Asociaci贸n Latinoamericana de Producci贸n Animal (ALPA)
Abstract
The "modern" pig began to consume less food to obtain greater body mass gain, especially protein. Likewise, this selection produced and continues to produce genotypes of greater weight when they reach the physiological age for reproduction, however with less voluntary feed intake throughout their reproductive life. Feeding the gilt should be seen as one of the most relevant phases of the breeding stock's nutritional program since the renewal of the effective breeding stock corresponds on average 30 to 50% of the total of active females. During pregnancy, amino acids play an important role in the development of the mammary gland, when they reach about four times the size. The growth culminates with an increase in the DNA content which involves about 148 g of protein gain per gland or about 2066 g for 14 functional glands which corresponds to 18 g of protein per day. During lactation, the metabolic dynamics involve mobilization of body reserves when there is a nutrient deficit in the diet. The excessive mobilization of body protein, however, affects the condition of the female and her subsequent reproductive performance. At birth, the mammary gland undergoes greater physiological changes when the cells of the epithelial tissue start to function actively in the synthesis and secretion of milk in the lumen that the next is released to the piglet. The size of amino acids must meet the demands of milk production and maintenance of optimal body conditions, aiming at the following reproduction. As a final consideration, it is noteworthy that the nutrition of the modern breeder deserves successive evaluations, especially in the first reproductive cycles, when it is still in the phase of body growth. Another relevant aspect is the direction that should be given to the study of the nutrition of this modern breeder, emphasizing the distinct genotypes that exist in the commercial swine market, without, however, belittling the importance of the other conditions, in which this female will be subjected
