Evaluation of piglet birth weight on growth performance and qualitative and quantitative characteristics of carcasses of immunocastrated pigs

The objective of this study was to determine the effect of birth weight on growth performance, carcass characteristics, and meat quality of immunocastrated male pigs. Seventy-two boars were assigned to three birth weight categories (BiW): light BiW pigs (LP: 0.98±0.083 kg BW; n = 24), normal BiW pigs (NP: 1.42±0.067 kg BW; n = 24), and heavy BiW pigs (HP: 1.85±0.096 kg BW; n = 24). For treatment design, we considered a weight range of two standard deviations (SD) in relation to the average population body weight (from 0.785 to 2.155 kg BW−1 ). The animals were housed in six pens with 12 animals per pen, with ad libitum access to water and feed throughout the study. In the growing and finishing phases, pigs were immunocastrated with two doses of vaccine at 112 and 161 days of age. The three BiW categories were different up to departure from the nursery (70 days). After this period, there was no difference between NP and HP in terms of BiW. Measurements showed that a low BiW reduced the loin eye area (9.4%), longissimus thoracis muscle depth (7.6%), and meat:fat ratio (21.6%). Backfat thickness (21.5%) and fat area (11.8%) were higher in LP as compared with the NP and HP categories. Light BiW pigs presented a lower weight steak (7.0%) and belly + rib (8.6%) compared with NP and HP, but did not differ within the LP group. Light BiW pigs required a greater lodging time (14 days), generating higher accumulated feed intake to reach the same slaughter BiW as the other categories. Growth performance and carcass characteristics are influenced by the birth weight (BiW) category. Light BiW pigs require more time and feed intake to reach the same slaughter weight. Birth weight has positive effects on meat quality and weight of commercial cuts.

Different sources of sulfur in diets of adult cats on the urinary parameters and acid-base balance / Efeitos da adição de diferentes fontes de enxofre na dieta de gatos adultos em parâmetros urinários e equilíbrio ácido-básico

Urolithiasis is a common disorder in the veterinary clinic and is considered as one of the most frequently cause of morbidity. This disorder is closely associated with urinary pH and nutrition plays a key role in the control of this disease, because through dietary manipulation it is possible to modify the urinary pH. Sulfur is considered macroelement with a strong influence on the acid-base status and may be crucial to control urinary pH in cats. The purpose of this study was to evaluate the effects of addition of different sources of sulfur (S) in the diet of cats on the urinary parameters and acid-base balance. Forty-two healthy adult cats were divided into 3 groups, and each group of 14 cats received 7 diets in a complete randomized block design. Calcium sulfate (CaSO4), DL-methionine (DLM) and methionine hydroxy analog (MHA) were added to a control diet in two levels (1.28g S/kg and 2.56g S/kg) to formulate 6 other experimental diets. The acid-base balance was evaluated by hemogasometry in samples of venous blood. The DLM at the highest level and MHA differed of the control diet in relation to urinary pH (P 0.05). Calcium sulfate; although, not differentiated from the control diet, has been shown to alter urinary pH despite its zero electrolyte balance. Apparently, the alkalizing effect of calcium was not sufficient to avoid sulfate acidification of the urine. Treatments showed no alteration of the acid-base balance of the animals and no affect the consumption of the diets.(AU)

A urolitíase é uma desordem comum na clínica veterinária, considerada como uma das maiores causas de morbidade. Esta desordem está intimamente associada ao pH urinário sendo que a nutrição desempenha papel fundamental no controle dessa doença, pois através da manipulação dietética é possível modificar o pH urinário. O enxofre é considerado um macroelemento com forte influência no equilíbrio ácido-básico e pode ser crucial para controlar o pH urinário em gatos. O objetivo deste estudo foi avaliar os efeitos da adição de diferentes fontes de enxofre (S) na dieta de gatos nos parâmetros urinários e no equilíbrio ácido-básico destes animais. 42 gatos adultos saudáveis foram divididos em 3 grupos e cada grupo de 14 gatos recebeu 7 dietas em um delineamento de blocos ao acaso. O sulfato de cálcio (CaSO4), a DL-metionina (DLM) e a metionina hidróxi-análoga (MHA) foram adicionados a uma dieta controle em dois níveis (1,28g S/kg e 2,56g S/kg) para formular outras 6 dietas experimentais. O equilíbrio ácido-básico foi avaliado por hemogasometria em amostras de sangue venoso. O DLM no teor mais alto e MHA diferiram da dieta controle em relação ao pH urinário (P 0,05). O sulfato de cálcio, embora não tenha diferido da dieta controle, demonstrou alterar o pH urinário apesar do seu equilíbrio eletrolítico nulo. Aparentemente, o efeito alcalinizante do cálcio não foi suficiente para anular a acidificação da urina pelo sulfato. Os tratamentos não apresentaram alteração do equilíbrio ácido-básico dos animais e não afetaram o consumo das dietas experimentais.(AU)

