Resumo Foi avaliado o efeito do estresse produzido pelo tempo de espera pré-abate sobre a produção de aminas biogênicas, pH e cor pelo sistema CIELab (onde três variáveis L*, a*, b* foram determinadas: L* indica a luminosidade, a* indica o vermelho e b* determina o amarelo) na carne de peito de frango. Antes do abate 25 frangos de carne foram selecionados e divididos em cinco grupos conforme o tempo de espera pré-abate (30 min ou 3 h), programação dia/noite (diurno ou noturno) e controle (sem tempo de espera). Após abate, os peitos (M. Pectoralis major) foram separados, estocados por 9 dias a 4°C, e analisados cada 3 dias. Os resultados evidenciaram uma redução do pH nas aves que aguardaram o abate na noite. Além disso durante a estocagem incrementou-se os valores de aminas biogênicas e da luminosidade (L*) e houve redução dos teores de vermelhos (a*) no tempo de espera de três horas (diurno ou noturno). As concentrações da cadaverina incrementaram-se a partir do dia 6 de estocagem. O tempo e horário de espera em frangos de carne pode é um fator de estresse pré-abate que afeta a qualidade da carne. Contudo, é recomendável realizar o abate dos frangos imediatamente após de sua chegada ao centro de abate.

Abstract The effect of pre-slaughter lairage stress on biogenic amines, pH, and color with the CIELab system (where three variables L*, a*, b* are estimated: L* for lightness, a* defines redness, and b* defines yellowness) in chicken breast meat was investigated. Before slaughtering, 25 broilers were selected and divided into five groups according to lairage holding time (30 min or 3 h), day/night schedule (daylight or nighttime) and control (no lairage). After slaughtering, breasts (M. Pectoralis major) were removed, stored for 9 days at 4 °C, and analyzed every 3 days. The results showed a pH decrease during nighttime holding. Also, a three-hour pre-slaughter holding (daytime or night) resulted in high biogenic amine concentration, increase in lightness (L*), and reduction in redness (a*) during storage. Cadaverine concentration showed a rapid increase from day 6 onward. The time and schedule of chicken lairage is a pre-slaughter stress factor that affects meat quality. Based on these observations, it is recommended to slaughter chickens immediately on arrival at the processing plants.

Abstract Enteric methane (CH4) is produced during the process of energetic fermentation and represents an energy loss of 2 to 15 %. The seeds of oleaginous plants in the feed of ruminants are an alternative for reducing the production of CH4. Therefore, the objective of the present study was to determine in vitro the production of CH4, carbon dioxide (CO2) and the fermentative characteristics in diets for lambs with different levels of sunflower seed. Treatments were 0 (T1), 6 (T2), 12 (T3) and 18 % (T4) of inclusion of sunflower seed in the base diet. The diets were evaluated for production of CH4, CO2, production of volatile fatty acids (VFA), degradation of dry matter (DEGDM), neutral detergent fiber (DEGNDF) and acid detergent fiber (DEGADF), as well as the total bacteria count (TB) at 72 h of incubation. The experimental design was completely randomized, and an analysis of orthogonal polynomials was made to evaluate the linear and quadratic effects of the treatments. When the content of sunflower seed in the diet was increased, there was a reduction of DEGDM, DEGNDF and DEGADF (p≤0.05). The content of VFA after 72 h of fermentation showed a linear reduction (p≤0.05) when the content of sunflower seed was increased. The production of CH4, CO2 and TB count did not present differences among treatments (p>0.05). Therefore, increasing the amount of sunflower seed in the diet reduced the degradation capacity of its components.

