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Alzina-Lopez A.,Campus de Ciencias Biologicas y Agropecuarias | Perez-Villegas A.A.,Campus de Ciencias Biologicas y Agropecuarias | Segura Correa J.C.,Campus de Ciencias Biologicas y Agropecuarias
Tropical and Subtropical Agroecosystems | Year: 2011

The effect of insemination at first estrous post-weaning or the application of gonadotropins and insemination at the second estrous on litter size of first parity sows was evaluated. Productive data of 2003 to 2005 and 2006 to 2007 from a commercial farm in Yucatan, Mexico were analyzed. The data of the sows farrowing from 2003 up to 2005 corresponded to the sows inseminated at the first estrous post-weaning and the data of the sows farrowed from 2006 to 2007 corresponded to sows that received at weaning an injection of PG-600 (400 IU of eCG and 200 IU of hCG); the estrous was skipped and the sows were inseminated until the second estrous. In both groups, an scheme of three inseminations each 12 hours was used. The data collected consisted of litter size at first and second parity for each group, number of piglets born alive and the interval weaning to first service. Data were analyzed using t tests for independent groups. Significant differences were found in litter size between groups. The application of gonadotropins and insemination at second estrous improved the litter size of the second farrowing.


Fortes D.,Institute Ciencia Animal | Herrera R.S.,Institute Ciencia Animal | Ramirez-Aviles L.,Campus de Ciencias Biologicas y Agropecuarias | Garcia M.,Institute Ciencia Animal | And 2 more authors.
Cuban Journal of Agricultural Science | Year: 2011

In order to study the performance of some morpho-agronomic indicators in strata of Pennisetum purpureum cv. Cuba CT-115, a completely randomized design was used with 15 repetitions. The treatments consisted of five strata: 0-30 cm, 30-60 cm, 60-90 cm, 90-120 cm and more than 120 cm. The results indicated that in the rejected material (immediately after grazing) the residue yield was stabilized up to the upper strata (P < 0.05), whereas there were no differences at 30 and 60 d of regrowth. At 90 d of regrowth it appeared plant material in the stratum of more than120 cm, with values of 0.64 kg DM/tuft, differing from the rest of the strata (P < 0.001), except the basal stratum (0-30 cm). The percentages of leaves from the residue for all regrowth ages were increased up to the upper strata, with maximum values of 18.67, 19.45, 21.66, and 46.51 % for the rejected material, 30, 60, and 90 d of regrowth, respectively. However, the percentages of stems and dead material were reduced. The basal tillers emerged since 60 d of regrowth, not showing differences so as to their yield between strata. The percentage of leaves in the basal tillers was increased (P < 0.001) up to the stratum of 30-60 cm, with values of 60.37 and 63.33 %, for 60 y 90 d, respectively. The stems had an inverse performance. It was concluded that the upper strata had the highest percentages of leaves, the lowest of stems and dead material, in the basal tillers as in the residue, for all the regrowth ages, favoring the nutritive value of the forage. Using this information for designing other management choices is recommended.


Escobedo-Amezcua F.,Morelia Institute of Technology | Nuncio-Ochoa M.G.J.,Morelia Institute of Technology | Herrera-Camacho J.,Universidad Michoacana de San Nicolás de Hidalgo | Gomez-Ramos B.,Universidad Michoacana de San Nicolás de Hidalgo | And 2 more authors.
Journal of Animal and Veterinary Advances | Year: 2010

The objective of this study was to determine the effect of the suckling systems on live body weight, body condition score and the onset of the postpartum ovarian activity in Bos taurus x Bos indicus cows under tropical humid conditions of Mexico. Sixty multiparous pregnant B. taurus x B. indicus cows, with average age and body weight of 6.38±2.4 years and 446.8±58.7 kg, respectively, were used. Cows were randomly assigned to two treatments: Continuous Suckling (CS; n = 30), the calves remained with the cows for 24 h daily; Restricted Suckling (RS; n = 30), the calves suckled once a day by 30 min, starting on the 7th day of the postpartum period until day 105. There was not significant effect of the suckling system on body weight and luteal phase duration (p>0.05). However, differences (p<0.02) were found for body condition score (3.01±0.06 vs. 3.33±0.06, for CS and RS, respectively). The ovulation rate was higher (p<0.001) in the RS group that in the CS (83.3 vs. 36.6%, respectively) and the interval calving-first ovulation was shorter (p<0.005) for the RS (58.7±6.2 days) than for the CS system (84.6±6.2 days). Pregnancy rate at 45 days postpartum was higher (p<0.001) in the RS system (50.0%), with regard to the CS group (13.3%). Under the present conditions of this study, the suckling system affected the body condition score, ovulation rate and conception rate of B. taurus x B. indicus cows. © Medwell Journals, 2010.


