Archivos de Zootecnia

**Producción de metano in vitro en mezcla de gramíneas-leguminosas del trópico alto colombiano**

Se determinó la producción de metano in vitro para mezclas de gramíneas: leguminosas del trópico alto colombiano, utilizando la técnica de producción de gas. En dos lotes diferentes, se recogieron muestras de dos gramíneas, ryegrass (Lolium perenne) y kikuyo (Pennisetum clandestinum), y dos leguminosas, trébol blanco (Trifolium repens) y lotus grande (Lotus uliginosus). Se evaluaron cuatro mezclas de las gramíneas y las leguminosas: kikuyo y lotus, kikuyo y trébol blanco, ryegrass y lotus y ryegrass y trébol en tres proporciones diferentes de gramínea: leguminosa (90:10, 70:30 y 50:50). La concentración de metano en el gas se determinó por cromatografía de gases. Al aumentar las proporciones de leguminosas en la mezcla con el kikuyo, la producción de metano por unidad de materia seca degradada disminuyó hasta un 14 % (p<0,05). Sin embargo, no se observaron diferencias cuando se mezclaron con el ryegrass. Para el lotus, una leguminosa tanífera, al aumentar su proporción en la mezcla se disminuyó la producción total de metano (p<0,05) y su proporción en el gas independientemente de la gramínea base sugiriendo un efecto del lotus sobre las poblaciones metanogénicas.

In vitro methane production was determined in mixtures of grasses and legumes of Colombian highlands were evaluated using the gas production technique. Samples of two grasses, ryegrass (Lolium perenne) and kikuyu (Pennisetum clandestinum), and two legumes, white clover (Trifolium repens) and big trefoil (Lotus uliginosus), from two different paddocks were harvested. The treatments were mixtures of kikuyu and lotus, kikuyu and white clover, ryegrass and lotus and ryegrass and clover in three different grass: legumes ratio (90:10, 70:30 and 50:50). The methane concentration in the gas was determined by gas chromatography. Methane production per unit of degraded dry matter decreased 14 % (p<0.05) when the proportions of legume increased associated with kikuyu. However, no differences were observed when legumes were mixed with ryegrass. When proportion of lotus, a tanniferous legume, increased total methane production decreased independently of grass suggesting an effect in methanogenic population.

Efecto del tipo genético y la maduración sobre la retención de agua en carne de toros castrados

La capacidad de retención de agua en crudo (CRAr) y en cocinado (CRAc) fue determinada en carne madurada a 7, 14 y 21 días post mórtem. Los músculos Longissimus dorsi (LD) y Semitendi-nosus (ST) de 164 machos castrados provenientes del cruce de machos de las razas Simmental, Normanda, Blanco Orejinegro, Braunvieh, Guzerat, Brahman Blanco, Brahman Rojo, Limousin y Romosinuano con hembras Brahman blanco. Para el parámetro CRAr en LD se presentó significancia de los factores tipo genético y maduración y en ST del factor maduración. Para el parámetro de CRAc en LD fue significativo el factor tipo genético y para ST ninguno de los dos factores fue significativo. No existieron interacciones significativas de los dos factores evaluados. Lo ideal es someter a tiempos cortos de maduración ambos músculos y tener en cuenta el tipo genético al cual pertenece el individuo con el fin de minimizar las pérdidas de exudado.

Water Holding Capacity (WHC) was established in raw meat (WHCr) through the press method and in cooked meat by cooking losses (WHCc). The beef was aged at 7, 14 and 21 days post mortem. The muscles Longissimus dorsi (LD) and Semitendinosus (ST) of 164 castrated males were used. These animals were F1 offsprings of Simmental, Normande, BON (Blanco Orejinegro), Braunvieh, Guzerat, White Brahman, Red Brahman, Limousin and Romosinuano bulls crossed with White Brahman females. In WHCr genetic type and ageing were significant factors in LD and ageing was significant in ST. Ideally, meat of ST and LD should be aged for short time post mortem and the genetic type can affect the water retention in LD.

Meta-analysis of lysine levels used in diets for finishing swine in Brazil: recommendations to optimize performance and reduce costs

O objetivo do trabalho foi estimar os níveis de lisina (Lys) em rações de suínos em terminação, adequados para otimizar o desempenho e reduzir os custos com alimentação, utilizando a técnica da metanálise. Para isso foram utilizados dados de conversão alimentar (CA) de 16 experimentos dose-resposta realizados no Brasil, publicados entre os anos de 2000 e 2011, que avaliaram níveis crescentes de lisina na ração. Após convertidos para uma base comum, os dados de conversão alimentar dos trabalhos selecionados foram submetidos á análises de regressão considerando o nivel de Lys como variável independente, utilizando os modelos exponencial, polinomial quadrático e Linear Response Plateau (LRP). Com base na equação exponencial, foi calculada a variação do custo com alimentação por kg de ganho de peso. Considerou-se o custo da ração basal (sem L-lisina HCl) como sendo R$ 0,70/kg, e atribuiu-se o valor de 2,80 (g/g) para a CA desejada. O nível ótimo de lisina total adequado para otimizar o desempenho, estimado a partir da utilização do modelo quadrático foi 1,036 %, enquanto o nível ótimo estimado para reduzir os custos com alimentação e aumentar a margem foi 0,980 % quando o kg de L-lisina HCl (78,5 %) custou R$ 4,71. Por outro lado quando o kg de L-lisina HCl (78,5 %) aumentou para R$ 7,85, o nfvel estimado reduziu para 0,880 %. Para simular o custo com alimentação por kg de GP de sufnos em crescimento/terminação propos-se uma equação.

