Archivos de Zootecnia

**Nitrogened metabolites in golden hamster fed with proteic diets based on Eisenia spp. meal**

Se evaluó en el plasma sanguíneo del hámster dorado (Mesocrisetus auratus L.) el contenido total de proteína (PT), albúmina (Alb), globulinas (Glb), urea (U), ácido úrico (AU), creatinina (Ct) y los niveles de transaminasas (glutámico oxalacética (TGO) y glutámico-pirúvica (TGP)) a partir del consumo de dietas (proteína bruta; PB= 13,5-19,6%) con harina de lombriz roja (HL) (Eisenia spp.) y dos alimentos convencionales (Conejarina®; PB= 11,4% y Ratarina®; PB= 21,1%). La concentración de PT, Alb, Glb y Ct osciló entre 5-6; 2-3; 2-3 g/dL y 0,3-0,4 mg/dL, respectivamente, sin observarse diferencias significativas entre las dietas (p>0,05). En todo el experimento los niveles de U y AU fluctuaron entre 23-101 y 3-9 mg/dL, respectivamente, en función del nivel de PB, la inclusión de HL y el momento de muestreo. Los niveles de transaminasas fueron elevados y variables, acorde al valor proteico de las dietas (TGO: 101-699 y TGP: 54-890 UI/L). Se comprobó que los contenidos séricos de PT, Glb, Alb y Ct fueron independientes de la inclusión de HL y los niveles de PB de cada alimento; mientras que la concentración de U (R²= 0,509*), TGO (R²= 0,661**) y TGP (R²= 0,524*) se encontraron relacionados con los valores proteicos de las raciones, y el contenido de U (R²= 0,502*) y AU (R²= 0,531*) con la inclusión de HL. La adición de HL en proporciones de 24, 27 y 30% a dietas formuladas para M. auratus aumenta significativamente los valores normales de U, AU y transaminasas.

Content of total protein (PT), albumin (Alb), globulins (Glb), urea (U), uric acid (AU), creatinine (Ct) and transaminase levels (oxalacetic-glutamic (TGO) and piruvic-glutamic (TGP)) was evaluated in the blood plasm of golden hamster (Mesocrisetus auratus L.), fed diets (crude protein; PB= 13.5-19.6%) with red worm (HL) (Eisenia spp.) meal and two conventional feeds (Conejarina®; PB= 11.4% and Ratarina®; PB= 21.1%). The PT, Alb, Glb and Ct concentration oscillated among 5-6, 2-3, 2-3 g/dL y 0,3-0,4 mg/dL, respectively, no significant differences among the treatments in the assay were observed (p>0.05). In the assay the U and AU content fluctuated between 23-101 y 3-9 mg/dL, respectively; according to the PB level, HL inclusion and measurement time. The transaminase levels were high and variables during the second week of assay, according to the proteic level diets (TGO: 101-699 y TGP: 54-890 UI/ L). The seric PT, Glb, Alb and Ct content were independent of PB diets and HL proportion, while the U (R²= 0.509*), TGO (R²= 0.661**) and TGP (R²= 0.524*) level were related with proteic level of diets, and the U (R²= 0.502*) and AU (R²= 0.531*) contents with the HL inclusion. The HL addition in 24, 27 and 30% for making formulated proteic diets to M. auratus cause significant variation in the normal values of U, AU and transaminases.

A wireless data acquisition system for cattle behavior monitoring in zootechnics E-Science

This paper studies the feasibility of a system of monitoring and data collection via the web, with the construction of an e-Science Zootechnical. Object-oriented modelling techniques were used and programming languages: php, C++, Java and MySql database for development of the computing environment. The system hardware, electronic communication device, and monitoring protocols were developed using the Float Base Sensor Network Protocol and techniques of electronic instrumentation. To test the system, an experiment was conducted with six Holstein animals equipped with data collection devices. The experimental environment was equipped with six antennas and a fixed IP camera. The results showed the efficiency of the collection system and receiving data through the antennas distributed in the area. Considering the methodology used in the project, as well as the results of the experiment, is possible conclude that, with the telemetric data collection in real time, the management and monitoring the animal during an experiment can be done, in addition to allowing free movement of the animal during the data collection.

Este artigo estuda a viabilidade de um sistema de monitoramento e coleta de dados através da WEB, com a construção de um e-Science Zootécnico. Foram utilizadas técnicas de modelagem orientada a objetos, linguagens de programação php, C++, Java e banco de dados MySql para a elaboração do ambiente computacional. O sistema de hardware, o dispositivo eletrônico de comunicação e os protocolos de monitoramento foram desenvolvidos utilizando o protocolo Float Base Sensor Network e técnicas de instrumentação eletrônica. Para testar o sistema desenvolvido, foi realizado um experimento com 6 animais da raça Holstein equipados com dispositivos de coleta de dados. O ambiente experimental foi equipado com 6 antenas fixas e uma câmera IP. Os resultados obtidos mostraram a eficiência do sistema de coleta e de recepção dos dados através das antenas distribuídas na área. A metodologia usada no projeto, bem como os resultados do experimento, permitem concluir que o objetivo de gerenciar e monitorar o animal durante um experimento, com a coleta de dados telemétricos em tempo real foi alcançada, além de possibilitar o deslocamento livre do animal durante a coleta dos dados.

