Archivos de Zootecnia

Asociación del valor genético del toro con caracteres productivos en vacas lecheras en Colombia

Actualmente en Colombia no existe un programa que permita la estimación de valores genéticos en bovinos de leche. El objetivo de esta investigación fue determinar la asociación de los EBV (Valor de Cría Estimado) de toros Holstein y Jersey, con el desempeño fenotípico de sus hijas en Colombia; para esto se analizó la asociación de sus EBV con algunos parámetros productivos y sanitarios analizados directamente en su progenie (hijas). Para la estimación de los componentes de varianza, parámetros genéticos y valores genéticos, se utilizó el método de máxima verosimilitud restringida (REML) empleando un algoritmo libre de derivadas con el software MTDFREML. La asociación de las características con los EBV de los toros se realizó utilizando un modelo lineal mixto. Las heredabilidades para producción de leche, proteína, grasa y células somáticas en raza Holstein fueron: 0,19±0,0; 0,37±0,04; 0,37±0,04 y 0,34±0,05 y en Jersey fueron: 0,20±0,0; 0,64±0,0; 0,55±0,0 y 0,14±0,26 respectivamente. Los EBV de los toros Holstein influyeron (p<0,01) sobre la producción, proteína y grasa de la leche. El valor genético también se asoció al conteo de células somáticas. En la raza Jersey se encontraron resultados similares. Los resultados demostraron que a pesar de las bajas confiabilidades estimadas en las evaluaciones en Colombia, las productividades han sido mejoradas con la utilización de genética extranjera.

Actually, in Colombia there is not a genetic improvement program to estimate breeding values in dairy cattle. The objective of this research was to determine the association of EBV (Estimated Breeding Value) of Holstein and Jersey bulls with the phenotypic performance (milk and health traits) measured directly in their daughters in Colombia. To calculate the variance components, genetic parameters and EBV, the restricted maximum likelihood method (RMLM) using a derivative-free algorithm with the MTDFREML software, was used. The association of milk traits with the bulls EBVs was performed using a mixed model. Heritabilities for milk yield, protein percentage, fat and somatic cell score were 0.19±0.0, 0.37±0.04, 0.37±0.04 and 0.34±0.05, respectively for Holstein animals. For the Jersey were 0.20±0.0; 0.64±0.0, 0.55±0.0 and 0.14±0.26 respectively. The EBV of Holstein bulls were highly significant (p<0.01) on milk production, milk protein and milk fat content. The EBV was also found associated with somatic cell count. Similar results were found in Jersey bulls. The results showed that despite the low reliabilities estimated in Colombia assessments, the productivities are enhanced with the use of foreign genetic.

Ambiente térmico y bienestar de los cerdos en el período de descanso previo al sacrificio

Se evaluó la relación entre el ambiente térmico de las pocilgas de descanso en un matadero de cerdos y la temperatura superficial (TS) de los animales, así como el efecto de la pulverización intermitente de agua sobre el confort térmico. Se llevaron a cabo dos visitas a un matadero comercial, y en cada uno de ellos fueron seleccionadas tres pocilgas de descanso, una destinada al tratamiento de control (sin pulverizar durante todo el período) y dos para el tratamiento de pulverización Intermitente de agua (sucesivamente 30 minutos con aspersión y 30 minutos sin aspersión). Las evaluaciones se iniciaron en el momento de la descarga de los animales, en la cual se registraron imágenes termográficas de los lotes con una cámara termográfica infrarroja. Después del alojamiento en la porqueriza se registraron imágenes termográficas y la frecuencia respiratoria (FR) de los animales cada cinco minutos durante cuatro horas. También fueron registradas la temperatura y la humedad relativa del aire y se calcularon los índices de temperatura y humedad (ITH). Considerando los valores de (ITH) se observó que los animales se mantuvieron en un estado de confort térmico sólo en el momento de su llegada al matadero. La TS y la FR de los animales mantenidos en la pocilga, sin el sistema de aspersión (control) presentaron una elevación lineal en función de la hora del día, o sea, conforme al aumento de la temperatura ambiental. En el tratamiento con aspersión intermitente de agua se observó un comportamiento sinusoidal del TS y FR, entretanto las mismas se mantuvieron siempre inferiores al tratamiento control, incluso en los momentos que los rociadores de agua se encontraban desconectados. El tiempo de aspersión necesario para la reducción y estabilización de la TS de los animales estuvo condicionado al binomio temperatura-humedad relativa del aire, siendo estimado en 25 minutos en los horarios de mayor ITH. La temperatura ambiente máxima durante las evaluaciones fue de 28,4 ºC.

The research aimed to evaluate the relationship between the thermal environment of the rest pens in a pig slaughterhouse and the surface temperature (ST) of the animals as well as the effect of intermittent water spraying on thermal comfort. There were two visits to slaughter industrial being in each selected three pens of rest, one for control treatment (no spray throughout the period) and two for the treatment of intermittent spraying water (30 minutes intervals with constant spray followed by 30 minutes then turned off). Assessments began at the time of discharging animals in which are taken the thermographic images from lots using an infrared thermographic camera. After housing in the pens, were registered the thermographic images and the respiratory frequency (RF) every five minutes for four hours. Were evaluated the temperature, relative humidity and temperature-humidity index (THI). Considering the values of THI was observed that the animals remained in a condition of comfort only at the time of his arrival at the slaughterhouse. The ST and RF of the animals kept in the pens without sprinkler system (control) showed a linear increase in function of time of day, with increasing temperature. The treatment with intermittent sprinkling of water was observed oscillatory behavior of the ST and RF, however it was always lower than the control treatment, even in times when the water sprinklers were turned off. The time required of spray to reduction and stabilization of the ST of the animals was limited to the combination of temperature and relative humidity, being estimated at 25 minutes at times of higher THI. The maximum environmental temperature during evaluation was 28.4 ºC.