The objective of the study was to determine optimal lysine levels (Lys) in diets for finishing pigs, suitable for optimize performance and reduce feed costs, using the meta-analysis technique. Feed conversion (FC) data from 16 dose-response experiments realized in Brazil (from 2000 to 2011), which evaluated increasing lysine levels in diets were used. The feed conversion data from selected works were converted to a common basis and submitted to regression analyzes considering the lysine level as independent variable by the exponential, quadratic model and Linear Response Plateau (LRP). Based on exponential equation was calculated the variation of feed cost per kg of weight gain. The cost of basal diet (without L-lysine) was considered as R$0.70/kg, and assigned the value of 2.80 (g/g) for the FC desired. The optimal total lysine level appropriate to optimize performance, recommended by quadratic model was 1.036 %, while the optimum level recommended to reduce feed costs and increase the margin was 0.980 %, when the cost of L-lysine HCl kg (78.5 %) was R$4.71. On the other hand, when the kg of L-lysine (78.5 %) increased to R$7.85, the recommended level was reduced to 0.880 %. To estimate the feed cost per kg of weight gain for growing/finishing pigs, an equation was proposed.

Estimación de curvas de crecimiento de codorniz japonesa utilizando el modelo Gompertz

This study was conducted to describe the growth pattern of Japanese quails with the Gompertz growth model using body weight measurements from an unselected, random bred quail population. The coefficient of determination (R²) was high for both male and female (0.98) indicating that the growth curves of the observed data were adequately described by the Gompertz model. However, male and female Japanese quails did not have identical growth patterns. Generally, females appeared to be heavier than males at all ages and this difference increased with age. Both male and female Japanese quail were 4 % mature at hatch but reached 98 and 96 % respectively, of their mature weights at 12 weeks of age. Thus, males matured faster than females though the latter had higher weights. Asymptotic weight (A) was higher (p<0.05) in females (168.83 g) than males ( 132.71 g) as was the case with integration constant (B). In contrast, maturity rate (k) was higher (p<0.05) in males (0.3765) compared to females (0.3262). Thus, a strong and negative relationship (-0.7981 and -0.8498 for male and female respectively) between maturation rate and asymptotic weight was observed. Age, weight and maximum gain at point of inflection for male and female Japanese quails were 2.48 vs. 2.91 weeks, 48.82 vs. 62.11 g and, 18.38 vs. 20.26 g respectively. Males reached the inflection point at a significantly (p<0.05) earlier age than females. Similarly, they had lower inflection weight and gain than female quail. And it explains difference between males and females Japanese quail in Nigeria.

Este estudio fue realizado para describir el crecimiento de la codorniz japonesa, mediante el modelo de Gompertz, empleando medidas del peso corporal, tomadas al azar, de una población no seleccionada de codornices. El coeficiente de determinación (R²) fue elevado (0,98) tanto para machos como para hembras, indicando que las curvas de crecimiento generadas con los datos obtenidos fueron adecuadamente descritas empleando el modelo de Gompertz. Sin embargo, los modelos de crecimiento de las codornices machos y hembras, no son iguales. Generalmente las hembras parecen más pesadas que los machos a cualquier edad y esta diferencia se incrementa con la edad. Tanto los machos como las hembras de codorniz japonesa estaban al 4% de su madurez al nacimiento, pero alcanzaron, respectivamente, el 98 y 96 % de sus pesos maduros a las doce semanas de edad. Es decir, los machos maduraron más rápidamente que las hembras aunque éstas tenían pesos más elevados. El peso asintótico (A) fue más alto (p<0,05) en las hembras (168,83 g) que en los machos (132,71 g), lo mismo sucedió con la constante de integración (B). En contraste, la tasa de maduración (k) fue mayor (p<0,05) en los machos (0,3765) que en las hembras (0,3262). Así, se observó una fuerte correlación negativa (-0,7981 y -0,8498 para machos y hembras respectivamente) entre la tasa de maduración y el peso asintótico. La edad, peso y ganacia máxima en el punto de inflexión para machos y hembras de codorniz japonesa fueron: 2,48 vs. 2,91 semanas; 48,82 vs. 62,11 g y 18,38 vs. 20,26 g, respectivamente. Los machos alcanzaron el punto de inflexión a edad más joven (p<0,05) que la de las hembras. De modo similar mostraron menor peso de inflexión y ganancia que las hembras. Ello explica las diferencias entre codornices japonesas machos y hembras en Nigeria.