Genetic polymorphism of the leptin and receptor growth hormone in goats

Objetivou-se estudar a relação entre o polimorfismo no gene da leptina (LEP), especificamente o éxon 2, e o microssatélite do receptor do hormônio do crescimento (SSR-GHR) com as características de crescimento em animais das raças Anglo-Nubiana e Boer, a fim de identificar marcadores que possam ser úteis na seleção desses animais da espécie caprina de elevado mérito genético. Foram obtidas as frequências alélicas e heterozigosidade com auxílio do programa Toolkit. O teste para o equilíbrio de Hardy-Weinberg foi feito com auxílio do GENEPOP, no qual os marcadores se mostraram em desequilíbrio para as populações. Para a LEP os valores de heterozigosidade observada foram bem maiores do que os esperados e todos os animais apresentaram o mesmo padrão eletroforétrico com dois alelos (150 e 152 pb). No loco do GHR observou-se cinco alelos com tamanho variando de 90 a 125 pb. Para verificar a influência dos genótipos dos fragmentos polimórficos do GHR e da leptina sobre o desenvolvimento dos animais foram utilizados os pesos ao nascer (PN) e ao desmame (PD), para os quais foi feito análise de variância e teste de médias com auxílio do procedimento GLM do programa SAS. Observouse efeito significativo dos genótipos sobre os pesos ao nascer (PN) e à desmame (PD). Sugerese, o estudo destes polimorfismos em maior número de animais para confirmação do efeito sobre características de crescimento.

This study aimed to evaluate the relationship between leptin gene polymorphism (LEP), specifically exon 2, and microsatellite of the growth hormone receptor (GHR-SSR) with the growth characteristics of Anglo-Nubian and Boer goats to identify useful markers for selecting animals with high genetic merit. The Toolkit program was used for obtaining the allele frequencies and heterozygosity. Hardy-Weinberg equilibrium test was performed with GENEPOP software. Markers were in desequilibrium in all populations studied. Observed heterozygosity values for LEP were greater than expected heterozygosity. All animals showed the same electrophoretic pattern with two alleles (150 and 152 bp). On GHR locus was detected five alleles ranging from 90 to 125 bp. Birth weight (BW) and weaning weight (PD) were used to evaluate the influence of polymorphic fragments on the animal growth. They were analyzed by GLM procedure of SAS software. The genotypes showed a significant effect on birth (BW) and weaning weight (PD). It is necessary to increase the number of samples to confirm the relationship among GHR and leptina polymorphic fragments GHR and growth characteristics.

Trust, norms and participation in social networks: Analysis of two dairy farmer organizations of Puebla, Mexico

Este estudio analiza la relación entre confianza, normas y participación en redes sociales en dos organizaciones de productores lecheros de la cuenca de Tecamachalco, en el estado mexicano de Puebla. Se utiliza un análisis de componentes principales, índices de correlación y regresión lineal múltiple. El método de componentes reveló tres factores subyacentes a los que se les realizó un análisis de fiabilidad para conocer el grado de consistencia de la escala aditiva construida. Se estableció un modelo lineal de regresión múltiple, en dónde la Confianza en el grupo se tomó como variable dependiente, mientras que Normas compartidas y Participación en grupos son variables explicativas (en conjunto con variables de control como edad de los productores, sexo, tamaño del hato lechero y organización a la que pertenecen). El análisis de varianza reveló que el modelo es estadísticamente significativo (p<0,05). Se confirma el efecto positivo que tienen tanto la participación en redes como las normas sobre la confianza. Sin embargo, los hallazgos obtenidos para las dos organizaciones estudiadas permiten afirmar que, si bien esta relación es cierta, no se presentó de la misma manera en los dos grupos.

This study examines the relationship between trust, norms and participation in social networks in two dairy organizations located in the Tecamachalco basin of the State of Puebla, Mexico. For the analysis we utilize principal components, correlation and multiple linear regression. Principal component analysis revealed three underlying factors. We performed a reliability analysis for each component to determine the degree of consistency of the additive scale constructed. Then, we built a linear multiple regression model with trustiness as the dependent variable; shared norms and participation in groups were used as explanatory variables (also controlling by producers' age and sex, herd's size and organization affiliation). Analysis of variance concludes that the model is statistically significant (p<0.05). A positive and statistically significant relationship of shared norms and participation with trustiness is confirmed. Nevertheless, the results suggest that although expected theoretical relationships work well, there is some specificities for each group.

**Production and chemical composition of sorghum (Sorghum bicolor) grown under nitrogen levels**

Objetivou-se avaliar a resposta produtiva e a composição bromatológica do sorgo híbrido BR 601 ao incremento da adubação nitrogenada. O delineamento experimental utilizado foi em blocos casualizados com cinco repetições. Os trata-mentos foram: 0, 50, 100, 150 e 200 kg/ha de N (sulfato de amônio). A produção variou de forma quadrática ao incremento da adubação nitrogenada, o ponto de máxima para a materia verde foi obtido com 143,19 kg de N/ha (37 996 kg/ha) e para matéria seca com 155,67 kg de N/ha (16 275 kg/ha). A produção de lâmina foliar e material morto na planta não diferiu entre os tratamentos. O percentual de colmo na planta diminuiu de forma quadrática até a dose de 100 kg/ha, o componente panícula aumentou de forma quadrática em 30,96%, o que explica que este componente foi o principal responsável pelo aumento na PMS. O percentual médio de matéria seca da planta variou de 34,84% no tratamento controle a 38,98% no tratamento com 200 kg de N/ha. Os teores de MM diminuíram (6,41 a 5,49%). O teor de PB incrementara linearmente com o aumento nas doses de adubo aplicadas, com variação no teor protéico de 4,99% a 6,23%, respectivamente nos tratamentos 0 e 200 kg de N/ha. Os teores de fibra em detergente neutro, fibra em detergente ácido e hemicelulose não diferiram em função da adubação nitrogenada. A adubação nitrogenada aumenta a produção de matéria seca e panícula sem alterar os constituintes fibrosos da planta.

