Metabolizable energy equivalence of guanidinoacetic acid in corn soybean meal-based broiler diets

ABSTRACT In this study, we evaluated how guanidinoacetic acid (GAA) addition in diets with various metabolizable energy (ME) contents affects the performance of broiler chickens. We also estimated the equivalence of GAA in ME. We distributed 1,280 one-day-old broilers in a completely randomized design with eight treatments, eight replicates, and twenty birds per experimental unit. Treatments were based on ME levels (2,775-2,875-2,975 kcal/kg; 2,850-2,950-3,050 kcal/kg; 2,925-3,025-3,125 kcal/kg; or 3,000-3,100-3,200 kcal/kg, from 1 to 7, 8 to 21, and 22 to 42 days of age) and the inclusion of GAA (0 or 600 mg/kg). Supplementation of GAA increased weight gain in broilers at an energy level of 2,908 kcal/kg and improved feed conversion ratio (FCR) at energy levels of 2,908 and 2,983 kcal/kg. There was a linear reduction in feed intake and an improvement in FCR of broilers with increasing levels of energy in diets, with and without GAA addition. Solving the equivalence equation, by applying each of the weighted average energy levels studied. indicates the GAA equivalence of 133, 103, 74, and 44 kcal/kg of diet. In conclusion, GAA supplementation improves broilers’ efficiency of energy use; the average ME equivalence of 600 mg/kg of GAA is 88.5 kcal/kg

Bioavailability of an organic zinc source for broilers

Objetivou-se avaliar o efeito da suplementação do mineral zinco de diferentes fontes, orgânica (quelato de zinco) e inorgânica (sulfato de zinco), sob o desempenho, o balanço e a biodisponibilidade relativa (BDR) em frangos de corte. Os animais foram criados de 1 a 9 dias recebendo uma dieta basal contendo, milho, farelo de soja e fitase, suplementada com 50% da recomendação de Rostagno et al. (2017), para o mineral zinco. Em seguida, de 10 a 20 dias, considerou-se o período experimental, onde as aves receberam as dietas experimentais, constituídos por suplementações de níveis de zinco, em, 0; 20; 40; e 80 mg/ Kg ração. Os demais microminerais foram fornecidos atendendo o recomendado pelo mesmo autor. Foram utilizados 400 pintos de corte machos distribuídos em delineamento experimental inteiramente casualizados (DIC) com 8 tratamentos, 10 repetições e 5 aves por unidade experimental. Todos animais e rações foram pesados no início e final do experimento, para mensuração do ganho de peso, peso final, consumo de ração e conversão alimentar. No 15o ao 20odia, foi realizada a coleta total de excretas, para determinar o consumo, excreção, retenção (mg/ave/dia) e balanço (%) de zinco. Os resultados indicaram que a suplementação de 32,5 mg/kg de zinco de fonte inorgânica maximiza o peso final dos animais (sendo este a necessidade mínima para que as aves melhoram seu desempenho). Foi observada menor excreção e maior retenção (P < 0,05) de zinco pelas aves submetidas aos tratamentos com a fonte orgânica, principalmente para os níveis de 40 e de 80 mg/kg, assim como para o balanço de Zn (P < 0,05). Os maiores valores de balanço (%) foram obtidos com 69,6 e 52,8 mg/kg, respectivamente para fontes inorgânica e orgânica. A BDR do zinco fonte orgânica, foi estimada em 165,6 % considerando o zinco inorgânico com biodisponibilidade de 100%. Palavras-chave: Biodisponibilidade. Quelato de zinco. Desempenho animal. Nutrição animal.It was objectified to evaluate the effect of supplementation of the zinc from different sources, organic (zinc chelate) and inorganic (zinc sulfate), underperformance, balance, and relative bioavailability (BDR) in broilers. The animals were bred from 1 to 9 days receiving a basal diet containing corn, soybean meal, and phytase, supplemented with 50% of the recommendation by Rostagno et al. (2017), for the mineral zinc. Then, from 10 to 20 days, the experimental period was considered, where the birds received the experimental diets, constituted by supplementations of zinc levels, in, 0; 20; 40; and 80 mg/kg feed. The other micro minerals were supplied in compliance with the recommendations of the same author. 400 male broiler chicks were used in a completely randomized design (DIC) with 8 treatments, 10 repetitions, and 5 birds per experimental unit. All animals and rations were weighed at the beginning and end of the experiment, to measure weight gain, final weight, feed consumption, and feed conversion. On the 15th to the 20th day, the total collection of excreta was carried out to determine the consumption, excretion, retention (mg/bird/day), and zinc balance (%). The results indicated that the supplementation of 32.5 mg/kg of inorganic zinc maximizes the final weight of the animals (this being the minimum need for birds to improve their performance). Less zinc excretion and greater retention (P <0.05) were observed in birds submitted to treatments with the organic source, mainly for the levels of 40 and 80 mg/kg, as well as for the Zn balance (P <0, 05). The highest balance values (%) were obtained with 69.6 and 52.8 mg/kg, respectively for inorganic and organic sources. The BDR of organic source zinc was estimated at 165.6% considering inorganic zinc with 100% bioavailability. Keywords: Bioavailability. Zinc chelate. Animal performance. Animal nutrition.Conselho Nacional de Desenvolvimento Científico e Tecnológic

Qualidade físico-química e sensorial de ovos de galinhas submetidos a tratamento superficial da casca armazenados sob refrigeração

