Genetic parameters for somatic cell score, milk yield and type traits in Nigerian Dwarf goats

Valencia-Posadas Mauricio,Lechuga-Arana Alma Arianna,Ávila-Ramos Fidel,Shepard Lisa,Montaldo Hugo H. 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.3

Objective: This study was conducted to estimate multi-trait genetic parameters for somatic cell score (SCS), milk yield and type traits in Nigerian Dwarf (ND) goats from the United States. Methods: Data from 1,041 ND goats in the United States with kiddings in 95 herds were used to estimate multi-trait genetic parameters for SCS, milk (MILK), fat (FAT), and protein (PROT) yields, and 14 type traits. An 18-trait mixed linear animal model for lactation mean SCS (Log2), MILK, FAT, PROT, and 14 type traits was applied. A factor analytic approach (FA1) in ASReml software was used to obtain convergence. Results: Averages for SCS were low (2.85±1.29 Log2), and were 314±110.6, 20.9±7.4, and 14±4.9 kg, respectively, for MILK, FAT, and PROT. Heritabilities for SCS, MILK, FAT, and PROT were 0.32, 0.16, 0.16, and 0.10, respectively. The highest heritabilities for type traits were for stature (0.72), teat diameter (0.49), and rump width (0.48), and the lowest estimates were for dairyness (0.003) and medial suspensory ligament (0.03). Genetic correlations of SCS with MILK, FAT, and PROT were positive but low (0.25, 0.18, and 0.23, respectively). Genetic and phenotypic correlations between MILK, FAT, and PROT were high and positive (≥0.66). Absolute values of genetic correlations involving SCS with type traits were generally low or no different from zero. Most of the phenotypic correlations involving SCS with type traits were low. No serious unfavorable genetic correlations between milk yield traits and SCS or between milk yield traits or SCS and type traits were found. Conclusion: Genetic variation exists in the ND breed for most studied traits. The development of selection programs based on these estimates may help accelerate favorable multitrait genetic changes in this breed. Objective: This study was conducted to estimate multi-trait genetic parameters for somatic cell score (SCS), milk yield and type traits in Nigerian Dwarf (ND) goats from the United States.Methods: Data from 1,041 ND goats in the United States with kiddings in 95 herds were used to estimate multi-trait genetic parameters for SCS, milk (MILK), fat (FAT), and protein (PROT) yields, and 14 type traits. An 18-trait mixed linear animal model for lactation mean SCS (Log2), MILK, FAT, PROT, and 14 type traits was applied. A factor analytic approach (FA1) in ASReml software was used to obtain convergence.Results: Averages for SCS were low (2.85±1.29 Log2), and were 314±110.6, 20.9±7.4, and 14±4.9 kg, respectively, for MILK, FAT, and PROT. Heritabilities for SCS, MILK, FAT, and PROT were 0.32, 0.16, 0.16, and 0.10, respectively. The highest heritabilities for type traits were for stature (0.72), teat diameter (0.49), and rump width (0.48), and the lowest estimates were for dairyness (0.003) and medial suspensory ligament (0.03). Genetic correlations of SCS with MILK, FAT, and PROT were positive but low (0.25, 0.18, and 0.23, respectively). Genetic and phenotypic correlations between MILK, FAT, and PROT were high and positive (≥0.66). Absolute values of genetic correlations involving SCS with type traits were generally low or no different from zero. Most of the phenotypic correlations involving SCS with type traits were low. No serious unfavorable genetic correlations between milk yield traits and SCS or between milk yield traits or SCS and type traits were found.Conclusion: Genetic variation exists in the ND breed for most studied traits. The development of selection programs based on these estimates may help accelerate favorable multitrait genetic changes in this breed.

