CENID Fisiologia y Mejoramiento Animal

Ajuchitlán del Progreso, Mexico

CENID Fisiologia y Mejoramiento Animal

Ajuchitlán del Progreso, Mexico

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Lopez-Velazquez M.M.,Colegio de Mexico | De La Cruz-Colin L.,INIFAP Hidalgo | De La Pena J.A.P.,CENID Fisiologia y Mejoramiento Animal | Torres-Hernandez G.,Colegio de Mexico | And 6 more authors.
Revista Mexicana De Ciencias Pecuarias | Year: 2016

The objective of the study was to evaluate the effects of sire breed (Charollais, Dorset and Texel), utilizing Hampshire ewes, lamb sex and birth type, on carcass traits of the lambs. After weaning (74±8 d), 45 lambs from these crosses were fattened during 63 d, consuming a balanced diet with 14% CP and 2.82 Mcal of ME/kg of DM. Lambs were weighed and slaughtered at 137 d of age; later, measures on slaughter weight and yield of hot and cold carcass, rib eye area, subcutaneous fat, carcass length, leg length, and rump perimeter were taken and the carcass compactness index was calculated. In addition, the carcass regional composition (shoulder, chest-belly, anterior-loin, leg, neck, and rear-loin) was determined. Data were analyzed utilizing a mixed model. Charollais-sired lambs had the highest (P<0.05) rib eye area (20.1±0.5 cm2), while Dorset-sired lambs were superior (P<0.05) in carcass length (66.3±0.9 cm) and leg length (34.8±0.3 cm). Ram lambs surpassed ewe lambs (P<0.05) in most traits analyzed. Lambs born as singles had higher means than twin lambs (P<0.05) in subcutaneous fat and leg length. In general, crosses with Charollais and Dorset showed superiority in carcass traits.


Pech C.I.V.M.,Campo Experimental Mococha | Vazquez J.A.T.,CENID Fisiologia y Mejoramiento Animal | Zepeda A.B.,Sitio Experimental El Verdineno | Utrera A.R.,Campo Experimental la Posta | And 4 more authors.
Revista Mexicana De Ciencias Pecuarias | Year: 2012

Genetic parameters for growth traits of Katahdin lambs were estimated using six variants of the animal model. Data on birth weight (BW; n= 13,099), weaning weight adjusted to 75 d (WW; n=11,509) and postweaning weight adjusted to 120 d (AW; n=6,886) were collected for seven years (2004-2010) in 20 states across Mexico. Analyses were carried out by ignoring or including maternal effects. The simplest model included the direct additive genetic effect as the only random effect. The most complete model included direct and maternal genetic effects, their covariance, and the maternal permanent environmental effect. Selection of the best model was based on likelihood-ratio test. When maternal effects were not taken into account, estimates of direct heritability and direct genetic variance were overestimated for all traits. Direct heritability estimates for the best model were 0.18 ± 0.03, 0.30 ± 0.04, and 0.20 ± 0.05 for BW, WW and AW, respectively. Maternal heritability estimates also varied depending on the model; estimates ranged from 0.05 to 0.23, 0.00 to 0.12, and 0.09 to 0.25 for BW, WW and AW. Ignoring maternal effects in the model would result in inaccurate genetic evaluation for growth traits in Katahdin sheep.


Utrera A.R.,Instituto Nacional de Investigaciones Nucleares | Velazquez G.M.,Sitio Experimental El Verdineno | Murillo V.E.V.,Instituto Nacional de Investigaciones Nucleares | Bermudez M.M.,CENID Fisiologia y Mejoramiento Animal
Revista Mexicana De Ciencias Pecuarias | Year: 2012

Genetic effects for growth traits of Mexican Charolais and Charbray cattle estimated with alternative models. Data recorded from 1997 to 2009 by the Charolais-Charbray Herd Book of Mexico were analyzed with six different animal models to estimate genetic parameters for birth weight (n=105,599), weaning weight adjusted to 205 d (n=89,111) and yearling weight adjusted to 365 days (n=55,284). Model 1 included direct additive genetic effects of the animal. Model 2 allowed for a common environmental effect due to the dam, fitting it as an additional random effect. Model 3 included the animal's direct genetic effect, and the dam's maternal genetic effect, assuming a covariance equal to zero between them. Model 4 was the same as Model 3 but it also allowed for a common environmental effect due to the dam. Model 5 is identical to Model 3, but included a covariance between direct and maternal genetic effects. Model 6 was fitted for all three random effects plus the covariance between direct and maternal genetic effects. Compared with any of the other models, the most complete model (Model 6) substantially reduced the -2log L (P<0.05), providing the best fit for the three growth traits. Comparison between Model 1 and Model 6 across traits showed that Model 1 yielded smaller estimates of direct genetic variance, in contrast with results from previous studies. However, estimates of the residual variance for Model 1 were significantly greater than estimates for Model 6.


