Efficacy Of Different Protocols Of Ovulation Synchronization And Resynchronization In Argentinian Buffalo Herds

During the last years bufalo reproductive researchers have been tried to develop and apply fxed timed artifcial insemination protocols to increase pregnancy rates to maximize improvement. The objective of this paper is to evaluate the pregnancy rates of diferent protocols of synchronization (Ovsynch and progesterone implants) and resynchronization of ovulation in a meat water bufalo herd during reproductive season of 2016. 194 mature Mediterranean females, were randomly assigned to four diferent protocols, ultrasound evaluation were used to determine cyclicity (presence of corpus luteum or follicles ≥7 mm de diameter). 18 days after insemination all females were resynchronized and at day 25 ultrasound were performed, those nonpregnant females were inseminated 28 days after frst insemination. All inseminations were performed by the same technician and only one bull was used. InfoStat software was used, statistical signifcance was considered when p value was lower than α of the 5%. No statistical signifcance were found within the protocols. Early embryonic dead 50 days after IA was 3.4%. Pregnancy rate was 47.9% and 53.5% for insemination and reinsemination respectively and the fnal pregnancy rate after the adjust for early pregnancy loss 73.2%, during the 28 days of the breeding period. The results obtained allow breeders to choose the best pharmacological option to use FTAI in their herds based on their own needs to improve production without afecting pregnancy rates.Fil: Crudeli, Gustavo Angel. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Konrad, José Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: de la Sota, Rodolfo Luzbel. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Yuponi, Roberto Gregorio. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Vallejos, Natalia. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Cardona Maya, Walter Darío. Universidad Nacional de Colombia; ColombiaFil: Berdugo, Jesus Alfredo. Universidad de Antioquia; Colombi

Growth of beef heifers from 7 to 11 months of age

The purpose of the experiment was to evaluate the effect of live weight gain on growth parameters of beef heifers rearing on native pasture supplemented during autumn and winter seasons post-weaning (04/21/2004 to 09/16/2004; 148 days). The live weight gain was -1.08; 19.52 e 57.83 kg for treatments MA (Maintenance), BA (Low) and MO (Moderate), respectively. In the same order, the supplement offered was equivalent to 0.54; 0.81 and 1.25% of their live weight. The experimental design was entirely randomized. Initially, the heifers were 7 month old and weighted 171.13 kg. The parameters evaluated were body condition score (5 point scale), hip height, hearth girth and weight:height ratio. At the end of the period, the evaluated parameters differed between treatments, with the exception of hip height parameter between MA and BA. Even if the heifers did not gain live weight the hip height increased. As much lower was the live weight gain, as stronger was the influence on the hip height and heart girth, showing positive linear effect for all treatments. The body condition score did not increase, even for the treatment with higher live weight gain. The linear live weight gain effect on wheight:height ratio was similar between heifers groups

Differences in Parameters of an Embryo In Vitro Production Program between Cattle (Bos Indicus) and Buffaloes (Bubalus bubalis)

In order to improve production, it is necessary to apply reproductive biotechnologies, including embryo transfer. Due to the management and physiology of the animals and the buffalo production system, the best system is the in vitro production of embryos (IVP). This work aims to compare the results of the (IVP) of cows (Bos indicus) and buffalo (Bubalus bubalis) from animals kept under the same conditions of feeding and handling. This study was conducted in an Argentinan commercial herd located in the province of Corrientes (-27.742859 latitude, -57.773611 longitude) that raise buffaloes and cattle, during the breeding season of 2018 (March-May). Twenty animals of each species were used. Antimullerian hormone (AMH) levels of each animal were determined using ELISA. Standardized protocols were used for oocyte aspiration, maturation, fertilization and culture of the embryos, frozen semen of a single proved bull was used in each species. Information about the number of follicles, oocytes, and embryos was recorded and analyzed individually and grouped by species. The normality of the data was evaluated with the D'Agostino and Shapiro-Wilk tests and the comparisons between species using the Mann Whitney and ANOVA tests. Values are shown as median and range. A p-value <0.05 was considered statistically significant. The AMH levels of the cows were 688.5 pg/ml (45.3-2394) and the buffaloes 73.8 pg/ml (14.8-262.5), p <0.001. Significant differences were found in the number of recovered oocytes 9 (0-23) cows vs. 4.5 (1-11) buffaloes (p> 0.05). There were no significant differences in the number of follicles and the quality of the oocytes. Significant differences were found in the number of oocytes cleaved 4 (0 -17) vs. 0.5 (0-4) and blastocysts/animal 1,5 (0-15) and 0,1 (0-2) l for cows and buffalos respectively. The number of blastocysts in relation to the number of oocytes cleaved did not show statistical significance. The differences in the levels of AMH and the marked differences in the IVP between buffaloes and cattle are confirmed, it is necessary to propose research proposals that explain the differences