Aplicação da alimentação de precisão para melhorar a eficiência do nitrogênio na produção de suínos: revisão de possíveis práticas e obstáculos / Applying precision feeding to improve the nitrogen efficiency of swine production: a review of possible practices and obstacles

Optimizing nutrient efficiency is essential in order to increase sustainability of pig production systems, especially where the growing demand for food must be met at an affordable cost, without compromising environmental resources. To make this happen, it is necessary to develop efficient methods to accurately estimate the nutritional requirements of animals, as well as develop equipment and systems that allow for applying such expertise in the production system. Estimating the nutritional requirement of pigs through mathematical models, considering several factors that can impact the requirement, is a key factor to reduce the environmental load from pig production. Likewise, feed formulation and feeding programs, can help to achieve this. In this context, increasing the number of feeding phases in pig production, as well as precision feeding techniques, may be a tool to the esure adequacy of nutritional requirements, since its use can bring economic and environmental benefits.

Otimizar a eficiência nutricional é essencial para aumentar a sustentabilidade do sistema de produção de suínos, especialmente em um momento onde a crescente demanda por alimentos deve ser atendida a um custo acessível, mas sem comprometer os recursos ambientais. Para tornar isso possível, é necessário o desenvolvimento de métodos eficientes e acurados para estimar as exigências nutricionais dos animais, bem como o desenvolvimento de equipamentos e sistemas que permitam aplicar esses métodos no sistema produtivo. Estimar as exigências nutricionais de suínos através de modelos matemáticos, considerando os vários fatores que impactam as exigências, pode ser um fator chave para reduzir a carga ambiental da suinocultura. Da mesma forma, formulações de rações e programas de alimentação podem auxiliar a alcançar isso. Neste contexto, o aumento do número de fases de alimentação na produção de suínos, bem como as técnicas de alimentação de precisão, podem ser ferramentas para a adequação das exigências nutricionais, uma vez que proporcionam benefícios econômicos e ambientais.

Aplicação da alimentação de precisão para melhorar a eficiência do nitrogênio na produção de suínos: revisão de possíveis práticas e obstáculos / Applying precision feeding to improve the nitrogen efficiency of swine production: a review of possible practices and obstacles

Optimizing nutrient efficiency is essential in order to increase sustainability of pig production systems, especially where the growing demand for food must be met at an affordable cost, without compromising environmental resources. To make this happen, it is necessary to develop efficient methods to accurately estimate the nutritional requirements of animals, as well as develop equipment and systems that allow for applying such expertise in the production system. Estimating the nutritional requirement of pigs through mathematical models, considering several factors that can impact the requirement, is a key factor to reduce the environmental load from pig production. Likewise, feed formulation and feeding programs, can help to achieve this. In this context, increasing the number of feeding phases in pig production, as well as precision feeding techniques, may be a tool to the esure adequacy of nutritional requirements, since its use can bring economic and environmental benefits.(AU)