Rios-Utrera A.,Campo Experimental la Posta | Vega-Murillo V.E.,Campo Experimental la Posta | Martinez-Velazquez G.,Sitio Experimental El Verdineno | Montano-Bermudez M.,CENID Fisiologia y Mejoramiento Animal
Tropical and Subtropical Agroecosystems | Year: 2011

Six models to estimate genetic parameters for birth weight (BW), weaning weight adjusted to 205 days (W205), and yearling weight adjusted to 365 days (W365) were compared. Model A included direct genetic effects. Model AP allowed for direct genetic and permanent environmental effect of the dam. Model AM included direct genetic and maternal genetic effects. Models AMC and AMP were the same as Model AM but they also allowed for the covariance between direct and maternal genetic effects, and the common environmental effect due to the dam, respectively; and Model AMCP was fitted for all three random effects plus the covariance between direct and maternal effects. Models were compared using the likelihood ratio text. The AMC model was selected to be the most appropriate for BW and W205, whereas Model A was chosen for W365. When maternal effects were included, direct genetic variance and direct heritability estimates were reduced for BW and W205. Direct heritability estimates with appropriate models were: 0.13, 0.21 and 0.20 for BW, W205 and W365. Heritability of maternal effects with appropriate models was: 0.15 and 0.32 for BW and W205, and direct-maternal genetic correlations with appropriate models were: -0.67 and -0.69 for BW and W205, respectively.


Vega-Murillo V.E.,Research Center Regional Golfo Centro | Rios-Utrera A.,Campo Experimental la Posta | Montano-Bermudez M.,CENID Fisiologia y Mejoramiento Animal | Martinez-Velazquez G.,Sitio Experimental El Verdineno
Tropical and Subtropical Agroecosystems | Year: 2012

Covariance components and genetic parameters were estimated in Simmental, Simbrah and Simmental x Zebu calves fitting six alternative models to birth weight (BW; n=105,297), 205-day weight (WW; n=82,752) and 365-day weight data (YW; n=49,450) provided by Asociación Mexicana de Criadores de Ganado Simmental Simbrah, A.C. Models ranged from a model which included direct additive genetic effects (Model 1) to a model which included direct and maternal additive genetic effects, their covariance and maternal permanent environmental effects (Model 6). Fixed effects were: contemporary group, age of dam, proportion of Simmental genes, heterozygosity and recombination losses. Estimates of direct and maternal heritability varied between alternative models. Due to the problems associated with the estimation of the direct-maternal correlation, which was extremely high (absolute value), Model 4, which included both dams' genetic and permanent environmental effects in addition to direct additive genetic effects, was considered to be the most appropriate for all traits. Application of any of the other models would result in inaccurate expected progeny differences, affecting selection efficiency. Model-4 estimates of direct heritability, maternal heritability and of the ratio of maternal permanent environmental variance to the total phenotypic variance were: 0.17, 0.01 and 0.03; 0.14, 0.02 and 0.04; and 0.15, 0.01 and 0.01 for BW, WW and YW, respectively.


Suazo F.M.,CENID Fisiologia y Mejoramiento Animal | Casanova L.G.,CENID Fisiologia y Mejoramiento Animal | Torres C.R.,CENASA SENASICA SAGARPA | Alarcon G.J.C.,Autonomous University of Queretaro | And 7 more authors.
Revista Mexicana De Ciencias Pecuarias | Year: 2012

The molecular fingerprints of 878 isolates of Mycobacterium bovis from cattle, mostly dairy cattle, collected from cattle between 2009 and 2010 in different regions of Mexico were obtained by spoligotyping. Seventy-two percent (72 %) of the spoligotypes fell into nine clusters, and 27 % of the isolates fell into only two spoligotypes; 149 were orphan spoligotypes. The two predominant spoligotypes, arbitrarily designated as SP1 and SP2, were found in almost all States in Mexico, especially in central Mexico, where a concentration of dairy cattle is known. In spite of the wide distribution of spoligotypes observed, some show high regional preference, especially those in geographically distant regions. Only a few spoligotypes show patterns completely different from those shown by the most frequent spoligotypes, suggesting strange sources of infection or the formation of new genetic lines derived from non-lethal mutations. Most States with predominantly high dairy cattle populations showed similar spoligotypes, suggesting exchange of animals between regions. Some spoligotypes are common to dairy and beef cattle, suggesting transmission between populations, most probably due to the movement of dairy cattle to non-dairy regions.


