Genetic variability of meat quality traits in Chianina beef cattle

The heritability of quality traits (chemical composition, colour, tenderness and water-holding capacity) of the meat derivingfrom three muscles (Triceps brachii, Longissimus dorsi and Semitendinosus) was evaluated in 92 young Chianinabulls. The animals were raised on two farms with different feeding programs, and were slaughtered at approximately 19months of age. Single pair correlations were considered in order to evidence the relationships between the same traitsdetected in the three muscles and between all the traits of the same muscle.The h2 values range from 0.00 to 0.24 for the chemical composition, from 0.00 to 0.19 for colour parameters, from 0.03to 0.31 for those observed after 48 h, and from 0.00 to 0.08 for tenderness and water-holding capacity. The values werenot homogeneous for the three muscles. The most heritable trait was yellowness (b*48) in all three muscles, with valuesof 0.11 in the Longissimus dorsi, 0.23 in the Semitendinosus, and 0.31 in the Triceps brachii. Conversely, tendernessappeared to have a low heritability, as did the parameters relating to the water-holding capacity. Colour traitsobserved before and after 48 h of storage generally were significantly and positively correlated, indicating that certaincolour characteristics are maintained even after 48 h of storage. There was not always a close relationship between thetraits of each muscles: significant correlations existed between the Triceps brachii and the Longissimus dorsi muscles,confirming the similar quality traits of their meat, while there were considerable differences between these muscles andthe Semitendinosus

Stochastic patterns in a 1D Rock–Paper–Scissor model with mutation

In the framework of a 1D cyclic competition model, the Rock-Paper-Scissor model, where bacteria are allowed to mutate and move in space, we study the formation of stochastic patterns, where all the bacteria species do coexist. We modelled the problem using an individual-based setting and using the system size van Kampen expansion to deal with the Master Equation, we have been able to characterise the spatio-temporal patterns using the power spectrum of the fluctuations. We proved that such patterns are robust against the intrinsic noise and they can be found for parameters values beyond the ones fixed by the deterministic approach. We complement such analytical results with numerical simulations based on the Gillespie's algorithm

Effect of diet energy source on weight gain and carcass characteristics of lambs

The effect of different sources of energy (lipids and carbohydrates) was studied on 36 Apennine male lambs divided by age, weight and paternity into three homogeneous groups receiving three different diets: lambs on diet 1 received ad libitum lucerne hay+concentrate supplemented with barley flakes (9%) (BC); lambs on diet 2 received ad libitum lucerne hay+concentrate supplemented with maize oil (5%) (MC) while lambs on diet 3 received only the concentrate given in diet 2 (MC). The two concentrates were isoenergetic and isonitrogenous. Lambs were slaughtered at 105 days of age. The conversion indices were similar (4.52, 4.77 and 4.61 Meat FU/kg gain) for the three treatments, but the diet 3 led to heavier carcasses (17.57kg), although with greater adipose covering, and better dressing percentages than the other two diets. The histological dissection of the proximal pelvic limb indicated a good tissue composition (total lean 56.16%) but confirmed the higher fat percentage (total fat 16.24%), particularly subcutaneous (11.44%), of the group receiving only MC. Animals on diet 3 gave carcasses with an adequate commercial weight at the age of 90–95 days and therefore it seems possible to anticipate slaughtering these animals earlier and perhaps obviate the excessive adiposity of the carcass. In general, this study further confirmed the good meat quality of Apennine carcasses slaughtered at 105 days