Otimizar a eficiência nutricional é essencial para aumentar a sustentabilidade do sistema de produção de suínos, especialmente em um momento onde a crescente demanda por alimentos deve ser atendida a um custo acessível, mas sem comprometer os recursos ambientais. Para tornar isso possível, é necessário o desenvolvimento de métodos eficientes e acurados para estimar as exigências nutricionais dos animais, bem como o desenvolvimento de equipamentos e sistemas que permitam aplicar esses métodos no sistema produtivo. Estimar as exigências nutricionais de suínos através de modelos matemáticos, considerando os vários fatores que impactam as exigências, pode ser um fator chave para reduzir a carga ambiental da suinocultura. Da mesma forma, formulações de rações e programas de alimentação podem auxiliar a alcançar isso. Neste contexto, o aumento do número de fases de alimentação na produção de suínos, bem como as técnicas de alimentação de precisão, podem ser ferramentas para a adequação das exigências nutricionais, uma vez que proporcionam benefícios econômicos e ambientais.(AU)

Performance of broilers fed different dietary choline sources and levels / Desempenho de frangos de corte suplementados com diferentes fontes e níveis de colina na dieta

Two experiments were carried out to evaluate the bioequivalence of a commercial phosphatidylcholine source (Biocholine™) as an alternative to choline chloride and the choline requirements of broilers of a fast-growth strain. In Experiment I, 672 broilers were fed four Biocholine™ levels (0, 100, 200, or 300 mg/kg) and three choline levels (200, 400, or 600 mg/kg) supplied as choline chloride between 4 and 28 days (d) of age. In Experiment II, 462 broilers received diets supplemented with 0, 200, 400, 600 or 800 mg/kg choline as choline chloride. In both experiments, diets were based on white rice, soybean meal, and corn gluten. In Experiment I, birds fed choline chloride presented higher feed intake than those fed Biocholine™. Both choline supplements linearly improved feed conversion ratio (FCR) between 15 and 28 d, but the curves presented different slopes, showing that one unit (U) of Biocholine™ was equivalent to 2.52 U of choline supplied as choline chloride. In Experiment II, the supplementation of choline had a quadratic effect on weight gain (WG) but did not affect FCR. Choline requirements for WG were determined as 778, 632, and 645 mg/kg for 1-7, 1-35, and 1-42 d of age, respectively.

Dois experimentos foram conduzidos para avaliar a bioequivalência de uma fonte comercial de fosfatidilcolina (Biocholine®) como alternativa ao cloreto de colina e as exigências de colina de frangos de rápido desempenho. No Experimento I, 672 frangos foram alimentados com quatro níveis de Biocholine® (0, 100, 200 ou 300 mg/kg) e três níveis de colina (200, 400 ou 600 mg/kg) supridas pelo cloreto de colina entre 4 e 28 dias de idade. No Experimento II, 462 frangos receberam dietas suplementadas com 0, 200, 400, 600 ou 800 mg/kg de colina através do cloreto de colina. Em ambos os experimentos, as dietas foram à base de arroz branco, farelo de soja e glúten de milho. No Experimento I, as aves alimentadas com cloreto de colina apresentaram maior consumo de ração em relação àquelas alimentadas com Biocholine®. Ambas as fontes de colina melhoraram linearmente a conversão alimentar entre 15 e 28 dias, mas as curvas apresentaram diferentes inclinações, mostrando que uma unidade de Biocholine® foi equivalente a 2,52 unidades de colina suprida na forma de cloreto de colina. No Experimento II, a suplementação de colina apresentou efeito quadrático sobre o ganho de peso sem afetar a conversão alimentar. As exigências de colina para ganho de peso foram 778, 632 e 645 mg/kg para as fases de 1-7, 1-35 e 1-42 dias de idade, respectivamente.

Performance of broilers fed different dietary choline sources and levels / Desempenho de frangos de corte suplementados com diferentes fontes e níveis de colina na dieta

Two experiments were carried out to evaluate the bioequivalence of a commercial phosphatidylcholine source (Biocholine™) as an alternative to choline chloride and the choline requirements of broilers of a fast-growth strain. In Experiment I, 672 broilers were fed four Biocholine™ levels (0, 100, 200, or 300 mg/kg) and three choline levels (200, 400, or 600 mg/kg) supplied as choline chloride between 4 and 28 days (d) of age. In Experiment II, 462 broilers received diets supplemented with 0, 200, 400, 600 or 800 mg/kg choline as choline chloride. In both experiments, diets were based on white rice, soybean meal, and corn gluten. In Experiment I, birds fed choline chloride presented higher feed intake than those fed Biocholine™. Both choline supplements linearly improved feed conversion ratio (FCR) between 15 and 28 d, but the curves presented different slopes, showing that one unit (U) of Biocholine™ was equivalent to 2.52 U of choline supplied as choline chloride. In Experiment II, the supplementation of choline had a quadratic effect on weight gain (WG) but did not affect FCR. Choline requirements for WG were determined as 778, 632, and 645 mg/kg for 1-7, 1-35, and 1-42 d of age, respectively.(AU)

