Raciel Javier Estrada-León

Se determinó el efecto de los factores genéticos y ambientales que inciden en el crecimiento pre-destete de las ovinos de pelo en el trópico mexicano. Se analizaron datos de 792 corderos durante dos años, registrando el peso al nacimiento (BW, kg), peso al destete (WW, kg), edad al destete (WA, días), peso al destete ajustado (AWW, kg) y de la ganancia diaria de peso (DWG, g/día). Los datos fueron agrupados por razas BlackBelly (BB), Katahdin (KT), Pelibuey Blanco (WPB), Pelibuey Canelo (RPB) y cruzas comerciales no definidas (UBC), año (2022, 2023) y época de nacimiento (seca, lluvia, norte), así como por el tipo de nacimiento (simple, doble, triple) y sexo (hembras, machos). Los resultados mostraron que el grupo genético, tipo de parto, sexo y edad al destete influyen significativamente sobre BW, WW, AWW y DWG, destacando a la raza KT por su mayor producción. Los partos simples y los corderos machos se asociaron con mejores desempeños en términos de crecimiento. Estos hallazgos subrayan la importancia de considerar la genética y los factores reproductivos en los programas de selección y manejo, con el fin de optimizar el rendimiento productivo en los sistemas de producción de ovinos en el trópico de México.

La genética del color del pelaje en los perros (Canis lupus familiaris) es un área de estudio compleja, influenciada por múltiples genes que interactúan para producir una amplia variedad de patrones de pigmentación. Este artículo explora los mecanismos hereditarios que subyacen a la variación del color del pelaje, centrándose en genes clave como MC1R, ASIP, TYRP1 y CBD103. Se discuten las vías moleculares involucradas en la producción de melanina, los patrones de herencia de diferentes colores y cómo la cría selectiva ha dado forma a la diversidad fenotípica entre razas. Además, se menciona el cariotipo de los caninos y representaciones gráficas de las interacciones génicas. Comprender estos principios genéticos es importante para criadores, veterinarios, genetistas y población que busca predecir y manejar los resultados del color del pelaje en perros.

The aim of the present study was to predict the carcass tissue composition of hair lambs reared on a commercial system, based on the characteristics of commercial cuts using multiple linear regression. In the study, thirty crossbred male lambs (Pelibuey × Dorper/Katahdin), with an average live weight of 51.12 ± 0.97 kg, were used. After slaughter of lambs, the carcasses were stored in refrigeration at 4 °C for 24 hours. Subsequently, they were weighed and split longitudinally. The left half of carcasses was divided into eight cuts (shank, neck, shoulder, rib, flank, loin, sirloin, and leg), which were individually weighed (kg) and dissected into muscle, fat, and bone. Also, the total weight of muscle, total fat content, and total bone content in the complete carcass was determined. In general, total weight of muscle, total fat content, and total bone contentshowed moderate to high positive correlations (0.32 ≤ r ≤ 0.87; P < 0.05, P < 0.001) with the characteristics of commercial cuts. The best predictors of total muscle content were shoulder muscle content, shank weight, leg muscle content, and rib muscle content (R² = 0.96; MSE = 3.94; AIC = -1.28). The total fat content can be adequately predicted using rib fat content, loin fat content, and shoulder fat content (R²=0.96; MSE=3.29; AIC=- 7.71). While total bone content can be predicted from leg bone content, sirloin bone content, shoulder bone content, and shank bone content (R2 = 0.91; MSE = 0.75; AIC = -16.42). All linear regression equations were found to be significant (P < .001). It is concluded that the carcass tissue composition of hair lambs is highly correlated with characteristics of commercial cuts. Consequently, the regression equations obtained in the study had high accuracy. Therefore, they can be used by technicians, producers, and researchers to obtain information on the carcass composition of hair lambs reared on commercial systems.

The objective of this research was to evaluate the physicochemical quality, bioactive compound content, and antioxidant capacity of pasta made with durum wheat semolina and partial substitutions of parota flour (Enterolobium cyclocarpum). Fettuccine pasta formulations were prepared with different percentages of parota flour (0%, 10%, 30%, and 50%). The methodologies included proximate chemical composition analysis, dietary fiber determination, total phenolic content, antioxidant capacity (ABTS assay), and reducing power, as well as cooking quality tests and color analysis. The results showed that the incorporation of parota flour significantly increased protein content (up to 22.06 g/100 g), total dietary fiber (up to 22.1 g/100 g), and total phenolic compounds (up to 23.35 mg/100 g). Additionally, higher antioxidant capacity and reducing power were observed in the pastas with higher parota flour content. In terms of cooking quality, the parota flour-enriched pastas exhibited reduced cooking time and higher cooking loss, but lower water absorption and weight of cooked pasta. The values for cooking loss and water absorption in cooked pasta suggest the need to optimize formulations in order to improve pasta quality. Color analysis revealed more reddish and yellowish tones with greater saturation. Parota flour enhances the nutritional and functional profile of the pasta, providing a healthier and more visually appealing product. These pastas enriched with parota flour show promise as functional foods by contributing to a balanced diet and encouraging the use of regional, sustainable ingredients.

Maternal effects in cattle genetics are defined as the causal influence of the phenotype or maternal genotype on the offspring’s phenotype by effects occurring when the genetic and environmental characteristics of the mother influence the phenotype of the offspring beyond the direct inheritance of genes. Its relevance has been strongly described in genetic models focused on the genetic improvement of preweaning traits in cow-calf beef cattle production systems. Here, basic concepts and the importance of maternal effects when using linear and animal model procedures for genetic evaluations of growth and live-weight traits in beef cattle are reviewed and discussed. A brief history of estimation methods from classical studies to recent studies used for the development of animal models for studying maternal effects is also provided. Some important biometric concepts for maternal effect estimation are described, and the antagonism between direct genetic effects and maternal effects, its biological basis, and sources of error in the estimation of direct genetic and maternal covariance are discussed. Finally, some genomic perspectives are presented.

