Relationships between firmness of dry-cured hams and breeding values for curing weight loss traits

Dry cured ham (DCH) is the most valuable product of the pig industry in Italy. Firmness is an important quality traits affecting slicing. Aim of this study was to investigate the relationship between firmness of DCH (subjective evalution with linear score from 0 to 4) and breeding values (EBV) of pigs for weight loss at the end of curing (WL) and for traits related to the dynamic of weight loss (WLD). Ham weights were recorded at arrival at the ham factory, 15 and 130 day since arrival, and at the end of seasoning (300 days). The dataset included records on left hams from 1602 crossbred heavy pigs (6428 weight records). The dynamic of weight loss was estimated by fitting a nonlinear model (Von Bertallanfy function) and instantaneous rates of weight loss (IS) were determined at different stages of curing (from 10 to 100 d by 10 d steps). Heritability of WL was 25%, whereas heritability of IS ranged from 17 to 30%, with higher values for later curing stages. EBV for WL and IS affected firmness of DCH. High firmness was associated to high EBV for WL and IS.