Dois experimentos foram conduzidos para avaliar a bioequivalência de uma fonte comercial de fosfatidilcolina (Biocholine®) como alternativa ao cloreto de colina e as exigências de colina de frangos de rápido desempenho. No Experimento I, 672 frangos foram alimentados com quatro níveis de Biocholine® (0, 100, 200 ou 300 mg/kg) e três níveis de colina (200, 400 ou 600 mg/kg) supridas pelo cloreto de colina entre 4 e 28 dias de idade. No Experimento II, 462 frangos receberam dietas suplementadas com 0, 200, 400, 600 ou 800 mg/kg de colina através do cloreto de colina. Em ambos os experimentos, as dietas foram à base de arroz branco, farelo de soja e glúten de milho. No Experimento I, as aves alimentadas com cloreto de colina apresentaram maior consumo de ração em relação àquelas alimentadas com Biocholine®. Ambas as fontes de colina melhoraram linearmente a conversão alimentar entre 15 e 28 dias, mas as curvas apresentaram diferentes inclinações, mostrando que uma unidade de Biocholine® foi equivalente a 2,52 unidades de colina suprida na forma de cloreto de colina. No Experimento II, a suplementação de colina apresentou efeito quadrático sobre o ganho de peso sem afetar a conversão alimentar. As exigências de colina para ganho de peso foram 778, 632 e 645 mg/kg para as fases de 1-7, 1-35 e 1-42 dias de idade, respectivamente.(AU)

PERFORMANCE OF BROILERS FED DIFFERENT DIETARY CHOLINE SOURCES AND LEVELS

Abstract Two experiments were carried out to evaluate the bioequivalence of a commercial phosphatidylcholine source (Biocholine) as an alternative to choline chloride and the choline requirements of broilers of a fast-growth strain. In Experiment I, 672 broilers were fed four Biocholine levels (0, 100, 200, or 300 mg/kg) and three choline levels (200, 400, or 600 mg/kg) supplied as choline chloride between 4 and 28 days (d) of age. In Experiment II, 462 broilers received diets supplemented with 0, 200, 400, 600 or 800 mg/kg choline as choline chloride. In both experiments, diets were based on white rice, soybean meal, and corn gluten. In Experiment I, birds fed choline chloride presented higher feed intake than those fed Biocholine. Both choline supplements linearly improved feed conversion ratio (FCR) between 15 and 28 d, but the curves presented different slopes, showing that one unit (U) of Biocholine was equivalent to 2.52 U of choline supplied as choline chloride. In Experiment II, the supplementation of choline had a quadratic effect on weight gain (WG) but did not affect FCR. Choline requirements for WG were determined as 778, 632, and 645 mg/kg for 1-7, 1-35, and 1-42 d of age, respectively.

Resumo Dois experimentos foram conduzidos para avaliar a bioequivalência de uma fonte comercial de fosfatidilcolina (Biocholine®) como alternativa ao cloreto de colina e as exigências de colina de frangos de rápido desempenho. No Experimento I, 672 frangos foram alimentados com quatro níveis de Biocholine® (0, 100, 200 ou 300 mg/kg) e três níveis de colina (200, 400 ou 600 mg/kg) supridas pelo cloreto de colina entre 4 e 28 dias de idade. No Experimento II, 462 frangos receberam dietas suplementadas com 0, 200, 400, 600 ou 800 mg/kg de colina através do cloreto de colina. Em ambos os experimentos, as dietas foram à base de arroz branco, farelo de soja e glúten de milho. No Experimento I, as aves alimentadas com cloreto de colina apresentaram maior consumo de ração em relação àquelas alimentadas com Biocholine®. Ambas as fontes de colina melhoraram linearmente a conversão alimentar entre 15 e 28 dias, mas as curvas apresentaram diferentes inclinações, mostrando que uma unidade de Biocholine® foi equivalente a 2,52 unidades de colina suprida na forma de cloreto de colina. No Experimento II, a suplementação de colina apresentou efeito quadrático sobre o ganho de peso sem afetar a conversão alimentar. As exigências de colina para ganho de peso foram 778, 632 e 645 mg/kg para as fases de 1-7, 1-35 e 1-42 dias de idade, respectivamente.