Avances y perspectivas en los programas de cruzamiento de ovinos de pelo en el trópico de América Latina

Se analizan los efectos de adicionar harina de semilla de B. alicastrum (30% HR, p/p) a botanas de maíz con diferentes métodos de cocción sobre la aceptación, capacidad antioxidante y la estabilidad oxidativa. Asimismo, se evaluaron los cambios fisicoquímicos durante el almacenamiento de las botanas con mayor aceptación. Cuando se fríe, la botana HR/TSD (tortilla sin deshidratar) tuvo la mayor capacidad antioxidante (39.36 ± 0.61 mM Trolox/100 g), mientras que la botana HR/TD (tortilla deshidratada) exhibió mayor estabilidad oxidativa (<29 TOTOX). Al respecto, la botana frita HR/TSD tuvo la mayor aceptación. Durante el almacenamiento, la botana HR/TSD tuvo el menor índice de peróxido. La adición de harina de B. alicastrum a la botana de maíz frito mejora la aceptabilidad del consumidor y su almacenamiento.

Ramon nut (B. alicastrum) is known to contain bioactive compounds and has been used for medicinal and food purposes for millennia. In the present study the objectives were to quantify and compare the proximal composition, phytochemical contents, in vitro antioxidant capacity and individual phenolic compounds in B. alicastrum leaf, fruit peel, seed and seed coat. Patterns were recognized using canonical discriminant analysis. After freeze-drying, proximate analyses were done. Phenolic compounds in the leaf, fruit peel, seed and seed coat of B. alicastrum were identified by HPLC-UV. Leaf had the highest ash, lipid and protein contents, seed coat had high crude fiber content and seeds high carbohydrates content. The highest (33.13 %) and lowest (4.77 %) yields of extraction (compounds) were obtained from the fruit peels and seed coat, respectively. Phytochemical screening revealed abundant terpenes and tannins in leaf tissue, and abundant sterols in seed coat. Total phenolic content (TPC) was highest (P≤0.05) in seeds (19.74 mg gallic acid equivalent GAE/g) and total flavonoids content (TFC) was highest (P≤0.05) in leaves (16.62 mg quercetin equivalent QE/g). The highest DPPH antioxidant capacity was identified in seed coat and the highest reducing power (RP) in leaf and fruit peel. The HPLC analysis identified caffeic acid as the most abundant phenolic compound in leaves, gallic acid as the most abundant in seeds, chlorogenic acid in seed coat and 3-hydroxytyrosol in fruit peel. Linear discriminant analysis (LDA) effectively differentiated the samples by tissue. Proximal chemical composition and bioactive compounds contents differed between B. alicastrum tissues, but they all contain bioactive compounds with antioxidant potential, highlighting their potential applications in food and non-food systems. Key words: antioxidants; phytochemicals; plant-extracts; Ramón.

The aim of this study was to estimate the (co)variance components and genetic parameters for milk yield adjusted to 305d (MY305), calving-to-conception interval (CCI), number of services per conception (NSC) and calving interval (CI) of Honduran Holstein cows, by fitting a bivariate animal model using Maximum Restricted Likelihood procedures. Model included the fixed effects of calving number, the contemporary calving group (farm-season-year of calving and the cow age as covariate). The estimated means and standard deviations for MY, CCI, NSC and CI were, 5098.60 ± 1564.32 kg, 168.27 ± 104.71 days, 2.46 ± 1.69 services, and 448.73 ± 109.16 days, respectively; and their estimated heritabilities were 0.21 ± 0.05, 0.03 ± 0.028, 0.02 ± 0.024 and 0.06 ± 0.04, respectively. The genetic correlations between MY305 and CCI, NSC and CI were positive and antagonist, with values of 0.64 ± 0.52, 0.99 ± 0.56, and 0.32 ± 0.24 respectively. Even though moderate to low heritability was estimated for MY305, systematic selection for milk yield, with a reduction in reproductive efficiency, if considered as the only selection criterion is important to be considered. By including reproductive traits and considering permanent environment effects into the breeding program, might yield a slow, but constant and permanent improvement over time.

Introduction. Livestock farming with Creole cattle is practiced in rural areas with challenging characteristics for species management. Objective. To describe the production system and the socio-cultural and technical-economic factors affecting the production of Nunkiní Creole cattle (Bos taurus). Materials and methods. The study was conducted from November 2020 to October 2021 in nine livestock production units of Nunkiní, Calkiní municipality, Campeche, Mexico. Information was obtained from an interview form with social, cultural, technical, and economic study variables, applied to selected producers. Data were analyzed using descriptive statistics and ANOVA. Results. Livestock farming was carried out by men (100 %), with an average age of 58.44 years. The average years of experience were 34.61. Younger producers had higher levels of education and less experience, and were responsible for the production units of higher technological levels. The size of the livestock production unit ranged from five to twenty-two cattle (average of 14). Feeding management followed a transhumance scheme, with cattle being free-ranging on ejido lands and from May to December and semi-stabled from January to April, grazing on cultivated pastures and supplemented with agricultural residues. With the zootechnical management implemented by the producers, an average pregnancy rate of 83 % was achieved. The main product marketed was fresh meat in cuts and direct sale to consumers, with an average price of 2.675 USD$/kg. Conclusion. It is traditional extensive system that takes advantage of the common use of grasslands. It involves experienced but older producers, with small investments, and serves to strengthen their family economy. This activity is threatened by the lack of revaluation of Creole cattle and the introduction of exotic breeds in the area to maximize production.