PRÁCTICAS DE MANEJO ASOCIADAS CON LA SEROEPIDEMIOLOGÍA DE PARATUBERCULOSIS OVINA EN SAN LUIS POTOSÍ

Flock management practices associated with the seroprevalence of paratuberculosis (Ptb) in sheep were identified, in San Luis Potosí, México. Blood samples (242) were diagnosed by using the immunodiffusion test in agar gel (IDAG). Through a survey, information about the flocks was grouped into variables of the farm, flock, management, origin and destination of the sheep. A logistic regression was used for analysis. The results obtained were a seroprevalence of 9.99 %, and it was found that age is a risk factor to diagnose sick sheep (OR=3.57). The Rambouillet breed presented greater risk of contracting the disease (OR=1.11). Not having sanitary practices was a risk factor for the disease (OR=9.49). The purchase of foreign animals can be a risk factor (OR=4.51 and 5.86). The results suggest that there is a higher risk of paratuberculosis when the total of animals is higher and the farm management is more intensive. Further studies will be necessary to clarify the factors of the host that are associated with resistance to infection, since it was found that there is a breed factor for seropositive animals, and the risk is greater when sheep are purchased outside the locality, without a sanitary revisionSe identificaron prácticas de manejo de rebaño asociadas con la seroprevalencia de paratuberculosis (Ptb) en ovinos en san Luis Potosí, México. Se diagnosticaron 242 muestras sanguíneas de ovejas usando la prueba de inmunodifusión en gel de agar (IDAG). A través de una encuesta la información de los rebaños fue agrupada en variables del predio, del rebaño, de manejo, origen y destino de los ovinos. Se usó una regresión logística para análisis. Los resultados obtenidos fueron una seroprevalencia de 9.99%. Encontrándose que la edad es un factor de riesgo para diagnosticar ovinos enfermos (OR=3.57). La raza Rambouillet presentó mayor riesgo de contraer la enfermedad (OR=1.11). No llevar prácticas sanitarias resultó un factor de riesgo para la enfermedad (OR=9.49). La compra de animales foráneos, puede ser un factor de riesgo (OR=4.51 y 5.86). Los resultados sugieren que existe más riesgo de paratuberculosis, conforme más grande sea el total de animales y más intensivo sea el manejo del predio. Será necesario más investigación para aclarar los factores del huésped que están asociados con la resistencia a la infección, ya que lo registrado fue que existe un factor racial para animales seropositivos, y el riesgo es mayor cuando se adquieren ovinos fuera de su localidad, sin chequeo sanitario

IMPACTO Y RELEVANCIA DE UN PROGRAMA DE INSEMINACIÓN ARTIFICIAL EN LA MEJORA PRODUCTIVA DE REBAÑOS DE OVINOS

In order to increase the production of lambs in Hidalgo, México, an artificial insemination (AI) program was implemented in the year 2010 on more than 2000 sheep, where they interacted in a coordinate way at different levels of the production chain; institutions, field technicians, reproduction specialists, and financing institutions. In the program 97 Production Units (PU) participated with 2,267 sheep of the Hampshire, Dorset and Suffolk breeds, distributed in 16 municipalities of the state. The program results with the oestrus induction during non-reproductive season were 51%, 54% and 54% of pregnancy, and 99.2%, 97.8% and 96% of lambing with a prolificacy of 1.4%, 1.6% and 1.5% for the Hampshire, Dorset andSuffolk breeds, respectively. The percentage of ewes that presented a return to estrus was inseminated by natural mating with studs from the PUs. The data at birth weight (BW) and daily weight gain (DWG) were compared. Increases of 13%, 16% and 12% of weight at weaning (WW) were observed, and 15%, 16% and 13% of DWG for Hampshire, Dorset and Suffolk, respectively; in lambs born from parents with referencedata compared to those from studs used in the PUs. The AI is a useful tool that allows increasing productive yields and propagating outstanding genetic material.Para aumentar la producción de corderos en Hidalgo, México, se implementó en el año 2010 un programa de inseminación artificial (IA) de más de 2000 ovejas, donde interactuaron de manera coordinada en diferentes niveles de la cadena de producción; instituciones, técnicos de campo, especialistas en reproducción e instituciones de financiamiento. En el programa participaron 97 Unidades de Producción (UP) con 2,267 ovejas de las razas Hampshire, Dorset y Suffolk, distribuidas en 16 municipios del estado. Los resultados del programa con la inducción de calores en época no reproductiva fueron 51%, 54% y 54% de gestación, y 99.2%, 97.8% y 96% de parición con una prolificidad de 1.4%, 1.6% y 1.5% para las razas Hampshire, Dorset y Suffolk, respectivamente. El porcentaje de las hembras que presentaron retornoa estro, fueron inseminadas por monta natural con sementales de las UP. Se compararon los datos de peso al nacimiento (PN) y ganancia diaria de peso (GDP). Se observaron aumentos de 13%,16% y 12% en peso al destete (PD) y 15%, 16% y 13% en GDP para Hampshire, Dorset y Suffolk, respectivamente; en aquellos corderos nacidos de padres con datos de referencia con respecto a los de sementales usados en las UP. La IA es una herramienta útil que permite incrementar rendimientos productivos y propagar material genético sobresaliente

