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1.
Animal ; 15(8): 100302, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34245953

RESUMO

Male reproductive performances are often ignored in cattle breeding programmes, although semen traits might be used to improve bull breeding soundness. Effects of genetic and environmental factors on semen production and quality traits were estimated in 693 Piemontese bulls with the aim of providing the first estimates of genetic parameters for semen traits for this breed. Volume and concentrations of individual ejaculates (up to three per each test-day), and volume, concentration, total number of spermatozoa and post-thawing progressive motility of within test-day pooled semen were available for 19 060 ejaculates. Bulls reached the maximum amount of daily semen production after their third year of age, with concentration rapidly increasing until 23 months of age, and then slowly decreasing. Semen volume was at its highest when collection days were at least 15 days apart, whereas the maximum concentration was reached when the interval was 6 days. Heritability estimates were generally moderate (0.14-0.26), and low for progressive motility (0.08). Estimates of genetic correlation among the volumes of the individual ejaculates were high and positive (≥0.79), as were the genetic correlations among their concentrations (≥0.46). Genetic correlations among volume and concentration traits varied from -0.47 (with a 95% high posterior density interval ranging from -0.65 to -0.23) to -0.32 (with a 95% high posterior density interval ranging from -0.55 to -0.09). Progressive motility was unrelated with the other traits, but moderately positively correlated with volumes of the second and third ejaculates. The magnitude of heritabilities showed that selection for semen traits is possible. However, the unfavourable relationship between volume and concentration must be taken into account if a future selection programme is to be established.


Assuntos
Sêmen , Motilidade dos Espermatozoides , Animais , Bovinos/genética , Masculino , Fenótipo , Análise do Sêmen/veterinária , Contagem de Espermatozoides/veterinária , Motilidade dos Espermatozoides/genética , Espermatozoides
3.
Animal ; 14(2): 243-252, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31414654

RESUMO

A key concern in beef production is how to improve carcass and meat quality traits. Identifying the genomic regions and biological pathways that contribute to explaining variability in these traits is of great importance for selection purposes. In this study, genome wide-association (GWAS) and pathway-based analyses of carcass traits (age at slaughter (AS), carcass weight (CW), carcass daily gain (CDG), conformation score and rib-eye muscle area) and meat quality traits (pH, Warner-Bratzler shear force, purge loss, cooking loss and colour parameters (lightness, redness, yellowness, chroma, hue)) were conducted using genotype data from the 'GeneSeek Genomic Profiler Bovine LD' array in a cohort of 1166 double-muscled Piemontese beef cattle. The genome wide-association analysis was based on the GRAMMAR-GC approach and identified 37 significant single nucleotide polymorphisms (SNPs), which were associated with 12 traits (P<5 × 10-5). In particular, 14 SNPs associated with CW, CDG and AS were located at 38.57 to 38.94 Mb on Bos taurus autosome 6 and mapped within four genes, that is, Leucine Aminopeptidase 3, Family with Sequence Similarity 184 Member B, Non-SMC Condensin I Complex Subunit G and Ligand-Dependent Nuclear Receptor Corepressor-Like. Strong pairwise linkage disequilibrium was found in this region. For meat quality traits, most associations were 1 SNP per trait, except for a signal on BTA25 (at ~11.96 Mb), which was significant for four of the five meat colour parameters assessed. Gene-set enrichment analyses yielded significant results for six traits (right-sided hypergeometric test, false discovery rate <0.05). In particular, several pathways related to transmembrane transport (i.e., oxygen, calcium, ion and cation) were overrepresented for meat colour parameters. The results obtained provide useful information for genomic selection for beef production and quality in the Piemontese breed.


Assuntos
Bovinos/genética , Estudo de Associação Genômica Ampla , Genoma/genética , Polimorfismo de Nucleotídeo Único/genética , Carne Vermelha/normas , Animais , Cruzamento , Bovinos/fisiologia , Mapeamento Cromossômico , Cor , Genômica , Genótipo , Desequilíbrio de Ligação , Masculino , Fenótipo , Carne Vermelha/análise
6.
J Laryngol Otol ; 133(4): 300-308, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30967159

RESUMO

OBJECTIVE: There is a growing interest in sodium hyaluronate for the clinical management of patients who undergo functional endoscopic sinus surgery for chronic rhinosinusitis, because of the mucosal regenerative properties of this macromolecule. However, its role in post-operative care is still debated. This study aimed to evaluate the effect of sodium hyaluronate administered via nasal irrigation with saline, in the post-operative period, after functional endoscopic sinus surgery. METHODS: A multicentric, prospective, randomised, double-blind, parallel group study was conducted on 56 consecutive patients who underwent functional endoscopic sinus surgery for chronic rhinosinusitis without polyps. Group 1 received the standard therapy of normal saline; group 2 received saline plus sodium hyaluronate. RESULTS: Both objective and subjective measurements, in terms of endoscopic appearance and patient-reported satisfaction, were significantly better in group 2 compared to group 1. CONCLUSION: Sodium hyaluronate may be a useful adjunct to nasal saline irrigation in the early post-operative period following functional endoscopic sinus surgery.