Nutritional and energetic value of rice by-products, with or without phytase, for growing pigs / Valor nutricional e energético de sub-produtos do arroz, com ou sem fitase, para suínos em crescimento

The objective of this study was to evaluate nutritional and energetic value of rice by-products, with or without phytase, using growing pigs. Thirty-six male pigs were housed in individual metabolic cages. Total collection of feces and urine was carried out in two periods of ten days: five days for adaptation and five days for collection. A randomized blocks design was used, considering the sampling period as a block, with five treatments and seven replicates. Two control diets (with and without phytase - Phy) were used in the digestibility calculations, the latter in order to evaluate the enzyme influence on energy digestibility of the tested ingredients. The control diet was replaced by 30% of one of the ingredients: defatted rice bran (DRB) with and without Phy and dephytinised defatted rice bran (DDRB). The use of Phy in the control diet did not influence DRB+Phy energy digestibility. Relative to DRB+Phy, dephytinised defatted rice bran had higher contents of ME and digestible protein but lower digestible P and Ca. Phy supplementation increased Ca and P utilization of DRB and improved energy and protein digestibility. The DRB without Phy showed the lowest digestibility coefficients for all responses. Metabolizable energy, digestible protein, phosphorus and calcium of DRB, DRB+Phy and DDRB were respectively, 2140, 2288 and 2519kcal kg-1; 79.25, 92.41 and 107.10g kg-1; 1.62, 3.41, and 2.11g kg-1 and 2.80, 3.79 and 2.90g kg-1.

O objetivo do presente trabalho foi avaliar o valor nutricional e energético de subprodutos do arroz, na presença ou não de fitase, para suínos em crescimento. Foram utilizados 36 suínos machos, castrados, alojados em gaiolas metabólicas individuais. Realizou-se a coleta total de fezes e urina em dois períodos de dez dias: cinco de adaptação e cinco de coleta. Utilizou-se o delineamento de blocos ao acaso, tendo-se considerado o período de coleta como bloco, com cinco tratamentos e sete repetições. Duas dietas controle (com e sem fitase - Fit) foram utilizadas nos cálculos de digestibilidade, a última para avaliar a influência da enzima na digestibilidade da energia dos ingredientes teste. A dieta controle foi substituída em 30% pelos subprodutos testados: farelo de arroz desengordurado (FAD) com ou sem Fit e farelo de arroz desengordurado desfitinizado (FADD). O uso de fitase na dieta controle não influenciou na digestibilidade da energia do FAD+Fit. Comparado ao FAD+Fit, o farelo de arroz desengordurado desfitinizado apresentou mais EM e proteína digestível, mas menos P e Ca digestíveis. A suplementação de fitase melhorou a utilização do P e Ca do FAD e aumentou a digestibilidade da energia e da proteína. O FAD sem fitase apresentou os menores coeficientes de digestibilidade para todas as respostas. Energia metabolizável, proteína, fósforo e cálcio digestíveis do FAD, FAD+Fit e FADD foram, respectivamente, 2.140; 2.288 e 2.519kcal kg-1; 79,25; 92,41 e 107,10g kg-1; 1,62; 3,41 e 2,11g kg-1 e 2,80; 3,79 e 2,90g kg-1.