This study evaluated the productive response and chemical composition of sorghum hybrid BR 601 to nitrogen fertilization. The experimental design was randomized blocks with five replications. The treatments were: 0, 50, 100, 150 and 200 kg N/ha (ammonium sulfate). There was a quadratic increase of yield with N fertilization, the higher value was obtained with 143.19 kg of N/ha for fresh matter (37996 kg/ha) and with 155.67 kg of N/ha for dry matter (16 275 kg/ha). The production of leaf and dead material at the plant did not differ between treatments. The percentage of stem in the plant decreased quadratically up to a dose of 100 kg/ha and the panicle component increased quadratically to 30,96%. So, this component was the main responsible for increase in DM yield. The average plant dry matter varied from 34.84% to 38.98% in the treatment with 200 kg N/ha. The levels of MM decreased (6.41 to 5.49%) and crude protein increased linearly (from 4.99% to 6.23%) with increasing doses of N. The levels of neutral detergent fiber, acid detergent fiber and hemicellulose did not differ in relation to nitrogen fertilization. The nitrogen increases the production of dry matter and panicle without changing the fiber constituents of the plant.

Measurement of locomotor problems and pad lesions in broilers

Este estudo foi conduzido na UTFPR, Campus Dois Vizinhos-PR, dividido em dois experimentos com 600 pintainhos de corte machos, de mesma linhagem (Cobb) e origem. O objetivo deste estudo foi avaliar distintas metodologias para mensuração de lesões no coxim plantar e lesões locomotoras em frangos de corte, bem como o efeito da densidade de alojamento na incidência de lesões. Para o experimento de incidência de problemas locomotores, em delineamento inteiramente casualizado e em esquema fatorial 3 x 3 x 2 (avaliadores x densidade x metodologias de problemas de locomoção). Para o experimento de incidência de lesões no coxim plantar, as aves foram distribuídas em delineamento inteiramente casualizado e em esquema fatorial 3 x 3 x 3 (avaliadores x densidade x metodologias de lesões no coxim plantar), com quatro repetições cada. Para a avaliação de cada metodologia adotada, foram utilizados três avaliadores distintos e previamente treinados sobre a aplicação dos métodos e sem qualquer interação entre si. As médias obtidas foram comparadas pelo Testes de Tukey ao nível de 5% de probabilidade do erro. A repetibilidade do método foi analisada pelos escores mensurados pelos avaliadores. O coeficiente de correlação intraclasse (ICC) foi aplicado com nível de significância de 5 %. Densidades de alojamento mais elevadas afetaram a intensidade de problemas locomotores e de lesões no coxim plantar das aves, aumentando com o desenvolvimento das mesmas. No geral, as metodologias de mensuração de problemas locomotores e de lesão no coxim plantar avaliadas neste estudo são passíveis de aplicação, porém não tão acessíveis de serem interpretadas.

This study was conducted in UTFPR, Campus Dois Vizinhos-PR and divided into two experiments with 600 male broilers of the same lineage and origin. The objective of this study was to evaluate different methodologies for measurement of footpad and locomotors lesions in broilers and the effect of housing density on the incidence of these injuries. For the experiment the incidence of locomotor problems in a completely randomized design and factorial 3 x 3 x 2 (density x evaluators x methods of locomotor problems). For the experiment of footpad dermatitis, the birds were distributed in a completely randomized design and factorial 3 x 3 x 3 (density x evaluators x methods of footpad lesions), with four replicates. For the evaluation of each methodology, we used three different evaluators who were previously trained on the application of methods and without any interaction between them. The averages were compared by Tukey tests at 5% probability of error. The repeatability of the method was analyzed from scores measurements taken by evaluators. The intraclass correlation coefficient (ICC) was applied with a significant level of 5%. Density of housing affects the higher intensity of locomotor problems and foot pad dermatitis of the birds, increasing their development. In general, the methods were not available to be interpreted and applied.

Whole hatchery waste meal as alternative protein and calcium sources in broiler diets

A study was conducted in which processed whole hatchery waste meal (WHWM) replaced fish meal (FM), protein for protein, in broiler diets at 0, 10, 20 and 30% levels. There were 45 birds per treatment and 15 birds per replicate. The feeding trial which lasted for 42 days, was carried out at the Poultry Unit, Agricultural Research Council, Glen. Chemical analysis of the two test ingredients indicated that WHWM had higher contents of ash (18.12%) and ether extract (23.94%). However, crude protein content of FM was 73.18% while that of WHWM was 42.26%. Calcium-phosphorus ratio was 16.6:1 for WHWM as against 1.5:1 in the FM. Broilers fed with diet 2 had highest values for feed intake (118.25 g/bird/day) and weight gain (50.16 g/bird/day) while those fed with diet 3 were superior in efficiency of feed utilization (2.31). Results obtained for carcass traits decreased with increase in the levels of WHWM in the diets. Broilers fed with control diet had highest mean values for eviscerated weight (2.20 kg) and dressing percentage (77.86%). Values recorded for abdominal fat and internal organs (liver, lungs, heart and gizzard) did not show any particular trend. Similarly there were slight variations in the results obtained for blood parameters. Cost of feed intake/bird decreased with increase in the levels of WHWM in the diets. It can be concluded from the results of this study that 10% of FM can be replaced with WHWM in broiler diets without adverse effects on growth and carcass traits. This approach of turning waste into a valuable product will provide alternative protein and calcium sources in broiler diets and solve the problem of hatching waste disposal in the hatchery industry.