Assuntos
Ácido Hialurônico/administração & dosagem , Lavagem Nasal/métodos , Rinite/cirurgia , Sinusite/cirurgia , Administração Intranasal , Adolescente , Adulto , Idoso , Criança , Método Duplo-Cego , Endoscopia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente/estatística & dados numéricos , Cuidados Pós-Operatórios , Estudos Prospectivos , Adulto Jovem
7.
Acta Otorhinolaryngol Ital ; 38(2): 145-150, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29967559

RESUMO

SUMMARY: Benign paroxysmal positional vertigo (BPPV) is a frequent benign vestibular condition usually managed with particle repositioning manoeuvres, such as Semont manoeuvre (SM). Since few authors have described prognostic aspects of liberatory manoeuvres, the purpose of the present study was to investigate the possibility of considering vertigo in the final sitting position of the SM as a prognostic symptom in the outcome of posterior BPPV. One hundred and thirteen patients with diagnosis of unilateral posterior BPPV were taking into account in our retrospective cohort study: 41 men and 72 women, aged 22 to 85 years. All were submitted to one repositioning SM and afterwards controlled 3 to 5 days later by means of an additional Dix-Hallpike manoeuvre. The main outcomes investigated were the occurrence of Ny and vertigo in the different phases of the SM, as well as their characteristics in relation to outcome of the disease. Among all patients, 75 (66%) presented both orthotropic Ny and vertigo in the second SM position and 72% obtained a complete resolution of the disease after the liberatory manoeuvre. Contrarily, 17 subjects (15%) manifested vertigo in the final sitting position of the SM and among these, only 7 (41%) completely recovered from BPPV. According to our data, in case of sudden vertigo returning to the final sitting position of the SM, the failure rate of the liberatory manoeuvre was higher, even though not statistically significant: therefore, it can be considered as a negative prognostic factor of posterior BPPV after SM.


Assuntos
Vertigem Posicional Paroxística Benigna/terapia , Postura Sentada , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Recidiva , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
8.
J Dairy Sci ; 98(7): 4914-27, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25958274

RESUMO

Cheese yield is the most important technological parameter in the dairy industry in many countries. The aim of this study was to infer (co)variance components for cheese yields (CY) and nutrient recoveries in curd (REC) predicted using Fourier-transform infrared (FTIR) spectroscopy of samples collected during milk recording on Holstein, Brown Swiss, and Simmental dairy cows. A total of 311,354 FTIR spectra representing the test-day records of 29,208 dairy cows (Holstein, Brown Swiss, and Simmental) from 654 herds, collected over a 3-yr period, were available for the study. The traits of interest for each cow consisted of 3 cheese yield traits (%CY: fresh curd, curd total solids, and curd water as a percent of the weight of the processed milk), 4 curd nutrient recovery traits (REC: fat, protein, total solids, and the energy of the curd as a percent of the same nutrient in the processed milk), and 3 daily cheese production traits (daily fresh curd, total solids, and the water of the curd per cow). Calibration equations (freely available upon request to the corresponding author) were used to predict individual test-day observations for these traits. The (co)variance components were estimated for the CY, REC, milk production, and milk composition traits via a set of 4-trait analyses within each breed. All analyses were performed using REML and linear animal models. The heritabilities of the %CY were always higher for Holstein and Brown Swiss cows (0.22 to 0.33) compared with Simmental cows (0.14 to 0.18). In general, the fresh cheese yield (%CYCURD) showed genetic variation and heritability estimates that were slightly higher than those of its components, %CYSOLIDS and %CYWATER. The parameter RECPROTEIN was the most heritable trait in all the 3 breeds, with values ranging from 0.32 to 0.41. Our estimation of the genetic relationships of the CY and REC with milk production and composition revealed that the current selection strategies used in dairy cattle are expected to exert only limited effects on the REC traits. Instead, breeders may be able to exploit genetic variations in the %CY, particularly RECFAT and RECPROTEIN. This last component is not explained by the milk protein content, suggesting that its direct selection could be beneficial for cheese production aptitude. Collectively, our findings indicate that breeding strategies aimed at enhancing CY and REC could be easily and rapidly implemented for dairy cattle populations in which FTIR spectra are routinely acquired from individual milk samples.