Utilización de nutrientes durante la incubación y crecimiento juvenil de pollos indígenas y exóticos en Nigeria

Nutrient utilization and early growth rate in three strains of chicken were investigated using 900 hatching eggs, 300 from each strain. The strains of chicken used were Nigerian indigenous chicken (NIC), ISA Brown (IB) and Nera Black strains (NB). Ten eggs per strain were randomly selected for breakout at embryonic day (ED) 7, 11, 15, and 18 of incubation to collect data on albumen weight in order to determine the embryonic albumen reduction rate during incubation and yolk weight to monitor its utilization. Blood samples were collected at hatch (day-old), weeks 1, 2, 3 and 4 post-hatch for triiodothyronine (T3), thyroxine (T4) and corticosterone level (CORT) determination. The chicks were randomly distributed into four rearing pens for a 28-day assessment of growth rate. The results showed that at day 18 of incubation (ED 18), weight of egg yolk and rate of yolk loss were similar among all the strains. Also, from ED 0 to 7 and11 to 15, albumen reduction rate in the eggs of IB was higher compared to NB and NIC, while it was lowest in NIC. From ED7 to 11, NIC showed highest reduction rate, followed by NB. Lowest reduction rate was shown in the eggs of IB. At day 7 and 28 of post-hatch growth, relative weight gain by the NIC was higher compared to NB and IB chicks. While IB and NB strains were similar at day 7, NB showed an intermediate relative weight gain at day 28. Strain did not significantly (p>0.05) affect body weight at all the ages. At day 14 and 21 of post-hatch growth, strain did not affect relative weight gain except at day 7 and 28. At day 7 and 28 relative weight gain by the NIC chicks was higher compared to NB and IB chicks. While IB and NB were similar at day 7, NB showed an intermediate relative weight gain at day 28. Plasma CORT level did not change from day-old until day 28 in all strains. Similarly, CORT levels did not differ among strains at each age of determination. T3 concentration increased from day-old until day 7 post-hatch and leveled out throughout the ages of observation in all the strains. The weight differences of the embryos at ED18 and day-old-chicks at the hatching day suggest the influence of genetic differences and possibly that of inadequate incubation protocol at this stage.

En tres líneas de pollos (Nigerian indigenous chicken, NIC; ISA Brown, IB y Nera Black, NB) se estudió la utilización de nutrientes durante la incubación y crecimiento juvenil, empleando 900 huevos (300 de cada línea). A los días embrionarios (ED) 7, 11, 15 y 18 de la incubación, diez huevos por línea fueron seleccionados al azar, para obtener datos sobre el peso del albumen y determinar su tasa de reducción embrionaria y peso de la yema. Se obtuvieron muestras de sangre con un día de edad (a la eclosión) y a las semanas 1, 2, 3 y 4 desde la eclosión para determinacion de triiodotironina (T3), tiroxina (T4) y corticosterona (CORT). Los pollos fueron distribuidos al azar en cuatro jaulas de cría para la evaluación del crecimiento durante 28 días. Los resultados demuestran que al día 18 de la incubación (ED18), el peso de la yema y la tasa de su consumo fueron similares en todas las líneas estudiadas. Además desde ED0 a ED7 y desde ED11 a ED15, la tasa de reducción del albumen en los huevos IB fue mayor que la de NB y NIC, siendo la de NIC la más baja. Desde el ED7 al ED11 NIC mostró la mayor velocidad de reducción seguida de NB, siendo la menor la de huevos IB. En los días 7 y 28 de crecimiento, la ganancia relativa de peso fue mayor en los pollos NIC, resultando similares entre sí los de IB y NB al día 7; NB demostró un crecimiento relativo intermedio al día 28. La línea no afectó significativamente al peso corporal en nuinguna etapa. En los días 14 y 21 de los pollos, la línea no afectó a la ganancia relativa de peso pero, a los 7 y 28 días de edad, la ganacia relativa de peso fue superior en los pollos NIC. IB y NB tuvieron incrementos relativos de peso similares al día 7 pero el de NB al día 28 fue intermedio. En ninguna línea el nivel plasmático de CORT varió desde el día 1 al 28, tampoco hubo diferencias entre líneas. La concentración de T3 aumentó desde el día 1 hasta el 7, estabilizándose después en todas las edades y cepas. Las diferencias de peso entre los embriones al ED18 y los pollos de un día, el día de la eclosión, sugieren la posibilidad de diferencias genéticas y posiblemente un inadecuado protocolo de incubación en esta etapa.

Residue from extraction of brown propolis in the diet to rumiants: in vitro digestibility and gas production

Objetivou-se avaliar o efeito de diferentes níveis de inclusão do resíduo da extração de própolis marrom na dieta de ruminantes, por meio de medidas de digestibilidade e produção de gás. Foram avaliados cinco níveis de inclusão da própolis marrom sobre a digestibilidade in vitro dos nutrientes, sob incubação de 72 horas (sem e com pepsina, consideradas digestão ruminal e total, respectivamente), e produção de gás in vitro. Como substrato foi utilizado feno de capim Tifton (Cynodon) e concentrado à base de farelo de soja e milho moído, com relação volumoso concentrado de 50:50, com base na matéria seca. Dois inóculos ruminais (oriundos de bovinos e ovinos) foram utilizados. Os tratamentos foram distribuídos em um delineamento inteiramente casualizado, com inclusão de 4 níveis de resíduo da extração de própolis marrom (5, 10, 15 e 20 g de resíduo/kg MS). O resíduo da extração de própolis apresentou efeito sobre a digestibilidade ruminal in vitro da matéria seca e fibra em detergente neutro, e a digestibilidade total in vitro também apresentou diferença significativa para digestibilidade da matéria seca, proteína bruta, fibra em detergente neutro, fibra em detergente ácido. O melhor nível de inclusão para digestibilidade total in vitro de 13,88 g de resíduo do extrato de própolis/kg MS. Enquanto que para a produção de gás, o melhor nível de inclusão in vitro do resíduo da extração de própolis para bovinos foi de 8,52 g/kg MS e para ovinos foi 5,53 g/kg MS.

