The aim of this study was to estimate genetic parameters of 26 individual and four composite type traits in first parity Cika cows. An analysis of variance was performed with the generalized linear model procedure of the SAS/STAT statistical package, where the fixed effects of year of recording, cow’s age at recording and days after calving as a linear regression were included in the model. The variance components for the direct additive genetic effect and the herd effect in all type traits were estimated using the REML method in the VCE-6 software package. The estimated heritabilities ranged from 0.42 to 0.67 for the measured body frame traits, from 0.36 to 0.80 for the scored autochthonous traits, from 0.11 to 0.61 for the scored body frame traits, and from 0.20 to 0.47 for the scored udder traits. The estimated heritabilities for the composite traits called “autochthonous characteristics”, “muscularity”, “body frame” and “udder” were 0.55, 0.19, 0.19, and 0.26, respectively. The estimated genetic correlations among the measured body frame traits were positive and high, while the majority of them among the scored body frame traits were low to moderate. The estimated proportions of variance explained by the herd effect for the composite traits “autochthonous characteristics,” “muscularity,” “body frame” and “udder” were 0.09, 0.28, 0.14, and 0.10, respectively. The estimated heritabilities for the type traits of first parity Cika cows were similar to those reported for other breeds where breeding values have been routinely predicted for a long time. All estimated genetic parameters are already used for breeding value prediction in the Cika cattle population.
The effects of breed, sex, age, muscle type (longissimus thoracis; LT vs semitendinosus; ST) and post mortem aging period (14 vs 28 days) on the physicochemical properties of horse meat were investigated. A total of 53 horses (21 females and 32 males) categorised into three groups (cold-blooded, CB; Posavje, P; crossbred, CS) were involved in this study. ST muscles showed a higher pH value, a greater intensity of lightness (L*) and yellowness, higher cooking losses and shear force values, and lower thawing losses than LT muscles. The breed affected only muscle redness, whereas sex had a minor effect on drip loss. An extended aging period was associated with higher thawing and cooking losses. An increase of age was followed by a decrease in pH value and L* value, and an increase in cooking loss and Warner–Bratzler shear force. An investigation of the interaction between muscle and aging showed that ST muscle with an aging period of 14 days had the lowest thawing losses. Among the numerous factors that can influence horse meat quality, the most important ones are age at slaughter and muscle type; these factors must be considered in the routine slaughtering practice and in further research.
Selection pressure on protein content (PC), and thus milk composition changes have manifested as an increasingly narrow fat -protein ratio (FPR). In addition, higher somatic cell count (SCC) in milk has been observed in recent years, and that is why it is hypothesized that milk composition changes affect cow's immune response resulting in higher SCC. 2,459,250 test day (TD) records of 127,499 Slovenian Simmental (SIM) cows from years 2004 to 2017 were used for this study. For the estimation of (co)variance components two multiple trait animal TD models were used (M1, M2). M1 included SCC and FPR while M2 included SCC, fat content (FC) and PC. For comparisson of results parameters from the routine single-trait national genetic evaluation were used. Heritability estimates (h²) for SCC, FC and PC from M2 (0.34, 0.29, 0.38 respectively) were very similar to those form national evaluation; h² for FPR was lower than for the other traits (0.22). Both, estimated genetic correlation (r g =-0.1) and estimated phenotypic correlation (r p =-0.007) among SCC and FPR in M1 were negative and low. r p in M2 were positive, but low for all three trait pairs (0.062-0.076) and r g for SCC-PC was similar (0.069). Conversely, FC-PC r g (0.502) was positive and moderate whereas SCC-FC r g (-0.046) was negative and low. Results confirm the hypothesis by suggesting the possibillity of unpredicted and unwanted long-term cumulative effect of seemingly irrelevantly small genetic changes of individual trait.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.