Objetivou-se avaliar a qualidade físico-química e sensorial de ovos de galinha, mantidas sob piso, tratados superficialmente com óleo mineral, gelatina sem sabor a 6% e soluções de própolis (15 e 20%) estocados sob refrigeração (Incubadora B.O.D: 7,9ºC e 41,9% de umidade relativa). Para o experimento de qualidade físico-química, realizou um delineamento inteiramente casualizado em esquema fatorial 5 x 5 (sem tratamento; própolis 15%; própolis 20%; gelatina a 6% e óleo mineral, durante cinco semanas de estocagem) com seis repetições de quatro ovos cada. Foram avaliados: perda de peso dos ovos (%); peso específico dos ovos (g/cm³); unidades Haugh; peso (g) e pH do albúmen; peso (g), pH, índice e cor da gema. O tratamento com óleo mineral seguido da gelatina e da solução de própolis a 15% promoveu proteção contra a perda progressiva de peso e diminuição do peso específico e das unidades Haugh. Foram realizados testes de aceitabilidade de ovos com 14 e 28 dias para avaliação dos atributos: cor, aroma, sabor e impressão global, através de uma escala hedônica de 9 pontos. Não houve diferença significativa aos 14 dias de armazenagem, contudo aos 28 dias houve diferença significativa para os atributos cor, sabor e impressão global, com menores notas atribuídas aos ovos tratados com óleo mineral. A qualidade físico-química e sensorial dos ovos de galinhas, submetidos a tratamento superficial da casca por imersão com óleo mineral, gelatina sem sabor a 6% e própolis a 15% e a 20% são preservadas por cinco semanas de estocagem sob refrigeração.The objective of this study was to evaluate the physical-chemical and sensorial quality of chicken eggs, kept under the floor, treated with mineral oil, 6% unflavored gelatin and propolis solutions (15 and 20%) stored under refrigeration (BOD incubator: 7.9oC e 41,9% relative humidity). For the physico-chemical quality experiment, a completely randomized design was carried out in a 5 x 5 factorial scheme (no treatment, 15% propolis, 20% propolis, 6% gelatin and mineral oil for five weeks of storage) with six Repetitions of four eggs each. The following were evaluated: egg weight loss (%); Specific weight of eggs (g/cm3); Haugh units; Weight (g) and pH of the albumen; Weight (g), pH, index and color of the yolk. Treatment with mineral oil followed by gelatin and 15% propolis solution provided protection against progressive loss of weight and reduction of specific weight and Haugh units. Eggs were accepted for acceptance of eggs with 14 and 28 days to assess the attributes: color, aroma, flavor and overall impression, through a hedonic scale of 9 points. No significant difference was found for 14 days of storage, however at 28 da differences for color,flavor and overall impression, were significative, with lower grades attributed to mineral oil treated. The physico-chemical and sensorial quality of hens eggs, submitted to surface treatment of the shell by immersion with mineral oil, 6% unflavored gelatin and 15% and 20% propolis, are preserved for five weeks under refrigerated storage

Semi-posed hens reared on different bed types

<p></p><p>SUMMARY In the system of creation in floor the hens are created directly in contact with the floor that can be covered by different types of materials. The aim of this study was to evaluate the thermal environment, behavior, zootechnical indexes and quality of chicken eggs created in two types of flooring, wooden shavings and synthetic grass, were used 120 semi-heavy laying hens, Hysex Brown®, of these, half were created on wooden shaving and half on synthetic grass (Carpet Astro Turf®) distributed in a completely randomized in repeated measures in time in two treatments and two replications of 30 laying hens, during 56 days (two periods of 28 days). Were evaluated temperatures maximum and minimum, dry and wet bulb temperature, black globe temperature, relative humidity, temperature and humidity index and black globe temperature and humidity index; the frequency of natural behavior; the daily egg production per bird, per bird housed, and marketable, viability, feed consumption and feed conversion per dozen and per mass, average egg weight, specific weight and egg shell thickness. Data were analyzed using analysis of variance and means compared by F test at 0.05 probability, except the frequency of natural behavior that was analyzed using the chi square analysis test. The results show that the values of the zootechnical indexes of the layers are consistent with the guide strains recommendations, having no influence from the kind of floor used as bed. Only significant differences were observed in the feed intakeper mass of birds grown under synthetic grass. Thus, it seems that synthetic grass could be an excellent substrate for the bed of semi-heavy laying hens in the egg production phase.</p><p></p

Purified lignin supplementation on the performance and antioxidant status of broilers subjected to cyclic heat stress

The objective of this study was to evaluate the effects of dietary supplementation of purified lignin on the performance, relative organ weights, serum metabolites, and gene expression profiles of broiler chickens subjected to cyclic heat stress (HS). At 22 days old, 280 broilers were distributed in a completely randomized design with four treatments, ten repetitions, and seven birds per experimental unit. The birds were subjected to daily cyclic HS. A high temperature of 32±1 °C was maintained for 10 h/day (08:00–18:00 h), while a temperature of 22±1 °C was maintained for the remaining time. Treatments were a basal diet or basal diet with the addition of 5, 10, or 15 g of purified lignin/kg of diet. Data were analyzed using one-way ANOVA and means were compared by Tukey’s test at 0.05 significance. There was no effect of lignin supplementation on performance, carcass yield, relative weights of the bursa, spleen, and liver, or serum levels of glucose, triglycerides, uric acid, malondialdehyde, triiodothyronine, or tetraiodothyronine. The abundance of mRNA of heat shock protein 70, nuclear factor-κB, glutathione peroxidase, and Cu,Zn-superoxide dismutase in the liver was similarly unaffected by treatments. Purified lignin supplementation does not improve performance or the antioxidant response of broiler chickens subjected to H