The objective of this work was to assess the effect of the different inclusion levels of residue from extraction of propolis in the ruminant diet, using the digestibility and gas production measures. Were evaluated five inclusion levels of brown propolis about the in vitro nutrient digestibility with 72 hours of the incubation (with and without pepsin, considered ruminal and total rumination, respectively), and in vitro gas production. Tifton hay (Cynodon) was utilized as substrate and the concentrate was made from the soybean meal and corn, with relation roughage:concentrate around 50:50, based on dry matter. Two ruminal inoculums (from cattle and sheep) were utilized. The treatments were distributed in completely randomized design, with inclusion of the four levels of residue from extraction of propolis (5,10,15 and 20 g/kg DM). The inclusion of residue from extraction of propolis had effect on in vitro ruminal digestibility for dry matter and neutral detergent fiber, and total digestibility in vitro had significative diference for dry matter digestibility, crude protein, neutral detergent fiber and acid detergent fiber. The best level of inclusion for total digestibility in vitro is 13.88 g of residue from extraction of propolis/kg DM. While for gas production, the best level in vitro of residue from extraction of propolis for cattle was 8.52 g/kg DM and for sheep was 5.53 g/kg DM.

Phenotypic and genetic parameters for ewe reproductive performances of Ouled-Djellal breed (Algeria)

Les performances reproductives, de 318 brebis de race Ouled-Djellal, ont été étudiées. Les paramètres génétiques ont été estimés pour cinq variables: fertilité, prolificité, taux de survie, taux de productivité numérique et taux de productivité pondéral. L'année, l'âge, le mois de saillie, la parité ont été considérés comme facteurs à effets fixés. Les effets génétiques directs et de l'environnement permanent de la brebis ont été considérés comme facteurs aléatoires. Les paramètres génétiques ont été estimés en utilisant le logiciel MTDFREML. Les héritabilités obtenues ont été faibles dans leur ensemble, ceci à cause de l'influence de l'environnement et du mode d'expression non normal de ces variables.

Reproductive traits from 318 Ouled-Djellal ewes were recorded from 2008 to 2010. Genetic parameters were estimated for three basic and two composite traits. The basic traits were fertility, prolificacy and rate of survival. The composite traits were lamb weaned per ewe joined and weight of lamb per ewe joined. Year, age, parity and mating month, were considered as fixed effects. Direct genetic effects, permanent environmental effects of ewe were considered to be random effects. A derivative-free algorithm was used to obtain REML estimates of genetic environmental parameters. Estimates of herita-bilities for animal genetic effects were mainly small, due to the typical high influence of environmental factors on reproductive traits and to non-normal distribution of traits.

Relationship between availability of grass, food intake and grazing activities of sheep

C'est dans le but de juger d'une complémentation adéquate en fonction du disponible alimentaire, lui-même fonction des saisons et dans la perspective d'améliorer la durabilité des systèmes d'élevage utilisateurs d'herbe, que on a entrepris ce travail en étudiant le comportement alimentaire et l'ingestion au pâturage de 5 béliers de race locale pâturant une prairie naturelle de plaine du nord-est algérien, et ce, durant trois saisons consécutives: automne, hiver et printemps. Parallèlement, la composition botanique et la valeur nutritive aussi bien de la prairie pâturée que des rations simulées par coup de dent des animaux (méthode de hand plucking) ont été évaluées. L'identification des espèces végétales constituant les rations ingérées, n'a cependant eu lieu qu'en période printa-nière, propice à cette opération. Les animaux ont ainsi privilégié la consommation de l'asphodèle (Asphodelus microcarpus) (70 %) en première position, puis des légumineuses (20 %) et enfin des graminées (10 %). Outre, durant les trois saisons, les béliers ont sélectionné une ration de meilleure qualité que le fourrage disponible (15,2 % matières azotées totales, MAT; 0,79 unité fourragère viande, UFV/kg MS et 14,5 % MAT; 0,71 UFV/kg MS pour le printemps). La quantité ingérée a été maximale au printemps (1,24 kg) et minimale en hiver (689 g) sans doute en relation avec le disponible alimentaire durant les deux saisons (627 vs. 97 kg MS/ha). Il en ressort que l'hiver et l'automne constituent la période creuse pour ces animaux en système extensif pour qui une complémentation en quantité s'avère nécessaire. D'un point de vue qualitatif, un déficit protéique s'observe durant les trois saisons surtout pour des animaux à l'engraissement.

The objective of this works was to evaluate a proper supplementation based on the seasonal availabililty of food to improve the sustainability of herbivore livestock systems. First feeding behaviour and food intake in grazing of five local rams in a native plain grassland in the north-east of Algeria were studied for three consecutive seasons: autumn, winter and spring. Meanwhile, the botanical composition and nutritional value of both the grazed meadow and the simulated animal bites (method of hand plucking) were evaluated. The identification of plant species ingested, however was done in springtime, the only season suitable for this operation. Animals preferred asphodel (Asphodelus microcarpus) (70 %), followed by legumes (20 %) and grasses (10 %). During the three seasons, the rams have selected a ration of better quality than the available forage (15.2 % CP, 0.79 UFV/kg DM and 14.5 % CP, 0.71 UFV/kg DM for spring). The amount ingested daily was maximum in spring (1.24 kg) and minimum in winter (689 g) probably related to the food available during the two seasons (627 vs. 97 kg DM/ha). It shows that the winter and autumn are the peak times for these animals in extensive systems for which a quantity supplementation is necessary. From a qualitative point of view, a protein deficiency is observed during the three seasons especially for fattening animals.

Efecto de la raza, peso de sacrificio y sexo en el quinto cuarto en razas ovinas canarias

Se estudiaron 60 corderos de raza Canaria y 60 de raza Canaria de Pelo, mitad machos y mitad hembras, sacrificados a 9,78±0,49 kg; 15,8±0,66 kg y 24,9±0,76 kg. El objetivo del trabajo fue conocer el efecto de la raza, sexo y peso de sacrificio sobre la importancia porcentual del quinto cuarto y sus componentes. El peso total del quinto cuarto fue mayor en la raza Canaria, aunque su porcentaje de órganos comestibles, fue inferior al de la raza Canaria de Pelo. Los intestinos, la piel y la cabeza fueron las partes que mayor peso porcentual tuvieron. Al aumentar el peso de sacrificio, la importancia del quinto cuarto se redujo debido al menor porcentaje de cabeza y autópodos. En los machos, la cabeza, vejiga y autópodos, alcanzaron mayor proporción y en las hembras, la piel. El porcentaje de piel incrementó al aumentar el peso de sacrificio sólo en los corderos de lana.

