková, Anna Brázdilová, Natalie Klessy, Pavel Suchý
The aim of this study was to evaluate the effects of domestication and the associated rearing system and rearing conditions on the carcass traits of ducks, assessed on the basis of weight and yield parameters, including skinless carcass weight, skinless breast muscle weight, skinless thigh weight, skinless thigh muscle weight, and the corresponding yield parameters. The study included 20 wild mallard ducks (Anas platyrhynchos) living under natural conditions and 20 domesticated Cherry Valley ducks (Anas platyrhynchos domesticus) reared under intensive indoor production conditions with controlled lighting, temperature, and feeding regimes. Wild duck group comprised females (DWF; n = 10) and males (DWM; n = 10), whereas Cherry Valley duck group comprised females (DDF; n = 10) and males (DDM; n = 10). Wild ducks were harvested during the hunting season in September and were presumed to be approximately one year old, Wild ducks were harvested during the hunting season in September. The age of the birds was determined according to standard hunting and ornithological criteria based on the evaluation of morphological characteristics, and all individuals were classified as one-year-old, whereas domesticated ducks were reared to 42 days of age. The results demonstrated that body weight, skinless carcass weight, skinless breast muscle weight, skinless thigh weight, and skinless thigh muscle weight were significantly higher (P ≤ 0.05) in Cherry Valley ducks. This pattern was confirmed in females, males, and in the analysis irrespective of sex. Among the evaluated yield parameters, Cherry Valley ducks exhibited significantly higher skinless thigh yield and skinless thigh muscle yield (P ≤ 0.05). In contrast, wild ducks showed significantly higher carcass yield and skinless breast muscle yield, both in females and males analysed separately and irrespective of sex (P ≤ 0.05). These findings confirm that domestication and intensive rearing have a significant influence on growth performance and carcass traits in ducks.
Herd management practices associated with bulk tank somatic cell count in dairy farms on Western TürkiyeOriginal Paper
Tarık Ayyılmaz, Can Uzmay
The objective of this study was to determine the associations between bulk tank somatic cell count (BTSCC) and herd management practices in dairy farms on Western Türkiye. The material of the study consisted of registered 81 dairy farms. The farms were visited at approximately one-month intervals. Somatic cell count was determined electronically in the milk samples. According to the average BTSCC values of the farms, 2 different BTSCC categories were created (low: ≤400 103 cells/mL with 40 farms and high: >400 103 cells/mL with 41 farms). A questionnaire form was created to determine the herd management practices. The association between herd management practices and BTSCC categories was evaluated using logistic regression analysis. According to multivariate analysis, the probability for a farm belonging to the low BTSCC category increased when maintaining clean resting surface to cows, having a calving pen, applying pre-milking teat disinfection, and shutting off vacuum to the claw before removing the milking cluster. In addition, the probability for a farm belonging to the low BTSCC tended to be high when not preferring a non-stanchion barn with a hard floor (concrete etc.) as resting surface in milking cow housing. According to univariate analysis, the probability for a farm belong to the low BTSCC category was increased significantly when; maintaining cleaner exercise area, cooling the cows, keeping records about udder health, ensuring that the teats are dry while attaching the milking cluster, applying post-milking teat disinfection, and having an automatic cluster remover. Consequently, if improvements are made in these management practices, the incidence of udder health problems and consequently BTSCC will decrease.
Gompertz – Putter - Gompertz: Resolving two centuries of debate on laws of biological growthOriginal Paper
Robert Gous, Gerald Emmans
The function of Gompertz (1825) can be derived from the growth equation of Putter (1920), using the modified form proposed by Kuhleitner et al. (2019). The genetic relative growth rate is derived as RG = dlnW/dt = BG.ln(AG/W). The genetic characteristics are AG, mature weight, and BG, the rate parameter; the state variable is weight, W. The integrated form is W = AG.exp-(-exp-(G0 + BG.t)), where G0 = -ln(-ln(W0/AG)) and W = W0 when t =0. The phenotypic equation is RP = qE.RG, where qE≤1 is a measure of the quality of the environment. This function is consistent with data, collected where qE can reasonably be assumed to be 1, on the post-hatching growth of domestic and wild altricial birds, and with data from both the pre-natal and post-natal growth of domestic mammals. The mean value of the rate parameter, scaled to AG0.27, for mammals and precocial birds unselected by humans, is about 0.037, with considerable variation in avian species. Human selection for growth traits in poultry has nearly doubled the value. The mean value for six altricial species was found to be nearly three times as that for the average precocial species. The Gompertz function is consistent with data collected where the environment is not limiting. It follows logically that any function that is inconsistent with the Gompertz is inconsistent with relevant data, and therefore not a sufficient description of genetic growth.
In vitro proliferative capacity of satellite cells derived from Brown Vietnamese cattle (Bos indicus)Original Paper
Nguyen Quynh Chi Ho, Thanh Long Le, Lu Chinh Nhan Phan, Thi Tung Loan Dang, Nguyen Van Hanh, Thi Nhung Nguyen, Thai Minh Han Nguyen, Thi Anh Linh Dinh, Nghia Son Hoang, Chinh Chung Doan, Thai Minh Nguyen
Finding suitable animal cell sources for cultured meat production remains a major challenge and continues to attract significant scientific interest, particularly in the development of bovine cultured meat. These cells must demonstrate robust proliferative capacity and the ability to maintain stemness. In this study, we aimed to evaluate the proliferation capacity and morphological alterations of bovine satellite cells (bSCs) derived from the Brown Vietnamese cattle during long-term in vitro expansion. The results showed that bSCs possessed a high proliferative potential, sustaining over 20 passages. These cells retained the expression of Pax7 and Pax3, specific markers for bovine satellite cells, in both early and late passages. Accumulation of bSCs in the G0/G1 phase at late passages indicated cell cycle arrest and reduced proliferation during prolonged culture. Morphological features of cellular senescence were also identified in late passage bSCs, including cytoplasmic enlargement, increased cell and nuclear size, and a decreased nucleocytoplasmic ratio. These findings suggest that bSCs from the Brown Vietnamese cattle represent a promising cell source for cultured meat research, demonstrating initial proliferative capacity and maintenance of cell identity, although proliferation potential declines under extended in vitro conditions due to cellular senescence.