Comparison of differences between morphometrical and biochemical-nutritional parameters of buffaloes (adults and young females) from Corrientes, Argentina

El objetivo del trabajo fue analizar las diferencias de algunos parámetros hematológicos, bioquímicos y morfométricos entre bubillas y búfalas de dos establecimientos (Itatí y Empedrado) de la Provincia de Corrientes, Argentina. Se emplearon 60 hembras bubalinas, raza mediterránea, 15 por categoría. Se registró el peso vivo (PV) y el perímetro torácico (PT). Se tomaron muestras sanguíneas para valorar hematocrito (HTO), hemoglobina (HB), recuento de eritrocitos (RGR) y leucocitos (RGB), volumen corpuscular medio (VCM), hemoglobina corpuscular media (HCM) y concentración de HCM (CHCM). En el suero se estimaron urea, proteínas totales (PRT), albúminas (ALB), globulinas (GLOB), relación albúmina-globulina (RAG), colesterol (CT, C-HDL y C-.LDL), triglicéridos (TR), calcio (CA), fósforo (FOS), magnesio (MG), glucosa y actividad de lactato deshidrogenasa (LDH). Se utilizó un diseño experimental de arreglo factorial, donde la variable independiente fue la localidad y el tratamiento la categoría, valorándose la interacción de localidad x edad. Con el programa InfoStat se efectuó la estadística descriptiva y el ANOVA. La interacción significativa de algunas variables motivó el tratamiento por sus efectos simples. Las búfalas de Empedrado presentaron mayores PV, PT, neutrófilos, eosinófilos, CT, TR y urea, mientras que las bubillas tuvieron elevados linfocitos, CA, glucosa y LDH. Las búfalas de Itatí revelaron mayores PV, PT, HTO, RGR, CT y las hembras jóvenes elevados niveles de LDH. El efecto edad influyó, por lo cual las búfalas ostentaron mayores porcentajes de monocitos, PRT y GLOB, en tanto que en las bubillas fueron más altos RGB, FOS, C-HDL y C-LDL. Para el factor localidad los animales de Empedrado revelaron mayores niveles de HB, HCM, CHCM, RGR, monocitos y MG; los de Itatí mostraran elevadas PRT, ALB y RAG. No hubo diferencias para VCM y basófilos. La obtención de intervalos de referencia bioquímicos regionales asume importancia como herramienta para evaluar el estado nutricional y optimizar el diagnóstico de enfermedades.The objective of this study was to analyze the differences in hematological, biochemical and morphometrical parameters between young and adult female buffaloes from two farms (Itatí and Empedrado) in Corrientes Province, Argentina. Sixteen Mediterranean buffaloes, 15 per category, were used. Weight and thoracic perimeter were recorded considering both geographic regions. Hematocrit, hemoglobin, erythrocyte and leukocyte counts, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration and relative leukocyte formula, were registered. Urea, total proteins, albumin, globulins, albumin-globulin ratio, cholesterol, triglycerides, calcium, phosphorous, magnesium, glucose and lactate dehydrogenase, were determined in serum. An experimental design of factorial arrangement was used, where the independent variable was the geographic region and the treatment the category, considering the interaction region x age. Descriptive statistics and analysis of variance were performed using InfoStat software. Empedrado buffaloes had higher values of live weight, total protein, neutrophils, eosinophils, cholesterol, triglycerides and urea, whereas young females had high values of lymphocytes, calcium, glucose and lactate dehydrogenase. Buffaloes from Itatí revealed higher values of weight, hematocrit, erythrocytes and cholesterol. Young females showed high lactate dehydrogenase levels. Age of animals influenced values, as adult buffaloes had higher percentages of monocytes, total proteins and globulins, while young females had higher values of leucocytes and phosphorus. Considering the geographic region, animals from Empedrado revealed higher levels of hemoglobin, erythrocytes, monocytes and magnesium. Animals from Itatí showed high protein, albumin and albumin-globulin ratio. The mean corpuscular volume and basophils were not modified. Regional biochemical reference intervals are of great importance as a tool to evaluate blood nutritional indicators and to optimize the diagnosis of diseases.Fil: Koza, Gabriela Alejandra. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Mussart, Norma Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; ArgentinaFil: Hernando, Josefina. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Konrad, José Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad Nacional del Nordeste. Facultad de Cs.veterinarias. Departamento de Producción Animal; ArgentinaFil: Crudeli, Gustavo Angel. Universidad Nacional del Nordeste. Facultad de Cs.veterinarias. Departamento de Producción Animal; Argentin