Suazo F.M.,CENID Fisiologia y Mejoramiento Animal | Harris B.,CENID Fisiologia y Mejoramiento Animal | Diaz C.A.,CENID Microbiologia | Thomsen B.,U.S. Department of Agriculture | And 6 more authors.
Tecnica Pecuaria en Mexico | Year: 2010

Quick diagnosis of tuberculosis in cattle is critical to decide whether or not to quarantine or depopulate a herd. Currently, decisions are based on culture, which takes between four and eight weeks to accomplish. Therefore, the purpose of this study was to evaluate relative sensitivity and specificity of two PCR's (MPB70 and IS6110) and spoligotyping as quick diagnostic tests for cattle tuberculosis in fresh tissue. Fifty tissue samples with TB-suspicious lesions from a herd with 25% prevalence of the disease and fifty tissue samples with no lesions from a TB-free herd were used in the study. Samples were split into two sets and each set was blind analyzed in two different laboratories under the same protocol. The three tests were used to diagnose tuberculosis in all samples using macerated tissue just before culturing. Relative sensitivity and specificity of all tests were estimated using presence/absence of lesion, histopathology and culture results as gold standards. MPB70 nested PCR showed consistently higher sensitivity (85 to 91%) and specificity (77 to 86%) in one of the laboratories with all gold standards; however, inter-laboratory differences occurred, in one of the laboratories sensitivity was from 89 to 91% and specificity from 57 to 63%. IS6110 nested PCR and spoligotyping behaved poorly. Relative sensitivity and specificity for MPB70 nested PCR suggest that this test could be useful as a complementary test for quick diagnosis of bovine TB in fresh tissue.


Suazo F.M.,CENID Fisiologia y Mejoramiento Animal | Harris B.,U.S. Department of Agriculture | Diaz C.A.,CENID Microbiologia | Thomsen B.,U.S. Department of Agriculture | And 6 more authors.
Revista Mexicana De Ciencias Pecuarias | Year: 2010

Quick diagnosis of tuberculosis in cattle is critical to decide whether or not to quarantine or depopulate a herd. Currently, decisions are based on culture, which takes between four and eight weeks to accomplish. Therefore, the purpose of this study was to evaluate relative sensitivity and specificity of two PCR's (MPB70 and IS6110) and spoligotyping as quick diagnostic tests for cattle tuberculosis in fresh tissue. Fifty tissue samples with TB-suspicious lesions from a herd with 25 % prevalence of the disease and fifty tissue samples with no lesions from a TB-free herd were used in the study. Samples were split into two sets and each set was blind analyzed in two different laboratories under the same protocol. The three tests were used to diagnose tuberculosis in all samples using macerated tissue just before culturing. Relative sensitivity and specificity of all tests were estimated using presence/absence of lesion, histopathology and culture results as gold standards. MPB70 nested PCR showed consistently higher sensitivity (85 to 91 %) and specificity (77 to 86 %) in one of the laboratories with all gold standards; however, inter-laboratory differences occurred, in one of the laboratories sensitivity was from 89 to 91 % and specificity from 57 to 63 %. IS6110 nested PCR and spoligotyping behaved poorly. Relative sensitivity and specificity for MPB70 nested PCR suggest that this test could be useful as a complementary test for quick diagnosis of bovine TB in fresh tissue.


Echeverria R.S.,National Autonomous University of Mexico | Echeverria R.S.,Instituto Nacional de Investigaciones Nucleares | Robles R.C.,Campo Experimental San Martinito | Avila H.R.V.,CENID Fisiologia y Mejoramiento Animal | And 5 more authors.
Revista Mexicana De Ciencias Pecuarias | Year: 2014

We evaluated the effect of kisspeptin-10 (Kiss-10) administered repeatedly on the release of LH and ovarian activity in prepubertal heifers. We also assessed the association of serum IGF-1 and leptin with these effects. Fourteen Holstein or Brown Swiss by Zebu female calves (11.2 ± 0.2 mo old, 187.4 ± 6.3 kg) were randomly assigned to receive every 2 h for three days an i.v. application of Kiss-10 (Kisspeptin-10; 5 ?g/kg of body weight, n= 7) or saline solution (control, n= 7). Blood was collected every 15 min for 0-6, 24-30 and 72-78 h, and every 2 h until 84 h. Each application of Kiss-10 was followed by an increase of LH whose magnitude (area under the curve) decreased (P>0.05) over time. Kiss-10 induced a preovulatory surge of LH and corpus luteum formation in 28.5 % of the calves. Ovulating calves had the highest (P>0.05) serum concentrations of IGF-1 and the lowest (P>0.05) leptin. During 63 posttreatment days, no changes were detected in follicular waves attributable to treatments (P<0.05) and heifers did not show cyclic ovarian activity. The conclusion is that Kiss-10 given repeatedly to prepubertal heifers is sufficient to evoke consistent increases of LH, to induce ovulation and luteal activity in animals with high IGF-1 and low leptin in peripheral blood but it is insufficient to establish regular estrous cyclicity.

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