Assuntos
Bovinos/genética , Laticínios/análise , Animais , Bovinos/fisiologia , Queijo/análise , Feminino , Leite/química , Espectroscopia de Infravermelho com Transformada de Fourier/veterinária , Soro do Leite/química
9.
Meat Sci ; 96(3): 1376-83, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24361557

RESUMO

The aim of this study was to investigate the association between 10 candidate genes and carcass weight and conformation, carcass daily gain, and meat quality (pH, color, cooking loss, drip loss and shear force) in 990 double-muscled Piemontese young bulls. Animals were genotyped at each of the following genes: growth hormone, growth hormone receptor, pro-opiomelanocortin, pro-opiomelanocortin class 1 homeobox 1, melanocortin-4 receptor, corticotrophin-releasing hormone, diacylglycerol O-acyltransferase-1, thyroglobulin, carboxypeptidase E and gamma-3 regulatory subunit of the AMP-activated protein kinase. All the investigated SNPs had additive effects which were relevant for at least one of the traits. Relevant associations between the investigated SNPs and carcass weight, carcass daily gain and carcass conformation were detected, whereas associations of SNPs with meat quality were moderate. Results confirmed some of previously reported associations, but diverged for others. Validation in other cattle breeds is required to use these SNPs in gene-assisted selection programs for enhancement of carcass traits and meat quality.


Assuntos
Qualidade dos Alimentos , Carne/análise , Fenótipo , Polimorfismo de Nucleotídeo Único , Proteínas Quinases Ativadas por AMP/genética , Animais , Peso Corporal , Cruzamento , Carboxipeptidase H/genética , Bovinos , Cor , Culinária , Diacilglicerol O-Aciltransferase/genética , Manipulação de Alimentos , Frequência do Gene , Genótipo , Hormônio do Crescimento/genética , Concentração de Íons de Hidrogênio , Masculino , Músculo Esquelético/química , Pró-Opiomelanocortina/genética , Receptor Tipo 4 de Melanocortina/genética , Receptores da Somatotropina/genética , Tireoglobulina/genética , Fator de Transcrição Pit-1/genética
10.
J Anim Sci ; 91(5): 2057-66, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23463552

RESUMO

The aim of this study was to investigate genetic relationships between beef traits of station-tested young bulls and carcass and meat quality traits (MQ) of commercial intact males in Piemontese cattle. Phenotypes for daily gain (DG) and live fleshiness traits (width at withers: WW; shoulder muscularity: SM; loin width: LW; loin thickness: LT; thigh muscularity: TM; thigh profile: TP) and thinness of the shin bone (BT) were available for 3,109 and 2,183 performance-tested young bulls, respectively. Carcass daily gain (CDG), carcass conformation (SEUS), pH at 24 h (pH24h) and 8 d after slaughter (pH8d), lightness (L*), redness (a*), yellowness (b*), hue angle (HA), saturation index (SI), drip loss (DL), cooking loss (CL), and shear force (SF) were assessed for 1,208 commercial intact males. (Co) variance components were estimated in a set of twelve 9-traits analyses using REML and linear animal models including all performance-test traits and 1 carcass or MQ trait at a time. Heritabilities ± SE of beef traits ranged from 0.26 ± 0.03 (LW) to 0.47 ± 0.01 (DG), whereas those of carcass traits and MQ from 0.06 ± 0.03 (CL) to 0.63 ± 0.04 (HA). The genetic correlation (rg) between DG and CDG was 0.75 ± 0.10, indicating that DG, as measured at the test station, is a good indicator of the carcass gain achieved by commercial animals under farms conditions. Daily BW gain of station-tested bulls correlated positively with color traits (from 0.11 ± 0.12 to 0.54 ± 0.09), ph8d (rg ± SE = 0.31 ± 0.11), DL (rg ± SE = 0.29 ± 0.17), and CL (rg ± SE = 0.27 ± 0.18). Live fleshiness of station-tested bulls exhibited genetic correlations with MQ of commercial animals that were positive for L* and b* (from 0.13 ± 0.08 to 0.65 ± 0.14) and negative for pH (from -0.27 ± 0.15 to -0.57 ± 0.11), CL (from -0.16 ± 0.23 to -0.43 ± 0.22), and SF (TM: rg ± SE = -0.31 ± 0.15; TP: rg ± SE = -0.41 ± 0.17). The thinness of the shin bone correlated unfavorably with CDG (rg ± SE = -0.74 ± 0.07) and favorably with SEUS (rg ± SE = 0.65 ± 0.17), CL (rg ± SE = -0.39 ± 0.13), and SF (rg ± SE = -0.32 ± 0.17). The estimated genetic correlations indicate that selection to increase DG, as measured at the test station, exerts moderate adverse effects on MQ. Because selection emphasis is greater for live fleshiness than for DG, the correlated response in MQ and carcass traits is expected to be influenced to a greater extent by selection for muscularity, even though these traits are less heritable than DG.


