Variabilidad en el alimento consumido por las vacas en lactancia : integración de las TIC a una materia optativa de grado de modalidad semipresencial

Trabajo Final (Especialización en Tecnologías Multimedia para Desarrollos Educativos)--UNC- Facultad de Ciencias Agropecuarias, 2015.Mediante la integración curricular de las TIC, junto a una propuesta de enseñanza- aprendizaje de tipo cognitivo-constructivista, los docentes podemos adaptarnos a los cambios que nuestra sociedad está sufriendo en el proceso de globalización. A su vez, en general, existe escaso conocimiento de los programas de manejo de la alimentación en sistemas de producción lechera en los egresados de las ciencias agropecuarias como Ingenieros Agrónomos y Médicos Veterinarios. Debido a la gran importancia que tiene la alimentación en los establecimientos lecheros, los profesionales deben conocer en detalle las características y los factores que afectan al resultado de estas actividades. Se desarrolló una propuesta curricular de una asignatura optativa de grado “Alimentación y variabilidad en el alimento consumido por las vacas en lactancia” con modalidad semipresencial e integración de las TIC, buscando que el alumno pueda analizar, investigar, colaborar, compartir, construir y generar su propio aprendizaje, basándose en lo que ya sabe. Para el desarrollo de la asignatura se utilizó un sitio web en Wix llamado “Alimentación y variabilidad en el alimento consumido por las vacas en lactancia” donde los alumnos tienen acceso a las características generales de la materia, las actividades de cada módulo, un blog de novedades, bibliografía y foros de intercambio. Este entorno virtual tiene la intención de promover la interacción y la construcción de conocimiento, propiciando un ambiente donde los estudiantes participen activamente a través del desarrollo de habilidades cognitivas. Mediante el desarrollo de esta propuesta innovadora, se puede comenzar a establecer la discusión respecto al modelo pedagógico, integración de las TIC y procesos de enseñanza en entornos virtuales en el ámbito docente de nuestra institución

Heifer management characterization in dairy herds from the west of Buenos Aires, Argentina

The replacement program in a dairy farm represents the second or third largest cost in a dairy operation. This study aimed to characterize and typify the practices related to the dairy heifer replacement program and describe the growth, development, and health parameters during this period in commercial dairy herds in Trenque Lauquen. A cross-sectional observational study was carried out, including 54 randomly selected dairy farms that were visited once to collect data about facilities and management through a semi-structured survey. Cluster and principal coordinates analysis were applied to classify the farms based on all variables collected, grouped in four main areas: pre-fresh cows, colostrum management, pre-weaning calf ’s management, and personnel. Additionally, growth, development, and health status were also recorded and described for calves and breeding heifers. Two similar-sized farm clusters were identified with differences in management and facilities in different areas of calves rearing. In one cluster there was a greater proportion of farms having a pre-fresh group, implementing appropriate health (colostrum, vaccination) and feeding management. Also, differences in personnel and technical support were relevant. The estimated body gain was 452 and 774 g/d for calves younger or older than 60 d of age, respectively. The age and weight farm averages in breeding heifers were 21.0 mo (range: 16.7-27.5) and 416.3 kg (range: 336.7-519.3), respectively. Diarrhea and respiratory affections were the major problems in pre-weaning calves and heifer rearing, respectively. The median mortality was 7.3, 7.6, and 2.9% at the calving, pre-weaning, and heifer rearing period, respectively. The results showed an improvement opportunity for producers, the design of precise and high impact programs that could lead to an improved replacement program. Nos rebanhos leiteiros, o programa de reposição representa o segundo ou o terceiro maior custo da atividade de produção de leite. O objetivo do presente trabalho foi caracterizar e tipificar as práticas relacionadas ao programa de reposição de novilhas leiteiras e descrever o crescimento, desenvolvimento e parâmetros de saúde durante este período em rebanhos leiteiros comerciais localizados em Trenque Lauquen, oeste de Buenos Aires, Argentina. Foi realizado um estudo  observacional transversal incluindo 54 fazendas de produção de leite selecionadas ao acaso e visitadas uma única vez para a colheita de dados relacionados a instalações e manejo empregando-se um questionário semi-estruturado. Foi efetuada a análise dos agrupamentos e das coordenadas principais para classificar as fazendas com base em todas as variáveis colhidas e agrupadas em quatro principais áreas: vacas pré-parto, manejo de colostro, manejo pré-desmame de bezerros e recursos humanos. Os dados referentes ao crescimento, desenvolvimento e estado de saúde dos animais também foram registrados e descritos para bezerros e novilhas. Dois grupos de fazendas de tamanho semelhante foram identificados com diferenças no manejo e instalações em distintas áreas de recria de bezerros. Em um grupo houve uma maior proporção de fazendas que tinham um grupo de vacas pré-parto, com implementação de adequado manejo de saúde (colostro, vacinações) e manejo alimentar. Também foram relevantes as diferenças em termos de pessoal e suporte técnico. O ganho de peso estimado foi de 452 e 774 gramas por dia, respectivamente, para os bezerros jovens e os com idade superior a 60 dias. As médias das fazendas da idade e do peso das novilhas de reprodução foram, respectivamente, 21,0 meses (variação de 16,7 a 27,5) e 416,3 kg (variação de 336,7 a 519,3). A diarreia e as afecções respiratórias foram os maiores problemas de saúde, respectivamente, nos bezerros em pré-desmama e novilhas em recria. A média de mortalidade foi de 7,3; 7,6 e 2,9%, respectivamente, ao parto, na pré-desmama e durante a recria de novilhas. Os resultados obtidos demonstraram a existência de oportunidades de melhoria para os produtores, com o delineamento de programas precisos e de alto impacto que poderão propiciar um programa de reposição aprimorado.