Application of biotechnologies for the increment of calves’ production

La Incorporación de las técnicas de Inseminación artificial y transferencia embrionaria(en ambos casos a tiempo fijo) y la aplicación de herramientas de sincronización y resincronización de celos, han demostrado ser capaces de aumentar la cantidad de terneros nacidos, incrementando por consiguiente la productividad y rentabilidad de las explotaciones ganaderas.The incorporation of artificial insemination and embryonic transfer techniques (in both cases at fixed times) and the application of heat synchronization and re-synchronization tools have demonstrated to be useful methods to increase the number of calves born, consequently increasing the productivity and profitability of cattle exploitations. Furthermore, the use of semen and embryos involve the genetic improvement of the farms. Such biotechnical benefits require special features, with emphasis on the appropriate control of the rodeo that includes female identification and the correct execution of the reproductive, sanitarium and nutritional procedures.Fil: Bontemps, Sophie. Universidade de Sao Paulo; BrasilFil: Marques, M. O.. Universidade de Sao Paulo; BrasilFil: Vieira, L. M.. Universidade de Sao Paulo; BrasilFil: Konrad, José Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad Nacional del Nordeste. Facultad de Cs.veterinarias. Departamento de Producción Animal; ArgentinaFil: Crudeli, Gustavo Angel. Universidad Nacional del Nordeste. Facultad de Cs.veterinarias. Departamento de Producción Animal; Argentin

Effect of melatonin on follicular development parameters in a fixed-timed artificial insemination programme in water buffalo

It is well known that buffaloes have seasonal anoestrus and that the use of melatonin reduces the effects of season in reproduction, particularly among sheep and goats. This study evaluates the use of melatonin on water buffaloes to increase pregnancy rates in a fixed-time insemination programme. The study was conducted on an Argentinian buffalo herd, located in the Corrientes Province, during an unfavourable reproductive season. Artificial insemination cycles were performed in September and December 2018. Sixty animals were selected, and melatonin was administered to 29 females at a dose of 18 mg/50 kg. Ten days after the melatonin implant, ovulation synchronization was started. Animals were inseminated with frozen semen of a single bull. Pregnancy was evaluated by ultrasound 35 days after insemination. The pregnancy rate of the two repetitions was 34.62% for September and 6.4% for December (P=0.007). No significant differences were found in the parameters associated with follicular development and formation of the corpus luteum. Analysis of the effects of melatonin on the two replicates showed that there was no statistically significant effect of ovarian response regarding the analysed follicular development parameters. There was also no effect on pregnancy rates (17.85% vs. 20.68%; P=0.15), or on follicular development for treatment and control. In conclusion, this study was not able to demonstrate an effect of melatonin on the ovarian response of buffaloes as reported by other authors. Other factors, such as environmental conditions of subtropical areas and species specificities, may have a more significant effect on buffalo endocrinology. These factors should be evaluated to improve the results of fixedtimed artificial insemination programmes.Fil: Berdugo, Jesus Alfredo. Universidad Nacional de Colombia; ColombiaFil: Konrad, José Luis. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Yuponi, Roberto Gregorio. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Bandeo, Alexis Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Camelino, Ramon. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Cardona Maya, Walter D.. Universidad de Antioquia; ColombiaFil: Crudeli, Gustavo Angel. Universidad Nacional del Chaco Austral; Argentin

Induction of oestrus with progesterone, chorionic gonadotropin and antero-hipofisary extract in postpartum anoestrus dairy cows

