ABSTRACT
ABSTRACT: The aim of this study was to measure the nitrogen (N) balance of pigs fed with lysine-limiting diets containing practical levels of wheat bran (WB) or soybean hulls (SH). Twelve pigs with average weights of 57.36±2.01 and 72.68±3.24 kg were used in trials 1 and 2, respectively. In trial 1, treatments were CT1 - control diet and WB - diet with inclusion of 15% WB. In trial 2, CT2 - control diet and SH - diet with inclusion of 6% SH. Fibrous diets increased (P<0.05) the fecal N in 63.54 and 60.55% in relation to CT1 and CT2, respectively. The urinary N was higher (P<0.05) in pigs receiving the WB diet, but was not influenced in the trial with SH. The N retention (NRET) was higher (P>0.05) in pigs ingesting the WB diet; although, when the proportion of NRET was expressed relative to N ingested (NING) there was no difference (P>0.05) between treatments. Inclusion of SH did not affect (P>0.05) the NRET when the result was expressed in absolute or proportional terms. In conclusion, inclusion of practical levels of WB and SH does not significantly affect the metabolic costs involved with nitrogen metabolism. However, only WB was able to contribute to the N balance of pigs, while the relative amount of N added by SH was fully recovered in feces.
RESUMO: O objetivo deste estudo foi medir o balanço de nitrogênio (N) de suínos alimentados com dietas limitantes em lisina contendo níveis práticos de inclusão de farelo de trigo (FT) ou casca de soja (CS). Foram utilizados 24 suínos machos castrados com peso médio inicial de 57,36±2,01 kg e 72,68±3,24 kg nos experimentos 1 e 2, respectivamente. No experimento 1 os tratamentos foram CT1 - dieta controle, e FT - dieta com inclusão de 15% de FT. No experimento 2 CT2 - dieta controle, e CS - dieta com inclusão de 6% CS. As dietas fibrosas aumentaram (P<0,05) o N fecal em 64,54 e 60,55% em relação a CT1 e CT2, respectivamente. O N urinário foi maior (P<0,05) nos suínos que receberam a dieta FT, mas não foi afetado no experimento com CS. A retenção de N (NRET) foi maior (P<0,05) nos suínos alimentados com a dieta FT, entretanto quando a proporção do NRET foi expressa em relação ao N ingerido (NING) não houve diferença entre os tratamentos (P<0,05). A inclusão de CS não afetou (P<0,05) a NRET quando os resultados foram expressos em termos absolutos ou proporcionais. Em conclusão, a inclusão de níveis práticos de FT ou CS não afeta significativamente o custo metabólico envolvido no metabolismo de N. Entretanto, apenas o FT foi capaz de contribuir para o balanço de N dos suínos, enquanto a quantidade N relativa a adição de CS foi totalmente recuperada nas fezes.
ABSTRACT
This study was conducted to obtain accurate data on the intake, digestibility and nitrogen balance of protein in Korean college women. Subjects were 8 female college students, aged from 21 to 23, and maintained their menu and life patterns regular during a 4-week study. The same amount of diet that the subjects had consumed, and feces and urine were collected and measured to extract their nitrogen content by Kjeldahl method. From this data, apparent digestibility and the body nitrogen balance were estimated by determing daily protein intake and excretion. The daily protein intake was 56.9+/-1.4g and daily fecal protein loss was 6.3+/-0.2g. The apparent digestibility of protein was 89.6+/-0.7%. The daily nitrogen intake measured by Kjeldahl method was 9.43+/-0.2g. The urinary nitrogen excretion was 7.64+/-0.23g and fecal nitrogen excretion was 1.02+/-0.03g. The nitrogen balance indicated a positive balance of 0.45+/-0.18g.