Se realizó un estudio en el que se sustituyó la proteína de harina de pescado (FM) por la proteína de residuos integrales de incubadora (WHWN) profesados en dietas de pollos a niveles del 0,10, 20 y 30%. Se utilizaron 45 aves por tratamiento y 15 por repetición. El ensayo de alimentación que duró 42 días fue llevado a cabo en la Unidad de Avicultura del Agricultural Research Council, Glen. Los ánalisis químicos de los ingredientes utilizados indicaron que el WHWM contenía mayor cantidad de ceniza (18,12%) y de extracto étereo (23,94%). Sin embargo el contenido de proteína bruta de FM fue de 73,18% mientras que el de WHWM fue de 42,26%. La relación calcio fósforo fue 16,6:1 y la de FM 1,5:1. Los pollos alimentados con la dieta 2 consumieron mayor cantidad de alimento (118,25 g/ave/día) y ganaron más peso (50,16 g/ave/día) mientras que los alimentados con la dieta 3 tuvieron mejor transformación de alimento (2,31). Los resultados obtenidos para las características de la canal fueron peores a medida que se aumentaba el nivel de WHWM. Las aves que consumieron la dieta control tuvieron mayores valores medios para peso eviscerado (2,20 kg) y rendimiento canal (77,86%). Los valores registrados para la grasa abdominal y órganos internos (hígado, pulmones, corazón y molleja) no mostraron ninguna tendencia particular. Del mismo modo se registraron pequeñas variaciones para los parámetros sanguíneos. El coste del alimento ingerido por ave disminuyó al aumentar los nivles de WHWM en las dietas. Puede concluirse que el 10% de FM puede ser reemplazado con WHWM en las dietas de pollos sin efectos adversos sobre el crecimiento o la canal. El avance de transformar un desperdicio en un producto valioso puede permitir suministrar fuentes alternativas de proteína y calcio en las dietas de pollos y contribuir a resolver el problema del manejo de los residuos de incubación.

Deactivation of tannin in high-moisture sorghum grain with polyethylene glycol or urea

Se realizó un ensayo in vivo para estudiar el efecto del polietilenglicol 4000 (PEG-4000) o la urea sobre la digestibilidad aparente y las características de la fermentación ruminal de bovinos alimentados con grano húmedo de sorgo con alto contenido de taninos. Los tratamientos quedaron generados de la siguiente manera: sorgo no tratado o testigo (T), sorgo tratado con 1 g PEG/g PB del grano (P) y sorgo tratado con 2% urea en base a la materia seca (U). Se utilizaron tres novillos (312 ± 38 kg PV) fistulados de rumen en un diseño cuadrado latino con 3 animales y 3 períodos experimentales donde consumieron una dieta con 70% de grano de sorgo de acuerdo a los tratamientos. Se estimó la digestibilidad aparente in vivo de la dieta y se caracterizó el ambiente ruminal y metabólico de los animales. Los tratamientos P y U generaron respuestas positivas, aumentando (p<0,05) la digestión total in vivo de la dieta. Además, produjeron una disminución (p<0,05) del pH ruminal y aumentaron las concentraciones de nitrógeno amoniacal (NH3-N) y de urea en plasma (p<0,05). La adición de PEG-4000 incrementó (p<0,05) la concentración de AGV totales; la relación acético/propiónico fue menor (p<0,05) en los tratamientos P y U. Las dietas que contenían granos con PEG-4000 y urea modificaron las proporciones molares de propiónico y valérico, sin alterar las de acético, butírico e isovalérico. La utilización de PEG-4000 y urea es efectiva para disminuir los efectos detrimentales de los taninos condensados del grano de sorgo, aumentando la digestión de la dieta y modificando los parámetros ruminales y plasmáticos de los animales.

An in vivo experiment was carried out to study the effect of polyethylene glycol-4000 (PEG-4000) or urea on apparent digestibility and ruminal fermentation characteristics in bovine fed high tannin high moisture sorghum grain. The treatments were generated as follows: sorghum untreated or control (T), sorghum treated with 1 g PEG/g CP of grain (P) and sorghum treated with 2% urea based on dry matter (U). Three ruminally fistulated steers (312 ± 38 kg BW) which consumed a diet with 70% sorghum grain were assigned according to treatment to a Latin square design (three animals and three experimental periods). In vivo apparent digestibility of the diet and ruminal and blood parameters were measured. The grain treatments with PEG-4000 or urea generated positive responses, increasing (p<0.05) in vivo total digestion of the diet. In addition, they decreased (p<0.05) ruminal pH and increased the concentration of NH3-N in the rumen in accordance with a higher concentration of urea in plasma (p<0.05). The PEG-4000 increased (p<0.05) total VFA concentration; acetate/propionate ratio was lower (p<0.05) in animals under P and U treatments. The diets containing grains with PEG-4000 or urea modified molar ratios of propionic and valeric, without altering those of acetic, butyric and isovaleric. The use of substances such as PEG4000 and urea is effective in reducing the detrimental effects of condensed tannins in sorghum grain, increasing the digestibility of the diet and changing ruminal and blood parameters of the animals.