Effect of cassava peel on meat quality and ruminal parameters of sheep

Objetivou-se com este trabalho, avaliar diferentes formas de processamento da casca de mandioca para uso na alimentação de ovinos e seus efeitos sobre a composição centesimal, qualidade de carne, perfil lipídico e morfometria ruminal. Para o experimento foram utilizados um total de 20 ovinos machos da raça Santa Inês desmamados com peso inicial 19,02±0,21 kg. O esquema fatorial utilizado foi um DIC (delineamento inteiramente casualizado), sendo 4 tratamentos (tratamento A: suplemento com casca de mandioca desidratada triturada em moinho com peneira de 12 mm; tratamento B: suplemento com casca de mandioca desidratada triturada em moinho com peneira de 5 mm; tratamento C: suplemento com casca de mandioca ensilada; tratamento D: suplemento com casca de mandioca hidrolisada), cada animal foi considerado uma repetição, totalizando 5 repetições por tratamento. Os animais foram criados em sistema semiextensivo, em pastagem de Brachiaria decumbens e o fornecimento dos tratamentos na forma de suplemento na proporção de 1,5 % do peso vivo (relação volumoso:concen-trado de 62,5:37,5 %), sendo a quantidade corrigida semanalmente em função do peso dos animais. O experimento teve duração de 84 dias, incluindo o período de 14 dias de adaptação às dietas e os animais foram abatidos com peso final de 30,72±1,46 kg, sendo coletado após abate e resfriamiento (24 horas a ±2 ºC), amostras do músculo Longissimus lumborum para realizacao das análises físico-químicas e do perfil lipídico. Os resultados mostraram que não houve diferenca significativa para as cinzas, umidade e proteína. Os animais que receberam suplemento com casca de mandioca hidrolisada apresentaram maiores valores de extrato etéreo. Não foi verificado modificacao do perfil de ácidos graxos em virtude do processamento da casca de mandioca. A avaliacao histológica revelou alteracao no epitélio do rúmen e área da lamina do omaso, com maiores valores no suplemento com uso da casca de mandioca moída grosseiramente. Para as variáveis da composicao físico-químicas não foram verificadas influéncia dos suplementos. Os diferentes suplementos não foram suficientes para alterar os parametros de qualidade de carne, entretanto, a casca de mandioca hidrolisada ocasionou maior acúmulo de lipídeos no músculo.

This work evaluated different forms of processing of cassava peel for use in sheep feeding and its effects upon composition, meat quality, lipid profile and rumen morphometrics. A total of 20 weaned Santa Ines male sheeps, with initial weight 19.02±0.21 kg, were used. The factorial scheme utilized was a completely randomized design, with 4 treatments (A: supplement with dehydrated cassava peel ground, using a 12 mm sieve; B: supplement with dehydrated cassava peel ground using a 5 mm sieve; C: supplement with ensiled cassava peel; D: supplement with hydrolyzed cassava peel). Each animal was considered a replication, with 5 replications per treatment. The animals were reared in semiextensive system, on Brachiaria decumbens pasture. Treatments were supplied as supplement at proportion of 1.5 % of live weight (ratio roughage: concentrate of 62.5:37.5 %), amounts of food were adjusted, every week, according to the animals' weight. The experiment lasted 84 days, including 14 days for adaptation to the diets. Animals were slaughtered at 30.72±1.46 kg final weight; after slaughter and cooling (24 hours at ±2 ºC), samples of Longissimus lumborum muscle were collected to carry out the physicochemical analyses, and establish lipid profile. There were no significant differences for ashes, moisture and protein. The animals fed supplement with hydrolyzed cassava peel, presented higher values for ether extract. The fatty acid profile was not affected by processing type of cassava peels. The histological evaluation revealed alteration in the rumen epithelium and area of the omasal lamina, with higher values for coarsely ground cassava peel supplement. No influence of the supplements was found for physicochemical composition. The different supplements were not enough to alter the meat quality parameters, however, hydrolyzed cassava peel brought about increased accumulation of lipids in the muscle.

Efecto de aditivos sobre la fermentación de ensilaje de hojas de yuca y el fluido ruminal en cabras enanas de África Occidental

A study was conducted to investigate the effects of different additives on the fermentation quality of ensiled cassava leaves and its effects on the ruminal fluid parameters using eighteen West African dwarf goats. Cassava leaves were ensiled alone (ECF), with 5 % (w/w) molasses (ECFM) and caged layer waste (ECFP) respectively as additives for 30 days. Results of chemical composition of the additive and non-additive silages indicated that ensiling with 5 % molasses reduced the DM content from 252.4 g/kg in ECF to 238.9 g/ kg in ECFM and increased with 5 % caged layer waste (ECFP) to 267.6 g/kg. The CP content of ECF was 207.6 g/kg and this decreased to 198.5 g/kg DM in ECFM. Addition of molasses and caged layer waste caused a reduction in the HCN contents from 95.8 mg/kg in non-additive silage (ECF) to 89.3 mg/kg in ECFP and 84.7 mg/kg in ECFM. The mean pH of non-additive silage of 3.66 was significantly (p<0.05) different from the value of 4.29 in ECFP. Animals fed silage ensiled with molasses (ECFM) had a DM intake of 503.42 g/d, followed by values of 485.17 g/d and 458.43 g/d for animals fed ECF and ECFP respectively. Crude protein intake was similar in ECF and ECFM but higher (p<0.05) than ECFP and ranged from 161.28172.71 g/d. The ruminal fluid parameters indicated no significant differences (p>0.05) in the pH, bc and lactic acid concentration in both the non-additive and additive silages. Ammonia-nitrogen concentration (NH3-N) however, ranged significantly (p<0.05) from 15.93 ± 0.20 (mg/dL) in ECF to 22.43 ± 0.61 (mg/dL) in ECFP. The study showed that ensiling cassava leaves with 5 % molasses and caged layer waste improved the silage conditions and the ruminal fluid parameters of West African Dwarf goats.