Resumen El metano (CH4) entérico se produce durante el proceso de fermentación energética y representa una pérdida energética de 2 a 15 %. Las semillas de oleaginosas en la alimentación de rumiantes son una alternativa para disminuir la producción de CH4. Por lo tanto, el objetivo del presente estudio fue determinar in vitro la producción de CH4, bióxido de carbono (CO2) y las características fermentativas en dietas para corderos con diferentes niveles de semilla de girasol. Los tratamientos fueron 0 (T1), 6 (T2), 12 (T3) y 18 % (T4) de inclusión de semilla de girasol en la dieta base. En las dietas se evaluó la producción de CH4, CO2, producción de ácidos grasos volátiles (AGV), degradación de la materia seca (DEGMS), fibra detergente neutro (DEGFDN) y fibra detergente ácida (DEGFDA); así como, el conteo total de bacterias (BT) a las 72 h de incubación. El diseño experimental fue completamente al azar y se realizó un análisis de polinomios ortogonales para evaluar los efectos lineal y cuadrático de los tratamientos. Al aumentar el contenido de semilla de girasol en la dieta se disminuyó DEGMS, DEGFDN y DEGFDA (p≤0.05). El contenido de AGV después de 72 h de fermentación mostró una disminución lineal (p≤0.05) al incrementar el contenido de semilla de girasol. La producción de CH4, CO2 y el conteo de BT no presentaron diferencias entre tratamientos (p>0.05). Así, el aumento de la semilla de girasol en la dieta disminuye la capacidad de degradación de sus componentes.

As an alternative for giving a selenium supplement, intraruminal boluses of 3 and 10 g (total weight) were designed and tested in lambs and adult sheep. The ingredients were: sodium selenite (5.23%) as source of Se; to regulate its release and maintain its mass and density, Fe 68.77%; cutin 25%; magnesium stearate 1%. Eight Pelibuey lambs (6 months of age) were used in metabolic cages for 15 d. Later, they received T type ruminal cannulas, and were fed a diet low in Se (0.06 µg g -1); the treatments were as follows: a control group without Se, and a group supplemented with bolus of Se (3 g). In the performance trial test, 20 Columbia ewes were used: 10 in the control group and 10 that received bolus (10 g). In the lambs, the bolus released Se without affecting the ruminal pH (p>0.05). The model for the degradation of the bolus in time effect within the ruminal medium was: Weight (g) = 3.0106 - 8-5(d) - 2-6(d)², (r = 0.97). In the behavior test with the ewes, the bolus of Se increased the concentrations of blood Se by 22.6 and 72% at 60 and 90 d (p<0.05). It is concluded that the intraruminal bolus used in this assay constitutes an adequate and reliable technology for correcting the deficiency of Se and maintaining adequate concentrations of Se in sheep.

Como alternativa para dar un suplemento de selenio se diseñaron y ensayaron bolos intrarruminales de 3 y 10 g (peso total) en corderos y ovinos adultos. Los ingredientes fueron: selenito de sodio (5.23%) como fuente de Se; para regular su liberación y mantener su masa y densidad, Fe 68.77%; cutina 25%; estearato de magnesio 1%. Se usaron ocho corderos Pelibuey (6 meses edad) en jaulas metabólicas por 15 d. Luego recibieron cánulas ruminales tipo T y fueron alimentados con una dieta baja en Se (0.06 µg g-1); los tratamientos fueron: un grupo testigo sin Se, y un grupo complementado con bolo de Se (3 g). En la prueba de comportamiento se usaron 20 ovejas Columbia: 10 en el grupo testigo y 10 que recibieron bolos (10 g). En los corderos, los bolos liberaron Se sin cambiar el pH ruminal (p>0.05). El modelo para la degradación del bolo en efecto tiempo dentro del medio ruminal fue: Peso (g) = 3.0106 - 8 -5(d) - 2-6(d)², (r=0.97). En la prueba de comportamiento con las ovejas el bolo de Se aumentó las concentraciones de Se sanguíneo en 22.6 y 72% a los 60 y 90 d (p<0.05). Se concluye que el uso de bolos intrarruminales es una tecnología adecuada y confiable para corregir la deficiencia de Se y mantener concentraciones adecuadas de Se en ovinos.