Sixty Canaria lambs and 60 Canaria Hair breed lambs (half male and half female), slaughtered to 9.78±0.49, 15.8±0.66 and 24.9±0.76 kg live weight were studied. The objective of study was to determine the effect of breed, slaughter weight and sex of lamb on percentages of fifth quarter and their components. Canaria breed lambs showed a higher weight for fifth quarter, and its percentage of edible organs was lower than in Canaria Hair breed. The intestines, skin and head were the parts that had greater weight percentage. The importance of the fifth quarter was reduced when slaughter weight increased due to lower percentage of head and legs. Males showed higher values for head, legs and bladder; females showed higher values for the skin. Skin percentage increased when increasing the slaughter weight only in wool lambs.

Levels of copra meal in piglet diets at nursery phase

Utilizou-se 32 leitões machos castrados e fêmeas de linhagem comercial, desmamados com 21 dias de idade e peso vivo médio de 6,20±0,92 kg, objetivando avaliar o desempenho e a avaliação econômica de níveis inclusão de farelo de coco (FC) em rações para leitões na fase de creche. Os animais foram distribuídos em um delineamento em blocos ao acaso, com quatro tratamentos (0, 7, 14 e 21 % de farelo de coco), oito repetições por tratamento e um animal por unidade experimental. Observou-se que dos 21 aos 42 dias de idade, a inclusão de níveis acima de 7 % de farelo de coco na ração resultou em efeito linear negativo (p<0,05) sobre o ganho de peso diário. Dos 43 aos 63 dias de idade e no período total (21 a 63 dias de idade), observou-se feito quadrático dos níveis de FC nas rações (p<0,05) sobre a conversão alimentar, estimando-se melhor nível de 14,33 e 13,99 %, respectivamente. Para a fase dos 21 a 42 dias de idade, não houve efeito da inclusão de farelo de coco sobre as variáveis econômicas avaliadas. No entanto, dos 43 aos 63 dias e no período total (21 a 63 dias), observou-se efeito quadrático para as variáveis econômicas em função dos níveis de farelo de coco nas rações (p<0,05), com melhores resultados ao nível estimado aproximado de 15 %. Recomenda-se a inclusão de até 7 % de farelo de coco em rações para leitões dos 21 aos 42 dias de idade. Para a fase posterior, dos 43 a 63 dias de idade, o nível estimado de 15 % resultou em melhores índices de desempenho e econômico. Recomenda-se a inclusão de até 7 % de farelo de coco em rações para leitões dos 21 a 42 dias de idade. Para a fase posterior, dos 43 aos 63 dias de idade, o nível estimado de 15 % resultou em melhores índices de desempenho.

A total of 32 male castrated boars and gilts of a commercial pig line aged 21 days and 6.20±0.92 kg of live weight were used to evaluate the performance and economical evaluation of copra meal inclusion in diets for piglets at nursery. Animals were allotted in a completely randomized block design with four treatments (0, 7, 14 and 21 % of copra meal), eight replicates per treatment and one animal as experimental unit. From 21 to 42 days of age, levels up to 7 % reduced daily weight gain of piglets (p<0.05). A quadratic trend on feed:gain ratio was observed from 42 to 63 days and total period (p<0.05), with better results at estimated level of 14.33 and 13.99 %, respectively. No effect of copra meal inclusion on economical variables was observed from 21 to 42 days of age. From 43 to 63 days and total period (21 to 63 days) a quadratic effect on economical indexes was observed with the inclusion of different levels of copra meal, with better results around 15 %. The inclusion of copra meal until the level of 7 % is recommended in piglet diets from 21 to 42 days of age. From 43 to 63 days, the estimated level of 15 % results in better performance and economical indexes. It is recommended to include up to 7 % of coconut meal in diets for pigs from 21 to 42 days old. From 43 to 63 days of age, the estimated level of 15 % resulted in better performance.

Performance of feedlot sterrs finisheed with different fat sources in diet

The objective of this study was to evaluate the effect of different fat sources in finishing diets on performance of feedlot steers. Twenty steers, with average age of 20 months and initial live weight of 260 ± 41.3 kg, were feedlot fed during 126 days. The animals received corn silage as roughage and the tested concentrates were: basic concentrate (BC); basic concentrate + whole rice bran and rice oil (WRB); basic concentrate + 3 % of fatty acids calcium salts (M3) and basic concentrate + 6 % of fatty acids calcium salts (M6). Each treatment had animals with the following genetic group: 1 pure Charolais (CH), 1 pure Nellore (NE), 2 11/16 CH 5/16 NE, 1 21/32 NE 11/ 32 CH. No significant differences were observed for crude protein, digestible energy, neutral and acid detergent fibers intakes. The animals that consumed 6 % of fatty acid calcium salts presented higher ether extract intake (0.77 kg/day), while those that consume 3 % or whole rice bran and oil showed intermediate value (0.51 kg/day) and the ones that consumed basic concentrated presented lower value (0.25 kg/day). Similar averages were observed for average daily weight gain (1.142, 1.199, 1.365 and 1.391 kg/day, for BC, WRB, M3 and M6, respectively) and final weight (421 kg).

O objetivo deste estudo foi avaliar efeito do uso de diferentes fontes de gordura na dieta sobre o desempenho de novilhos confinados em fase de terminação. Foram utilizados 20 novilhos, com idade média inicial de 20 meses e peso vivo médio inicial de 260 ± 41,3 kg, que permaneceram confinados por 126 dias. Os animais receberam silagem de milho como volumoso e os concentrados testados foram: concentrado base (BC); concentrado base + farelo de arroz integral e óleo de arroz (WRB); concentrado base + 3 % de sais de cálcio de ácidos graxos (M3) e concentrado base + 6 % de sais de cálcio de ácidos graxos (M6). Cada tratamento possuiu animais pertencendo aos seguintes grupos genéticos: 1 puro Charolês (CH), 1 puro Nelore (NE), 2 11/16 CH 5/16 NE, 1 21/ 32 NE 11/32 CH. Não foram observadas diferenças entre os consumos de proteína bruta, energia digestível, fibras em detergente neutro e ácido. Os animais que consumiram 6 % de sais de ácidos graxos apresentaram o maior consumo de extrato etéreo (0,77 kg/dia), enquanto que aqueles que consumiram a dieta M3 e WRB apresentaram valor intermediário de consumo (0,51 kg/dia) e os que consumiram BC mostraram o menor valor (0,25 kg/ dia). Similaridades de valores foram observadas para o ganho de peso médio diário (1,142; 1,199; 1,365 e 1,391 kg/dia, respectivamente para CB, WRB, M3 e M6) e peso final (421 kg).