Caracterização da gestão de novilhas em rebanhos leiteiros do oeste de Buenos Aires, Argentina

The replacement program in a dairy farm represents the second or third largest cost in a dairy operation. This study aimed to characterize and typify the practices related to the dairy heifer replacement program and describe the growth, development, and health parameters during this period in commercial dairy herds in Trenque Lauquen. A cross-sectional observational study was carried out, including 54 randomly selected dairy farms that were visited once to collect data about facilities and management through a semi-structured survey. Cluster and principal coordinates analysis were applied to classify the farms based on all variables collected, grouped in four main areas: pre-fresh cows, colostrum management, pre-weaning calf ’s management, and personnel. Additionally, growth, development, and health status were also recorded and described for calves and breeding heifers. Two similar-sized farm clusters were identified with differences in management and facilities in different areas of calves rearing. In one cluster there was a greater proportion of farms having a pre-fresh group, implementing appropriate health (colostrum, vaccination) and feeding management. Also, differences in personnel and technical support were relevant. The estimated body gain was 452 and 774 g/d for calves younger or older than 60 d of age, respectively. The age and weight farm averages in breeding heifers were 21.0 mo (range: 16.7-27.5) and 416.3 kg (range: 336.7-519.3), respectively. Diarrhea and respiratory affections were the major problems in pre-weaning calves and heifer rearing, respectively. The median mortality was 7.3, 7.6, and 2.9% at the calving, pre-weaning, and heifer rearing period, respectively. The results showed an improvement opportunity for producers, the design of precise and high impact programs that could lead to an improved replacement program.Nos rebanhos leiteiros, o programa de reposição representa o segundo ou o terceiro maior custo da atividade de produção de leite. O objetivo do presente trabalho foi caracterizar e tipificar as práticas relacionadas ao programa de reposição de novilhas leiteiras e descrever o crescimento, desenvolvimento e parâmetros de saúde durante este período em rebanhos leiteiros comerciais localizados em Trenque Lauquen, oeste de Buenos Aires, Argentina. Foi realizado um estudo observacional transversal incluindo 54 fazendas de produção de leite selecionadas ao acaso e visitadas uma única vez para a colheita de dados relacionados a instalações e manejo empregando-se um questionário semi-estruturado. Foi efetuada a análise dos agrupamentos e das coordenadas principais para classificar as fazendas com base em todas as variáveis colhidas e agrupadas em quatro principais áreas: vacas pré-parto, manejo de colostro, manejo pré-desmame de bezerros e recursos humanos. Os dados referentes ao crescimento, desenvolvimento e estado de saúde dos animais também foram registrados e descritos para bezerros e novilhas. Dois grupos de fazendas de tamanho semelhante foram identificados com diferenças no manejo e instalações em distintas áreas de recria de bezerros. Em um grupo houve uma maior proporção de fazendas que tinham um grupo de vacas pré-parto, com implementação de adequada manejo de saúde (colostro, vacinações) e manejo alimentar, também, foram relevantes as diferenças em termos de pessoal e suporte técnico. O ganho de peso estimado foi de 452 e 774 gramas por dia, respectivamente, para os bezerros jovens e os com idade superior a 60 dias. As médias das fazendas da idade e do peso das novilhas de reprodução foram, respectivamente, 21,0 meses (variação de 16,7 a 27,5) e 416,3 kg (variação de 336,7 a 519,3). A diarreia e as afecções respiratórias foram os maiores problemas de saúde, respectivamente, nos bezerros em pré-desmama e novilhas em recria. A média de mortalidade foi de 7,3; 7,6 e 2,9%, respectivamente, ao parto, na pré-desmama e durante a recria de novilhas. Os resultados obtidos demonstraram a existência de oportunidades de melhoria para os produtores, com o delineamento de programas precisos e de alto impacto que poderão propiciar um programa de reposição aprimorado.Fil: Demateis Lllera, Federico. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Buenos Aires Norte. Estacion Experimental Agropecuaria General Villegas. Agencia de Extension Rural Trenque Lauquen.; ArgentinaFil: Vissio, Claudina. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; Argentina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Patología Animal; ArgentinaFil: Turiello, María Paula. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Producción Animal; ArgentinaFil: Herrero, Alejandra. Universidad de Buenos Aires; ArgentinaFil: Larriestra, Alejandro Jose. Universidad Nacional de Villa María. Instituto Académico Pedagógico de Ciencias Básicas y Aplicadas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Patología Animal; Argentin