El objetivo del presente estudio fue inducir la ciclicidad de vacas lecheras en anestro posparto tras la aplicación de dos extractos gonadotróficos (gonadotrofina coriónica equina eCG y extracto de pituitaria anterior equina HAP). Se trabajó con 7 planteles, ubicados en la región sur de Chile, en los cuales se seleccionaron 89 vacas en anestro con más 60 días de paridas. Las vacas seleccionadas fueron distribuidas aleatoriamente en 3 grupos; dos recibieron un dispositivo intravaginal con 1,38 g de progesterona por 7 días, uno de ellos recibió además 2 dosis de 50 mg de HAP al 7º y 8º días, y el otro grupo recibió 400 UI de eCG al 7º día. El tercer grupo fue el control sin tratamiento. La presentación de celos fue mayor (p<0,05) en los grupos que recibieron los tratamientos gonadotróficos, comparados con el grupo control. Se logró reducir significativamente el lapso tratamiento primer servicio en vacas tratadas con HAP (11,8 días) y eCG (13 días) respecto del control (34,2 días). Los porcentajes de ovulación en vacas tratadas con HAP (48,4%) y eCG (56,7%) superaron con significación estadística (p<0,05) a los controles (14,3%). Al finalizar el lapso tratamiento-concepción, no se encontraron diferencias estadísticamente significativas entre los grupos tratados con HAP (16,7 días), eCG (20,8 días) y controles (31,7 días). La preñez total a los 25 días de concluido los tratamientos fue de 35,5%, 30% y 10,7% para los grupos HAP, eCG y control respectivamente. Los tratamientos gonadotróficos se revelan como herramientas útiles en el manejo reproductivo del anestro posparto en vacas lecheras.The aim of the present study was to induce oestrus in postpartum anoestrus dairy cows after the application of two hormonal treatments. With this purpose a group of 89 dairy cows in anoestrus, with 60 or more days from calving, were selected in the south region of Chile. The animals were randomly allocated in three groups. Groups 1 and 2 received an intravaginal device with 1.38 g of progesterone for 7 days. Group 1 received two doses of 50 mg of horse anterior pituitary extract (HAP) on days 7 and 8, and group 2 received 400 UI of equine chorionic gonadotrophin (eCG) on day 7. Group 3 was left as control, without treatment. Oestrus induction was evaluated by two times daily detection and was statistically higher (p<0.05) in cows that received gonadotrophic treatments (groups 1 and 2) compared to control cows. The treatments significantly reduced the interval treatment to first service in cows that receive HAP (11.8 days) and eCG (13 days), compared to control cows (34.2 days). The percentage of ovulated cows was greater in the groups receiving HAP (48.4%) and eCG (56.7%) compared to controls (14.3%). The pregnancy rate was significantly improved (p<0.05) within 25 days in cows treated with HAP (35.5%) over the control group (10.7%). The gonadotrophic treatments may be useful tools for the reproductive management of postpartum anestrus in dairy cows.Fil: kizur, A.. Universidad Austral de Chile; ChileFil: Garrido, María José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad Nacional del Nordeste. Facultad de Cs.veterinarias. Departamento de Producción Animal; ArgentinaFil: Konrad, José Luis. Universidad Nacional del Nordeste. Facultad de Cs.veterinarias. Departamento de Producción Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Crudeli, Gustavo Angel. Universidad Nacional del Nordeste. Facultad de Cs.veterinarias. Departamento de Producción Animal; ArgentinaFil: Gatica García, R.. Universidad Austral de Chile; Chil

Circunferência escrotal e medidas corporais de touros Hereford e Braford do Nordeste da Argentina