Aplicación de biotecnologías reproductivas para el mejoramiento genético de rebaños de ovinos

La sincronización de celo e inseminación artificial en ovejas con razas puras cárnicas, y la mejora de la organización de productores, equipo, instalaciones y capacitación teórico-práctica permanente, permite la generación del concepto empresarial en este sector de la ganadería. Se presentan resultados obtenidos de lo anterior en una muestra de rebaños pertenecientes al sistema producto ovino del Distrito Federal, México, con impactos sobre el mayor peso de los corderos al nacer, factibilidad de apareamiento más de una vez al año, valores de gestación de 72.9%, parición de 54.3% e índice de prolificidad de 1.2% en condiciones de anestro estacional

RIESGO DE TRANSMISIÓN DE Mycobacterium avium subespecie paratuberculosis (Map) EN ESPECIES DOMÉSTICAS Y SILVESTRES

The microorganism Mycobacterium avium subspecies paratuberculosis (Map) is the cause of severe gastroenteritis granulomatous in ruminants. It is known as Johne’s disease and is characterized by persistent diarrhea and progressive emaciation, which eventually causes death in animals, particularly young ones since they are more susceptible to being infected through oral-fecal transmission through the consumption of contaminated grass, colostrum, milk and via transplacentary conduction. Its control and prevention is based on reliable diagnoses that detect the agent before the beginning of clinical signs, and thus avoid its dissemination in the flock. This disease is distributed worldwide and is responsible for important economic losses in the industry of cattle and sheep production, and in wild animal breeding centers. A revision about the risks of transmission between domestic and wild animals is done.El microorganismo Mycobacterium avium subespecie paratuberculosis (Map) es el causante de una gastroenteritis granulomatosa severa en rumiantes. Se conoce como enfermedad de Johne y se caracteriza por diarrea persistente y emaciación progresiva, que finalmente causa la muerte en animales, sobre todo en los jóvenes por ser más susceptibles a infectarse por transmisión oro-fecal, consumo de pasto contaminado, calostro, leche y por vía transplacentaria. Su control y prevención se basa en diagnósticos confiables que detecten al agente antes del inicio de los signos clínicos, y así evitar su diseminación en el rebaño. Esta enfermedad es de distribución mundial y es responsable de importantes pérdidas económicas en la industria de la producción bovina, ovina y criaderos de animales silvestres. Se hace una revisión sobre los riesgos de transmisión entre los animales domésticos y silvestres

External stimuli help restore post-partum ovarian activity in Pelibuey sheep

Post-partum anestrus is a problem on farms, and its duration depends on the frequency and intensity of suckling which affects reproduction and production efficiency to become a determining economic factor. The aim of this study was to determine the post-partum reproductive response in ewe to a "male effect" with an ovulation induction protocol of five days using progesterone and the application of a metabolic restorative (MR; Metabolase ®). One hundred and twenty females were randomly assigned to one of four treatments: T1: Continuous suckling (CS; n = 29), T2: CS + MR (n = 29), T3: CS + Male Effect (ME; n = 32), and T4: CS + MR + ME. The percentage of females in ovulation, weight changes among females and lambs, the onset of estrus, calving, fecundity, and prolificacy were also determined. The ovulation percentage was higher in CS + ME and CS + MR + ME (75.0 and 73.3%) than in the other treatments. Weight changes in females and lambs were different among periods. The onset of estrus was similar for CS and CS + MR (25.9 ± 1.9 and 25.7 ± 0.7 h, respectively). The calving percentage was higher for CS + MR (86.2%) than other treatments. Male presence positively affected the postpartum cyclic ovarian re-establishment and the metabolic restorative could even improve the fertility of hair ewes in continuous suckling with similar hormone protocolKeywords: Male effect, metabolic stimulation, post-partum anestru

“Male effect” and “temporary weaning” in synchronization of post-partum ovarian activity in Pelibuey ewes

To evaluate the response of the “male effect” and “temporary weaning” on the synchronization of post-partum ovarian activity in Pelibuey ewes, an experiment was carried out using 78 Pelibuey ewes with suckling lambs. The ewes were separated from their offspring for 48 hours and randomly assigned to one of four treatments derived from the arrangement of two factors, “male effect” and “temporary weaning”, each at two levels. Treatments were: T1 (n = 20) control ewes, without “male effect” and without “temporary weaning”); T2 (n = 19) ewes without “male effect” and with “temporary weaning”; T3 (n = 20) ewes with “male effect” and without “temporary weaning”; and T4 (n = 19), ewes with “male effect” and with “temporary weaning”. The response to oestrus, return to oestrus, gestation rate and lambing rate were analysed using logistic regression. The onset of oestrus was analysed using survival curves. No significant differences were found for lambing rate and prolificacy among treatments. “Temporary weaning” (T2) and “male effect” (T3) did not influence the response to oestrus, rate and duration of return to oestrus, or gestation rate and fertility, and was similar to the control group (T1). The interaction of “male effect” with “temporary weaning” (T4) increased the response to oestrus, reduced the rate and duration of return to oestrus, and the gestation rate, but increased fertility. Synchronizing post-partum ovarian activity with “male effect” and “temporary weaning” reduces the onset of oestrus and the rate of return to oestrus, but increases the response to oestrus and fecundity in Pelibuey ewes.Keywords: Biostimulation, progestogens, prolificacy, prostaglandins, sucklin

