Desempenho de frangos de corte de 1 a 21 dias de idade alimentados com rações contendo extrato de leveduras e prebiótico e criados em diferentes temperaturas

Abstract

(1 a 7 dias), de modo que, a partir do oitavo dia, todas as aves receberam a mesma ração. Adotou-se o delineamento experimental inteiramente casualizado, em arranjo fatorial 3 × 2 × 2, composto de 3 temperaturas de criação (alta 34 ± 1 o C; controle 32 ± 2 o C; e baixa 27 ± 2 o C), 2 níveis de extrato de levedura (com ou sem) e 2 níveis de prebiótico (com ou sem).As temperaturas ambiente alta e baixa prejudicaram o desempenho das aves aos 7 e aos 21 dias de idade. A inclusão de prebiótico na ração pré-inicial melhora o ganho de peso das aves criadas sob baixa temperatura aos 21 dias de idade e aumenta a viabilidade até os 21 dias de idade. A adição do extrato de leveduras melhora a conversão alimentar aos 21 dias de idade. Palavras-chave: estresse térmico, mananoligossacarídeos, ração pré-inicial, Saccharomyces cerevisiae Performance of broilers from 1 to 21 days old fed diets with yeast extract and prebiotic, reared at different temperaturesABSTRACT -The performance of broilers reared at different temperatures and fed diet with or without yeast extract and/or prebiotic in the starter phase was evaluated. One thousand, four hundred and forty 1-d male Cobb-500® were reared at different climatic chambers. The diets with or without yeast extract or prebiotic were fed only in the starter phase(1 to 7 days), and from the 8 th day on all broiler were fed the same commercial diet. It was used a complete randomized experimental design, as a 3 × 2 × 2 factorial arrangement, with 3 rearing temperatures (high 34 ± 1 o C, control 32 ± 2 o C and low 27 ± 2 o C), 2 yeast extract level (with or without) and 2 prebiotic level (with or without). High and low temperatures decreased the performance of brids at 7 and 21 days old. The inclusion of prebiotic in the pre-starter phase increased weight gain of birds under low temperature at 21 days old and the viability until 21 days old. The inclusion of yeast extract increase feed conversion at 21 days old.

Thermal comfort temperature update for broiler chickens up to 21 days of age

“…However, from this point, there is a reduction in weight gain with increasing temperature. These results differ from those found by MAY & LOTT (2000), who found higher values of weight gain of male chicks during the second week of growth, for the temperature range of between 25.8 ºC and 27.9 ºC and the results of SILVA et al (2009), who observed higher values of weight gain at 28±2 ºC.…”

“…Again, it was found that temperature bands of comfort, heretofore proposed, are above those really best suited to the performance of broiler chickens of all ages. SILVA et al (2009) also observed increased feed conversion in broilers subjected to heat stress (31±3 °C) compared to those kept in thermal comfort conditions (28±2 °C) during the second week of life. Body weight and room temperature Figure 3 shows the effect of room temperature on body weight of the broilers.…”

“…Thus, there can be reduced 2.7 °C in room temperature, relative to that ideal as hitherto understood, resulting in energy savings for heating in the initial growth without compromising broilers performance. However, SILVA et al (2009) reported values of weight gain of the broilers in the first phase of growth, 12% higher when kept at temperature of 31.4 ºC, compared to those maintained at 34±1 ºC.…”

Effect of thermal environment on performance of broiler chickens using fuzzy modeling

“…The results of this work are similar to those found by Oliveira et al (2006), working with 1-21-day-old broilers, observed a 14% reduction in FI in birds kept in hightemperature environments. Silva et al (2009), evaluating the performance of 1-21-day-old broilers raised at different temperatures, concluded that the high temperature in stage 1-7 days old increased FC, which presented the best values in control , respectively, corresponding to the percentage error measured of 1.20, 0.02, and 2.17% (Table 3). According to the linear regressions, with straight adjustment through the origin, R 2 = 0.998, 0.999, and 0.995 for FI, WG, and FC, respectively (Figure 3).…”

Avaliação do uso de leveduras (Saccharomyces cerevisiae) inativas e hidrolizadas nas dietas iniciais de leitões

“…Na forma de ácidos nucléicos, os nucleotídeos são de importância fundamental por serem as bases do código genético. Os ácidos nucléicos quando conjugados a proteínas são chamados de nucleoproteínas(LEHNINGER et al, 1995).Os nucleotídeos são tradicionalmente utilizados na alimentação humana, principalmente em dietas para recém-nascidos, e atuam no desenvolvimento do trato gastrintestinal, no funcionamento do sistema imune e na manutenção da flora intestinal(SILVA et al, 2009). Para que os nucleotídeos presentes nas leveduras se tornem disponíveis é necessário um tratamento enzimático que consiste de autólise em que a própria levedura é induzida a produzir enzimas.…”