Se realizó un estudio para investigar los efectos de diferentes aditivos sobre la calidad de la fermentación de ensilaje de hojas de yuca y sus efectos sobre los parámetros del fluido ruminal en dieciocho cabras Enanas de África occidental. Las hojas de yuca fueron ensiladas, durante 30 días, solas (ECF) y con adición de 5 % de melaza (ECFM) o excretas de ponedoras en batería (ECFP) como aditivos. La adición de 5 % de melaza redujo el contenido de materia seca, 252,4 g/kg en ECF, a 238,9 g/kg en ECFM; con adición de 5 % de excretas (ECFP) la MS aumentó hasta 267,6 g/kg. El nivel de PB (207,6 g/kg en ECF) disminuyó a 198,5 g/kg en ECFM. Tanto la adición de melazas o excretas determinaron la reducción del contenido de HCN desde 98,5 g/kg en ECF (sin aditivos) a 89,3 en ECFP y 84,7 g/kg en ECFM. El pH medio del ensilaje sin aditivos (3,66) fue menor (p<0,05) que el de ECFP (4,29). La ingesta en los animales alimentados con ensilado melazado (ECFM) fue de 503,43 g/d; 485,17 g/d para ECF y 458,43 g/d para ECFP. La ingestión de PB varió entre 161,28 y 172,71 g/d, siendo similar en ECF y ECFM y más baja (p<0,05) en EFCP. Los parámetros del fluido ruminal no mostraron diferencias significativas en pH, capacidad tampón o concentración de ácido láctico para ninguno de los tipos de ensilado. Sin embargo, la concentración de nitrógeno amoniacal (NH3-N) varió (p<0,05) entre 15,93 ± 0,20 (mg/dL) en ECF a 22,43 ± 0,61 (mg/dL) en ECFP. El trabajo demostró que el ensilaje de hojas de yuca con 5 % de melazas o excretas de aves en batería, mejoró su calidad y repercutió favorablemente sobre los parámetros ruminales de cabras Enanas de África Occidental.

Von Mises distribution in the evaluation of apicultural data

A estatística circular é aplicada a dados em que é possível notar um comportamento periódico que caracteriza a obtenção dos chamados dados circulares. A existência de um ritmo circadiano no metabolismo de abelhas africanizadas pode influenciar no horário de mortalidade de operárias e de emergência de rainhas, sendo obtidas nesse caso, medidas circulares, caracterizadas pelo horário de ocorrencia de tais eventos. As visitas de abelhas às flores de uma planta podem, igualmente, fornecer dados circulares. A finalidade do trabalho foi verificar aplicabilidade da estatística circular em dados apícolas. Utilizaram-se os dados de três experimentos: 1- forrageamento de abelhas em alecrim do campo; 2- emergência de rainhas e 3- horário de mortalidade de operárias (considerando-se o horário de montagem de experimento à noite (19 h 30 min) e durante o dia (7 h 30 min)). Todos os conjuntos de dados utilizados foram testados em relação a duas distribuições: uniforme e Von Mises (ou normal circular) e foram ajustados à segunda. Concluiu-se que, para o forrageamento de abelhas no alecrim o modelo da normal circular é com um horário médio de forrageamento igual a 11 h 29 min com grande dispersào. Existe também um ritmo circadiano que regula o horário de emergência de rainhas e de mortalidade das abelhas operárias. Para o experimento de emergência de rainhas obteve-se o intervalo de confiança a 95 % para a média circular igual a (4 h 12 min; 9 h 05 min). O horário médio de mortalidade no caso da montagem realizada durante o dia ocorre após 4 h 18 min, com longevidade estimada em 8 h e 37 min, enquanto para individuos mantidos sob as mesmas condições, sendo alterado apenas o horário de montagem do experimento para as19 h 30 min, estima-se uma longevidade de 19 horas e 37 minutos. É recomendável, portanto que, para a execução de experimentos laboratoriais com adultos de abelhas, seja incluído na metodologia experimental o horário de montagem do experimento.

Circular statistics is applied to data that show a periodic behavior, which characterizes the obtaining of what is called circular data. The existence of a circadian rhythm in the metabolism of Africanized bees can influence the mortality time of workers and the emergence of queen bees, in which case we obtain circular data characterized by the time of occurrence of these events. Bees' visits to flowers of a plant can also provide circular data. The aim of this research was to verify the applicability of circular statistics to apicultural data. data from three experiments were used: 1- bees foraging for field rosemary; 2-emergence of queen bees; 3- the mortality time of workers (considering the experimental setup time at night (19:30) and during the day (7:30)). All data sets used were tested in relation to two distributions: uniform and Von Mises (or circular normal), and fitted to the latter. it was concluded that, when bees are foraging on rosemary, the circular normal model mean time equals 11 h 29 min with large dispersion. There is also a circadian rhythm that regulates the emergence time of queens and the mortality of worker bees. In the experiment on the emergence of queen bees, a confidence interval of 95 % was obtained for the circular mean equal to (4 h 12 min; 9 h 05 min). The mean mortality time in the setup carried out during the day occurs after 4 h 18 min, with longevity estimated at 8 h 37 min. The life expectancy of individuals maintained under the same conditions, except for an experimental setup time at 19 h 30 min, is estimated at 19 h 37 min. Therefore, in order to carry out laboratory experiments on adult bees, it is advisable to include the experimental setup time in the experimental methodology.

Efectos climáticos sobre la ocurrencia de mastitis clínica en diferentes razas de vacas y búfalas

The study was conducted to find out the effect of different seasons on incidence of mastitis throughout the year in Indigenous cows, crossbred cows and Murrah buffaloes. Lactation records pertaining to the 12 year period were collected and incidence of mastitis was plotted against the climograph of the Karnal zone, Haryana, India. The hot humid climate was found to adversely affect the incidence of mastitis in all the breeds of cows and Murrah buffaloes. The incidence was significantly affected by the season (p<0.01) in all the breeds, however incidence was lowest in Murrah buffaloes in comparison to cows. Further incidence was more in Sahiwal and Tharparkar cows (p<0.01) than the crossbred Karan Swiss and Karan Fries cows. The increase in temperature humidity index resulted in increased incidence of mastitis in cows (p<0.01) but Murrah buffaloes were less affected.

Este estudio fue realizado para hallar la influencia estacional sobre la incidencia de la mastitis a lo largo del año, en vacas indígenas, vacas cruzadas y búfalas Murrah. Se analizaron los registros de lactación correspondientes a un periodo de 12 años, la incidencia de mastitis fue comparada con los climogramas de la zona de Karnal, Haryana, India. El clima cálido y húmedo afectó negativamente a la incidencia de mastitis en todas las razas bovinas y los búfalos. La incidencia fue afectada significativamente por la estación (p<0,01) en todas las razas, aunque el efecto fue menor en las búfalas Murrah. El registro de mastitis fue más elevado en las razas Sahiwal y Tharparkar (p<0,01) que en los cruces Karan-Suiza y Karan-Fries. El incremento del índice de temperatura y humedad dio lugar a una mayor incidencia de mastitis en las vacas (p<0,01), aunque las búfalas Murrah resultaron menos afectadas.

Análisis multivariante de caracteres morfológicos de patos Muscovy nigerianos (cairina moschata)

This study was designed to investigate the possibility of classifying Nigerian Muscovy ducks into distinct ecotypes using stepwise discriminant analysis and Euclidean distance. Data were collected on ten morphological traits (body weight, body length, body girth, wing length, shank length, shank circumference, thigh length, total leg length, bill length and bill width) of one thousand and twenty (1020) adult Muscovy ducks comprising 203, 598 and 289 randomly sampled ducks from the rain forest, derived savanna and Guinea savanna ecotypes, respectively. The results of the descriptive statistics revealed highly (p<0.001) significant effects of ecotype on eight of the morphological traits except bill width and body length. Stepwise discriminant analysis indicated that bill length and body length had highest discriminating powers among the six distinguishing variables. Result of the cross validation of the correct assignment of ducks into distinct ecotypes was low; 53.7, 41.8 and 42.3 % of samples drawn from the rain forest, derived savanna and Guinea savanna ecotypes were correctly classified into their expected ecotypes. Euclidean distance between ecotypes was small; shortest distance was between rain forest and derived savanna ducks (2010) while the longest distance (3758) was between rain forest and Guinea savanna ducks. It is evident that due to the low classification success rate of discriminant analysis and short Euclidean genetic distance between ecotypes, they could not be classified into distinct ecotypes on the bases of morphostructural traits and appreciable heterosis is practically impossible from crossing Nigerian Muscovy ducks originating from different ecotypes.

Este estudio fue realizado para investigar la posibilidad de clasificar los patos Muscovy nigerianos en distintos ecotipos utilizando el análisis discriminante secuencial y la distancia euclidiana. Se obtuvieron datos de diez caracteres morfologicos (peso, longitud y perímetro corporal, longitud del ala, longitud y circunferencia del tarso, longitud del muslo, longitud total de la pierna, longitud y anchura del pico) de 1020 patos Moscovy adultos obtenidos al azar en los ecotipos de bosque lluvioso (203), de sabana derivada (598) y de sabana de Guinea (289). La estadística descriptiva reveló (p<0,001) la influencia del ecotipo sobre ocho de las medidas estudiadas, exceptuando la amplitud del pico y longitud corporal. El análisis discriminante secuencial puso de manifiesto que el mayor poder discriminante corresponde a las longitudes del pico y del cuerpo. La validación cruzada puso de manifiesto una baja asignación correcta a los correspondientes ecotipos; el 53,7; 41,8 y 42,3 % de las muestras fueron atribuidas correctamente a los ecotipos bosque lluvioso, sabana derivada y sabana de Guinea respectivamente. La distancia euclidiana entre ecotipos resultó pequeña, la más corta se registró entre el ecotipo bosque lluvioso y el savana derivada (2010) mientras que la distancia mayor, se registró entre los patos del bosque lluvioso y los de la sabana Guinea. Es evidente que debido al escaso éxito de la clasificación del análisis discriminante y la pequeña distancia euclidiana, los posibles ecotipos estudiados no pueden considerarse diferentes sobre la base de caracteres morfoestructurales y la obtención de una apreciable heterosis es prácticamente imposible a partir del cruzamiento de estos ecotipos nigerianos.

Parámetros genéticos para caracteres productivos y reproductivos en Holstein y Jersey colombiano

El objetivo de este estudio fue estimar parámetros genéticos y fenotípicos en características productivas y reproductivas en ganado Holstein y Jersey de Antioquia, Colombia. La información fue obtenida de 85 hatos lecheros de raza Holstein y 7 hatos de raza Jersey, ubicados en 18 municipios del departamento de Antioquia. Las características productivas evaluadas fueron: producción de leche (PL), porcentaje de proteína (PP), porcentaje de grasa (PG) y puntaje de células somáticas (SCS) y las características reproductivas evaluadas fueron: intervalo entre partos (IEP), días abiertos (DA), número de servicios por concepción (NSC) y tasa de concepción (TC). Los componentes de (co)varianza, los parámetros genéticos y fenotípicos fueron estimados empleando modelos mixtos univariados y bivariados y las soluciones de las ecuaciones de los modelos mixtos fueron obtenidas mediante el método de máxima verosimilitud restricta libre de derivadas. Las heredabilidades obtenidas para características productivas oscilaron entre 0,22 y 0,35, excepto para SCS que fueron bajas (h²<0,11) y para las características reproductivas oscilaron entre 0,03 y 0,15. Las correlaciones genéticas más altas obtenidas para Holstein fueron: r gIEPxPL= 0,77; r gIEPxPP= 0,61; r gIEPxPL= 0,77 y r gDAxSCS= 0,73 y para Jersey: r gIEPxPP = 0,56; r g|EPxSCS= 0,49; r gTCxPG= - 0,52 y r gTCxSCS= -0,72. Las correlaciones fenotípicas fueron bajas en todos los casos, variaron entre -0,17 y 0,16. Las características productivas, son mucho más heredables que las características reproductivas. No obstante, las correlaciones genéticas sugieren que es recomendable construir índices de selección a partir de estas características para obtener un mayor progreso genético pero equilibrado en sus componentes productivos y reproductivos.

The objective of this study was to estimate genetic and phenotypic parameters in milk production and reproduction traits in Holstein and Jersey from Antioquia, Colombia. The information was obtained from 85 Holstein dairy herds and 7 Jersey dairy herds. The milk production traits evaluated were: milk yield (PL), protein percentage (PP), fat percentage (PG) and somatic cell score (SCS) and the reproduction traits evaluated were: calving interval (IEP), days open (DA), number of services per conception (NSC) and conception rate (TC). The (co) variance components, genetic and phenotypic parameters were estimated by using univariate and bivariate linear mixed models and the solutions of the mixed model equations were obtained through derivative-free restricted maximum likelihood method. The heritabilities obtained for milk production traits ranged from 0.22 to 0.35, except for SCS that were low (h²<0.11) and for reproduction traits ranged between 0.03 and 0.15. The highest genetic correlations for HolStein Were: r gIEPxPL= 0,77; r gIEPxPP= 0,61; r gIEPxPL= 0,77 and r gDAxSCS= 0,73 and for Jersey were: r gIEPxPP = 0,56; r g|EPxSCS= 0,49; r gTCxPG= - 0,52 y r gTCxSCS= -0,72. Phenotypic correlations were low in all cases, ranged from -0.17 to 0.16. Milk production traits are more heritable than reproduction traits. However, genetic correlations suggest that it is favorable to construct selection indices from these traits to gain more genetic progress but balanced in their productive and reproductive components.

Meat quality of finishing pigs fed with different ractopamine levels

O experimento foi conduzido no Departamento de Zootecnia da Universidade Federal de Lavras com o objetivo de avaliar características químicas, físicas e sensoriais da carne de suínos recebendo diferentes níveis de ractopamina na dieta, no período de 28 dias. Foram utilizados 72 suínos híbridos, sendo 30 machos castrados e 30 fêmeas, selecionados para alta deposição de carne, com peso inicial de 84,27±2,26 kg. O delineamento experimental foi em bloco casualizado, com 6 tratamentos (0, 3, 6, 9, 12 e 15 ppm de ractopamina) e 6 repetições, com a parcela experimental representada por 1 macho e 1 fêmea. A adição de ractopamina nas dietas dos suínos nos níveis testados melhorou a composição química tanto do lombo quanto da copa, contribuindo para uma maior deposição proteica e uma menor porcen-tagem de lipídeos nos cortes. Nas características físicas os níveis mais altos de ractopamina comprometeram a textura e alteraram a cor, além da aceitação pelos consumidores. Já em relação a estabilidade oxidativa, tanto para os lombos armazenados sob resfriamento quanto sob congelamento, a adição de ractopamina as dietas de suínos em terminação auxiliou na prevenção da oxidação lipídica.

The experiment was conducted in the Department of Animal Science of the Federal University of Lavras. The objectives were to obtain chemical, physical and sensory characteristics of pork meat receiving different levels of ractopamine in the diet, in the period of 28 days. Sixty hybrids pigs were used, being 30 castrated males and 30 females, selected for high deposition of lean meat, with initial weight of 84,27±2,26 kg. The experimental design was a completely randomized block design with six treatments (0, 3, 6, 9, 12 and 15 ppm of ractopamine) and 6 repetitions with the experimental plot represented by a male and a female. The addition of ractopamine in the diets of the pigs at the levels tested improved the chemical composition both for the loin as for the cup, contributing to greater protein deposition and a lower percentage of lipids in the cuts. In physical characteristics the highest levels of ractopamine agreed to texture and changed the color, in addition to the acceptance by consumers. Already in relation to oxidative stability, both for the loins stored under refrigeration as under freezing, the addition of ractopamine diets for pigs in the finishing phase helped in the prevention of lipid oxidation.

Análisis y diagnóstico de los sistemas de producción ovina en el sureste español

En el presente estudio se analiza la situación actual del sector ovino de carne en el espacio geográfico de la IGP (Indicación Geográfica Protegida) Cordero Segureño. Se presentan los resultados descriptivos de las 93 encuestas realizadas donde se analizan las principales fortalezas y debilidades que presenta la situación actual de los ganaderos. Se trata de una cabaña ganadera de alta rusticidad cuyo rendimiento productivo puede aumentar con una selección genética encaminada hacia una mayor pureza racial. Existe una buena predisposición a utilizar el sello de calidad, si bien el asociacionismo tanto en la producción como en la comercialización es bajo. El relevo generacional podría aumentarse si se logra mejorar a medio plazo el rendimiento productivo de las explotaciones con políticas de producción basadas en la calidad. Ternasco de Aragón, podría ser un buen referente cara a inspirar las medidas de mejora en la difusión de la nueva IGP Cordero Segureño.