Economic return from cage production of Pacu in itaipu reservoir, Brazil

O objetivo deste trabalho foi avaliar a rentabilidade econômica de um projeto aquícola em tanques-rede para o cultivo de pacu (Piaractus mesopotâmicus) com peso médio final de 1 kg, propiciando assim informações para a tomada de decisão de investidores, produtores, técnicos, órgãos de fomento e demais instituições afetas à área. Para avaliação dos cenários de rentabilidade econômica utilizou-se o método determinístico com auxílio de uma planilha eletrônica. Verificouse que os índices de retorno econômico na produção de pacu em 160 tanques-rede no reservatório de Itaipu apresentaram os piores resultados no cenário I com índice de lucratividade de -17,22%, devido à conversão alimentar de 3,58 e o preço da ração de R$ 0,75 kg. A análise do retorno sobre o investimento (ROI) apresentou os índices de 1,30; 1,36; 1,47 e 1,54 R$/kg entre os cenários A a D, respectivamente. O ponto de equilíbrio financeiro médio entre as projeções foi de R$ 226921,1 e a média do volume mínimo a ser produzido foi de 55286,7 kg de pacu, baseandose no ponto de equilíbrio físico do projeto com 160 tanques-rede. Para o melhor retorno econômico deve-se produzir no mínimo 40 946,4 kg de pacu em 160 tanques-rede com uma conversão alimentar de 1:2,49 e preço de venda do peixe a 4,00 atingindo 31,78% de lucratividade sobre a receita bruta com um ROI de 1,5393 R$ por quilo produzido.

The aim of this study was to evaluate the economic profitability a project of aquiculture in cage for the cultivation of pacu (Piaractus mesopotamicus) with an initial medium weight of 1 kg. The study was done to provide information for decision making investors, farmers, technicians, foment organs and other institutions related to the area. To evaluate the economic profitability scenery, a deterministic method, with the help of an electronic spread sheet, was used. It could be verified that the economic outcome indexes in pacu breeding in 160 cages in the Itaipu reservoir, presented the worst results in scenery I with a profitability index of -17.22%, due to diet conversion of 3.58 and the ration price (R$ 0.75 kg). The analysis of return on investment (ROI) presented indexes of 1.30, 1.36, 1.47 and 1.54 R$/kg between A and D sceneries, respectively. The medium financial equilibrium point between the projections was of R$ 226921.12 and the average of minimum value to be produced was of 55 286.7 kg pacu, based on the physical equilibrium point of the project with one hundred and sixty net ponds. For a better economic return it is necessary to breed at least 40 946.4 kg pacu in one hundred and sixty net ponds with a diet conversion of 1:2.49 and the fish selling price of 4.00, reaching a profitability of 31.78% on the gross revenue with a ROI of 1.54 R$/kg produced.

Least cost beef cattle ration formulation model based on NRC 2000 system

Los requerimientos nutricionales del ganado de carne descrito por el NRC (2000) se establecen mediante ecuaciones, siendo algunas de ellas no lineales o no aditivas lo cual dificulta su incorporación a modelos de programación lineal para formular raciones al mínimo costo. El presente trabajo describe un modelo de programación lineal entero mixto para formular dietas de mínimo costo que incorpora las recomendaciones del Modelo Nivel Uno del NRC (2000). La falta de aditividad o linealidad de algunas funciones fueron superadas empleando restricciones alternativas modeladas con variables binarias. El modelo considera factores ambientales que modifican los requerimientos de los animales y los efectos de la dieta que afectan la eficiencia de síntesis de proteína microbiana a nivel ruminal y el consumo potencial voluntario de alimentos. Se consideran los requerimientos de energía, proteína metabolizable, calcio, fósforo y fibra efectiva. Se acota el consumo de pastura al consumo voluntario de la misma y el consumo de suplemento al máximo nivel de suplementación permitido. Se presenta un ejemplo de aplicación del modelo y se describen posibles ampliaciones.

Nutritional requirements of beef cattle described by NRC (2000) are determinated by equations, some of which are nonlinear or non additive which makes it difficult for modelling with linear programming. This paper describes a model of mixed integer linear programming to formulate least-cost diet that incorporates the recommendations of Model Level One of NRC (2000). The lack of additivity or linearity of some functions were overcome using alternatives restrictions modelling with binary variables. The model considers environmental factors that modify the requirements of the animals and the effects of the diet that affects the efficiency of microbial protein synthesis in the rumen and the level of voluntary feed intake. This model considers the requirements of energy, metabolizable protein, calcium, phosphorus and effective fiber. The intake of pasture is limited by the potential intake of pasture at grazing and the intake of supplement is limited by the maximum level of supplementation permitted. This paper shows an example of application of the model and describes possible extensions.

Dietary digestible valine levels for barrows from 15 to 30 kg

O objetivo deste trabalho foi o de avaliar níveis de valina digestível para suínos machos castrados, dos 15 aos 30 kg de peso. No primeiro experimento, para determinação do balanço de nitrogênio, foram utilizados 20 suínos, machos castrados, com peso inicial de 22,88±1,19 kg, distribuídos individualmente em gaiolas de metabolismo, em delineamento experimental de blocos ao acaso, constituído de cinco tratamentos (0,60; 0,67; 0,74; 0,81 e 0,88% de valina digestível) e quatro repetições. No segundo experimento, de desempenho, foram utilizados 40 suínos, machos castrados, com peso inicial de 15,49±0,06 kg, submetidos aos mesmos tratamentos, repetições e delineamento experimental utilizados no primeiro experimento. A relação N retido:N absorvido apresentou resposta quadrática, indicando um nível ótimo de valina digestível de 0,748%. A excreção total de N apresentou efeito quadrático em função dos níveis de valina digestíveis, sendo reduzida até o nível de 0,730% de valina digestível e a partir deste nível a excreção de N aumentou novamente. A eficiência de utilização de valina, para ganho de peso reduziu de forma linear à medida que aumentaram os níveis de valina digestível nas rações, e ao utilizar o modelo linear response plateou obteve-se a redução deste parâmetro até 0,790% de valina digestível. Concluise que o nível de 0,748% de valina digestível foi o mais adequado, ao se considerar o N retido: N absorvido, para suínos machos castrados dos 15 aos 30 kg de peso.