Nutritional and energetic value of rice by-products, with or without phytase, for growing pigs / Valor nutricional e energético de sub-produtos do arroz, com ou sem fitase, para suínos em crescimento

The objective of this study was to evaluate nutritional and energetic value of rice by-products, with or without phytase, using growing pigs. Thirty-six male pigs were housed in individual metabolic cages. Total collection of feces and urine was carried out in two periods of ten days: five days for adaptation and five days for collection. A randomized blocks design was used, considering the sampling period as a block, with five treatments and seven replicates. Two control diets (with and without phytase - Phy) were used in the digestibility calculations, the latter in order to evaluate the enzyme influence on energy digestibility of the tested ingredients. The control diet was replaced by 30% of one of the ingredients: defatted rice bran (DRB) with and without Phy and dephytinised defatted rice bran (DDRB). The use of Phy in the control diet did not influence DRB+Phy energy digestibility. Relative to DRB+Phy, dephytinised defatted rice bran had higher contents of ME and digestible protein but lower digestible P and Ca. Phy supplementation increased Ca and P utilization of DRB and improved energy and protein digestibility. The DRB without Phy showed the lowest digestibility coefficients for all responses. Metabolizable energy, digestible protein, phosphorus and calcium of DRB, DRB+Phy and DDRB were respectively, 2140, 2288 and 2519kcal kg-1; 79.25, 92.41 and 107.10g kg-1; 1.62, 3.41, and 2.11g kg-1 and 2.80, 3.79 and 2.90g kg-1.(AU)

O objetivo do presente trabalho foi avaliar o valor nutricional e energético de subprodutos do arroz, na presença ou não de fitase, para suínos em crescimento. Foram utilizados 36 suínos machos, castrados, alojados em gaiolas metabólicas individuais. Realizou-se a coleta total de fezes e urina em dois períodos de dez dias: cinco de adaptação e cinco de coleta. Utilizou-se o delineamento de blocos ao acaso, tendo-se considerado o período de coleta como bloco, com cinco tratamentos e sete repetições. Duas dietas controle (com e sem fitase - Fit) foram utilizadas nos cálculos de digestibilidade, a última para avaliar a influência da enzima na digestibilidade da energia dos ingredientes teste. A dieta controle foi substituída em 30% pelos subprodutos testados: farelo de arroz desengordurado (FAD) com ou sem Fit e farelo de arroz desengordurado desfitinizado (FADD). O uso de fitase na dieta controle não influenciou na digestibilidade da energia do FAD+Fit. Comparado ao FAD+Fit, o farelo de arroz desengordurado desfitinizado apresentou mais EM e proteína digestível, mas menos P e Ca digestíveis. A suplementação de fitase melhorou a utilização do P e Ca do FAD e aumentou a digestibilidade da energia e da proteína. O FAD sem fitase apresentou os menores coeficientes de digestibilidade para todas as respostas. Energia metabolizável, proteína, fósforo e cálcio digestíveis do FAD, FAD+Fit e FADD foram, respectivamente, 2.140; 2.288 e 2.519kcal kg-1; 79,25; 92,41 e 107,10g kg-1; 1,62; 3,41 e 2,11g kg-1 e 2,80; 3,79 e 2,90g kg-1.(AU)

Effects of diets containing organic and inorganic zinc sources on hair characteristics, zinc concentration in blood and hair, and the immune response of dogs