Niveles de proteína para cerdos en fase starter: un meta-análisis

Para determinar el nivel óptimo de proteína bruta (PB) se realizó un meta-análisis con datos de siete experimentos con 240 cerdos híbridos de aproximadamente 37 días de edad y peso vivo inicial promedio de 12,57 kg en fase starter y alojados individualmente. Se evaluó el comportamiento productivo, características de la canal y concentración de urea en plasma. Se realizó análisis de varianza y de regresión utilizando un modelo de superficie de respuesta con el procedimiento RSREG de SAS tomando en cuenta el nivel de PB y el efecto del experimento, año y época del año; se determinaron los niveles óptimos de PB para cada variable (ganancia diaria de peso= 19,25; grasa dorsal= 18,1; conversión alimenticia= 17,3 y urea en plasma= 16,5 %), los cuales se corroboraron con un experimento adicional utilizando 40 cerdos híbridos en fase starter de 36 días de edad con 11,5 kg de peso inicial durante 21 días, en un diseño completamente al azar con diez repeticiones por tratamiento. El meta-análisis indicó que la ganancia diaria de peso, ganancia de carne magra y urea en plasma disminuyen al bajar la PB (p≤0,05); y la conversión alimenticia mejora cuando se reduce la PB hasta 16,5 % (p≤0,05). En el experimento realizado para corroborar los niveles óptimos de PB, no hubo diferencias en las variables analizadas, excepto para porcentaje de carne magra, que mejoró (p≤0,05) cuando se utilizaron 16,5 y 19,25 % PB. Los resultados indican que el nivel óptimo de PB es de 16,5 % para cerdos en fase starter con dietas a base de sorgo-harina de soja adicionadas con AA sintéticos, ya que en este nivel de PB no se afectan las variables productivas, características de la canal y se disminuye la concentración de urea en plasma.

To determine the optimum level of crude protein (CP), a meta-analysis with data of seven trials with 240 hybrid nursery pigs individually penned with average body weight 12.57 kg. Growth performance, carcass characteristics, and plasma urea nitrogen concentration were evaluated. ANOVA and regression analysis were performed using a surface response model with RSREG of SAS procedure considering the crude protein (CP) level as well as the effect of trial, year and season; the optimum CP levels were determined to each variable (average daily body gain= 19.25, dorsal fat= 18.1, feed:gain ratio= 17.3 and plasma urea N= 16.5 %), and were corroborated with an additional experiment using 40 hybrid nursery pigs with 11.5 kg of initial weight during 21 d, in a completely randomized design with ten replicates per treatment. The meta-analysis indicated that average daily gain, lean meat gain and plasma urea nitrogen concentration were reduced when CP was lowered (p≤0.05); feed/ gain ratio was improved when CP was reduced (p≤0.05). In the experiment conducted to corroborate the optimum CP levels, there was no difference in the analyzed variables, except the percentage of lean meat, that improved (p≤0.05) when pigs were fed 16.5 and 19.25 % CP. The results indicate that the optimal level of CP is 16.5 % for nursery pigs diets based on sorghum-soybean meal with synthetic AA added, because of at this level of CP, neither production variables nor carcass characteristics were affected and urea concentration in plasma decreased.

Crecimiento juvenil y parámetros fisiológicos en pollos exóticos y nigerianos durante la estación seca

This study evaluated early growth and plasma hormonal profile in exotic strains of broiler and Nigerian indigenous chicken. A total of 1200 hatching eggs, 300 each from four strains of chicken were used for this study. The strains included the Nigerian indigenous chicken (NIC), the Arbor acre, Hubbard, and Marshall broiler strains. Chicks weights were monitored weekly. Blood samples were collected at hatch (day-old), weeks 1, 2, 3 and 4 post-hatch for triiodothyronine (T3) and corticosterone level determination. The chicks were randomly distributed into four rearing pens for a 28-d assessment of growth rate. Results showed that the body weights (g) in the broiler strains were higher than that of the NIC throughout the rearing period. There was no significant difference (p>0.05) in the levels of T3 at day-old and at week 1 until later in the growth phase. Corticosterone levels did not differ significantly at day-old but became different from week 1 post-hatch. The levels of T3 were not statistically different in the first week of growth. In the second week of post-hatch growth, there was a statistical difference in the levels of T3 among the four strains of chicken. The level in the NIC was comparable (p<0.05) to those of Arbor acre and Marshall strains. The level in the Hubbard was significantly lower than that of the NIC, Arbor acre and Marshall. In the third week of growth, the level in the NIC was similar to that of Marshall strain and higher than those of Hubbard and Arbor acre strains. This study showed that at hatching, there was no difference (p>0.05) in the metabolic rate and the stress level among the strains of chicken as shown by the levels of T3 and corticosterone respectively. The day-old chick weight and the weights in subsequent weeks post-hatch were smaller in the NIC than the broiler strains possibly as a result of low hatching weight. The early growth difference could not be explained by physiological parameters such as T3 and corticosterone. However, the differences in post-hatch physiological and metabolic parameters may be due partly to genetic differences.

