Effect of Consuming Beef with Varying Fatty Acid Compositions as a Major Source of Protein in Volunteers under a Personalized Nutritional Program

Beef is an excellent source of nutrients; unfortunately, most nutritional recommendations suggest limiting or even avoiding it. Studies have shown that the fatty acid composition of meat influences weight loss. This randomized controlled clinical trial evaluated the anthropometric and serum lipid changes after a food intervention that included frequent beef consumption (120 g consumed four days/week for four weeks). Volunteers were randomly assigned to the commercial or Wagyu-Cross beef groups, with the latter beef possessing higher fat and MUFA contents. Both groups exhibited reductions in body measurements and lipid profiles; however, the Wagyu-Cross group exhibited greater changes in weight (−3.75 vs. −2.90 kg) and BMI (−1.49 vs. −1.03) than the commercial group, without a significant difference between them. No significant group differences in lipid profiles were observed; however, the Wagyu-Cross group exhibited a more favorable change in decreasing the TC concentration (−7.00 mg/dL) and LDL-C concentration (−12.5 mg/dL). We suggest that high MUFA beef could be included in weight-loss programs since it does not affect weight loss and hasn’t a negative influence on lipid metabolism.

Improvement of serum lipid parameters in consumers of Mexican Wagyu-Cross beef: A randomized controlled trial

Beef is considered an excellent source of high-quality protein and micronutrients. The high saturated fatty acid (SFA) composition of beef has been associated with cardiovascular diseases; however, this is a controversial issue because at present, no evidence has scientifically proven such an association. Wagyu cattle have been used as an option to generate high-quality fatty acids (FAs) in beef and have been crossed with local beef cattle (Wagyu-Cross). In Mexico, Wagyu-Cross is marketed assuming the same quality as purebred Wagyu meat without scientific support. This study aimed to determine whether the differences in the FA composition of Wagyu-Cross and commercial beef affected lipid metabolism in frequent consumers of beef. The study is a randomized, controlled, double-blinded phase IV clinical trial. Thirty-four volunteers completed treatments in which 120 g ground beef was consumed 3 days per week for 2 weeks. Volunteers were randomized to the "A" (commercial meat) or "B" (Wagyu-Cross meat) groups. The beef fat content was 87% higher, the SFA content was 2.3% lower, and the monounsaturated fatty acid (MUFA) C18:1 n-9 concentrations were higher in Wagyu-Cross beef than in commercial beef. The B group exhibited a significantly larger change from baseline in the serum lipid profile in total cholesterol (TC) (-4.7% versus +6.9%), low-density lipoprotein (LDL) (-4.1% versus +10.0%), nonhigh-density lipoprotein (non-HDL) (-6.1% versus +4.9%), and the ratio of three atherogenic indexes-TC/HDL (-3.5% versus +6.4%), LDL/HDL (-2.8% versus +14.6%), and non-HDL/HDL (-4.7% versus +9.3%)-than the A group. This result confirms that meat FA composition is a key point for redirecting cattle breeding strategies and promotes beef as a healthful protein source. PRACTICAL APPLICATION: Here, we found new evidence based on a clinical trial that beef with a favorable fatty acid composition (i.e., monounsaturated fatty acid and polyunsaturated fatty acid content) is a key factor in improving parameters associated with consumer health. This information will support the design of cattle breeding strategies as an option to promote beef consumption as a healthier protein source and create opportunities for the development of the functional food industry.

Accuracies of direct genomic breeding values for birth and weaning weights of registered Charolais cattle in Mexico

Context Genomic prediction is now routinely used in many livestock species to rank individuals based on genomic breeding values (GEBV). Aims This study reports the first assessment aimed to evaluate the accuracy of direct GEBV for birth (BW) and weaning (WW) weights of registered Charolais cattle in Mexico. Methods The population assessed included 823 animals genotyped with an array of 77000 single nucleotide polymorphisms. Genomic prediction used genomic best linear unbiased prediction (GBLUP), Bayes C (BC), and single-step Bayesian regression (SSBR) methods in comparison with a pedigree-based BLUP method. Key results Our results show that the genomic prediction methods provided low and similar accuracies to BLUP. The prediction accuracy of GBLUP and BC were identical at 0.31 for BW and 0.29 for WW, similar to BLUP. Prediction accuracies of SSBR for BW and WW were up to 4% higher than those by BLUP. Conclusions Genomic prediction is feasible under current conditions, and provides a slight improvement using SSBR. Implications Some limitations on reference population size and structure were identified and need to be addressed to obtain more accurate predictions in liveweight traits under the prevalent cattle breeding conditions of Mexico.