Analysis of virulence traits of Staphylococcus aureus isolated from bovine mastitis in semi-intensive and family dairy farms

Jaquelina J. Guzmán-Rodríguez,Ma. Fabiola León-Galván,José E. Barboza-Corona,Mauricio Valencia-Posadas,Pedro D. Loeza-Lara,Mónica Sánchez-Ceja,Alejandra Ochoa-Zarzosa,Joel E. López-Meza,Abner J. Gutié 대한수의학회 2020 Journal of Veterinary Science Vol.21 No.5

Background: Staphylococcus aureus is one of the main microorganisms that causes bovine mastitis, and its well-known virulence characteristics and interactions with the environment are used to aid the design of more efficient therapies. Objectives: To determine whether the virulence traits, such as antibiotic resistance and biofilm-forming and internalization abilities, of S. aureus isolated from bovine mastitis are related to dairy production system types. Methods: The study was performed in the Mexican states of Guanajuato and Michoacan. Semi-intensive dairy farms (SIDFs) and family dairy farms (FDFs) (454 and 363 cows, respectively) were included. The 194 milk samples from mastitis affected quarters were collected and 92 strains of S. aureus were isolated and identified by biochemical and molecular tests. Antibiotic resistance, biofilm and internalization assays were performed on 30 randomly selected isolated strains to determine virulence traits, and these strains were equally allocated to the 2 dairy production systems. Results: All 30 selected strains displayed a high degree of resistance (50%–91.7%) to the antibiotics tested, but no significant difference was found between SIDF and FDF isolates. S. aureus strains from SIDFs had an average biofilm forming capacity of up to 36% (18.9%–53.1%), while S. aureus strains from FDFs registered an average of up to 53% (31.5%–77.8%) (p > 0.05). Internalization assays revealed a higher frequency of internalization capacity for strains isolated from FDFs (33.3%) than for those isolated from SIDFs (6.7%) (p > 0.05). fnbpA gen was detected in 46.6% of FDF strains and 33.3% of SIDF strains, and this difference was significant (p < 0.05). Conclusions: Our findings show that the virulence traits of S. aureus isolates analyzed in this study, depend significantly on several factors, such as phenotype, genotype, and environmental conditions, which are significantly related to dairy production system type and daily management practices.

Grafting improves salinity tolerance of bell pepper plants during greenhouse production

Blanca E. Orosco-Alcalá,Héctor G. Núñez-Palenius,Fidel Díaz-Serrano,Luis Pérez-Moreno,Mauricio Valencia-Posadas,Libia I. Trejo-Tellez,Nicacio Cruz-Huerta,Juan I. Valiente-Banuet 한국원예학회 2021 Horticulture, Environment, and Biotechnology Vol.62 No.6

Biotic and abiotic stresses aff ect plant growth and productivity. High-salinity stress aff ects crop yield, causing fi nancialloss to growers. The use of salt-tolerant rootstocks is a strategy that has been used to reduce salt damage in crops. A studywas conducted to evaluate the eff ect of salinity-resistant rootstocks on the physiological and morphological characteristicsof bell pepper plants grown under greenhouse conditions. A factorial experiment was conducted using a completely randomizeddesign with two factors. The bell pepper ‘Viper’ cultivar was grafted on two reported salinity-tolerant rootstocks(E21R10144 and E21R10197), and non-grafted (NG) plants were used as the control. Four salinity levels were applied tothe plants (electrical conductivity treatments using NaCl of 2, 4, 6, and 8 dS m −1 ) in Steiner nutritive solution (100%). Theresponse to salinity was determined using morphological and physiological plant parameters, including fruit yield. Increasedtolerance to salinity conditions (NaCl) was observed in the ‘Viper’ bell pepper grafted on E21R10144, which allowed greaterplant height, stem diameter, leaf size, as well as fresh and dry biomass of both the roots and canopy. The impacts on plantphysiological response, including photosynthesis, stomatal conductance, transpiration, water content, stomatal density, andfoliar area, were also determined. Our results indicate that the use of the salinity-tolerant bell pepper rootstock E21R10144maintained plant homeostasis and minimized the damage caused by salts to the morphology and physiology, as well as eff ectson fruit yield; thus, it is a promising tool for the management of salt stress.