En este estudio se evaluó el crecimiento juvenil y perfil de hormonas plasmáticas en cepas exóticas de broilers y pollos nigerianos, empleando un total de 1200 huevos eclosionados, 300 de cada una de las cuatro líneas estudiadas. Las líneas estudiadas fueron Pollo Indígena Nigeriano (NIC) y las líneas Arbor Acre, Hubbard y Marshall. Semanalmente se controló el peso y se tomaron muestras de sangre a la eclosión (1 día) y semanas 1, 2, 3 y 4 de vida para la determinación de triyodotironina (T3) y corticosterona. Los pollos fueron distribuidos al azar en cuatro jaulas de cría para evaluación del crecimiento en 28 días. Los resultados mostraron que el peso en las líneas de broilers fueron mayores que en los pollos NIC en todo el periodo. No hubo diferencias significativas en los niveles de T3 a 1 día de edad y semana 1 hasta el final de la fase de crecimiento. Los niveles de corticosterona no variaron en el día 1, pero se hicieron diferentes desde la semana 1. Los niveles de T3 no fueron diferentes en la primera semana de crecimiento. En la segunda semana de crecimiento hubo diferencias entre las cuatro líneas estudiadas. El nivel en NIC fue conmparable al de las líneas Arbor Acre y Marshall. El nivel en la línea Hubbard fue inferior al de NIC, Arbor Acre y Marshall. En la tercera semana de crecimiento, el nivel en NIC fue similar al de Marshall y superior al de Hubbard y Arbor Acre. El estudio demostró que a la eclosión, no hubo diferencias en la tasa metabólica y nivel de estrés entre las cepas estudiadas como se comprueba por los niveles de T3 y corticosterona respectivamente. El peso de los pollos de un día y el peso en las siguientes semanas fueron más bajos en los pollos NIC. Sin embargo, las diferencias en los parámetros fisiológicos y metabólicos en el crecimiento juvenil, pueden ser parcialmente debidas a las diferencias genéticas.

Preferencias y comportamiento alimentario de dos especies de caracoles terrestres gigantes africanos

The feed preferences and time of peak feeding behaviour in A. achatina and A. marginata snails were studied, measuring activity on several feedstuffs, hourly from 19:30 to 00:30 h daily. The study involved 120 juvenile snails (60/genotype) shared into three replicates of 20 snails each per genotype. Each replicate was housed in a cage measuring 30 x 20 x 24 cm. The animals were provided 8 feed stuffs namely: layers mash (LM), ripped banana fruit (RBF) and peel (RBP), ripped pawpaw fruit (RPF), Telferia occidentalis (TO), poultry dropping (PD), rumen digesta (RD) and a diet containing 10 % rumen digesta (RD10). Animals were fed only during the nocturnal period. Data were collected hourly from 19:30 to 00:30 h each day for 7 days. Results showed significant (p<0.05) differences in the preference of the different feed stuffs by each snail species as well as species differences in feed preferences and time of peak feeding behaviour. The three most appetent feed stuffs were LM, RD10 and PD for A. achatina and LM, RPF and RD10 for A. marginata. Overall, feeding behaviour peaked between 22:30 and 23:30 h in A. achatina and 20:30 and 21:30 h in A. marginata. Snail species should therefore be fed on the most preferred feed stuffs and within the periods of peak feeding behaviour for optimal performance and to minimize wastage.

El objetivo del estudio fue evaluar las preferencias y el tiempo de máxima actividad de alimentación en caracoles A. Achatina y A. marginata, midiendo la distribución horaria sobre los alimentos empleados de 19:30 a 00:30 horas. En el estudio participaron 120 caracoles juveniles (60/ genotipo) en tres repeticiones de 20 caracoles por cada genotipo. Cada réplica fue alojada en una jaula de 30 x 20 x 24 cm. A los animales se les proporcionó los siguientes 8 alimentos: mezcla de ponedoras (LM), frutos maduros de banano (RBF) y sus pieles (RBP), frutos maduros de papaya (FPR), Telferia occidentalis (TO), excretas de aves de corral (PD), digesta ruminal (RD) dieta con 10 % de digesta ruminal secada al sol (RD10). Los animales fueron alimentados sólo durante el periodo nocturno. Los datos fueron recolectados cada hora 19:30-00:30, cada día, durante 7 días. Los resultados mostraron diferencias (p<0,05) en la preferencia de los alimentos entre las especies de caracoles, así como en sus preferencias de alimentación y el tiempo de máxima actividad. Los tres alimentos más preferidos fueron: LM, RPF y RD10 para A. marginata. La actividad de alimentación tuvo su máximo entre 22:30 y 23:30 para A. achatina y entre 20:30 y 21:30 para A. marginata. Por tanto, estas especies de caracoles deberían ser alimentadas con los alimentos preferidos y dentro de los períodos de máxima actividad para un rendimiento óptimo y mínimo desperdicio.

Genetic diversity and population structure in remnant subpopulations of Nordestino horse breed

This study analyzed four remnant subpopulations of Nordestino horse breed to detect genetic structure and diversity through 14 microsatellite markers. Hair root follicles from a total of 393 horses were collected. There were 61 animals from Salitre Valley (JUAZ-BA) located at Bahia state, 89 from North and Central North ecoregions located at Piauí state (NCEN-PI), 185 animals from Sertão and Sertão do São Francisco ecoregions (SERT-PE) and 58 animals from Agrestina city (AGRE-PE) located at Pernambuco state. Genetic diversity, genetic differentiation and bottleneck effects were examined in the 4 remnant subpopulations of Nordestino horse breed. There was high allelic diversity and the Fis value did not show evidence of a significant predominance of mating among relatives, probably because of crossbreeding among populations. Recent bottleneck effects were not detected in the 4 subpopulations, but the IAM and TPM model did suggest a bottleneck effect. This may be a reflection of the decreased number of breeding animals caused by castration of males, mechanization processes and changes in life style in the rural areas. The bottleneck event was not enough to lead a genetic differentiation among the 4 remnant subpopulations of Nordestino horse. There was no evidence of genetic differentiation, so the 4 subpopulations formed one genetic group.

O presente trabalho teve como objetivo avaliar a estrutura e diversidade genética de quatro subpopulações do cavalo Nordestino utilizando 14 marcadores microssatélites. Amostras de bulbo capilar de 393 cavalos foram coletadas, distribuídos em: 61 animais do vale do Salitre (JUAZ-BA) localizado no estado da Bahia, 89 das mesorregiões Norte e Centro-Norte do estado do Piauí, 58 animais da cidade de Agrestina (AGRE-PE) e 185 das mesorregiões Sertão e Sertão do São Francisco localizado no estado de Pernambuco (SERT-PE). A diversidade genética, diferenciação genética e efeito de gargalo genético foram avaliados nas 4 subpopulações do cavalo Nordestino. Observou-se elevada diversidade genética e valores de Fis que não evidenciaram níveis de consanguinidade significativa, provavelmente isso se deve à acasalamentos entre as subpopulações. Efeito de gargalo genético recente não foi detectado para as quatro subpopulações, porém os modelos IAM e TPM sugeriram um efeito de gargalo genético não recente. Isso pode ser reflexo da redução no número de reprodutores decorrente da castração de machos, processo de mecanização e mudanças no estilo de vida das populações da zona rural. Eventos mais antigos do efeito de gargalo genético não foram suficientes para evidenciar uma diferenciação genética entre as 4 subpopulações, portanto elas formam um só grupo genético.