Background: There are two commercial forms of zinc, organic and inorganic, and its form may influence absorption and utilization by the animals. The inorganic form dissociates to Zn2+ in the gastrointestinal tract and can interact with other substances that the animal cannot absorb. The interest in using organic minerals has increased because of the reported potential of higher bioavailability compared to inorganic sources. In dogs, little research has been done concerning the bioavailability of organic and inorganic mineral sources. This study compared the effects of diets containing organic and inorganic zinc on hair characteristics, zinc concentration in blood and hair, and the influence of organic minerals on the immune response of dogs. Materials, Methods & Results: Eighteen healthy adult dogs of different breeds (Labrador, German Shepherd, Malinois Shepherd, and Rottweiler) were separated into two groups of nine animals per treatment and fed diets for 30 days. Two diets were used: an inorganic mineral source diet (IMSD) and an organic mineral source diet (OMSD). Four parameters were evaluated (days -14, 0, 10, 20, 30) to determine the hair characteristics: brightness, texture, looseness, and greasiness. On days 0 and 30, two blood samples were taken and two hair samples were collected to measure zinc concentrations. On the 10th day of the trial period, the animals received an injection of 4 mL of a 10% solution of sheep red blood cells (SRBC) subcutaneously as a stimulus to assess the humoral response. Blood samples were taken prior to injection as well as on days 10 and 20 post-injection for antibody titer. All dogs consumed adequate amount of the diets and body weight did not change during the experiment. The daily dry matter, energy, and zinc consumption did not differ between groups. The zinc concentration in the blood remained stable throughout the experiment in animals fed the OMSD but decreased significantly in the animals fed the IMSD (P = 0.0145). The zinc concentration in hair increased (P = 0.0075) in dogs fed the OMSD, while the dogs fed the IMSD had no difference. The consumption of the OMSD resulted in higher brightness in the hair of the face, muzzle, armpit, back, abdomen, and tail compared with the IMSD. The animals fed the chelated mineral-supplemented diet also showed better texture in hair of the abdomen (P = 0.0327), chest (P = 0.0335), and tail (P = 0.0291). The parameters looseness and greasiness showed no significant differences. No differences were observed in the production of antibodies against SRBC between groups; however, the antibody concentration was maintained throughout the experiment in the animals supplemented with OMSD, in contrast to the animals supplemented with IMSD, which reduced their antibody concentration. Discussion: There is controversy in the literature regarding the benefits of organic over inorganic zinc source. This may be due to two factors: the time of zinc supplementation, and the levels of zinc included in the diets, which varies in each experiment. In the present study, both criteria were adequate for the responses evaluated and the results suggest that organic zinc is suitable for supplementation into the commercial dog foods and could enhance the hair characteristics of adult dogs. Moreover, the improvement in immune status, although subtle, must be taken into account. It should be noted that the diets were formulated with high levels of minerals, especially calcium, which increases the possibility of interactions and competition in the absorptive process, increasing the challenge and impairing absorption of divalent minerals.

Efeito da forma física e da restrição alimentar sobre o desempenho de poedeiras leves / Effect of physical form and feed restriction on the performance of light laying hens

O experimento objetivou testar os efeitos da forma física da ração (farelada vs. peletizada) e da restrição alimentar (à vontade vs.10% de restrição) em 160 poedeiras leves H & N. Foram aplicados quatro tratamentos, com vinte repetições de duas aves cada, em um delineamento completamente casualizado, em arranjo fatorial 2 x 2, de 26 a 44 semanas de idade das aves. Avaliaram-se consumo de ração (CR), ganhos de peso (GP), conversão alimentar (CA), produção de ovos (PO), peso médio de ovos (PMO) e gravidade específica (GE). A ração farelada proporcionou maior CR no período total (P<0,001) e a ração peletizada propiciou maior CR somente a partir das 42 semanas de idade, indicando a necessidade de adaptação das aves à nova forma física. Produção de ovos, PMO, CA e GE não foram diferentes nas duas formas físicas, no período total. GP tendeu a ser maior durante todo o período para as aves com ração peletizada. A restrição de ração a 90% do consumo à vontade mostrou piores resultados para todas as variáveis estudadas e nenhuma forma física da ração foi capaz de compensar os efeitos negativos da restrição.(AU)

The experiment aimed at testing the effects of feed physical form (mash vs. pelleted) and feed allowance (ad libitum vs. 10% restriction) in 160 H & N laying hens. Four treatments were applied, with 20 replications of two 26-44-week-old birds each in a completely randomized design, in a 2 x 2 factorial arrangement. Feed intake (FI), body weight gain (BWG), feed conversion (FC), egg production (EP), egg weight (EW) and egg specific gravity (EG) were evaluated. The mash diet provided greater FI in the total period (P<0.0001), whereas pelleted diet showed greater FI only after 42 weeks of age, indicating that birds need to adapt to the new physical form of diet. Egg production, EW, FC, and EG were not different for the two physical forms in the total period. BWG tended to be greater throughout the experiment period for birds eating pelleted diet. Ninety percent of feed restriction from ad libitum intake showed the worst results for all studied variables and none of the physical forms was able to compensate the negative effects of restriction.(AU)