Un estudio de las estrategias de asignación de valor de aminoácidos a las fitasas

Abstract

Se evaluó el comportamiento productivo de cerdos sometidos a una reducción de aminoácidos en la dieta. Durante 63 días, con un total de 96 cerdos en dos bloques y con peso inicial promedio de 42.7±4.58 kg, se estudiaron seis tratamientos producto de un arreglo factorial 2 × 3 (2 dietas, CP= dieta convencional y CN= dieta reducida en aminoácidos) y (3 equipares de fitasa: 0, sin fitasa; Fitasa A y Fitasa B). Semanalmente se registró el consumo de alimento; los cerdos se pesaron en intervalos de 21 días y se midió la profundidad de grasa y del músculo largo dorsal con un ultrasonido de tiempo real al inicio y final del ensayo; en los días 10, 31 y 52 del experimento, se determinó además la concentración plasmática de nitrógeno de urea. No hubo efectos en ninguna de las variables productivas (P>0.15), excepto en la eficiencia alimenticia acumulada a los 63 días (P<0.08), donde los tratamientos con fitasa fueron superiores. En la utilización de nutrientes, sólo hubo efecto de la dieta para lisina digestible (P<0.03), pero las concentraciones plasmáticas de nitrógeno de urea fueron las mismas (P<0.18). En conclusión, reducir la concentración de aminoácidos en dietas para cerdos desde los 40 kg de peso corporal, no afecta el comportamiento productivo por su capacidad para compensar diferencias en la densidad de nutrientes por el consumo; así el uso de fitasas debe proyectarse por la liberación de P y de energía.PALABRAS CLAVE: Cerdos, Crecimiento, Comportamiento productivo, Fitasa, Aminoácidos. ABSTRACTThe objective of this study was to evaluate the productive performance of growing pigs fed reduced amino acids diets by the use of phytase. During 63 d (three 21 d feeding phases), a total of 96 pigs in two blocks (consecutive farrowing groups), of an average initial weight of 42.7 ± 4.58 kg, were randomized to six treatments which consisted of a 2 x 3 factorial arrangement (conventional diet, a positive control= CP or reduced in amino acids by the addition of phytase, a negative control= CN) and (3 leads of phytase: 0, Phytase A or Phytase B). Weekly feed intake was recorded. At start and the end of each feeding-phase pigs were weighed and fat and muscle depths were measured using real time ultrasound. At the end of each feeding phase, blood samples were drawn to determine plasma urea nitrogen. Aside for final feed efficiency, which was slightly improved by phytase (P<0.08), there were no significant effects on any of the dependent variables during the 63 d trial (P>0.15). On the efficiency of utilization of nutrients, there was an obvious effect by level of digestible lysine (P<0.03), better in the lower lysine diets, although plasma urea nitrogen levels were the same for all treatments (P<0.18). In conclusion, a slight reduction in the concentration of amino acids, nor the addition of phytase to diets for pigs from 40 kg of body weight affect productive performance due to the inherent variation of the apportion and of the requirements.

Benzoic Acid Inclusion Effects on Health Status and Growth Performance of Juvenile Pacific White Shrimp Penaeus vannamei

“…Benzoic acid (BA; C 6 H 5 -COOH) is a common OA used in the food industry (Zuo et al 2002;Qualley et al 2012;Olmo et al 2017). It has fungal and microorganism growth inhibition properties and is used for preservation and flavor enhancement in fruit juices, wines, and pickles, as well as being used in the pharmaceutical industry (Chipley 2005;Pérez-Alvarado et al 2013;Giannenas et al 2014;Ng and Koh 2017;Olmo et al 2017). Although BA is considered safe, it has been reported to cause eye, skin, and respiratory tract irritation during short exposure periods.…”

“…It has fungal and microorganism growth inhibition properties and is used for preservation and flavor enhancement in fruit juices, wines, and pickles, as well as being used in the pharmaceutical industry (Chipley 2005; Pérez‐Alvarado et al. 2013; Giannenas et al. 2014; Ng and Koh 2017; Olmo et al.…”