ABSTRACT
Abstract Background: Creatine and its precursor, guanidinoacetic acid (GAA), decrease protein degradation, avoiding amino acid offset to gluconeogenesis. Objective: To evaluate the inclusion of GAA in the pre-initial diet (1 to 7 days) on performance, digestibility, and blood parameters of broilers from one to 21 days of age. Methods: 252 male broiler chickens aged one day were distributed in a completely randomized design with seven replicates and 12 animals per experimental unit. Treatments consisted of a basal diet, and the basal added with 0.10 and 0.20% GAA. Results: From days 1 to 7, a tendency on improved feed conversion (FC) was observed for broilers receiving 0.20% GAA (p<0.10). Between 7 and 14 days, FC improved, as well as a tendency was observed on improved weight gain in animals fed 0.20% GAA. Animals that received 0.20% GAA showed higher blood concentrations of creatine kinase. Blood creatine and blood glucose did not differ between treatments at day six. The assimilation coefficient of crude protein increased during days 3 to 7 for animals receiving 0.20% GAA. On the period between 17 and 21 days, no difference was observed between treatments. Intestinal weight and length did not show significant differences. Conclusion: Dietary inclusion of 0.20% GAA during the pre-initial stage could improve weight gain and feed conversion of broilers between 1 and 14 days of age.
Resumen Antecedentes: La creatina suministra energía y el ácido guanidinoacético (GAA) es su precursor y actúa como sustrato energético, reduciendo la degradación proteica y evitando el desvío de aminoácidos para gluconeogénesis. Objetivo: Evaluar el GAA en la dieta de pre-iniciación (1 a 7 dias) sobre el desempeño, la digestibilidad y los parámetros sanguíneos de pollos entre 1 y 21 dias de edad. Métodos: Se utilizaron 252 pollitos de engorde machos de un día de edad, distribuidos en un diseño completamente al azar, con siete repeticiones y 12 aves por unidad experimental. Los tratamientos consistieron en: ración basal y ración basal adicionada con 0,10 y 0,20% de GAA. Resultados: En el período de 1 a 7 días se observó una tendencia de mejora de la conversión alimenticia (FC) en las aves que recibieron 0,20% de GAA (p<0,10). De 7 a 14 días hubo mejoría en FC y tendencia de mejora en ganancia de peso de los animales que recibieron 0,20% de GAA. Los animales que recibieron 0,20% de GAA presentaron mayor concentración sanguínea de creatina quinasa. La creatinina y la glucosa sanguínea a los seis días no difirieron entre los tratamientos. El coeficiente de metabolización de la proteína bruta aumentó en el período de 3 a 7 días en los animales que recibieron 0,20% de GAA. Para el período de 17 a 21 días no hubo diferencia entre los tratamientos. Para peso y longitud del intestino no se presentaron diferencias significativas. Conclusión: El GAA a un nivel de 0,20% en la dieta pre- inicial podria mejorar la ganancia de peso, y la conversión alimenticia en el período de 1 a 14 días de edad en pollos de engorde.
Resumo Antecedentes: A creatina é uma substância que fornece energia e o ácido guanidinoacético (GAA) é seu precursor atuando como substrato energético, menor degradação proteica evitando o desvio de aminoácidos para gliconeogênese. Objetivo: Avaliar o GAA em dietas pré-iniciais sobre o desempenho, a digestibilidade e parâmetros sanguíneos. Métodos: Foram utilizados 252 pintos de corte machos de um a 21 dias de idade distribuído sem delineamento inteiramente casualizado, sete repetições e 12 aves por unidade experimental. Os tratamentos consistiram: ração basal e rações com 0,10 e 0,20% de GAA. Resultados: No período de 1 a 7 dias foi observada tendência de melhora da conversão alimentar (FC) (p<0,10) quando as aves receberam 0,20% de GAA. No período de 7 a 14 dias houve melhora na FC e tendência de melhora do ganho de peso dos animais que receberam 0,20% de GAA. Animais que receberam 0,20% de GAA apresentaram concentração sanguínea da enzima creatina quinase maior. A creatinina sanguínea aos seis dias e glicose sanguínea não diferiram entre os tratamentos. O coeficiente de metabolização da proteína bruta foi aumentado no período de 3 a 7 dias para animais que receberam 0,20% de GAA, para o período de 17 a 21 dias não houve diferença entre os tratamentos. Peso e comprimento do intestino não apresentaram diferenças significativas. Conclusão: O GAA em nível de 0,20% na dieta pré-inicial melhoram o ganho de peso, e a conversão alimentar no período de 1 a 14 dias de idade em frangos.
ABSTRACT
Calorie restriction (CR) has been reported to have pro-longevity effects in a myriad of species. However, a deleterious effect of CR on reproduction is also observed, though seemingly negligible if CR is very mild. Full or partial suppression of reproduction by CR is worthy of concern when envisioning the use of this methodology to prolong lifespan in humans. Our aim was to investigate the effects of mild CR on several reproductive parameters, such as the onset of puberty, fertility, reproductive organ bi ometry, testis morphometry and testosterone and cholesterol plasma levels. Therefore, male Wistar rats were subjected to 30%CR from age 24 days until the ages of 50 and 150 days. Age-matched animals received food ad libitum (AL) and served as controls. The day of onset of balano-preputial separation, indicative of puberty, showed no difference between diet groups. In relation to the fertility parameters evaluated, considering mainly the number of pups per female, there was a trend for better performance in CR rats. Body weight, as well as the absolute and relative weights of the epididymal fat pad, was reduced by CR at both ages investigated, whereas testosterone and cholesterol plasma levels were not changed. The weight of ventral prostate, also the tubular diameter and luminal size were smaller in CR rats at age 50 days, but seemed to recover later since no differences were observed at age 150 days. In conclusion, our results suggested that 30%CR does not compromise reproduction in male Wistar rats.(AU)
Subject(s)
Animals , Rats , /physiology , Biometry/methods , Rats, Wistar/classification , Rats/classificationABSTRACT
Calorie restriction (CR) has been reported to have pro-longevity effects in a myriad of species. However, a deleterious effect of CR on reproduction is also observed, though seemingly negligible if CR is very mild. Full or partial suppression of reproduction by CR is worthy of concern when envisioning the use of this methodology to prolong lifespan in humans. Our aim was to investigate the effects of mild CR on several reproductive parameters, such as the onset of puberty, fertility, reproductive organ bi ometry, testis morphometry and testosterone and cholesterol plasma levels. Therefore, male Wistar rats were subjected to 30%CR from age 24 days until the ages of 50 and 150 days. Age-matched animals received food ad libitum (AL) and served as controls. The day of onset of balano-preputial separation, indicative of puberty, showed no difference between diet groups. In relation to the fertility parameters evaluated, considering mainly the number of pups per female, there was a trend for better performance in CR rats. Body weight, as well as the absolute and relative weights of the epididymal fat pad, was reduced by CR at both ages investigated, whereas testosterone and cholesterol plasma levels were not changed. The weight of ventral prostate, also the tubular diameter and luminal size were smaller in CR rats at age 50 days, but seemed to recover later since no differences were observed at age 150 days. In conclusion, our results suggested that 30%CR does not compromise reproduction in male Wistar rats.