The objective of this study was to evaluate the digestible valine levels for barrows from 15 to 30 kg of weight. In the first experiment, to determine the nitrogen balance, were used 20 barrows, averaging 22.88±1.19 kg of initial weight, individually allotted in metabolic cages in a randomized blocks design, consisting of five treatments (0.60, 0.67, 0.74, 0.81, 0.88% of digestible valine) and 4 replications. In the second experiment we determined animal performance in 40 barrows, with initial weight of 15.49±0.06 kg, submitted to the same treatments, experimental design and replicates used in the first experiment. The retained N: absorbed N ratio showed a quadratic effect, indicating 0.748% as an optimum level of digestible valine. Total N excretion showed a quadratic effect depending on the digestible valine levels, being reduced until 0.730% of digestible valine and from this level the N excretion increased again. The efficiency of valine utilization for weight gain decreased linearly as the digestible valine increased in the diets, and according to the Linear Response Plateau model was observed a reduction of this parameter up to 0.790% digestible valine. It was concluded that the level of 0.748% of digestible valine was the most appropriate when considering the retained N: absorbed N ratio, for barrows from 15 to 30 kg of live weight.

Persistence of pathogens and the salinomycin antibiotic in composting piles of poultry litter

A cama de aviário pode causar contaminação ambiental pelo excesso de nutrientes, microorganismos patogênicos e resíduos químicos. Para minimizar estes impactos pode-se fazer compostagem da cama de aviário antes de sua aplicação como fertilizante, porém, ainda existem muitas dúvidas sobre a eficiência deste tratamento. O objetivo deste trabalho foi analisar a persistência de patógenos e do antibiótico salinomicina em cama de aviário submetida à pilhas estáticas de compostagem. Os três tratamentos usados foram: CSC (cama de aviário com camadas de solo e coberto com capim) CP (cama de aviário coberta com polietileno) e CCC (cama de aviário com camadas de capim e coberto com capim). Acompanhou-se a evolução da temperatura nas pilhas, pH, níveis de Escherichia coli, oocistos de eimérias e concentrações do antibiótico salinomicina. O tratamento CP foi o menos eficiente na degradação do antibiótico salinomicina até os 90 dias. A compostagem da cama de aviário, independente dos tratamentos, é eficiente na eliminação de E. coli.

The high concentration of poultry litter in some regions has caused environmental pollution because of excess of nutrients, pathogenic microorganisms and chemical residues. In order to minimize these impacts, the producers have been stimulated to composting the poultry litter before its application as a fertilizer, however there are many doubts concerning the efficiency of this treatment. The goal of this research was analyse the persistence of pathogens and the salinomycin antibiotic in unturned static composting piles of poultry litter. The three used composting treatments were: CSC treatment (poultry litter with soil layers and covered with grass), CP (poultry litter covered with polyethylene) and CCC (poultry litter with grass layers and covered with grass). It was attended the evolution of the temperature of the layers, humidity, Escherichia coli level, oocysts of Eimeria and concentrations of salinomycin antibiotic until 90 days. The CP treatment is less efficient for degradation of the salinomycin antibiotic. Independent of the treatments, the composting of poultry litter is efficient in elimination of E coli.

**Performance, carcass and cuts of broilers caipira Francês Barré (Gris Barré Cou Plumé)**

Objetivou-se analisar os efeitos dos níveis de energia metabolizável e da idade de abate sobre o desempenho zootécnico, rendimento de carcaça e cortes de frangos da linhagem Caipira Francês Barré. O experimento foi conduzido em galpão experimental localizado em Parauapebas, PA. Foram utilizados 192 pintos, mistos, de 1 dia, criados em sistema intensivo. O delineamento experimental utilizado foi inteiramente casualizado, com 3 tratamentos. Cada tratamento foi formado de 4 repetições, sendo a unidade experimental 1 box de 16 aves. Os tratamentos foram definidos de acordo com os níveis de energia metabolizável das rações inicial (1 a 28 dias) e final (29 a 90 dias), respectivamente: T1 - 3000 e 3100 kcal de EM/kg; T2 - 3100 e 3200 kcal de EM/kg; T3 - 3200 e 3300 kcal de EM/kg. As variáveis estudadas foram peso inicial, peso final, consumo de ração e conversão alimentar, proteína bruta consumida, proteína metabolizada consumida, eficiência energética e eficiência protéica. As características de carcaças das aves, analisadas com 77, 84 e 91 dias de idade, foram o rendimento de carcaça, peito, coxas, sobrecoxas, asa, dorso, asas, pés, cabeça e pescoço. A análise estatística dos dados foi realizada utilizando o procedimento ANOVA, para um modelo inteiramente casualizado, com o programa Sistema para análise estatística e genética (SAEG, 2007). As diferenças entre as médias das variáveis estudadas foram realizadas pelo Teste de Tukey a um nível de 5%. Os níveis de energia nas dietas não interferiram no desempenho zootécnico e no rendimento de carcaça, peito, coxas, sobrecoxas, asas, pés e cabeça + pescoço das aves. O nível de 3200 kcal de EM/kg proporcionou melhor rendimento de dorso. A proteína bruta e a energia metabolizada consumida pelas aves melhoraram com o incremento energético da ração, durante a fase de engorda. A idade de abate não influenciou no rendimento de carcaça, entretanto as aves abatidas aos 90 dias de idade apresentaram maior rendimento de peito.

