Nutrición proteica de conejos en engorde : Indicadores productivos y parámetros de calidad de res y carne

En el presente trabajo experimental se evaluó el nivel y fuente de proteína, así como el efecto de la adición de proteasas sobre su digestibilidad, en dietas de conejos en engorde, sobre la performance de crecimiento y la calidad de res y carne. Trescientos ochenta y cuatro conejos (Nueva Zelanda x California) fueron distribuidos completamente al azar y alojados en jaulas individuales desde el destete (28d) a la faena (2,200-2,400kg), alimentados ad libitum con diferentes dietas según la experiencia. Se probaron dos niveles proteicos (control: 17% y bajo nivel: 14%), dos fuentes alternativas (harina de pluma hidrolizada y harina de pescado) y la adición de proteasas a dietas con 14%PB. Se registró el peso semanal y el consumo diario. Sobre 10 animales/tratamiento se evaluó la digestibilidad, utilizando jaulas con recolector de heces. A faena, se determinaron las taras, el rendimiento y se realizaron evaluaciones cualitativas y analíticas de la calidad de res y carne. Las dietas con 14%PB mostraron similares niveles de producción, rendimiento y calidad de res y carne respecto al control; la adición de proteasas a las dietas de baja proteína disminuyeron la mortalidad en postdestete. Tanto la harina de plumas como la harina de pescado resultaron adecuadas para su inclusión en dietas de conejos, con resultados productivos y cualitativos similares a los obtenidos con harina de carne. En general, el uso de estas fuentes proteicas alternativas permite opciones diferenciales en la formulación de dietas sin variaciones de importancia en sus parámetros productivos y cualitativos, generando mayor disponibilidad de alimentos que no compitan con los utilizados para la alimentación humana. El menor nivel proteico permitiría disminuir el costo del balanceado sin afectar la productividad, reduciendo los niveles de contaminación ambiental por menos excreción de nitrógeno. La adición de proteasas incrementaría la supervivencia postdestete.Facultad de Ciencias Veterinaria

Effects of Hull Inclusión in Diets for Rabbits

Improving efficiency of digestion and use of balanced diets is one of the challenges ahead, both to improve the health conditions of animals and to design production systems compatible with the environment. The aim of this work was to study the effect of the addition of hull to the diet of meat rabbits on days to slaughter, on mortality in the fattening period and N (nitrogen) and P (phosphorous) percentages excreted in feces. 64 rabbits were used weaned at 28 days. They were fed ad libitum. Diets consisted of two commercial formulations (Ga and Ge) with and without husk of wheat and oats by 10% (P / P). Time of fattening and mortality was recorded for each diet. Feces were collected from 48 cages at the beginning and end of fattening (45 and 65 days) and percentage of NT (total nitrogen) was determined by micro-Kjeldahl and TP (total phosphorus) by colorimetry with metavanadate. The animals fed with husks in the diet showed a higher slaughter age and mortality decrease. The only factor tested that caused significant differences in nitrogen excretion was the addition of hull. The oat hull diet showed a significantly lower nitrogen removal. Phosphorus excretion showed a significant difference according to the type of commercial diet fed, the addition of husk and the fattening stage. While adding outside fiber to food causes a delay in the time of slaughter, this would be partially offset by a reduction in mortality. The addition of oat hulls would be a viable alternative to reduce emissions of nitrogen and phosphorus to the environment via feces.Facultad de Ciencias Agrarias y Forestale

Effects of Hull Inclusión in Diets for Rabbits

Improving efficiency of digestion and use of balanced diets is one of the challenges ahead, both to improve the health conditions of animals and to design production systems compatible with the environment. The aim of this work was to study the effect of the addition of hull to the diet of meat rabbits on days to slaughter, on mortality in the fattening period and N (nitrogen) and P (phosphorous) percentages excreted in feces. 64 rabbits were used weaned at 28 days. They were fed ad libitum. Diets consisted of two commercial formulations (Ga and Ge) with and without husk of wheat and oats by 10% (P / P). Time of fattening and mortality was recorded for each diet. Feces were collected from 48 cages at the beginning and end of fattening (45 and 65 days) and percentage of NT (total nitrogen) was determined by micro-Kjeldahl and TP (total phosphorus) by colorimetry with metavanadate. The animals fed with husks in the diet showed a higher slaughter age and mortality decrease. The only factor tested that caused significant differences in nitrogen excretion was the addition of hull. The oat hull diet showed a significantly lower nitrogen removal. Phosphorus excretion showed a significant difference according to the type of commercial diet fed, the addition of husk and the fattening stage. While adding outside fiber to food causes a delay in the time of slaughter, this would be partially offset by a reduction in mortality. The addition of oat hulls would be a viable alternative to reduce emissions of nitrogen and phosphorus to the environment via feces.Facultad de Ciencias Agrarias y Forestale

Analysis of Morphofaneroptic Markers of the Caprine Population of the National University of La Plata Influence Zone (Buenos Aires Province, Argentina)

The goat is included within the class Mammals, order Ungulates, family Bovidae, genus Capra¸ species Capra hircus. There are numerous theories regarding the origin of the goat, being the most accepted Auschler theory, which includes three original types of domestic goat: Capra prisca, currently extinct, domesticated in the Caucasus region, Capra aegagrus, in Asia and Capra falconeri (Kashmir goat). (Bedotti, 2000).Facultad de Ciencias Veterinaria

Analysis of Morphofaneroptic Markers of the Caprine Population of the National University of La Plata Influence Zone (Buenos Aires Province, Argentina)

The goat is included within the class Mammals, order Ungulates, family Bovidae, genus Capra¸ species Capra hircus. There are numerous theories regarding the origin of the goat, being the most accepted Auschler theory, which includes three original types of domestic goat: Capra prisca, currently extinct, domesticated in the Caucasus region, Capra aegagrus, in Asia and Capra falconeri (Kashmir goat). (Bedotti, 2000).Facultad de Ciencias Veterinaria

Effect of type of hay and concentrate level on ruminal pH in diets for goats

El objetivo del siguiente trabajo fue evaluar el efecto del tipo de heno y nivel de concentrado sobre el pH ruminal en dietas para caprinos. Se utilizaron 4 cabras (criolla x Nubian) en un cuadrado latino de 4×4. Experimento I. 4 dietas: heno de alfalfa, heno de alfalfa + grano molido de maíz al 0,5%, 1% y 1,5% del PV/día. Experimento II. 4 dietas: heno de campo natural (CN), heno de CN + grano molido de maíz al 0,5%, 1% y 1,5% del PV/día. Se determinó el pH ruminal y se calculó el área bajo la curva, pH promedio del día, tiempo en horas con pH por debajo de 6, efecto del tiempo pos alimentación e interacción hora/tratamiento. El experimento I, verificó un incremento lineal (p< 0,05) del área bajo la curva del pH umbral y del tiempo con pH menor a 6 con el aumento de maíz en la dieta. El pH ruminal promedio del día disminuyó linealmente (p< 0,05) con el aumento del concentrado. El pH ruminal disminuyó (p 0,05). Se registraron diferencias (p< 0,05) en las horas post alimentación, sobre el pH ruminal, con interacción significativa (p< 0,05) hora-tratamiento. Se concluye que los niveles ensayados de suplementación disminuyeron el pH ruminal y el tipo de heno utilizado provocó un efecto buffer diferente en el ambiente ruminal caprino.The objective was to evaluate the effect of the level of hay and concentrate on ruminal pH in diets for goats. Four goats (Creole x Nubian) were used in a 4×4 Latin square. Experiment I. 4 diets: alfalfa hay, alfalfa hay ground grain corn + 0.5%, 1% and 1.5% LW/day. Experiment II. 4 diets: natural hay field hay natural field ground grain corn + 0.5%, 1% and 1.5% LW/day. Ruminal pH is determined and the area under the curve, the average pH of the day, time in hours with pH below 6, the effect of time after feeding and interaction time / treatment. In Experiment I, a linear increase (P &lt;0.05) the area under the curve of pH threshold and less time to 6 with increasing pH corn diet was verified. The mean ruminal pH decreased linearly day (p &lt;0.05) with the increase of the concentrate. The ruminal pH decreased (p &lt;0.05) independent power post treatment, no interaction (p &lt;0.05) between time-treatment. In experiment II, a cubic effect (p &lt;0.05) the area under the curve and the average pH of the day, with increasing corn 0 to 1.5% of PV was observed. Regarding the hours with pH below 6, no effects (p&gt; 0.05) were verified. Differences (p &lt;0.05) in the post feed hours, on ruminal pH, with significant interaction (p &lt;0.05) were recorded hour-treatment. It is concluded that supplementation levels tested decreased ruminal pH and type of hay used buffer caused a different effect on the rumen environment goat.Facultad de Ciencias Agrarias y ForestalesFacultad de Ciencias Veterinaria

Collective co-authorship: analysis of a classroom practice in the university environment

El presente ensayo da cuenta del análisis de una práctica de enseñanza en el ámbito universitario que consistió en la construcción colectiva de la Guía de Estudio del Módulo de Reproducción Animal en coautoría entre los estudiantes de segundo año de la carrera de Ingeniería Agronómica y el equipo docente del Curso de Introducción a la Producción Animal de la Facultad de Ciencias Agrarias y Forestales de la Universidad Nacional de La Plata. Metodológicamente se fundó en el trabajo grupal y en el uso de las nuevas tecnologías informáticas de comunicación como promotores de búsqueda de información en las redes y espacios virtuales académicos. La sistematización y análisis de toda la producción escrita por los estudiantes como la edición final estuvo a cargo del equipo docente. Se concluye que el análisis de nuestras prácticas de enseñanzas en el ámbito áulico nos propone desde un enfoque crítico y reflexivo la indagación como herramienta para la formación profesional continua del ser docente.This essay gives an account of the analysis of a teaching practice in the university environment that consisted in the collective development of the Study Guide of the Animal Reproduction Module by second year students of the Agricultural Engineering degree course in co-authorship with the teaching team of the Introduction to Animal Production Course of the Faculty of Agricultural and Forestry Sciences of the National University of La Plata. Methodologically, it was based on group work and the use of new communication technologies as promoters of information search in virtual academic networks and spaces. The systematization and analysis of all the production written by the students as the final edition was carried out by the teaching team. It is concluded that the analysis of our teaching practices in the classroom proposes us inquiry from a critical and reflexive approach as a tool for the continuous professional training of the teacher.Especialización en Docencia Universitari

Collective co-authorship: analysis of a classroom practice in the university environment

El presente ensayo da cuenta del análisis de una práctica de enseñanza en el ámbito universitario que consistió en la construcción colectiva de la Guía de Estudio del Módulo de Reproducción Animal en coautoría entre los estudiantes de segundo año de la carrera de Ingeniería Agronómica y el equipo docente del Curso de Introducción a la Producción Animal de la Facultad de Ciencias Agrarias y Forestales de la Universidad Nacional de La Plata. Metodológicamente se fundó en el trabajo grupal y en el uso de las nuevas tecnologías informáticas de comunicación como promotores de búsqueda de información en las redes y espacios virtuales académicos. La sistematización y análisis de toda la producción escrita por los estudiantes como la edición final estuvo a cargo del equipo docente. Se concluye que el análisis de nuestras prácticas de enseñanzas en el ámbito áulico nos propone desde un enfoque crítico y reflexivo la indagación como herramienta para la formación profesional continua del ser docente.This essay gives an account of the analysis of a teaching practice in the university environment that consisted in the collective development of the Study Guide of the Animal Reproduction Module by second year students of the Agricultural Engineering degree course in co-authorship with the teaching team of the Introduction to Animal Production Course of the Faculty of Agricultural and Forestry Sciences of the National University of La Plata. Methodologically, it was based on group work and the use of new communication technologies as promoters of information search in virtual academic networks and spaces. The systematization and analysis of all the production written by the students as the final edition was carried out by the teaching team. It is concluded that the analysis of our teaching practices in the classroom proposes us inquiry from a critical and reflexive approach as a tool for the continuous professional training of the teacher.Especialización en Docencia Universitari

Effect of Type of Hay and Concentrate Level in Intake and Digestibility in Diets for Goats

The aim of this study was to evaluate the effect of the level of hay and concentrate on total hay intake and supplied already, the additive/substitutive effect and total apparent digestibility of the diet intake in diets for goats. Experiment I: diets: Alfalfa hay (A1), Alfalfa hay + corn (0.5% LW/day) (A2), + 1% LW/day (A3), + 1.5% LW/day (A4). Experiment II: diets: Natural grassland hay (CN) (R1), hay CN + corn (0.5% LW/day) (R2), hay CN + corn (1% of LW/day) (R3), + 1.5% of LW/day) (R4). Intake, ratio forage/concentrate and total apparent digestibility were calculated. Experiment I: There were no effects (p&gt; 0.05) on the CMST for the corn tested levels and recorded a linear decrease (p &lt;0.05) in the CTFDN, CTFDA and CTPB. The CMSF decreased linearly (p &lt;0.05) with increasing amounts of corn by verifying a hay effect on the concentrate. The F/C was different (p &lt;0.05) in all treatments. The DTAIVMS increases linearly (p &lt;0.05) with the content of corn in the diet. Experiment II: a linear increase (p &lt;0.05) on the CMST and CTPB with increasing corn in diet and no differences (p&gt; 0.05) on the CMSF, CTFDN and CTFDA is observed. The F/C and CTPB differ (p &lt;0.05) among all the diets tested. The DTAIVMS increases linearly (p &lt;0.05) with the content of corn in the diet. Therefore, it can be concluded that the increase of maize levels improved the total digestibility of the ration consumed and the substitute or additive effect depended on the quality of the hay used.Facultad de Ciencias Veterinaria

Ground and Whole Grain Corn: Effect on Ruminal pH in Goats Diets

The objective of this study was to evaluate the effects of whole and ground corn grain in ruminal pH and total dry matter intake in diets for goats. Eight crossbreed goats (Creole x Nubian) was fitted with a rumen cannula and assigned in a replicated 4 x 4 Latin square experimental design. Two experiments were conducted; in the first test we used whole grain corn and second, ground corn grain. Ruminal pH data was measured for each goat as average pH, area between the curve and a horizontal line at pH 6, and duration less than pH 6 . In the first experiment, there were not differences (p> 0.05) on area between the curve and a horizontal line at pH 6, average pH and duration less than pH 6 among diets. A tendency was observed (p= 0.08) to decrease in DMI and the F/C decreased linearly (p< 0.05) with increasing whole corn in ration. In the second experiment, a significant linear increase was observed (p< 0.05) on area between the curve and a horizontal line at pH 6, with increasing ground corn. A linear decrease (p <0.05) was observed in average ruminal pH and linear increase (p <0.05) in duration less than pH 6. There was no difference in DMI and linear decrease (p <0.05) in F/C with increasing whole. The milling corn grain, increase the hydrolysis rate of the starch, possibly because to increased bacterial colonization of the horny endosperm surface, lowering ruminal pH.Facultad de Ciencias Agrarias y Forestale