Effect of Humidity Level in a Warm Growing Environment on Porcine Carcass Composition and Quality

T HE use of confinement systems in swine production sometimes produces unusual environmental conditions. The relative humidity of these housing systems is usually higher than that of the natural environment (Addis et al., 1965). Studies of the effect of humidity level on the well-being of the pig indicate that bodyheat loss by ventilation becomes increasingly difficult as the humidity level is raised (Ingram, 1965). However, in the research reported by Thomas et al. (1966) the ultimate muscle quality of pigs reared in high relative humidity was superior to that of pigs reared in low relative humidity, particularly under conditions of fluctuating environmental temperature. Clausen and Thomsen (1956) and Ludvigsen (1960) observed that Danish pigs (reared in close confinement), which had muscular carcasses that were low in backfat, tended to have poor muscle quality. However, possible interrelationships among humidity level, muscularity and muscle quality have not been reported. The purpose of this experiment was to determine the effects of humidity level, when combined with high environmental temperature during growth, on (1) carcass composition, (2) processing qualities of the musculature and (3) relationships between quantitative and qualitative carcass traits of Landrace pigs.