Effects of the addition of pure glycerin supplementation in the drinking water on the performance of broilers submitted to heat stress and feed restriction

The experiment was conducted to study the effect of pure glycerin supplementation (GLYC) in the drinking water of broilers subjected to heat stress and feed restriction. Water with 0, 1, or 2% glycerin was provided ad libitum to broilers in six hours of feed restriction. The birds were housed in two environments: thermoneutral (TN) - 25 ° C, and cyclic heat stress (HS) - 12h with 250C, 6h with 320C, 3h of 250 to 320C and 3h of 320 to 250C. The experimental design was randomized in a factorial arrangement of 2 x 3 + 2, with three GLYC levels, two environments and one control group with ad libitum feeding each environment. When submitted to HS, broiler receiving 2% glycerin presented higher weight gain (WG), water consumption (WC), feed intake (FI) and energy consumption (EI) than those in the other treatments, contrarily to birds in TN, where increasing GLYC levels decreased those responses. Broilers submitted to feed restriction presented reduced FI, but better feed conversion (FCR), independently of rearing environment or GLYC levels. Broilers under HS submitted to feed restriction and receiving 2% GLYC presented higher WC (p < 0.05) and similar WG as the controls, differently from the restricted-fed broilers under TN receiving 2% GLYC, which WC and WG were lower than the controls. The inclusion of 2% pure glycerin in the drinking water may compensate the negative effects on performance caused by feed restriction in broilers submitted to heat stress.(AU)

Effects of the addition of pure glycerin supplementation in the drinking water on the performance of broilers submitted to heat stress and feed restriction

The experiment was conducted to study the effect of pure glycerin supplementation (GLYC) in the drinking water of broilers subjected to heat stress and feed restriction. Water with 0, 1, or 2% glycerin was provided ad libitum to broilers in six hours of feed restriction. The birds were housed in two environments: thermoneutral (TN) - 25 ° C, and cyclic heat stress (HS) - 12h with 250C, 6h with 320C, 3h of 250 to 320C and 3h of 320 to 250C. The experimental design was randomized in a factorial arrangement of 2 x 3 + 2, with three GLYC levels, two environments and one control group with ad libitum feeding each environment. When submitted to HS, broiler receiving 2% glycerin presented higher weight gain (WG), water consumption (WC), feed intake (FI) and energy consumption (EI) than those in the other treatments, contrarily to birds in TN, where increasing GLYC levels decreased those responses. Broilers submitted to feed restriction presented reduced FI, but better feed conversion (FCR), independently of rearing environment or GLYC levels. Broilers under HS submitted to feed restriction and receiving 2% GLYC presented higher WC (p < 0.05) and similar WG as the controls, differently from the restricted-fed broilers under TN receiving 2% GLYC, which WC and WG were lower than the controls. The inclusion of 2% pure glycerin in the drinking water may compensate the negative effects on performance caused by feed restriction in broilers submitted to heat stress.

Alimentação de suínos em terminação com dietas contendo extratos cítricos e ractopamina: características químicas e perfil de ácidos graxos / Do músculo longissimus dorsi feeding finishing pigs with diets containing ractopamine and citrus extracts: chemical characteristics and fatty acid profile of longissimus dorsi muscle

Um experimento foi realizado para avaliar o efeito da adição de extratos cítricos e ractopamina a dietas de suínos em terminação. Foram utilizados 108 suínos (54 machos e 54 fêmeas), homogêneos geneticamente e peso vivo médio inicial de 61 quilogramas. O delineamento experimental foi o inteiramente casualizado, bloqueado por sexo e com nove tratamentos: T1. controle (C) (0 ppm de ractopamina e 0 ppm de extratos cítricos), T2. C + 10 RAC (ractopamina, em ppm), T3. C + 20 RAC, T4. C + 250 EC (extratos cítricos, em ppm), T5. C+ 500 EC, T6. C + 250 EC + 10 RAC, T7. C + 250 EC + 20 RAC, T8. C+ 500 EC + 10 RAC e T9. C + 500 EC + 20 RAC. Foram utilizados dois sexos, com duas repetições e seis animais por unidade experimental. Foram avaliadas amostras do músculo Longissimus dorsi quanto à umidade, cinzas, proteínas, lipídios e perfil de ácidos graxos. Os teores de proteína para a inclusão de 20 ppm de RAC foram em média 5,5% superiores (P<0,05) aos dois níveis de EC na dieta. A umidade do músculo nas amostras dos animais que receberam 500 ppm de EC e 20 ppm de RAC foi 4,3% superior (P<0.05) ao controle e 500 ppm de extratos cítricos. Os teores do ácido linoléico da interação 500 ppm de EC e 10 ppm de RAC foi 18% superior (P<0,05) em relação à inclusão de 500 ppm de extratos cítricos. Os teores do ácido a-Linolênico do controle foi 33,5% superior (P<0,05) aos níveis de extratos cítricos, ractopamina e suas interações. A concentração do ácido araquidônico da interação 250 ppm de EC e 20 ppm de RAC foi 36% superior (P<0,05) aos teores de 20 ppm de ractopamina. Níveis mais altos de ractopamina às dietas influenciam os teores de proteína e umidade do músculo. Os extratos cítricos influenciam os teores do ácido graxo láurico. A adição de ractopamina altera o perfil de alguns ácidos graxos insaturados do músculo Longissimus dorsi.

This study was carried out to evaluate the effect of the addition of the citrus extracts and ractopamine in finishing pig diets. Hundred eight pigs were used (54 males and 54 females) in a completely randomized design, blocked by sex and distributed in nine treatments: T1. control (C) (0 ppm of the ractopamine e 0 ppm of the citrus extracts), T2. C + 10 RAC (ractopamine, ppm), T3. C + 20 RAC, T4. C + 250 EC (citrus extracts, ppm), T5. C+ 500 EC, T6. C + 250 EC + 10 RAC, T7. C+ 250 EC + 20 RAC, T8. C+ 500 EC + 10 RAC e T9. C+ 500 EC + 20 RAC. We used two sexes, with two replications and six animals per experimental unit. The levels of protein for the inclusion of 20 ppm of RAC were on average 5.5% higher (P <0.05) the two EC levels in the diet. The moisture in the muscle samples from the animals that received 500 ppm EC and 20 ppm RAC was 4.3% higher (P <0.05) the control and 500 ppm of citrus extracts. The levels of linoleic acid in the interaction of 500 ppm EC and 10 ppm RAC was 18% higher (P <0.05) compared to the inclusion of 500 ppm of citrus extracts. The levels of a-linolenic acid of the control was 33.5% higher (P <0.05) of citrus extracts levels, ractopamine and their interactions. The concentration of arachidonic acid from the interaction of EC 250 ppm and 20 ppm RAC was 36% higher (P <0.05) to levels of 20 ppm of ractopamine. Higher levels of ractopamine in the diet influence the levels of protein and moisture of the muscle. Citrus extracts influence the levels of the fatty acid lauric acid. The addition of ractopamine change the profile of some unsaturated fatty acids of the Longissimus dorsi.