This study aimed to analyze the effects of metabolizable energy levels and the age at slaughter on growth performance, carcass yield and cuts broilers Caipira French Barré. The experiment was conducted in Parauapebas, PA. We used 192 one day chicks reared in intensive system. The experimental design was completely randomized with three treatments. Each treatment consisted of four replications, the experimental unit being a box of 16 birds. The treatments were defined according to the levels of metabolizable energy diets (1 to 28 days) and late (29 to 90 days),respectively: T1 - 3000 and 3100 kcal of ME/kg, T2 - 3100 and 3200 kcal/kg, T3 - 3200 and 3300 kcal of ME/kg. The variables studied were initial weight, final weight, feed intake and feed conversion, protein consumed, metabolized protein consumed, energy efficiency and protein efficiency. The characteristics of carcasses of birds, analyzed with 77, 84 and 91 days of age were the carcass, breast, thigh, drumstick, wing, back, wings, feet, head and neck. The statistical analysis was performed using the ANOVA procedure for a completely randomized model with the System for statistical analysis and genetics (SAEG, 2007). Differences between means of variables were performed by Tukey's test at a level of 5%. The energy levels in the diets did not affect on the performance and carcass yield, breast, thighs, drumsticks, wings, feet and head + neck in birds. The level of 3200 kcal/kg provided better yield back. The protein and metabolic energy consumed by the birds improved with higher energy content of feed during the fattening stage. Age at slaughter did not affect carcass yield, however the birds slaughtered at 90 days of age showed higher breast yield.

**Time of parturition in goats at the valley of Mexico (Capra hircus)**

Con el objetivo de determinar el patrón en los horarios de ocurrencia de partos en la cabra doméstica del valle de México, se evaluó la información en registros de 832 nacimientos de 1991 a 1997 y del año 2000 al 2007. En la evaluación de la información se consideraron horarios diurnos (07:00-19:00 h) y nocturnos (19:00-07:00 h). Se utilizaron tablas de contingencia y modelos lineales, considerando la raza, el tipo de parto, el sexo y peso de las crías, así como la estación del año. La distribución de los partos durante el día no fue homogénea (p<0,01) y el 82% de ellos se concentró en horarios diurnos, con un claro pico (31,4%) entre las 11:00 y las 13:00 h. El horario de los nacimientos no se asoció con la raza de la madre, el tipo de parto, el peso de las crías, el sexo de la cría ni la estación del año (p>0,05). Se concluye que, en el valle de México, la mayoría de los partos (>80%) en la cabra ocurre en horarios diurnos, con una mayor incidencia entre las 11:00 y las 13:00 h.

With the aim of determining the time pattern in parturition in the domestic goat in the valley of Mexico, the information of 832 births from 1991 to 1997 and 2000 to 2007 was evaluated. Diurnal (07:00-19:00 h) and nocturnal times (19:00-07:00 h) were considered in analysis. Tables of contingency and linear models were used, considering the breed, type of parturition, sex and weight of the kid and the season of the year. Distribution of parturition during the day was not homogenous (p<0.01). A high percentage of them (82%) were concentrated in diurnal times, with a clear peak (31%) between 11:00 and 13:00 h. Time of birth was neither associated with the breed of the mother, type of parturition, weight of the kid, sex of the young nor the season of the year (p>0.05). It is concluded that, in the valley of Mexico, the most of the goats' births (>80%) occurs during diurnal times, with a greater incidence between 11:00 and 13:00 h.

**Water intake in sheeps fed different levels of prickly pear (Opuntia ficus indica) in Brazil**

En 45 ovinos machos Santa Inés (peso vivo medio de 27,50 ± 0, 48 kg) se evaluó el consumo de agua, al consumir raciones con niveles crecientes (0, 25, 50, 75, 100%) de nopal (Opuntia fícus indica Mill) en sustitución al maíz molido. El diseño fue en bloques al azar con nueve repeticiones. El consumo de materia seca respondió de modo cuadrático, perjudicando el peso final, que disminuyó, con el aumento del nopal en la dieta. Aumentó el consumo de materia natural disminuyendo el de agua, el consumo total de agua aumentó en el tratamiento con mayor cantidad de nopal. La relación de consumos: agua voluntaria/ materia seca, disminuyó al aumentar el nopal. El nopal constituye una reserva de agua para ovinos Santa Inés en condiciones semiáridas de Brasil.

The water intake in 45 male (27.50 ± 0.48 kg of mena body weight) Santa Ines sheep fed with increasing levels (0, 25, 50, 75, 100% DM basis) of prickly pear (Opuntia ficus indica Mill) to replace corn was studied. A completely randomized block design with nine replications per treatment was used. Quadratic behavior was observed for the intake of dry matter, hitting the final weight, which decreased with increasing the cactus in the diet. There was an increase in the intake of natural material and a decrease in voluntary water intake; total water intake increased, and the ratio of intakes: water/dry matter, decreased in the treatment with larger cactus proportion. The pryckly pear constitues a water reservoir for Santa Inês sheep in Brazilian semiarid conditions.

