Gastric protein breakdown and pancreatic enzyme activities in response to two different dietary protein sources in newly weaned pigs

Abstract

Seventy pigs were weaned at 25 d of age and fed diets based on either skim-milk powder (SMP) or soybean protein concentrate (SOY). At 0, 3, 6, and 10 d after weaning, pigs were anesthetized, their pancreases were removed, and digesta were collected from different sections of the digestive tract. The ratio between trichloroacetic acid (TCA)-precipitable protein and total (crude) protein (pp:cp) in gastric digesta was higher with SOY feed than with SMP feed. In the jejunum, no difference was found; hence, the degree of protein breakdown in jejunal chyme did not differ between protein sources. Trypsin activities in jejunal chyme and in pancreatic tissue increased (P < .01) after weaning. Chymotrypsin activity in pancreatic tissue tended to decrease after weaning and did not reach "weaning levels" for at least 10 d. Pancreatic trypsin developed more rapidly than chymotrypsin after weaning. Chymotrypsin activities in jejunal digesta were higher (P < .05) for the pigs fed SMP than for those fed SOY. Protease activities in the jejunum at d 6 after weaning were clearly affected (P < .05) by feed intake after weaning. The ratio between trypsin and chymotrypsin activity in jejunal chyme was higher (P < .05) for SOY-fed pigs than for SMP-fed pigs. It was concluded that the stomach plays an important role in the digestion of milk protein and that the development of pancreatic proteases after weaning (synthesis, secretion, breakdown) depends on feed intake and on dietary protein source.

Ileal amino acids digestibility of sorghum in weaned piglets and growing pigs

“…The low protein digestibility could be caused by the negative effect of tannins or the presence of a-kaffirin; and be aggravated by the lower capacity of weaned piglets to digest vegetable protein when compared with growing pigs (Mariscal-Landín et al, 2008). For this reason the use of highly digestible proteins is recommended in starter feeds (Makkink et al, 1994;Shon et al, 1994).…”

Neutral detergent fibre in piglet diets: performance and gastrointestinal implications

“…In relation to the pH of the small intestine, pH values below the optimum range (7.8 to 8.1) were observed for the action of trypsin and chymotrypsin in accordance with Makkink et al (1994). Thus, independently of the level of fibre in the diet, the physiological immaturity of the digestive system of piglets up to 42 days may result in less utilization of protein.…”

Adição de enzimas exôgenas para leitões dos 10 aos 30 kg de peso

“…Os resultados de atividade enzimática são semelhantes aos obtidos por SHIELDS et al (1980), LINDENMAN et al (1986), TARDIN (1985), CHESSON, (1993), MAKKINK et al (1994 e SO-ARES (1995), em que o peso, a idade, o tipo e a quantidade de ração consumida aumentam a atividade das enzimas pancreáticas na digesta, porém diferem dos obtidos por SOUFFRANT (1993), que não encontrou diferenças na atividade enzimática em suínos alimentados com diferentes tipos de dietas durante a sexta e a décima semana de vida, período de maior consumo alimentar e mais rápido índice de crescimento desses animais. O aumento crescente na atividade da amilase, à medida que o leitão ganha peso, pode ser explicado pela necessidade do animal em hidrolisar grandes quantidades de amido.…”

“…As enzimas digestivas que hidrolisam proteínas são chamadas proteases e sintetizadas como zimogênios inativos no estômago e no pâncreas. A enzima pepsina digere proteínas no ambiente ácido do estômago (TARDIN, 1985;MAKKINK et. al., 1994) e a quimotripsina e a tripsina, no intestino delgado (TARDIN, 1985).…”

“…O consumo de alimento diminui após a desmama, visto que o sistema digestivo dos leitões tem de se adaptar ao alimento sólido, adequando o pH às secreções enzimáticas e à motilidade intestinal, além dos transtornos digestivos ocasionados pela proteína da soja, a qual contém fatores antinutricionais e de antígenos, capazes de provocar aos leitões uma série de disfunções intestinais (MAKKINK, 1994).…”