The choice of the most suitable litter treatment should be based on scientific evidence. This systematic review assessed the effectiveness of litter treatments on ammonia concentration, pH, moisture and pathogenic microbiota of the litter and their effects on body weight, feed intake, feed conversion and mortality of broilers. Methods The systematic literature search was conducted using PubMed (Medline), Google Scholar, ScienceDirect and Scielo databases to retrieve articles published from January 1998 to august 2019. Means, standard deviations and sample sizes were extracted from each study. The response variables were analyzed using the mean difference (MD) or standardized mean difference (SMD), (litter treatment minus control group). All variables were analyzed using random effects meta-analyses. Results Subgroup meta-analysis revealed that acidifiers reduce pH (P<0.001), moisture (P = 0.002) ammonia (P = 0.011) and pathogenic microbiota (P <0.001) of the litter and improves the weight gain (P = 0.019) and decreases the mortality rate of broilers (P<0.001) when compared with controls. Gypsum had a positive effect on ammonia reduction (P = 0.012) and improved feed conversion (P = 0.023). Alkalizing agents raise the pH (P = 0.035), worsen feed conversion (P<0.001), increase the mortality rate (P <0.001), decrease the moisture content (P<0.001) and reduce the pathogenic microbiota of the litter (P<0.001) once compared to controls. Superphosphate and adsorbents reduce, respectively, pH (P<0.001) and moisture (P = 0.007) of the litter compared to control groups.
RESUMO Objetivou-se avaliar os efeitos do óleo ácido de soja (OAS) sobre coeficientes de extinção específica da oxidação (K232 e K270) e a metabolizabilidade das dietas e o desempenho produtivo em codornas. Um total de 80 codornas de duplo propósito foram usadas num experimento com duração de 56 dias. Foi utilizado um delineamento completamente ao acaso com cinco níveis de tratamentos para OAS (0, 25, 50, 75 e 100%), com oito repetições de duas aves cada, como substituto ao óleo de soja refinado (OS) incluído até um nível máximo de 8% na formulação da dieta. O índice de acidez e os coeficientes K232 e K270 mostraram um efeito linear crescente (P<0,001) com o aumento dos níveis de inclusão de OAS na formulação das dietas. Os coeficientes K232 e K270 não foram alterados com o armazenamento das rações durante 7 dias. A suplementação com OAS durante 56 dias não afetou o desempenho produtivo das codornas. Os resultados não mostraram efeitos do OAS sobre a metabolizabilidade de ingredientes, exceto para gordura bruta que exibiu um efeito quadrático decrescente até o nível de 50% de substituição do óleo de soja por OAS (y= 94,31-1,186x+0,018x2, R2= 0,28, P= 0,02). Em conclusão, a inclusão de até 8% de OAS na dieta durante um período curto de tempo (56 dias) não produz efeitos adversos no desempenho produtivo de codornas.
The effects of diet supplementation with α-tocopherol acetate (VE) and selenium yeast (SeL) on the water holding capacity (WHC), cooking weight loss (CL), drip loss (DL), pH, colour and selenium concentration of the breast of chickens fed diets based on corn or brown rice were studied. From 21 days of age, a total of 200 birds were housed in 38 floor pens (experimental unit) in a randomised 2 3 factorial arrangement. The levels of supplementation were VE (0 and 200 mg/kg), organic selenium (0 and 0.3 ppm) and two diets (100% corn and 100% brown rice) in a total of eight treatments: T1) corn + 0 SeL + 0 VE (control); T2) corn + 200 mg/kg VE + 0 SeL; T3) corn + 0 VE + 0.3 ppm SeL; T4) corn + 200 mg/kg VE + 0.3 ppm SeL; T5) brown rice + 0 VE +0 SeL; T6) brown rice + 200 mg/kg VE + 0 SeL; T7) brown rice + 0 VE + 0.3 ppm SeL; T8) brown rice + 200 mg/kg VE + 0.3 ppm SeL. The concentration of selenium in the breast increased with VE supplementation in the diet (P < 0.001). However, a positive interaction between VE and SeL on selenium concentration in the meat was found (P = 0.06). A better WHC with the inclusion of SeL and VE was found only in the rice-based diets. The replacement of corn by brown rice decreased (P<0.05) the yellowness of the meat. CL and DL were not significantly affected by the treatments. Broilers fed with SeL supplemented diets showed a higher pH in the breast than diets without supplementation. In conclusion, the interaction between VE and SeL increased selenium in meat but improved WHC only in rice-based diets. The replacement of corn by brown rice decreased the yellowness of chicken breast meat. Key words: Colour. Cooking weight loss. Drip loss. pH. Water retention capacity.
ResumoForam estudados os efeitos da suplementação com acetato de alfa-tocoferol (VE) e seleno-levedura (SeL) Sel-Plex, Alltech® Inc, sobre o pH, a capacidade de retenção de água (CRA), perdas por cocção (PC), perdas por gotejamento (PG), cor do músculo e a concentração de selênio no peito de frangos alimentados com dietas a base de milho ou arroz. A partir de 21 dias de idade 200 frangos de corte Cobb foram alojados em 38 boxes (unidade experimental) num delineamento casualizado num arranjo fatorial 2x2x2 em que foram fixados os níveis de suplementação "on top" de VE (0 e 200 mg/kg), SeL (0 e 0,3 ppm) e dois ingredientes da dieta (100% milho e 100% arroz integral) totalizando oito tratamentos: T1) milho + 0SeL + 0VE (controle); T2) milho + 200mg/kg VE + 0SeL; T3) milho + 0VE + 0,3ppm SeL; T4) milho + 200mg/kg VE + 0,3ppm SeL; T5) arroz + 0VE +0SeL; T6) arroz + 200mg/kg VE + 0SeL; T7) arroz + 0VE + 0,3ppm SeL; T8) arroz + 200mg/kg VE + 0,3ppm SeL. A quantidade de selênio no peito foi maior (P < 0,0001) com a inclusão de 200mg/kg de VE, em comparação com os demais tratamentos. Entretanto, observou-se uma interação positiva entre VE e SeL na dieta sobre a quantidade de selênio recuperada na carne (P = 0,06). Foi encontrada melhor CRA com a inclusão de SeL e VE em dietas a base de arroz. A substituição do milho por arro...
The effects of increasing levels of soybean acid oil in diets of quails on the quality of eggs were evaluated over a period of 56 days. A completely randomized design with five treatment levels of soybean acid oil (0, 2, 4, 6, and 8%) as a replacer for soybean oil and eight replicates of two quails each were used. A total of 240 fresh eggs were used for quality analysis, and 400 eggs were stored at 23ºC over a period of 0, 7, 14, 21, and 28 days for analysis of shelf-life. Polynomial regression and ANOVA with repeated measurements and Tukey´s tests were used. Soybean acid oil linearly increased the intensity of red (a* = -5.26 + 0.14 x, R 2 = 0.89, P = 0.01) and yellow (b* = 42.32 + 0.44 x, R 2 = 0.88 P = 0.01). All other variables of egg qualitywere not affected by the treatments, with the exception of sensory attributes, such as odor and aftertaste, which were more pronounced with soybean acid oil. In conclusion, soybean acid oil affects the intensity of yellow and red color of the yolk. Trained assessors detected differences in odor and aftertaste of eggs when soybean acid oil was included in the quail diet.
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