La valutazione morfologica dei bovini: evoluzione e obiettivi nella razza Piemontese

The morphological evaluation has undergone several changes over the years concerning the methods with which it is performed and also regarding the evaluation cards, also within the Piemontese cattle breed. Currently, model 6 is used for the morphological evaluation of the breeding animals present in the farms, while model 7 is used for the bulls present at the Test Station and subjected to the performance test; both have 9-code scales and the final score, which expresses the morphological beauty, is a value between 70 and 99. The differences between the two models are given by the fact that the second one, compared to the first one, reports the most important dimensions of the animal and the muscularity is evaluated for the different parts of the body rather than as an overall judgement. Initially, the evaluation was carried out with the aim of finding the most suitable animals for breeding, but over the time it has become the pillar for determining the breed selection indexes. Regarding Piemontese breed, its morphological evaluation has made it possible to select the double muscled character, deriving from muscle hypertrophy, which distinguishes it and to preserve it until the present days, becoming a symbol of quality among meat breeds. In fact, hypertrophy causes an increase in the number of muscle cells through hyperplasia and an increase in muscle fibres, related to a smaller quantity of adipose and connective tissue: in this way we have a more tender meat with less fat. However, this trait was associated with calving difficulties and abnormalities in new born calves, but the application of the correct selection procedure allowed the elimination of these defects. In the past the breed had a triple productive aptitude (work, milk and meat), but later the selection objective shifted to specialize the Piemontese in the production of meat. Currently, the breed standard, which have been defined in 1976 by the Italian Ministry of Agriculture, states that the main objective to be achieved concerns earliness intended as earlier slaughtering time with a good yield, but also the growth of the average daily gains in terms of weight and the improvement of the feed conversion index, without neglecting the fecundity and longevity of the breeding stock. In order to operate a correct selection process from a morphological point of view it is important that the animals reflect the standard characteristics of the breed indicated in the Technical Bylaws for the selection of the Piemontese breed. The selection takes place at the facilities of the National Association of Piemontese Bovine Breeders, the Test Station for carrying out the Performance test and the A.I. Station where the seminal material is produced, with which the brood cows will then be made pregnant. The selective scheme consists of two selective lines (Breeding and Meat) with the aim of making the system more effective; in fact, the factors that contribute to the production of meat are selected through the performance test, as they are easily heritable, while those linked to birth, therefore to breeding, can be chosen through the progeny test, because they have low heritability and it is not possible to determine certain features directly on the bull.