Buffalo meat from animals fed with agro industrial in Eastern Amazon

The quality of buffalo (Bubalus bubalis) meat, finished in a silvopastoral system with feed supplementation in the Amazon, was evaluated. Five crossbred buffaloes were used in each treatment with supplements of two different feeds, elaborated with agroindustrial by-products of coconut or palm oil extraction and a traditional one based on corn and soy. Physical, physical-chemical, microbiological, and sensorial analyses were performed on the Longissimus dorsi muscle, and the results were analyzed through the analysis of variance and averages, compared by t-test. The coconut and palm treatments had the largest percentage of saturated fatty acids. On the other hand, the ω6/ω3 ratio were within the healthy dietary standards. According to the results of pH, color, and shear force analyses, the meat was classified into RFN (Red, Firm and Normal) or ideal standards. Through subjective and objective analyses, the meat of the treatments was considered tender. The quality of the meat produced is due to the farming system used. Moreover, the use of agro-industrial waste minimizes environmental impact and the cost of animal feed, thus increasing the revenue of the rural worker.

Foi avaliada a qualidade da carne de búfalo (Bubalus bubalis), terminados em um sistema silvopastoril com suplementação alimentar na Amazônia. Cinco búfalos mestiços foram utilizados em cada tratamento alimentados com dois diferentes suplementos, elaborados com subprodutos agroindustriais, coco e dendê após extração do óleo e um tradicional à base de milho e soja. Análises físicas, físico-químicas, microbiológicas e sensoriais foram realizadas no músculo Longissimus dorsi, e os resultados foram analisados através da análise de variância e as médias comparadas pelo teste t. Os tratamentos de coco e dendê tiveram o maior percentual de ácidos graxos saturados. No entanto, a razão ω6/ω3 estavam dentro dos padrões alimentares saudáveis. De acordo com os resultados das análises de pH, cor e força de cisalhamento, a carne foi classificada em RFN (Red, Firm e Normal) ou padrões ideais. Através de análises subjetivas e objetivas, a carne dos tratamentos foi considerada macia. A qualidade da carne produzida é devido ao sistema de exploração utilizado. Além disso, a utilização de resíduos agro-industrial minimiza o impacto ambiental e os custos de alimentação animal, aumentando assim o rendimento do trabalhador rural.

Primera caracterización morfoestructural y faneróptica del perro ovejero Magallánico, Chile

El presente estudio se realizó con el objetivo de proporcionar una primera aproximación etnológica del perro Ovejero Magallánico. Esta población canina se ubica en la región de Magallanes (48º37' a los 56º30' latitud sur), Chile, en donde cumple un rol fundamental como animal de trabajo en la ganadería ovina de la zona. Esta población canina es el producto de la cruza de perros ovejeros británicos llegados a la zona a fines del siglo XIX y comienzos del XX, que se han adaptado por más de un siglo a las duras condiciones climáticas de la Patagonia Chilena. Se realizó un muestreo dirigido a perros que cumplieran con las características morfológicas que los ganaderos de Magallanes asocian a esta población canina. Se analizaron variables zoométricas en 75 perros (43 machos y 32 hembras) adultos. Para las variables fanerópticas se utilizaron los 75 perros, mientras que para la variable morfoestructural solo fueron considerados 62 perros, ya que 13 individuos entre 1 y 2 años presentaron excesiva variabilidad. Los resultados obtenidos permiten establecer que el Ovejero Magallánico presenta una marcada uniformidad morfoestructural, definido dimorfismo sexual y un conjunto de caracteres fanerópticos distintivos, aspectos que son importantes en la definición racial de una población canina. Este estudio constituye la primera caracterización zoométrica del perro Ovejero Magallánico y contribuye a establecer las bases para estudios posteriores necesarios para implementar el estándar oficial de la raza.

The goal of the present study was to achieve the first ethnological characterization of the Magellan Sheepdog. This dog is distributed throughout the Magallanes region (48º37' to 56º30' south latitude) in Southern Chile where it plays a fundamental role in sheep farming. This dog population is the result of breeding between British sheepdogs arrived in Chile in the late nineteenth and early twentieth centuries and has developed a high adaptation to the Chilean Patagonia climate conditions. Seventy five dogs (43 male and 32 female) were analyzed under morphometric and phanae-roptical criteria. All the dogs were selected by their phenotypical resemblance to Magellan Sheepdog according to local breeder's perceptions. Seventy five dogs were analyzed for the phanaeroptical features. For the morphostructural features only 62 dogs were analyzed. Thirteen dogs between 1-2 years old were excluded from the analysis due to extreme variability. The results obtained allow us to conclude that the Magellan Sheepdog has high morphostructural uniformity, definite sexual dimorphism and an ensemble of phanaeroptical features important to its definition as a different dog breed population. This study is the first zoometric characterization of the Magellan Sheepdog and establishes the foundation for further studies needed to implement the official breed standard.

Interaction cow-milker and behavioral, productive and economic responses of the animals

O objetivo deste estudo foi avaliar a influência do manejo de 3 ordenhadores sobre o comportamento de vacas leiteiras, manejo de ordenha e a produção dos animais, associando a distância de fuga e retorno econômico do manejo. Foram realizadas observações diretas, contínuas e com amostragem visual do comportamento dos ordenhadores e das vacas. As vacas participaram dos três tratamentos (ordenhadores), constituindo o delineamento experimental cross-over. Na análise comparativa do comportamento humano e animal foi utilizado o teste não paramétrico Qui-quadrado (χ²). Para os dados de produção de leite, distância de fuga e tempo de ordenha aplicou-se a análise de variância (ANOVA). Na avaliação econômica utilizou-se uma análise descritiva dos resultados de produção. Concluiu-se que o tipo de manejo do ordenhador influencia as características produtivas e comportamentais de vacas em lactação.

