Assessment of enzymatic efficiency on protein digestion in the tilapia Oreochromis niloticus.

The present study develops an experimental procedure aimed to estimate the efficiency of protein digestion in fish by measuring both gut transit rate and total amount of the main intestinal proteases (trypsin and chymotrypsin). The selected species was the Nile tilapia (Oreochromis niloticus). Total time for digestion, calculated through the estimation of gut transit rate using differently colored feeds, was 7.15 h. Mean production of trypsin and chymotrypsin was 15.94 and 24.11 mU in the proximal intestine and much lower (2,39, 4.90 mU) in the distal intestine. The enzyme efficiency, calculated from the average enzyme activity and time of residence of the digesta in each intestinal section, points to the major role of proximal intestine in protein digestion for this species. Results are discussed in relation to the main features characterizing digestion in stomachless fish.

[The program for the promotion of breast feeding in the Hospital General de México: an evaluation study]. / Programa de promoción de la lactancia materna en el Hospital General de México: un estudio evaluativo.

The malnutrition and infection seen in the infant population can be reduced with correct breast feeding practice. In 1988 and 1989, La Leche League of Mexico and the Mexico City General Hospital, Secretary of Health, carried out a breast feeding promotion program in the same hospital. The program had three components: 1) in-service training for health care personnel in the pediatric and obstetric services; 2) changes in perinatal care procedures aimed at improving the start of maternal nursing during the hospital stay; and 3) classes concerning breast feeding advantages and techniques for primiparas. As a result of the program, 110 hospital workers received lactation management training and there was improvement in several breast feeding related indicators measured during the post-partum hospital stay (reduction in the mean time between the arrival of the newborn to the rooming-in area and first maternal nursing, greater proportion of infants observed receiving the breast, and a better interaction between mothers and newborns when offering the breast) and the primiparas who participated in the program breast fed their infants for longer periods than did a program control group (median of 17 and 12 weeks, respectively; the difference in the proportion of infants still being nursed at 16 weeks was statistically significant).