The main objective of this study was to compare body mensuraments and the scrotal circumference of Hereford and Braford bulls from birth until one year of age in Northeastern Argentina and study the relationship between these two measuraments. The bodyweight (BW), scrotal circumference (SC), rump height (RH) and thoracic circumference (TC) wererecordede in 225 Braford and 224 Hereford bulls from five farms. The data were analyzed for normal distribution and comparison of the means by the Dunnett test at 5% probability, followed by analysis of variance utilizing the effects of breed, farm within the state and year. Pairwise correlations were calculated among the traits. The scrotal circumference at one year of age was greater in Hereford bulls (27.86 ± 2.91 cm) than the Braford bulls. The thoracic circumference (156.62 ± 17.15 cm) and the rump height (120.51±11.00 cm) were greaterin Braford than in Hereford bulls animals. There were differences among the farms (P&lt; 0.05). Farm 2 had animals with the greatest BW and TC, while the animals of Farm 1 had the greatest SC. The animals of farm 2 presented significant differences in BW (P&lt; 0.05) than the animals of the other farms. The correlation was strong (r =0,55 a 0,80) between BW and weaning weight; and SC, BW and TC presented high pairwise correlations (r =0.55 to 0.80). In conclusion,we observed similar development of the animals of the two breeds in Northeastern Argentina.El objetivo de este estudio fue comparar medidas corporales y&nbsp; circunferencia escrotal de machos Hereford y Braford desde el nacimiento hasta el año de esda en el norte Argentino, y verificar la relación entre esas dos caracteristicas. Fueron evaluados el peso (P) , circunferencia escrotal (CE), altura de grupa (AG) y circunferencia torácica (CT),&nbsp; de registros de 225 animales Braford &nbsp;y 224 Hereford. Se analizó la distribución normal de los datos y la comparación de las medias mediante el test&nbsp; de Dunnett al 5 % de probabilidad, seguida de un análisis de varianza utilizando los efectos de la raza, la propiedad &nbsp;dentro de las provincias &nbsp;y&nbsp; año. Se calcularon las &nbsp;correlaciones&nbsp; entre las caracteristicas. La circunferencia escrotal al año de edad fue mayor para los animales Hereford (27,86±2,91 cm) que para los Braford. La circunferencia torácica (156,62±17,15 cm) y la altura a la grupa (120,51±11,00 cm) fueron mayores entre los animales Braford. Con respecto al efecto de la propiedad, no hubo diferencias entre las provincias, pero sí se observaron diferencias significativas entre las propiedades. La Propiedad 2 tuvo animales con mayor peso al año (PA) y CT, mientras que los animales de la Propiedad &nbsp;1 tuvieron mayor CE. En la &nbsp;Propiedad 2 presentaron diferencias significativas en PA (P&lt; 0.05) que los animales de las demas Propiedades. Se observó fluctuación de los resultados de las características evaluadas, a lo largo de los años. La correlación fue alta entre PA &nbsp;y el peso al destete (PD);&nbsp; CE, PA y CT presentaron altas correlaciones entre si (r =0,55 a 0,80). En conjunto, observamos un desarrollo similar de los animales de las dos razas en el nordeste argentino.O objetivo deste estudo foi comparar&nbsp; medidas corporais e a circunferência escrotal de machos Hereford e Braford desde o nascimento até o ano de idade no Norte Argentino, e verificar a relação entre essas duas caracteristicas. Foram avaliados o peso, circunferência escrotal, altura de garupa e perímetro torácico de registros de 225 animais Braford e 224 animais Hereford. Foi feita análise estatística de normalidade dos dados, comparação das médias pelo teste de “DUNNETT” ao nível de 5% de probabilidade, análise de variância utilizando efeitos de raça, propriedade dentro de estado e ano, e calculadas as correlações entre as características. A circunferência escrotal ao ano de idade foi maior para os animais Hereford (27.86±2.91cm) do que nos Braford. O perímetro torácico (156.62±17.15) e altura da garupa (120.51±11.00cm) foram maiores nos animais Braford. Quanto ao efeito da propriedade não houve diferenças entre as provincias.&nbsp; Foram observadas diferenças significativas entre propriedades, a Propiedade 2 foi a que teve animais com maior peso ao ano (PA) e maior PT, e Propriedade 1 com CE maior. Na Propiedade 2, para PA apresentou diferença significativa (P&lt; 0,05) com as demais propriedades. Foi observado flutuação dos resultados das caracteristicas avaliadas ao longo dos anos. As características PA e PD; CE, PA e PT apresentaram alta correlação entre si (r =0,55 a 0,80). Um desenvolvimento similar foi observado entre os animais das duas raças na região do Nordeste da Argentina

Utilización de la ultrasonografía para determinar el estado genital en la sincronización e inseminación artificial en vacas