The objective was to evaluate the influence of the handling of three milkers on the behavior of dairy cows, milking management and animal production. Direct observations were made, continuous and with visual sampling of the milkers behavior and of the cows. The cows participated of the three treatments (milkers), constituting the cross-over experimental design. In the comparative analysis of the human and animal behavior the nonparametric chi-square (χ2) test was used. For data on milk production, flight distance and milking time it was applied the variance analysis (ANOVA). In the economic evaluation it was used a descriptive analysis of the production results. It was concluded that the type of handling of the milker influenced milk production, milking time, flight distance and the reaction of the animals.

Agronomic characterization of maize genotypes for silage

O objetivo deste trabalho foi avaliar às características agronômicas e a produtividade de seis genótipos de milho de ciclo super precoce quanto à produção de silagem no município de Dois Vizinhos, Paraná. O experimento foi conduzido na área experimental da Universidade Tecnológica Federal do Paraná. A altura média diferiu entre os cultivares, variando de 1,62 (Al-Piratininga) a 0,90 m (BMX 739). O híbrido AGN30A03 apresentou menor resistência ao acamamento de plantas e ao quebramento do colmo. Os genótipos BMX 739, CD 304, PRE22T11 e Al-Piratininga obtiveram as maiores produtividades de massa verde (638,81; 455,18; 620,98; 460,12 g planta-1, respectivamente). A variedade Al-Piratininga apresentou número de espigas planta-1 (1,11) superior ao das demais. Entre os materiais avaliados, o genótipo BMX 739, se destacou pelo rendimento de matéria seca ensilável por área e pela participação percentual de espiga (29 %) e grãos (26 %) na fitomassa.

The aim of this work was to evaluate the agronomic characteristics and yield of six maize genotypes cycle super early in the production of silage in Dois Vizinhos, Paraná. The experiment was conducted at experimental area of the Universidade Tecnológica Federal do Paraná. The average height difference among cultivars, ranging from 1.62 (Al-Piratininga) to 0.90 m (BMX 739). The hybrid AGN30A03 showed less resistance to lodging of plants and culm breakage. The genotypes BMX 739, CD 304, PRE22T11 and Al-Piratininga obtained the highest yield of fresh forage (638.81, 455.18, 620.98, 460.12 g plant-1, respectively). The variety Al-Piratininga presented a higher number of ears per plant (1,11) than those of the other varieties. Among the materials tested, the genotype BMX 739, showed the highest dry matter yield per area and the percentage share of spike (29 %) and grains (26 %) in the phytomass.

Estimación de tasa de consanguinidad y riesgo de extinción en cuarenta y una razas belgas de pollos en 2005 y 2010

In Belgium, as generally in Europe, the dominant position of the high producing commercial strains specialized in meat or eggs production threats of extinction the local traditional breeds. In this work, a follow up of the changes in populations size, and the rates of inbreeding of the Belgian poultry breeds, has been carried out in 2005 and 2010. About forty breeds were concerned. The Belgian hen breeds being overwhelmingly under threat of extinction, because of the low number of individuals by breed. For each of these breeds, various criteria were considered, risk status, breeding male to breeding female ratio, effective population size, effective population size to actual size ratio and rate of inbreeding.

En Bélgica, y generalmente en Europa, la posición dominante de estirpes comerciales altamente productivas, especializadas en la producción de carne o huevos, amenaza de extinción a las razas locales tradicionales. Se ha realizado, en 2005 y 2010, un seguimiento de las tasas de consanguinidad de razas de gallinas belgas. Unas cuarenta razas han sido consideradas. Las razas belgas de gallinas se encuentran abrumado-ramente en peligro de extinción a causa del escaso número de individuos en cada raza. Para cada una de las razas fueron considerados varios criterios: estado de riesgo, relación reproductores machos/reproductores hembra, tamaño efectivo de población, relación tamaño efectivo/tamaño actual y tasa de consanguinidad.

**Perfiles sanguíneos de priogesterona y estradiol del Pecari Tajacu en cautiverio**

El objetivo fue caracterizar los perfiles de progesterona (P4) y 17β estradiol (E-17β) sanguíneos de 11 hembras adultas de P. tajacu mantenidas en cautiverio. Las hembras estaban en presencia del macho pero separadas de éste mediante una malla. Las muestras sanguíneas se tomaron cada 6 días durante 3 meses. La estimación de hormonas esteroides se efectuó por radioinmunoanálisis en fase sólida. Los perfiles hormonales fueron graficados con respecto al tiempo para determinar la duración de cada ciclo ovárico y la cantidad de ciclos. Nueve hembras ciclaron y 2 no. La duración promedio del ciclo ovárico fue 26,8±4,8 días. La concentración media de P4 en la fase luteal fue 22,95±4,94 ng/mL, y durante la fase folicular 1,2±0,73 ng/mL (p<0,05). Los niveles de E-17β en la fase luteal fueron 6,89±2,79 pg/mL y 32,17±7,29 pg/mL en la fase folicular (p<0,05). La presentación de los ciclos ováricos fue variable, aunque la duración estuvo dentro de los rangos establecidos para esta especie en cautiverio. La sincronía de los perfiles hormonales de P4 y E-17β fue inversa durante el ciclo ovárico.

The objective was to characterize the levels of progesterone (P4) and 17β estradiol (E-17β) in blood of 11 Pecari tajacu adult females in captivity. The females were in the presence of males but separated by a wire mesh. Blood samples were taken every 6 days during 3 months. The estimation of the levels of the steroid hormones was carried out by radioimmunoassay in solid phase. Hormonal profiles were plotted against time, to determine the duration of each ovarian cycle and the number of cycles. Nine animals showed estrous cycle and 2 did not. The average duration of the ovarian cycle was 26.8±4.8 days. The average concentration of P4 in the luteal phase was 22.95±4.94 ng/mL, and during the follicular phase was 1.2±0.73 ng/mL (p<0.05). The levels of E-17β in the luteal phase were 6.89±2.79 pg/mL, and 32.17±7.29 pg/mL in the follicular phase (p<0.05). The presence of the ovarian cycles was variable, although the duration was within the range of values established for this species under captivity. The synchrony of the hormonal profiles of P4 and E-17β during the ovarian cycle was inverted.