Investigating mutations in the genes GDF9 and BMP15 in Pelibuey sheep through the amplification-refractory mutation system with tetra-primers

Single Nucleotide Polymorphisms (SNP) or mutations are variations with a broad distribution in the genome and, as part of genetic studies, SNP allow the identification of allelic variants related to characteristics of economic importance in sheep production. However, the identification of SNP and their genotypes through sequencing is expensive, as it requires specialized materials and equipment. The objective of this study was to identify polymorphisms and their genotypes in the growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) genes in Pelibuey sheep using the tetra-primer amplification-refractory mutation system through polymerase chain reaction (T-ARMS-PCR). DNA extraction and amplification of BMP15 and GDF9 were conducted from blood samples contained in WhatmanTM FTATM cards from 60 multiparous Pelibuey ewes with reproductive records. The T-ARMS-PCR methodology allowed the identification of wild-type genotypes and mutated homozygous genotypes in polymorphisms G4 and G6 of GDF9, whereas mutations in the BMP15 gene were not found. These results were confirmed by sequencing. In conclusion, the T-ARMS-PCR methodology allowed the identification of mutated and wild-type genotypes in SNP G4 and G6 of GDF9, although no mutations were found in BMP15 in Pelibuey sheep. This technique was found to be reliable, rapid, and easily applied to identify polymorphic genotypes

Administration of royal jelly in estrus synchronization protocols for wool and hair sheep

Objetive: To know the most representative results of the use of royal jelly in reproductive protocols in wool and hair sheep,Desing/methodology/approach: A review of studies referenced in scientific databases published in the livestock sector was carried out. Results: In sheep, the administration of royal jelly in conjunction with reproductive management protocols improves the response to oestrus timing, oestrus onset time and duration, number of large follicles, ovulatory rate, and gestation rate. Study limitations/implications: Royal jelly is a substance that has beneficial effects on sheep reproductive variables, however the cost can be a limitation for its incorporation into the synchronization protocols, in addition to being necessary to elucidate the active metabolites that exert the action and the most effective route of administration.Findings/conclusions: Royal jelly can be an alternative to be incorporated in the estrous synchronization programs in sheep in order to replace some hormonal and without reducing reproductive variables.Objective: To assess the most relevant results on the usage of royal jelly in reproductive protocols of wool and hair sheep. Design/methodology/approach: A review of studies referenced and published in scientific databases regard the livestock sector. Results: In ewes, administration of “royal jelly” in addition to reproductive management protocols improves the response to estrus synchronization, time of onset and duration of estrus, number of large follicles, ovulatory rate and gestation rate. Study limitations/implications: Royal jelly is a substance with beneficial effects on reproductive variables in ewes; however, the cost may be a limitation for its incorporation in synchronization protocols. Additionally, it is necessary to clarify the active metabolites that exert the action and the most effective route of administration. Findings/conclusions: Royal jelly can be an alternative incorporated to estrus synchronization programs in ewes to substitute some hormones without decreasing reproductive variables

Reproductive management in white-tailed deer (Odocoileus virginianus Zimmermann)

Objective: To review information related with the reproductive physiology and management of white-tailed deer for reproductive specialists and producers. Design/methodology/approach: The information presented in this document relies on the review of scientific papers and on experience gained in white-tail deer production systems. Results: White-tailed deer is a species with seasonal reproduction and one of the most important hunting species in Mexico. Currently, all reproductive biotechnologies applied to small ruminants can be used in white-tailed deer. Limitations of the study/implications: Information regard the physiology and reproductive management of white-tailed deer is limited, probably due to conditions specific to its production system. Findings/conclusions: Research and publication of information regard the physiology and reproductive management of white-tailed deer is needed

Reproductive activity of dairy cattle in the postpartum anestrus period

Objective: To review the metabolic and hormonal processes that regulate reproductive activity in dairy cattleduring the postpartum anestrus period.Design/methodology/approach: Analysis of scientific documents and systematization of information relatedto the reproductive physiology and management of dairy cattle in postpartum anestrus.Results: Postpartum anestrus is an event that occurs naturally and is necessary for restoration of the homeostasisof the cow’s body following calving. However, failure to reestablish this homeostasis actually increases itsduration and negatively affects the subsequent reproductive performance of the individual cow.Limitations on study/implications: Reproductive management decisions must be based on scientificknowledge.Findings/conclusions: Management of dairy cattle in the postpartum anestrus period should focus onreestablishment of the state of homeostasis and the subsequent reproductive activity, with nutritional andhormonal strategies implemented to induce cyclicity, ovulation and formation of the first corpus luteum in thatperiod, through application of exogenous hormones after day ten postpartum