303 Identification of candidate genes related to temperament in Brahman cattle

The objective of this study was to identify genomic regions and genes associated with beef cattle temperament. Temperament, measured as exit velocity (EV; m/s), was recorded in 1,370 Brahman cattle from Texas A&M AgriLife Research at Overton, TX. We identified two groups of temperament-contrasting animals. Cows were calm if their EV of 0.16–3.41 m/s and bulls if their EV was 0.4–3.12 m/s (n-119). Cows were temperamental if their EV was 3.55–7.66 m/s and bulls if their EV was 3.13–10.83 m/s (n = 79). The 198 animals were genotyped using the GGP-HD-150K chip. 139,376 SNPs were evaluated for association with temperament. 13 SNP′s were associated with EV (P < 4.0E-05). The SNPs GABRG2-26484, NRXN3-26436 and TBX20-191081 are located in introns of the GABRG2, NRXN3 and TBX20 genes, respectively. The GABRG2 gene encodes a GABA receptor, the major inhibitory neurotransmitter in the mammalian brain. The NRXN3 gene encodes receptor proteins related to chemical transmission at synapses. TBX20 is a member of the T-box transcription factor family expressed in the developing stages of heart, limbs, eye and ventral neural tube. To test the effect of these 3 SNP′s on EV, Pen-Score and Temperament-Score, a general linear model was fitted including the fixed effects of sex of calf and year of birth, and the individual effect of the 3 SNPs. The marker TBX20-191081 was associated with the three traits evaluated (P < 0.01), where the GG genotype was associated with the calmest temperament. The GG genotype had a significant effect on EV (P < 0.0001) that was 1.35 and 1.95 m/s slower than AG and AA, respectively. For TS, the GG genotype had a TS that was 1.41 and 1.24 DS less than those of the AA and GA genotypes. Our study indicates that genetic control of cattle temperament has a wide network of genes with divergent functions and genetic background specificity.

Influence of genetic markers on the feeding behavior of yearling bulls

Background: The search for gene and marker effects on economically important traits is aimed not only to understanding the genetic architecture of complex traits but also to applying the information to breeding schemes. Objective: To analyze the effect of two temperament-related SNPs (rs109576799 located in the DRD3 gene, and rs43696138 in the HTR2A gene) on feeding performance of Mexican beef cattle. Methods: One hundred and thirty-six young beef bulls were included in a centralized feed efficiency performance test based on residual feed intake (RFI), with 20 d for adaptation and 70 d of feed efficiency testing. In addition to feeding traits, temperament was assessed at the beginning of the trial using pen score (PS) and exit velocity (EV). All animals were genotyped with two markers located in the HTR2A and DRD3 genes, and an association analysis was conducted between these genotypes and the measured traits. Results: For Brangus breed, a significant association was obtained between average daily gain (ADG; p=0.019), and the rs43696138 marker, resulting in higher gains for homozygous genotype GG (1.69 ± 0.04 kg), when compared to the heterozygous genotype GA (1.54 ± 0.04 kg). Conclusion: The previously reported association of these markers with temperament was not confirmed in the evaluated breeds; however, the rs43696138 marker showed an effect on a feeding performance trait. Further studies are needed to determine the effect of this and other markers on both RFI and temperament.Keywords: beef cattle, feed efficiency, residual feed intake, single nucleotide polymorphism, temperament.  Resumen Antecedentes: La búsqueda de efectos genéticos y marcadores de rasgos económicamente relevantes no solo se basa en el interés biológico de comprender la arquitectura genética de rasgos complejos, sino también en aplicar la información en los esquemas prácticos de mejoramiento. Objetivo: Analizar el efecto de dos SNPs relacionados con el temperamento (rs109576799 localizado en el gen DRD3, y rs43696138 localizado en el gen HTR2A) sobre la eficiencia alimenticia en el ganado bovino mexicano. Métodos: Ciento treinta y seis toretes de carne jóvenes fueron sometidos a una prueba de comportamiento alimenticio basada en el consumo residual de alimento (RFI), con 20 d de adaptación y 70 d de prueba para la eficiencia alimenticia. Además de los rasgos de comportamiento alimenticio, se evaluó el temperamento de los animales al inicio de la prueba, mediante la evaluación de comportamiento en el corral (PS), y la velocidad de salida (EV). Todas las muestras se tipificaron con dos marcadores localizados en los genes DRD3 y HTR2A para posteriormente realizar un análisis de asociación de los genotipos con los rasgos evaluados. Resultados: En la raza Brangus, se observó una asociación significativa de la media de ganancia diaria de peso (ADG, p=0,019) con el marcador rs43696138, localizado en el gen HTR2A, resultando en mayores ganancias para el genotipo GG (1,69 ± 0,04 kg) en comparación con los toros heterocigóticos GA (1,54 ± 0,04 kg). Conclusión: No se confirmó la asociación de estos marcadores previamente reportados con el temperamento en las razas evaluadas; sin embargo, el marcador rs43696138 mostró efecto en un rasgo de comportamiento alimenticio. Se necesitan más estudios para determinar el efecto de éste y otros marcadores en el consumo residual de alimento (RFI) y el temperamento.Palabras clave: consumo residual de alimento, eficiencia alimenticia, ganado de carne, polimorfismo de un solo nucleótido, temperamento.  Resumo Antecedentes: A busca de efeitos genéticos e marcadores de características economicamente relevantes não se baseia apenas no interesse biológico de compreender a arquitetura genética de traços complexos, mas também na aplicação da informação nos esquemas práticos de melhoria. Objetivo: Analisar o efeito de dois SNPs relacionados ao temperamento (rs109576799 localizado no gene DRD3 e rs43696138 localizado no gene HTR2A) sobre a eficiência nutricional no gado mexicano. Métodos: Cento e trinta e seis touros jovens foram submetidos a um teste de comportamento alimentar com base na entrada de alimentação residual (RFI), com 20 d de adaptação e 70 d de teste para eficiência de alimentação. Além dos traços de comportamento alimentar, o temperamento dos animais foi avaliado no início do teste, através da avaliação do comportamento na caneta (PS) e da velocidade de saída (EV). Todas as amostras foram digitadas com dois marcadores localizados nos genes DRD3 e HTR2A para posteriormente realizar uma análise de associação dos genótipos com os traços avaliados. Resultados: Na raça Brangus, observou-se uma associação significativa do ganho diário médio (ADG, p = 0,019) com o marcador rs43696138, localizado no gene HTR2A, resultando em maiores ganhos para o genótipo GG (1,69 ± 0,04 kg), em comparação com os touros heterozigóticos GA (1,54 ± 0,04 kg). Conclusão: A associação destes marcadores previamente relatados com o temperamento nas raças avaliadas não foi confirmada; no entanto, o marcador rs43696138 mostrou um efeito sobre uma característica de comportamento alimentar. Mais estudos são necessários para determinar o efeito deste e outros marcadores com ingestão alimentar residual (RFI) e temperamento.Palavras-chave: consumo residual de alimentos, eficiência alimentar, gado bovino, polimorfismo de nucleotídeo único, temperamento.

Genetic trends for live weight traits reflect breeding strategies in registered Charolais Farms in Mexico

Genetic trends are commonly used to verify genetic improvement; however, there are few reports on beef cattle in Mexico. Data from 1998 to 2013 from four Charolais bull breeding farms were examined to verify the genetic responses to different breeding management and selection criteria. Analysis included the comparison of regression lines of breeding values for birth (BW), weaning (WW) and yearling weights (YW), and maternal weaning weight (MWW) on the year of birth of the animals. Results revealed differential genetic progress for BW and YW and indicated that the overall analysis may have diluted the perception of genetic progress from the farmer's point of view. The use of breeding values as a tool for selection is effective to achieve genetic progress, even in negatively correlated traits, such as birth weight and yearling weight.

Association of polymorphisms in growth hormone and leptin candidate genes with live weight traits of Brahman cattle

Polymorphisms in candidate genes can produce significant and favorable changes in the phenotype, and therefore are useful for the identification of the best combination of favorable variants for marker-assisted selection. In the present study, an assessment to evaluate the effect of 11 single nucleotide polymorphisms (SNPs) in candidate genes on live weight traits of registered Brahman cattle was performed. Data from purebred bulls were used in this assessment. The dataset included birth (BW), weaning (WW), and yearling (YW) weights. A panel of 11 SNP markers, selected by their formerly reported or apparent direct and indirect association with live weight traits, was included in an assessment previously confirming their minimum allele frequency (<0.05). Live weights were adjusted BW (aBW), WW (aWW), and YW (aYW) using a generalized linear model, which included the fixed effects of herd and season of birth and the random effect of the sire and year of birth. An SNP in a growth hormone gene (GH4.1) was significantly related to aWW (P = 0.035) with an estimate substitution effect of 3.97 kg (P = 0.0210). In addition, a leptin SNP (LEPg.978) was significantly associated with aYW (P = 0.003) with an estimate substitution effect of 9.57 kg (P = 0.0007). The results suggest that markers GH4.1 and LEPg.978 can be considered as candidate loci for assisted genetic improvement programs in Mexican Brahman cattle.

Bovine dopamine receptors DRD1, DRD4, and DRD5: genetic polymorphisms and diversities among ten cattle breeds

The aim of this study was to analyze the allelic frequency distribution and segregation among breeds and/or between different cattle genetic groups of four novel single nucleotide polymorphisms of the bovine DRD1 and DRD5 genes and one reported SNP from the DRD4 gene. One hundred and nine-animals from ten different cattle breeds were genotyped and allelic frequencies for each locus were estimated. There were significant differences in the allelic frequencies (P < 0.05) among breeds for the DRD1 and DRD5 markers. The allelic frequencies for markers DRD1-825A>G and DRD5-378C>T were also significantly different between groups differing in genetic background. Because differences in temperament have been reported between Bos taurus taurus and B. taurus indicus breeds and their crosses, further studies are needed to investigate if any association exists between described markers and cattle behavior traits.

Complex microsatellite dynamics in the myostatin gene within ruminants

A microsatellite has previously been identified in myostatin in cattle. Sequencing of this region from other artiodactyls coupled with phylogenetic analysis has been used to uncover the potential origins of the microsatellite event, which appears either to have been born twice or to have been gained and lost within ruminants. While caprids and ovids share the ancestral state with pigs and other mammals, microsatellite activity (length polymorphism) is uncovered in both deer and bovids. The dynamic process of microsatellite evolution, including birth, is discussed here in light of several models. Finally, these models are evaluated in the context of patterns of microsatellite conservation between closely related mammalian genomes.

Microsatellite polymorphism in intron 1 of the bovine myostatin gene

Microsatellites within genes have become important because of their association with genetic diseases in humans. A novel microsatellite was identified in the first intron of the bovine myostatin gene. It is characterized by a mononucleotide core motif that exhibits polymorphic sequence variants (from 12 to 21 repeats) within and between some bovine breeds. Structural analysis of the microsatellite region in bovines as well as in closely related species permitted to trace the possible mechanisms for its structural evolution across the order Artiodactyla.

Antibody detection tests for Onchocerca volvulus: comparison of the sensitivity of a cocktail of recombinant antigens used in the indirect enzyme-linked immunosorbent assay with a rapid-format antibody card test

There is a need for a specific, sensitive, and practical diagnostic test to monitor onchocerciasis elimination campaigns. In April 2001, an enzyme-linked immunosorbent assay (ELISA) using 3 recombinant antigens and a rapid-format antibody card test (immunochromatographic test; ICT) using an individual antigen were compared in a Mexican population with onchocerciasis. The sensitivity of the ELISA and ICT was 97% and 86%, respectively.

Detection and differentiation of the six Brucella species by polymerase chain reaction

BACKGROUND

Brucelosis is a severe acute febrile disease caused by bacteria of the genus Brucella. Its current diagnosis is based on clinical observations that may be complemented by serology and microbiological culture tests; however, the former is limited in sensitivity and specificity, the latter is time consuming. To improve brucelosis diagnosis we developed a test which is specific and sensitive and is capable of differentiating the six species of Brucella.

MATERIALS AND METHODS

Four primers were designed from B. abortus sequences at the well-conserved Omp2 locus that are able to amplify the DNAs of all six species of Brucella.

RESULTS

Our test detected all six species of Brucella. Their differentiation resulted directly from differences in the amplification patterns or was achieved indirectly using a RFLP present in one of the PCR products. The sensitivity and specificity of the new test were then determined; it was applied successfully in confirming the diagnosis of a patient whose clinical history and serology indicated infection with Brucella.

CONCLUSIONS

The results make possible the use of a PCR test for Brucella detection and differentiation without relying on the measurement of the antibodies or microorganism culture. Our first results showed that the PCR test can confirm the presence of Brucella in blood samples of infected patients.