This study analyzes the current situation of the sheep meat industry in the geographical area of the IGP (Protected Geographical Indication) Cordero Segureno. We present the descriptive results of the 93 surveys that analyze the strengths and weaknesses that presents the current situation of farmers. This is a high rusticity livestock whose yield can be increased with a genetic selection aimed toward greater racial purity. There is a willingness to use the quality mark, although the associations both in the production and marketing is low. The generational change could be increased if it can improve the medium-term growth performance of farms with production policies based on quality. Ternasco de Aragón, could be a good reference face to inspire improvement measures for distributing the new IGP Cordero Segureño.

Genotipo, alimento y refrigeración, en la actividad antioxidante y estabilidad oxidativa del lomo de conejo

El objetivo del presente trabajo fue evaluar el efecto de la actividad antioxidante (AA) de cuatro alimentos comerciales sobre la AA y la estabilidad oxidativa (EO) de lomo crudo (Longissimus dorsi) de conejos de tres genotipos (Nueva-Zelanda, NZ, California, CAL, y NZ*CAL) a tres tiempos de refrigeración (0, 3 y 6 días). La AA de todos los alimentos disminuyó (p<0,05) a los 30 días de su almacenamiento; sin embargo, el alimento 1 presentó la mayor AA (p<0,05). Con todos los genotipos y alimentos, la AA del lomo crudo disminuyó al día 6 de refrigeración excepto con NZ*CAL con el alimento 1. El genotipo NZ*CAL presentó mayor AA con el alimento 1 (p<0,05) y menor con el alimento 3. Contrariamente, el genotipo NZ presentó menor AA con el alimento 1 y mayor con el alimento 3. La cruza NZ*CAL presentó la mejor EO cuando recibió el alimento 1 y la peor cuando recibió el alimento 3. Contrariamente, NZ presentó la peor estabilidad oxidativa con el alimento 1 y la mejor con el alimento 3 con respecto a la cruza, esto indica que la EO mejoró al aumentar la actividad antioxidante. El genotipo NZ presentó la menor EO con el alimento 4 durante todo el periodo de refrigeración (p<0,05). Adicionalmente, la EO del lomo crudo disminuyó al transcurrir el tiempo de refrigeración (p<0,05). Se sugiere alimentar a NZ*CAL con alimentos con más de 85 % de AA y no refrigerar más de 6 días para prevenir el deterioro oxidativo del lomo crudo.

The objective of the present study was to evaluate the antioxidant activity (AA) of four commercial feeds on the AA and oxidative stability (EO) of raw loin meat (Longissimus dorsi) of rabbits of three genotypes (New Zealand, NZ, California, CAL, and NZ* CAL), during three refrigerated storage times (0, 3, and 6 days). The AA of all feeds decreased at 30 days of storage; however, feed 1 showed greater AA (p<0.05). In all genotypes and feeds the AA of the raw loin declined at day 6 of refrigeration, except with NZ*CAL fed feed I.The NZ*CAL genotype showed higher AA fed feed 1 (p<0.05) and lower with feed 3. In contrast, the NZ genotype showed lower AA with feed 1 and higher with feed 3. The NZ*CAL crossbreed meat had the best EO when it received feed 1 and the worst with feed 3. On the other hand, NZ showed the worst EO with feed 1 and the best with fed 3 with respect to NZ*CAL, this indicates that EO improved when AA increased. The NZ genotype showed lower EO with feed 4 during all refrigeration days (p<0.05). In addition, the EO of the raw loin decreased over time in refrigeration (p<0.05). It is suggested feeding NZ*CAL rabbits with feeds with more than 85 % of AA and do not refrigerate raw loin meat more than 6 days to avoid deterioration oxidative of the meat.

Associations between andrology and quality of carcass traits in Nellore bulls

Objetivou-se com este estudo verificar a existência de associações genéticas entre características de carcaça e características andrológicas em touros Nelore jovens. Realizou-se avaliação andrológica e da carcaça de 223 machos Nelore com média de 21 meses de idade. Para estimação dos parâmetros genéticos utilizou-se a inferência bayesiana por meio do software THRGIBBS1F90. As estimativas de herdabilidade obtidas para DEFMAI, DEFMEN, DEFTOT, AR, AOL, EG e P8 foram 0,33; 0,20; 0,21; 0,35; 0,32; 0,28 e 0,29, respectivamente. As estimativas de correlação genética de DEFTOT com AOL, EG e P8 foram -0,46; -0,28 e -0,19, respectivamente; já de AR com estas mesmas características foram -0,60; -0,03 e -0,12, respectivamente. Os resultados obtidos neste estudo demonstram haver resposta correlacionada favorável entre as características reprodutivas e de carcaça estudadas.

The aim with this study was to verify the existence of genetic associations among carcass traits, and andrology traits in Nellore young bulls. Breeding soundness and carcass examinations were done on 223 Nellore males with average of 21 months age. To estimate the genetic parameters the bayesian inference was used through the software THRGIBBS1F90. The heritability estimates was obtained for DEFMAI, DEFMEN, DEFTOT, AR, AOL, EG and P8 were 0.33, 0.20, 0.21, 0.35, 0.32, 0.28, and 0.29, respectively. The genetic correlation estimates of DEFTOT with AOL, EG and P8 were -0.46, -0.28, and -0.19, respectively; to AR with these same characteristics were -0.60, -0.03, and -0.12, respectively. The results of this study demonstrate that there is a favorable correlated response between reproductive and carcass traits studied.

Análisis de diluyentes comerciales de semen porcino refrigerado durante 4 días: resultados preliminares

La utilización de semen enfriado en inseminación artificial (IA) porcina sigue siendo una limitante, ya que la respuesta frente a temperaturas menores a 16 ºC es aleatoria entre cerdos, y aún entre eyaculados del mismo cerdo. El objetivo del presente trabajo fue jerarquizar la capacidad para la conservación de dosis refrigeradas durante 4 días de tres diluyentes comerciales (de larga o media duración) de semen porcino (Androstar Plus®, MRA® y MIII®), analizando: viabilidad, funcionalidad de membrana, integridad acrosomal y movilidad en 11 eyaculados procedentes de 3 verracos. No existieron diferencias (p>0,05) entre diluyentes por lo que sería similar su capacidad de conservación durante un período de 4 días.

The use of cold preserved semen is still a limiting factor in artificial insemination, because of the random response of boar semen to temperatures below 16 ºC, even between ejaculates from the same male. The aim of this work was to analyze and rank three commercial (long and medium term) boar semen extenders (Androstar Plus®, MRA® y MIII®), based on their capability to preserve refrigerated semen for four days analyzing: viability, membrane functionality acrosome integrity and motility. Eleven ejaculates were assessed. There were not differences (p>0.05) between extenders for any of the parameters studied, evidencing a similar preservation capability in a four-day period.

Computerized phenotypic characterization of the Calabrese donkey population

Lo studio ha riguardato la caratterizzazione fenotipica di 56 soggetti (tra 2 e 30 anni di età) riconducibili alla popolazione asinina Calabrese, allevati in 23 aziende. Su ciascun soggetto sono stati eseguiti i più significativi rilievi morfometrici mediante l'impiego di un sistema di analisi d'immagine computerizzato. Tali dati sono stati successivamente utilizzati per il calcolo dei più significativi indici biometrici. Inoltre sono stati presi in considerazione il colore e le eventuali particolarità del mantello. Gli indici biometrici ricavati ci hanno permesso di inquadrare questa popolazione asinina nel tipo dolicomorfo, come evidenziato dai valori dell'Indice di conformazione laterale del corpo (97,78), dell'Indice toracico di profilo (44,85), dell'Indice di Compattezza (90,80), dell'Indice lunghezza torace (100,79) e dell'Indice di ossatura (12,82). Il colore del mantello è risultato essere principalmente morello (75 %) anche se si è osservata la presenza di soggetti baio scuro (20 %) e grigio (5 %). Il colore dell'addome costantemente bianco come anche il muso e le occhiaie. Il colore dell'ano, vulva e mammella è costantemente nero.

A study on the phenotypic characterization of the Calabrese asinine population was carried out. Fifty-six donkey (2 years to 30 years) reared in 23 farms were identified. The most significant morphometric traits, using a computerized system of image analysis with a digital camera, were measured, the bio-metric indices calculated and the characteristics of the coat evaluated. The bio-metric index mean values tend towards diametrical proportions of the dolichomorphic type; in fact, the results show: height-length proportion index of 97.78, thoracic index of 44.85, body proportion index of 90.80, chest length index of 100.79 and dactylo-thoracic index of 12.82. Calabrese donkeys are characterised by black (75 %), bay (20 %) and gray (5 %) coat, white abdomen, snout and orbit, black anus, vulva and udder.

Changes in Tifton 85 bermudagrass hay storage in the field or under shed

The variations of chemical composition, and occurrence of fungi in Tifton 85 bermudagrass hay stored in the field or under shed for 30 days were evaluated. The desing used was completely randomized design with plots subdivided by time with two storage systems, four assessment periods. After 30 days, crude protein was reduced and acid detergent insoluble protein (ADIP) contents increased, with low occurrence of fungi Aspergillus, Rizophus, and Cladosporium and high occurrence of Geotrichium, Phoma, Penicillium, and Diploccocum.

Avaliou-se as variações de composição quimica e ocorrencia de fungos no feno de Tifton 85 armazenado à campo ou em galpão por 30 dias. 0 delineamento experimental foi inteiramente casualizado em parcelas subdivididas no tempo, com dois sistemas de armazenamento e quatro periodos de avaliação. Verificou-se que, dentro de um curto periodo de tempo (30 dias), houve redução da PB e aumento da PIDA com baixa ocorrencia de fungos Aspergillus, Rizophus e Cladosporium e alta ocorrencia de Geotrichium, Phoma, Penicillium e Diploccocum.

Avances en clasificación de sistemas de producción con bovinos doble propósito en Colombia

El objetivo de la investigación es clasificar y presentar algunas características de los sistemas de producción bovina en el Piedemonte Llanero del Departamento del Meta y del sur del Casanare. Para tal fin, se seleccionaron 14 explotaciones representativas de la región. Para clasificar los sistemas de producción se empleó un análisis de conglomerados. De esta forma, se obtienen tres tipologías de sistemas de producción bovina, así: 1) Tradicional, el cual tiene una baja capacidad empresarial y tecnológica; 2) Mejorado, el cual tiene una moderada capacidad empresarial y tecnológica y 3) Intensivo, que cuenta con alta capacidad empresarial y tecnológica. Los tres sistemas de producción encontrados, complementan los trabajos de otros investigadores y contribuye a tener parámetros de gestión tecnológica para el desarrollo de las ganaderías de la región.

The aim of the research is to classify and show some features of the bovine production systems in Piedemonte Llanero of Meta Department and South of Casanare. For this purpose, we selected 14 farms representative of the region. To classify production systems we used a cluster analysis. Thus, we obtained three types of production systems: 1) Traditional, which has a low economic-business and technological capacity; 2) Improved, which has a moderate economic-business and technological capacity and 3) Intensive, which has high economic-business and technological capacity. These production systems complement the works of others researchers and it helps to have parameters for technology management and the development of farms in the region.