Effects of nutritional restriction on placental blood vessels development in goats

El objetivo fue estudiar los efectos de la restricción alimentaria sobre la angiogénesis placentaria en cabras Anglo nubian. Se utilizaron 19 placentas a término de tres grupos de estudios: control, restringido y restringido con monensina. Los cortes placentarios se procesaron con técnicas histológicas de rutina e inmunomarcaron con anticuerpo anti-VEGF y se cuantificó el área y perímetro de los vasos sanguíneos. El perímetro de los vasos de los grupos restringidos fue mayor estadísticamente con respecto al control. Mientras que el área de los mismos no mostró diferencias estadísticamente significativas en ninguno de los tres grupos. El VEGF se localizó en las células epiteliales trofoblásticas de los grupos control y restringido, además en éstos últimos también se localizó en el endotelio vascular. El número de células inmunomarcadas con el VEGF fue significativamente mayor en los grupos restringidos coincidiendo con el mayor perímetro de los vasos, lo que sugiere que el VEGF estimula el crecimiento endotelial. Las diferencias encontradas entre los grupos estudiados, indicarían que hubo una adaptación compensatoria en las cabras que fueron sometidas a una dieta restringida, ya que el área vascular se mantuvo sin modificaciones a expensas del aumento del perímetro de los vasos.The aim was to study the effects of nutritional restriction on placental angiogenesis in Anglo nubian goats. 19 term placenta of three groups were used: control, restricted and restricted with monensin. Tissue sections were processed by routine histological techniques and immunostained with the anti-VEGF antibody and the area and perimeter of the blood vessels were quantified. The perimeter of vessels of the restricted groups was statistically higher compared to the control. While the area of the vessels do not show significant differences in any of the 3 groups. VEGF was localized in trophoblastic epithelial cells control and restricted, also in the latter was also localized to the vascular endothelium. The number of immunolabeled VEGF cells was higher in the restricted groups, coinciding in these groups with the larger perimeter of the vessels, so VEGF would stimulate the growth of the vascular endothelium. The differences between the restricted and the control groups, suggest that there was a compensatory adaptation of goats subjected to a restricted diet, because the vascular area remained unchanged due to the increase of the perimeter of the blood vessels.Fil: Coniglio, María Valeria. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Producción Animal; ArgentinaFil: Merkis, Cecilia Inés. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Patología Animal; ArgentinaFil: Díaz, Tomás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal. Laboratorio de Biología Cecular y Embriologia; ArgentinaFil: Romanini, María Cristina. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal. Laboratorio de Biología Cecular y Embriologia; ArgentinaFil: Turiello, María Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Producción Animal; ArgentinaFil: Bozzo, Aida Andrea. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal. Laboratorio de Biología Cecular y Embriologia; ArgentinaFil: Cots, Debora Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal. Laboratorio de Biología Cecular y Embriologia; ArgentinaFil: Rolando, Alicia Nelida. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Anatomia Animal. Laboratorio de Biología Cecular y Embriologia; Argentin

Effects of milk replacer supplementation to whole milk fed to Holstein dairy calves during the first month of life on intake, performance, and health under 2 feeding programs

Objective: The aim of this study was to evaluate the effects of adding milk replacer to milk fed to calves during their first month of life on intake, performance, and health under 2 milk feeding programs. Materials and Methods: Sixty female Holstein calves were blocked at birth by dam parity and assigned in a randomized block design to 1 of 4 treatments (n = 15/treatment). Calves were fed whole milk under either a conventional (CF) or a step-up/step-down (SF) feeding program for 8 wk. Both feeding programs were tested with (+MR) and without 0.5 kg/d of milk replacer during the first 28 d. Results and Discussion: The maximum rate of liquid feed supply was ~1.5 kg of DM. No difference in intake was found during the last week of the experiment. Daily gain varied among treatments. Heifers on SF+MR were the heaviest at the end of the experiment, although they were not different from those on CF+MR. There was no difference in final BW between CF+MR and SF. No difference in diarrhea status was observed. Implications and Applications: Under the conditions of this experiment, calves achieved greater nutrient intake by concentrating the milk feeding during the first month, inducing a greater daily gain during the entire liquid feeding period, neither compromising starter intake at weaning nor affecting diarrhea incidence. Milk replacer supplementation only during the first month of life can be used under both feeding programs, with the conventional being more practical and less time consuming.Fil: Bogni, Agostina. Teknal S.a.; ArgentinaFil: Vissio, Claudina. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; Argentina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; ArgentinaFil: Larriestra, Alejandro Jose. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; Argentina. Universidad Nacional de Villa María. Instituto Académico Pedagógico de Ciencias Básicas y Aplicadas; ArgentinaFil: Turiello, María Paula. Universidad Nacional de Villa María. Instituto Académico Pedagógico de Ciencias Básicas y Aplicadas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Formación E Investigación En Nutrición Animal; Argentin

Sources of variation in corn silage and total mixed rations of commercial dairy farms

Information on sources of variation in feed and diet characteristics is needed to develop appropriate strategies to reduce uncertainty and to separate true variation from that associated with measurements. The objectives were to determine sources of variation in DM content and particle size distribution in corn silage (CS) and TMR. Ten dairy farms in Argentina were visited on 3 consecutive days, samples of CS and TMR were taken, and an audit of feed management was conducted. Corn silage and TMR were sampled in duplicate each day. Variance components were calculated with the Mixed Linear Models of InfoStat for CS and Generalized Linear Mixed Models for TMR. For CS, the model included the effects of farm and day within farm, and for TMR, the model included farm, pen within farm, day within pen, and feed bunk site within pen. Residual effects accounted for sampling and analytical variation. Farm was the greatest source of variation for DM and particle size distribution of CS and TMR, explaining 40 to 92% of total variation. For CS, day within farm variation was greater compared with residual variation in DM (7 and 0.6%, respectively), meaning real changes occurred from one day to the other. For TMR, daily variation in DM content was high and possibly associated with feed management errors. For particle size distribution in TMR, sampling and assaying variation was greater than feed bunk site variation, indicating increased replication and averaging is needed to increase precision.Fil: Turiello, María Paula. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Producción Animal; ArgentinaFil: Larriestra, Alejandro Jose. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Patología Animal; ArgentinaFil: Bargo, Fernando. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: Relling, Alejandro Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina. Ohio State University; Estados UnidosFil: Weiss, William. Ohio State University; Estados Unido

Partial coalescence in cream-like emulsions prepared with alternative fats: Effect of controlled stirring and temperature cycles

The objective was to study the partial coalescence as a consequence of controlled stirring and temperature cycles in oil-in-water emulsions prepared with skimmed cow milk and nondairy fats: low trans vegetable fat (LT), bovine fat (BF), partially hydrogenated soybean oil (HS) and sunflower oil as control. The partial coalescence rates (%/min) of the stirred emulsions were LT, 89.8±4.3; BF, 29.7±3.1; HS, 23.8±3.1. This result was attributed to the lower solid fat content (%) of emulsion LT (19.2±1.2 versus 25.9±1.1 in BF and 56.8±1.1 in HS). A temperature cycle with partial melting of fats led to hardening of texture in emulsions BF and HS due to partial coalescence, favored by the recrystallization of the fat at the interface. Emulsion LT did not show changes after the same treatment, probably because its lower solid fat content did not favor partial coalescence in the absence of mechanical work.Fil: Pérez, María Paula. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Investigación en Funcionalidad y Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tesei, M.F.. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Investigación en Funcionalidad y Tecnología de Alimentos; ArgentinaFil: Wagner, Jorge Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Investigación en Funcionalidad y Tecnología de Alimentos; ArgentinaFil: Márquez Turiello, Ricardo Luis Andres. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Investigación en Funcionalidad y Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Impact of age at first calving on performance and economics in commercial dairy herds in Argentina

Dairy herd efficiency depends on an adequate replacement program, and one of the main management factors affecting the replacement cost is age at first calving (AFC). The primary objective of this study was to evaluate the impact of AFC on performance and economic results in commercial dairy herds in Argentina. A retrospective study was conducted to analyze data from a total of 26,614 first lactation cows from 290 argentinian dairy farms calved for the first time during the calendar year 2016. Milk yield for first lactation cows having at least 5 milk test days was used to analyze production (n=15,181). Records were stratified by AFC into 5 groups: 1) 18–21 mo (n=202), 2) 22-25 mo (n=5,569), 3) 26-29 mo (n=5,579), 4) 30-33 mo (n=2,389), 5) 34-37 mo (n=1,442). The overall median of AFC was 27 mo. Although milk yield at the beginning of the lactation was lower for lower AFC categories, the differences between categories 2, 3, and 4 disappeared by the fourth test day at approximately 113 days in milk. No effect of AFC category was detected for milk fat and protein content and for SCC. Considering AFC categories, cows calving for the first time at 22–25 mo of age needed the shortest period after calving to conceive. The lower income associated with the mild milk losses may be compensated by the cost of more than 80 extra d in the rearing period and the increment in days open estimated for the upper categories.Fil: Turiello, María Paula. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Producción Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Vissio, Claudina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Patología Animal; Argentina. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; ArgentinaFil: Heinrichs, Arlyn Jud. State University of Pennsylvania; Estados UnidosFil: Issaly, Liliana Cristina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; ArgentinaFil: Larriestra, Alejandro Jose. Universidad Nacional de Villa María. Instituto Académico Pedagógico de Ciencias Básicas y Aplicadas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Patología Animal; Argentin

Effect of prepubertal nutrition on cellular apoptosis and proliferation in at term placenta of Anglo-Nubian goats

The aim of this study was to evaluate the effect of feed restriction with or without monensin supplementation, followed by a re-feeding period on cellular apoptosis and proliferation in at term placenta of Anglo-Nubian goats. To evaluate the induction of apoptosis through the intrinsic pathway, proteins Bax and Bcl-2 were determinated. The apoptosis was related with the cell proliferation indices through Ki67 determination. The treatments were applied for 250 days and were (a) ad libitum feeding (control; n = 5); (b) restricted feeding at 70% of control (restricted; n = 7); and (c) restricted with monensin supplementation (monensin; n = 7). After treatments, all the animals were fed to support their requirements. After parturition, 27 placentas were gathered. The placental cellular structure was studied by high-resolution light microscopy and transmission electron microscopy; the cellular proliferation was determined by Ki67 index, and Bax and Bcl-2 proteins were localized by immunohistochemical analysis. Differences in cell proliferation through the Ki67 index were found in monensin group placentas. Monensin supplementation stimulated the placental cell proliferation reversing the effect of feed restriction during the peripuberal period. A significant increase of Bcl-2 in placentas of restricted group was found, and it would provide a protective effect on the placental structure. A lack of the Bcl-2 protective effect was observed in control and monensin group placentas, probably meaning that the observed apoptosis would be induced through the intrinsic signalling pathway. A balance between apoptosis and cell proliferation is necessary to maintain tissue homoeostasis during caprine placental development.Fil: Turiello, María Paula. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Departamento de Producción Animal. Cátedra de Nutrición Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cristofolini, Andrea Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Patología Animal; ArgentinaFil: Fiorimanti, Mariana Rit. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Patología Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Díaz, Tomás. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Anatomía Animal; ArgentinaFil: Cavaglieri, Lilia Reneé. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; ArgentinaFil: Merkis, Cecilia Inés. Universidad Nacional de Río Cuarto; Argentina. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria; Argentin