Synergistic effects of insulin-like growth factor (IGF-II) and FSH on bovine granulosa cells

The synergistic effects of insulin-like growth factor II (IGF-II) and follicle stimulating hormone (FSH) and the effect of IGF-II alone on progesterone and estradiol production by bovine granulosa cells (GC) cultured in vitro were determined. Granulosa cells obtained from ovaries of slaughtered cows were cultured for four days in carbon (IV) oxide incubator at 37ºC, 5% CO2 in atmospheric air and 100% relative humidity, using Tissue Culture Medium 199 (TCM 199) as culture medium. The medium was changed on the second day and testosterone added to serve as substrate for estradiol production. IGF-II alone, or IGF-II (10 ng/ mL)+ FSH was added to culture medium at 0, 0.1, 1.0, 10, 50, and 100 (ng/mL) levels of inclusion. Concentrations of progesterone and estradiol produced were measured by radioimmunoassay. Data collected was statistically analysed using analysis of variance method. The results obtained showed that IGF-II alone and IGF-II + FSH had significant effects (p<0.05) on progesterone and estradiol produced by cultured GC. From the result obtained, it can be concluded that IGF-II + FSH gave better synergistic effects on bovine granulosa progesterone and estradiol production.

Se estudiaron los efectos sinérgicos del factor de crecimiento II similar a la insulina (ICF-II) solo o asociado a hormona folículo estimulante (FSH), sobre la producción de progesterona y estradiol por las células de granulosa bovinas (GC) cultivadas in vitro. Las GC, obtenidas de ovarios de vacas sacrificadas, fueron cultivadas durante cuatro días en incubador óxido de carbono (IV) a 37ºC y 5% de CO2 en aire atmosférico y 100% de humedad relativa, usando el medio de cultivo de tejidos 199 (TCM 199). El medio, fue cambiado al segundo día y se añadió testosterona como sustrato para la producción de estradiol. El IGFII solo o IGF-II (10 ng/mL) + FSH, se añadieron a las proporciones de 0; 0,1; 1,0; 10; 50 y 100 (ng/mL). Las concentraciones de progesterona y estradiol producidos se midieron mediante radioinmunoensayo. Los datos obtenidos se sometireron a análisis de varianza. Los resultados obtenidos demuestran que el IGF-II, solo o IGF-II + FSH tuvieron efectos significativos (p<0,05) sobre la progesterona y el estradiol producidos por las GC cultivadas. La asociación IGF-II + FSH mostró efecto sinérgico sobre la producción, de progesterona y estradiol por la granulosa bovina.

**Use of trypan blue to determine viability of bovine oocytes for in vitro fertilization**

Se estudió la tinción supravital con azul tripán (AT) para diferenciar ovocitos inmaduros bovinos vivos y muertos. Es importante conocer la viabilidad de los ovocitos para descartar los muertos antes de la fertilización in vitro (FIV). Se puncionaron folículos menores de 6 mm de ovarios provenientes de matadero. Los complejos cúmulo ovocitos (COC), se clasificaron en A, B y C. Se consideraron los de calidad A y B. Se formaron 2 estratos (otoño-invierno y primavera-verano) y 4 grupos dentro de cada estrato: un grupo control (GC), el cual no se sometió al AT y tres grupos: G1, G2, G3 que se sometieron al AT por 2, 5 y 10 minutos, respectivamente. Los COC teñidos de azul (muertos), se descartaron, los vivos se cultivaron 22 h para maduración y se volvieron a someter al AT, respetando los mismos tiempos de exposición. Se realizó la inseminación y se controló el desarrollo hasta mórulas compactas para evaluar la posible incidencia del AT y de las estaciones del año. En conclusión, la tinción con AT hasta 10 minutos, es útil para diferenciar ovocitos vivos y muertos sin producir efectos deletéreos.

The supravital stain with tripan blue (AT) was used for differentiating live bovine immature oocytes from dead ones. It is important to know the viability of the oocytes, in order to discard the dead ones before the in vitro fertilization (FIV). Smaller than 6 mm follicles were punctured, from ovaries obtained from an abattoir. The cumulus oocyte complexes (COC) were classified as A, B or C. Only those of quality A or B were taken into account. Two categories were formed (autumnwinter and spring-summer) and 4 groups within each category were considered: a control group (CG), which was not stained with AT and three groups: G1, G2 and G3 stained with AT for 2, 5 and 10 minutes, respectively. Blue stained COC (dead) were discarded, live COC were cultured for 22 h in a maturation culture and were stained again, maintaining the same exposure times. Insemination was then performed and compact morules counted, in order to evaluate the efect of AT and season. In conclusion, AT stain can be used up to 10 minutes to differentiate live and dead oocytes, without any deleterious effect on the gametes.

Effect of three diets on growth of hatchlings of american crocodile Crocodylus acutus

Se estudió el efecto de tres dietas con sustitución de pescado marino (20 y 40%) por hígado de res en el crecimiento y supervivencia, así como el efecto de la temperatura en el consumo de alimento de crías de Crocodylus acutus. Los cocodrilos alimentados con la dieta de 40% de hígado tuvieron el mayor crecimiento y un 100% de supervivencia, con potencial de mayor tolerancia a condiciones invernales.

The effect of three diets with replacement of marine fish (20 and 40%) for beef liver in the growth and survival, and the effect of temperature on feed intake of young Crocodylus acutus was studied. Crocodiles fed the 40% of liver had the highest growth and 100% survival, with potential for greater tolerance to winter conditions.