Comparación del cerdo criollo y Duroc Jersey en cuanto a crecimiento y utilización del alimento

A series of studies were carried out to compare the response to diets of the same nutritive quality, of native Guatemalan and Duroc Jersey pigs. The native pig represents 90 per cent of the swine population of the country; therefore, an efficient production of same could well help in solving the protein-caloric problem of the human population. In one study both types of pigs were fed diets containing 6.1 and 14.6 per cent protein with equal essential amino acid content per gram of total nitrogen. In a second study groups of native and Duroc Jersey pigs were fed corn with or without lysine and tryptophan supplementation. The responses were measured by means of three parameters: weight changes, feed utilization, and serum proteins. With diets containing 14.6 per cent protein, Duroc Jersey pigs gained significantly more weight and showed higher efficiency feed utilization rates than did the native ones. However, when the protein level was 6.1 per cent no difference in weight gain was observed between the two, even though Duroc Jersey pigs prove to have better feed utilization. Total serum proteins of animals fed on 14.6 per cent protein diets were similar, although albumin concentration was higher in the native swine. With the lou protein diet, the latter showed higher total serum protein and albumin content than the Duroc; nevertheless, their amino acid balance is probably the same. The results of the study in wich the two types of pigs were fed corn supplemented or unsupplemented with lysine and tryptophan as the sole source of protein, gave unexpected results. However, although both types of animals showed a good response to the amino acid supplements, a high mortality occurred among the native pigs. The surviving animals had higher total serum protein and albumin content than the Duroc pig. Because of their practical applications, we deem it necessary to reconfirm these findings.