Manrique-Saide P.,Autonomous University of Yucatán | Bolio-Gonzalez M.,Campus de Ciencias Biologicas y Agropecuarias | Sauri-Arceo C.,Campus de Ciencias Biologicas y Agropecuarias | Dzib-Florez S.,Autonomous University of Yucatán | And 3 more authors.
Medical and Veterinary Entomology | Year: 2010

Mosquito collections were carried out on microfilaraemic dogs, positive for Dirofilaria sp., for 18 consecutive nights in the coastal town of Celestún, Yucatan, southeast Mexico, during the rainy season (August) of 2007. A total of 292 female mosquitoes representing 12 species of dipteran Culicidae were collected: Anopheles albimanus (Wiedemann); Anopheles crucians (Wiedemann); Anopheles pseudopunctipennis (Theobald); Culex coronator (Dyar & Knab); Culex interrogator (Dyar & Knab); Culex nigripalpus (Theobald); Culex quinquefasciatus (Say); Culex salinarius (Coquillett); Aedes aegypti (Linnaeus); Aedes scapularis (Rondani); Aedes sollicitans (Walker), and Aedes taeniorhynchus (Wiedemann). Aedes taeniorhynchus and Cx. quinquefasciatus were the species found most commonly feeding on the dogs. Filarial nematodes were observed by microscopy in nine of the mosquito species collected; however, third-instar larvae were only observed in Ae. taeniorhynchus and An. crucians. Of 76 Ae. taeniorhynchus specimens found positive for Dirofilaria sp. by dissection, 14 were confirmed to be positive for Dirofilaria immitis (Leidy) by polymerase chain reaction (PCR). The resulting infection rate for D. immitis confirmed by PCR (6.2%) is higher than any infection rate for Ae. taeniorhynchus previously reported from the Americas. © 2010 The Authors. Medical and Veterinary Entomology © 2010 The Royal Entomological Society.


PubMed | Biocontrol, Campus de Ciencias Biologicas y Agropecuarias, U.S. Department of Agriculture, Texas A&M University and 2 more.
Type: Journal Article | Journal: Archives of insect biochemistry and physiology | Year: 2016

Emerging and re-emerging tick-borne diseases threaten public health and the wellbeing of domestic animals and wildlife globally. The adoption of an evolutionary ecology framework aimed to diminish the impact of tick-borne diseases needs to be part of strategies to protect human and animal populations. We present a review of current knowledge on the adaptation of ticks to their environment, and the impact that global change could have on their geographic distribution in North America. Environmental pressures will affect tick population genetics by selecting genotypes able to withstand new and changing environments and by altering the connectivity and isolation of several tick populations. Research in these areas is particularly lacking in the southern United States and most of Mexico with knowledge gaps on the ecology of these diseases, including a void in the identity of reservoir hosts for several tick-borne pathogens. Additionally, the way in which anthropogenic changes to landscapes may influence tick-borne disease ecology remains to be fully understood. Enhanced knowledge in these areas is needed in order to implement effective and sustainable integrated tick management strategies. We propose to refocus ecology studies with emphasis on metacommunity-based approaches to enable a holistic perspective addressing whole pathogen and host assemblages. Network analyses could be used to develop mechanistic models involving multihost-pathogen communities. An increase in our understanding of the ecology of tick-borne diseases across their geographic distribution will aid in the design of effective area-wide tick control strategies aimed to diminish the burden of pathogens transmitted by ticks.

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