El objetivo del trabajo fue evaluar el uso de tratamientos de control del ciclo estral, determinando el estado genital mediante ultrasonografía, sobre la eficiencia de detección y distribución de celos, y la preñez en vacas inseminadas artificialmente. El trabajo se realizó con 380 vacas. Los vientres fueron clasificados por medio de ultrasonografía según las estructuras ováricas y asignadas a cada tratamiento. En el tratamiento 1 se incluyeron vacas que presentaron cuerpo lúteo; se aplicó una dosis de prostaglandina y se realizó detección de celos e inseminación artificial por siete días. Para el tratamiento 2 se utilizaron las vacas que poseían folículos ≥ 8 milímetros de diámetro, se aplicó una dosis de hormona liberadora de gonadotrofinas, siete días después de colocó una dosis de prostaglandina y se procedió a la detección de celos e inseminación artificial por siete días. En el tratamiento 3 se realizó inseminación artificial a tiempo fijo con vacas que tenían folículos ≥ 8 milímetros o cuerpo lúteo. El tratamiento 4 se llevó a cabo con vacas presentaron folículos ≥ 8 milímetros o cuerpo lúteo, se realizó inseminación artificial a celo detectado durante 21 días sin aplicación alguna de drogas. A los 30 días de finalizadas las inseminaciones se realizó diagnóstico de gestación por ultrasonografía para determinar las preñeces. La evaluación de la detección de los celos fue del 81,8%, 84,5% y 46% (p0,05), para los tratamiento 1, 2, 3 y 4 respectivamente. El uso de tratamientos hormonales permitió mejorar el porcentaje de vacas detectadas en celo, y la preñez por inseminación fue mayor en los tratamientos donde se inseminó a celo detectado.The objective of the study was to evaluate the use of estrous control treatments, determining genital status by ultrasonography, efficiency of detection and distribution of heat, and pregnancy in artificially inseminated cows. The work was carried out with 380 females. The cows was classified by ultrasonography according to the present ovarian structures and assigned to each treatment. In the treatment 1 were included cows that presented corpus luteum; was applied a dose of prostaglandin and from the next day was held the heat detection and artificial insemination for seven days. For the treatment 2 were used cows who had follicles ≥ 8 millimeters of diameter, was applied a dose of gonadotrifins releasing hormone, seven days after was applied a dose of prostaglandin and proceeded to the heat detection and artificial insemination for seven days. In the treatment 3 was performed the fixed-time artificial insemination with cows who had follicles ≥ 8 millimeters or corpus luteum. The treatment 4 or control was made with cows who had follicles ≥ 8 millimeters or corpus luteum, was performed artificial insemination with heat detection during twenty one days without the application of some drugs. The heat detection rate was 81,8%, 84,5% and 46% for treatments 1, 2 and 4 respectively (p0,05) respectively. The use of hormonal treatments improved the percentage of cows detected in estrus, and pregnancy by insemination was higher in treatments where detected estrus and inseminated.Fil: Konrad, José Luis. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Crudeli, Gustavo Angel. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentin

The buffalos in Argentina

El búfalo fue introducido en Argentina a comienzo del siglo XX, mediante la importación de razas Mediterránea, Murrah y Jafarabadi. En la actualidad la población bubalina es de 147.785 cabezas distribuidas en 19 de las 23 provincias argentinas que componen el territorio nacional. El 88 % de la población de búfalos se encuentra en el nordeste argentino, siendo las provincias de Corrientes y Formosa las que cuentan con las mayores densidades poblacionales. Existen actualmente 1193 productores de búfalos en todo el país. Las proyecciones de población bubalina para el año 2030 alcanzan la cifra de 430.000 cabezas.The buffalo was introduced in Argentina at the beginning of the 20th century, through the importation of Mediterranean, Murrah and Jafarabadi breeds. At present the buffalo population is 147,785 heads distributed in 19 of the 23 Argentine provinces that make up the national territory. 88% of the buffalo population is found in the northeast of Argentina, being the provinces of Corrientes and Formosa the ones with the highest population densities. There are currently 1,193 buffalo producers across the country. The buffalo population projections for the year 2030 reach the figure of 432,262.Fil: Crudeli, Gustavo Angel. Universidad Nacional del Chaco Austral; ArgentinaFil: Patiño, E. M.. Universidad Nacional del Chaco Austral; ArgentinaFil: Maldonado Vargas, Pablo. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias. Departamento de Producción Animal; ArgentinaFil: Konrad, José Luis. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias. Departamento de Producción Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin