El mayor desafio del mejoramiento genetico animal consiste en lograr identificar lo mas precisame... more El mayor desafio del mejoramiento genetico animal consiste en lograr identificar lo mas precisamente posible los individuos geneticamente superiores, esto es, lograr minimizar la modificacion que introduce el ambiente de manera de lograr la mayor coincidencia entre fenotipo y genotipo. Actualmente es posible con las metodologias modernas incluir en los modelos matematicos los factores ambientales que pueden ser eliminados (sexo, edad, mes o ano de nacimiento) y asi depurar la estimacion de genotipo a partir del fenotipo. Afortunadamente existe suficiente diversidad genetica para diferentes sistemas o regiones. Si se considera la cria en zona templada, con una recria o cierta invernada para el mercado local, la opcion logica pueden ser las razas britanicas tradicionales. Si pensamos en una invernada de exportacion con animales pesados, se puede optar por cruzamientos con razas continentales europeas (Limousin, Charolais, Fleckvieh, etc.) para generar novillos de alta capacidad de cre...
FABP4 is a protein primarily expressed in adipocytes and macrophages that plays a key role in fat... more FABP4 is a protein primarily expressed in adipocytes and macrophages that plays a key role in fatty acid trafficking and lipid hydrolysis. FABP4 gene polymorphisms have been associated with meat quality traits in cattle, mostly in Asian breeds under feedlot conditions. The objectives of this work were to characterize FABP4 genetic variation in several worldwide cattle breeds and evaluate possible genotype effects on fat content in a pasture-fed crossbred (Angus-Hereford-Limousin) population. We re-sequenced 43 unrelated animals from nine cattle breeds (Angus, Brahman, Creole, Hereford, Holstein, Limousin, Nelore, Shorthorn, and Wagyu) and obtained 22 single nucleotide polymorphisms (SNPs) over 3,164 bp, including four novel polymorphisms. Haplotypes and linkage disequilibrium analyses showed a high variability. Five SNPs were selected to perform validation and association studies in our crossbred population. Four SNPs showed well-balanced allele frequencies (minor frequency > 0.159), and three showed no significant deviations from Hardy-Weinberg proportions. SNPs showed significant effects on backfat thickness and fatty acid composition (P < 0.05). The protein structure of one of the missense SNPs was analyzed to elucidate its possible effect on fat content in our studied population. Our results revealed a possible blockage of the fatty acid binding site by the missense mutation.
Resumen Las razas compuestas con participación de cebú han tenido gran difusión por su adaptación... more Resumen Las razas compuestas con participación de cebú han tenido gran difusión por su adaptación y rusticidad. Sin embargo, el cebú tiene desventajas reconocidas en calidad de carne, particularmente terneza. El conocimiento sobre genes que explican diferencias en terneza permite hacer selección asistida por marcadores a favor de este atributo. El objetivo de este trabajo es la evaluación de marcadores en el gen que codifica la subunidad mayor de la enzima micro-calpaína (CAPN1) sobre la terneza de la carne en 193 novillos Brangus, criados sobre pasturas en la zona templada de Argentina. Se estudió la asociación de dos SNP (Single Nucleotide Polymorphisms): CAPN316 (C/G) y CAPN4751 (C/T) con la resistencia al corte de muestras de carne conservadas a 5 °C durante 1, 7 o 14 días. Los SNP se identificaron mediante amplificación con PCR y digestión con enzimas de restricción. La frecuencia de los alelos C fue respectivamente 0,29 en CAPN316 y 0,49 en CAPN4751. El tratamiento de maduraci...
With the objective of determining genetic × environmental interaction for beef production under d... more With the objective of determining genetic × environmental interaction for beef production under direct grazing conditions, measured as both individual average daily gain (ADG) and per ha (PROD), 160 steers were utilized through 2 years, from two breeds of different growth potential, and four stocking rates (SR) tending to establish different nutritional environments. The breeds were Aberdeen Angus (A) and high-grade Limousin crossbred (L) and the SRs established were 2·25, 2·87, 3-50 and 4·13 steers per ha. The pasture where the steers grazed was Festuca arundinacea. Response variables were analysed by least-squares using a fixed model of year, breed, SR and their two-way interactions. There were highly significant effects (P < 0·01) of the interaction of breed × SR for ADG and PROD. Quadratic and linear regressions (P < 0·01) were adjusted for PROD and ADG on SR respectively using the least-squares means. The proportional superiority of L on A at the lowest SR was 0·27, while...
ABSTRACTMilk consumption was estimated for crossbred suckled calves from birth to weaning during ... more ABSTRACTMilk consumption was estimated for crossbred suckled calves from birth to weaning during 2 years. Breed groups utilized were Aberdeen Angus (A) and Charolais (C) sires on Fl Angus-Hereford (and their reciprocals) dams in the 1st year and in the 2nd year, sires A and Nelore (Bos indicus) (N) were used on the same type of dam. The weigh-suckle-weigh technique was employed twice a day to estimate milk consumption on a weekly basis. Estimations were adjusted by least-squares for the effects of genetic group, week of estimation, and their interaction, with sex of calf and calf and cow weights in the week of estimation as covariables. Then a non-lineal regression equation of the form: y = b0Wb1e -b2b2W was fitted for each individual, where y = milk consumption and W = week of estimation. Curves for A and C were very close in their shape, but with a greater consumption (P< 0·01) for C. For the 2nd year, there were differences among A and N both in the shape of the curve and in c...
Brody, Gompertz, Logistic, Richards and von Bertalanffy functions were compared as descriptors of... more Brody, Gompertz, Logistic, Richards and von Bertalanffy functions were compared as descriptors of growth in 319 coypus (Myocastor coypus) of Greenland and Silver varieties, from birth to 10–19 months of age. Several criteria were considered for the selection of the model: (a) bias in the asymptotic weight; (b) bias in birth weight; (c) error sum of squares; (d) error mean squares weighted by the number of animals converging in all functions; (e) determination coefficient. To adjust the curves NLIN procedure from SAS and iterative method of Marquardt were applied. A mixed model was used to analyse the parameters of the selected growth curve (asymptotic weight, A; constant of integration, B; and maturation rate, k) which included effects of farm, variety, sex, sire within farm and variety, reproductive status within sex, birth season and first order interactions. The effect of sire was considered as random. The von Bertalanffy function was selected and mean values for the parameters o...
The PPARGC1A gene (peroxysome proliferator-activated receptor-gamma coactivator 1alpha gene) cont... more The PPARGC1A gene (peroxysome proliferator-activated receptor-gamma coactivator 1alpha gene) controls muscle fiber type and brown adipocyte differentiation; therefore, it is a candidate gene for beef quality traits (tenderness and fat content). Two SNPs (Single Nucleotide Polymorphisms) were identified within exon 8 by multiple alignment of DNA sequences obtained from 24 bulls: a transition G/A (SNP 1181) and a transversion A/T (SNP 1299). The SNP 1181 is a novel SNP, corresponding to a non-conservative substitution (AGT/AAT) that could be the cause of amino acid substitution ((364)Serine/(364)Asparagine). A Mismatch PCR method was designed to determine genotypes of 73 bulls and 268 steers for SNP 1181. Growth, slaughter and meat quality information were available for the group of steers. Allele A of SNP 1181 was not found in Angus. In 243 steers, no significant differences (P &gt; 0.05) were found for either final live body weight, gain in backfat thickness in Spring, kidney fat weight, kidney fat percentage, Warner-Bratzler shear force at 7 days postmortem, intramuscular fat percentage or meat colour between genotype GG and AG. This SNP could be included in breed composition and population admixture analyses because there are marked differences in allelic frequencies between Bos taurus and Bos indicus breeds.
Brangus steers (n=247) finished on pasture were used to evaluate the effects of post-mortem agein... more Brangus steers (n=247) finished on pasture were used to evaluate the effects of post-mortem ageing and polymorphism CAPN1 316 and CAPN1 4751 markers on meat tenderness and objective colour measurements (CIEL*a*b*) of m. Longissimus dorsi. Ageing meat for 7 days decreased shear force (SF) by 13.7% and improved a* (8.4%) and b* (10%) compared to ageing for 1 day. No difference between 7 and 14 days of ageing was found for SF, a* and b*. However, L* increased markedly with ageing. Fitting both markers simultaneously, CAPN1 316 showed association with SF and L* and CAPN1 4751 with a* and b*. Fitting the markers individually, CAPN1 4751 affected all traits and CAPN1 316 showed association with SF and L*. Post-mortem ageing and the use of markers represent two independent and alternative tools that could be used for improving quality of meat from Brangus cattle.
With the objective of studying the response patterns of two biotypes of different body (structura... more With the objective of studying the response patterns of two biotypes of different body (structural) size to stocking rate (SR) in terms of individual growth rate (ADG), meat production per ha (PROD) and backfat thickness (BFT) under grazing conditions, 64 steers of two biotypes of the Angus breed of different body size were used: small-sized (SB: frame score of 1·3 (s.d. 0·7)) and medium-sized (MB: 2·9 (s.d. 0·6)). Four levels of SR were applied (1·8, 2·3, 2·8 and 3·3 steers per ha). The experiment lasted 241 days (April to December). Animals were weighed every 14 days, forage availability (FA) was estimated on four occasions and BFT was recorded at the end of the experiment (between 12th and 13th ribs). There were no differences between biotypes in ADG. SB tended to be earlier maturing showing higher BFT (4·39v.3·97 mm; P = 0·22). ADG was affected by SR and was higher at lower SR (0·612, 0·529, 0·414 and 0·375 kg/day, for 1·8, 2·3, 2·8 and 3·3 steers per ha, respectively). Individu...
Reproductive performance of purebred Angus (A) and Criollo (C) cows and crossbred CA and AC cows ... more Reproductive performance of purebred Angus (A) and Criollo (C) cows and crossbred CA and AC cows in the temperate area of Buenos Aires, Argentina, was assessed through the study of reproductive rates, calving date, first insemination date, number of inseminations and weight related variables. The herd was grazed on pastures all year round. Matings were by artificial insemination with visual oestrus detection, from October to December. Heifers first calving was at 3 years of age. All traits were analysed with general linear models including, as corresponded, fixed effects of dam and calf genetic groups, calving year and month, dam physiological status, calving age and first order interactions. Female genetic group adjusted means were used to estimate direct (gl) and maternal (gM) breed differences and heterosis (hl) effects on reproductive traits. Weaning rate was mostly determined by oestrons detection rate. Due to the inhibitory effects of nursing on reproduction, female genetic gr...
El mayor desafio del mejoramiento genetico animal consiste en lograr identificar lo mas precisame... more El mayor desafio del mejoramiento genetico animal consiste en lograr identificar lo mas precisamente posible los individuos geneticamente superiores, esto es, lograr minimizar la modificacion que introduce el ambiente de manera de lograr la mayor coincidencia entre fenotipo y genotipo. Actualmente es posible con las metodologias modernas incluir en los modelos matematicos los factores ambientales que pueden ser eliminados (sexo, edad, mes o ano de nacimiento) y asi depurar la estimacion de genotipo a partir del fenotipo. Afortunadamente existe suficiente diversidad genetica para diferentes sistemas o regiones. Si se considera la cria en zona templada, con una recria o cierta invernada para el mercado local, la opcion logica pueden ser las razas britanicas tradicionales. Si pensamos en una invernada de exportacion con animales pesados, se puede optar por cruzamientos con razas continentales europeas (Limousin, Charolais, Fleckvieh, etc.) para generar novillos de alta capacidad de cre...
FABP4 is a protein primarily expressed in adipocytes and macrophages that plays a key role in fat... more FABP4 is a protein primarily expressed in adipocytes and macrophages that plays a key role in fatty acid trafficking and lipid hydrolysis. FABP4 gene polymorphisms have been associated with meat quality traits in cattle, mostly in Asian breeds under feedlot conditions. The objectives of this work were to characterize FABP4 genetic variation in several worldwide cattle breeds and evaluate possible genotype effects on fat content in a pasture-fed crossbred (Angus-Hereford-Limousin) population. We re-sequenced 43 unrelated animals from nine cattle breeds (Angus, Brahman, Creole, Hereford, Holstein, Limousin, Nelore, Shorthorn, and Wagyu) and obtained 22 single nucleotide polymorphisms (SNPs) over 3,164 bp, including four novel polymorphisms. Haplotypes and linkage disequilibrium analyses showed a high variability. Five SNPs were selected to perform validation and association studies in our crossbred population. Four SNPs showed well-balanced allele frequencies (minor frequency &amp;amp;amp;amp;amp;amp;gt; 0.159), and three showed no significant deviations from Hardy-Weinberg proportions. SNPs showed significant effects on backfat thickness and fatty acid composition (P &amp;amp;amp;amp;amp;amp;lt; 0.05). The protein structure of one of the missense SNPs was analyzed to elucidate its possible effect on fat content in our studied population. Our results revealed a possible blockage of the fatty acid binding site by the missense mutation.
Resumen Las razas compuestas con participación de cebú han tenido gran difusión por su adaptación... more Resumen Las razas compuestas con participación de cebú han tenido gran difusión por su adaptación y rusticidad. Sin embargo, el cebú tiene desventajas reconocidas en calidad de carne, particularmente terneza. El conocimiento sobre genes que explican diferencias en terneza permite hacer selección asistida por marcadores a favor de este atributo. El objetivo de este trabajo es la evaluación de marcadores en el gen que codifica la subunidad mayor de la enzima micro-calpaína (CAPN1) sobre la terneza de la carne en 193 novillos Brangus, criados sobre pasturas en la zona templada de Argentina. Se estudió la asociación de dos SNP (Single Nucleotide Polymorphisms): CAPN316 (C/G) y CAPN4751 (C/T) con la resistencia al corte de muestras de carne conservadas a 5 °C durante 1, 7 o 14 días. Los SNP se identificaron mediante amplificación con PCR y digestión con enzimas de restricción. La frecuencia de los alelos C fue respectivamente 0,29 en CAPN316 y 0,49 en CAPN4751. El tratamiento de maduraci...
With the objective of determining genetic × environmental interaction for beef production under d... more With the objective of determining genetic × environmental interaction for beef production under direct grazing conditions, measured as both individual average daily gain (ADG) and per ha (PROD), 160 steers were utilized through 2 years, from two breeds of different growth potential, and four stocking rates (SR) tending to establish different nutritional environments. The breeds were Aberdeen Angus (A) and high-grade Limousin crossbred (L) and the SRs established were 2·25, 2·87, 3-50 and 4·13 steers per ha. The pasture where the steers grazed was Festuca arundinacea. Response variables were analysed by least-squares using a fixed model of year, breed, SR and their two-way interactions. There were highly significant effects (P < 0·01) of the interaction of breed × SR for ADG and PROD. Quadratic and linear regressions (P < 0·01) were adjusted for PROD and ADG on SR respectively using the least-squares means. The proportional superiority of L on A at the lowest SR was 0·27, while...
ABSTRACTMilk consumption was estimated for crossbred suckled calves from birth to weaning during ... more ABSTRACTMilk consumption was estimated for crossbred suckled calves from birth to weaning during 2 years. Breed groups utilized were Aberdeen Angus (A) and Charolais (C) sires on Fl Angus-Hereford (and their reciprocals) dams in the 1st year and in the 2nd year, sires A and Nelore (Bos indicus) (N) were used on the same type of dam. The weigh-suckle-weigh technique was employed twice a day to estimate milk consumption on a weekly basis. Estimations were adjusted by least-squares for the effects of genetic group, week of estimation, and their interaction, with sex of calf and calf and cow weights in the week of estimation as covariables. Then a non-lineal regression equation of the form: y = b0Wb1e -b2b2W was fitted for each individual, where y = milk consumption and W = week of estimation. Curves for A and C were very close in their shape, but with a greater consumption (P< 0·01) for C. For the 2nd year, there were differences among A and N both in the shape of the curve and in c...
Brody, Gompertz, Logistic, Richards and von Bertalanffy functions were compared as descriptors of... more Brody, Gompertz, Logistic, Richards and von Bertalanffy functions were compared as descriptors of growth in 319 coypus (Myocastor coypus) of Greenland and Silver varieties, from birth to 10–19 months of age. Several criteria were considered for the selection of the model: (a) bias in the asymptotic weight; (b) bias in birth weight; (c) error sum of squares; (d) error mean squares weighted by the number of animals converging in all functions; (e) determination coefficient. To adjust the curves NLIN procedure from SAS and iterative method of Marquardt were applied. A mixed model was used to analyse the parameters of the selected growth curve (asymptotic weight, A; constant of integration, B; and maturation rate, k) which included effects of farm, variety, sex, sire within farm and variety, reproductive status within sex, birth season and first order interactions. The effect of sire was considered as random. The von Bertalanffy function was selected and mean values for the parameters o...
The PPARGC1A gene (peroxysome proliferator-activated receptor-gamma coactivator 1alpha gene) cont... more The PPARGC1A gene (peroxysome proliferator-activated receptor-gamma coactivator 1alpha gene) controls muscle fiber type and brown adipocyte differentiation; therefore, it is a candidate gene for beef quality traits (tenderness and fat content). Two SNPs (Single Nucleotide Polymorphisms) were identified within exon 8 by multiple alignment of DNA sequences obtained from 24 bulls: a transition G/A (SNP 1181) and a transversion A/T (SNP 1299). The SNP 1181 is a novel SNP, corresponding to a non-conservative substitution (AGT/AAT) that could be the cause of amino acid substitution ((364)Serine/(364)Asparagine). A Mismatch PCR method was designed to determine genotypes of 73 bulls and 268 steers for SNP 1181. Growth, slaughter and meat quality information were available for the group of steers. Allele A of SNP 1181 was not found in Angus. In 243 steers, no significant differences (P &gt; 0.05) were found for either final live body weight, gain in backfat thickness in Spring, kidney fat weight, kidney fat percentage, Warner-Bratzler shear force at 7 days postmortem, intramuscular fat percentage or meat colour between genotype GG and AG. This SNP could be included in breed composition and population admixture analyses because there are marked differences in allelic frequencies between Bos taurus and Bos indicus breeds.
Brangus steers (n=247) finished on pasture were used to evaluate the effects of post-mortem agein... more Brangus steers (n=247) finished on pasture were used to evaluate the effects of post-mortem ageing and polymorphism CAPN1 316 and CAPN1 4751 markers on meat tenderness and objective colour measurements (CIEL*a*b*) of m. Longissimus dorsi. Ageing meat for 7 days decreased shear force (SF) by 13.7% and improved a* (8.4%) and b* (10%) compared to ageing for 1 day. No difference between 7 and 14 days of ageing was found for SF, a* and b*. However, L* increased markedly with ageing. Fitting both markers simultaneously, CAPN1 316 showed association with SF and L* and CAPN1 4751 with a* and b*. Fitting the markers individually, CAPN1 4751 affected all traits and CAPN1 316 showed association with SF and L*. Post-mortem ageing and the use of markers represent two independent and alternative tools that could be used for improving quality of meat from Brangus cattle.
With the objective of studying the response patterns of two biotypes of different body (structura... more With the objective of studying the response patterns of two biotypes of different body (structural) size to stocking rate (SR) in terms of individual growth rate (ADG), meat production per ha (PROD) and backfat thickness (BFT) under grazing conditions, 64 steers of two biotypes of the Angus breed of different body size were used: small-sized (SB: frame score of 1·3 (s.d. 0·7)) and medium-sized (MB: 2·9 (s.d. 0·6)). Four levels of SR were applied (1·8, 2·3, 2·8 and 3·3 steers per ha). The experiment lasted 241 days (April to December). Animals were weighed every 14 days, forage availability (FA) was estimated on four occasions and BFT was recorded at the end of the experiment (between 12th and 13th ribs). There were no differences between biotypes in ADG. SB tended to be earlier maturing showing higher BFT (4·39v.3·97 mm; P = 0·22). ADG was affected by SR and was higher at lower SR (0·612, 0·529, 0·414 and 0·375 kg/day, for 1·8, 2·3, 2·8 and 3·3 steers per ha, respectively). Individu...
Reproductive performance of purebred Angus (A) and Criollo (C) cows and crossbred CA and AC cows ... more Reproductive performance of purebred Angus (A) and Criollo (C) cows and crossbred CA and AC cows in the temperate area of Buenos Aires, Argentina, was assessed through the study of reproductive rates, calving date, first insemination date, number of inseminations and weight related variables. The herd was grazed on pastures all year round. Matings were by artificial insemination with visual oestrus detection, from October to December. Heifers first calving was at 3 years of age. All traits were analysed with general linear models including, as corresponded, fixed effects of dam and calf genetic groups, calving year and month, dam physiological status, calving age and first order interactions. Female genetic group adjusted means were used to estimate direct (gl) and maternal (gM) breed differences and heterosis (hl) effects on reproductive traits. Weaning rate was mostly determined by oestrons detection rate. Due to the inhibitory effects of nursing on reproduction, female genetic gr...
Uploads
Papers by Carlos Mezzadra