Assuntos
Peso Corporal , Bovinos/fisiologia , Carne/análise , Músculo Esquelético/fisiologia , Criação de Animais Domésticos , Animais , Bovinos/genética , Bovinos/crescimento & desenvolvimento , Itália , Modelos Lineares , Masculino , Modelos Biológicos
11.
Meat Sci ; 89(1): 84-90, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21546169

RESUMO

Genetic parameters of meat quality (MQ) were estimated on Longissimus thoracis muscle of 1208 Piemontese young bulls, progeny of 109 AI sires. Carcass weight (CW), conformation (EUS) and pH (pH24h) were recorded at 24h and lightness (L*), redness (a*), yellowness (b*), pH (pH8d), drip loss (DL), cooking loss (CL) and shear force (SF) were assessed. The heritability (h(2)) of pH24h was very low (0.06), but h2 of pH8d was markedly higher (0.42). Heritability was 0.32, 0.33, and, 0.14, for L*, a* and b*, respectively, whereas was 0.24, 0.07 and 0.14, for DL, CL, and SF, respectively. The two pH measures showed opposite genetic relationships with color measures. Genetic correlations of DL and CL were positive with L* and b* and negative with a*. Genetic correlations between carcass traits and MQ suggest that animals with superior growth potential tend to exhibit reduced EUS scores and pale meat with lower tenderness and water holding capacity. Conversely, improvement of EUS score through selection would lead to light, bright, and tender meat with enhanced water holding capacity.


Assuntos
Bovinos/genética , Carne , Músculo Esquelético/crescimento & desenvolvimento , Característica Quantitativa Herdável , Animais , Composição Corporal , Cruzamento , Fenômenos Químicos , Culinária , Variação Genética , Concentração de Íons de Hidrogênio , Modelos Lineares , Masculino , Fenótipo
12.
J Anim Sci ; 89(9): 2687-95, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21454870

RESUMO

The aims of this study were 1) to investigate the potential application of near-infrared spectroscopy (NIRS) to predict beef quality (BQ) traits, 2) to assess genetic variations of BQ measures and their predictions obtained by NIRS, and 3) to infer the genetic relationship between measures of BQ and their predictions. Young Piedmontese bulls (n = 1,230) were raised and fattened on 124 farms and slaughtered at the same commercial abattoir. The BQ traits evaluated were shear force (SF, kg), cooking loss (CL, %), drip loss (DL, %), lightness (L*), redness (a*), yellowness (b*), saturation index (SI), and hue angle. Near-infrared spectra were collected using a Foss NIRSystems 5000 instrument over a spectral range of 1,100 to 2,498 nm every 2 nm, in reflectance mode. After editing, prediction models were developed on a calibration subset (n = 268) using partial least squares regressions, followed by application of these models to the validation subset (n = 940). Estimations of (co)variance for measures of BQ and NIRS-based predictions were obtained through a set of bivariate Bayesian analyses on the validation subset. Near-infrared predictions were satisfactory for measurements of L* (R(2) = 0.64), a* (R(2) = 0.68), hue angle (R(2) = 0.81), and saturation index (R(2) = 0.59), but not for b*, DL, CL, and SF. The loss of additive genetic variance of predicted vs. measured L*, a*, DL, CL, and SF was generally high and was similar to the loss of residual variance, being a function of the calibration parameter R(2). As a consequence, estimated heritabilities of measures and predictions of BQ were similar for traits with high calibration R(2) values. Genetic correlations between BQ measures and predictions were high for all color traits and DL, and were greater than the corresponding phenotypic correlations, whereas both the phenotypic and genetic correlations for SF and CL were nil. Results suggest that NIRS-based predictions for color features and DL may be used as indicator traits to improve meat quality of the Piedmontese breed.


Assuntos
Cruzamento/métodos , Bovinos/genética , Carne/normas , Característica Quantitativa Herdável , Espectroscopia de Luz Próxima ao Infravermelho/veterinária , Animais , Estudos de Associação Genética/veterinária , Masculino , Fenótipo
13.
J Anim Sci ; 88(11): 3504-12, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20675599

RESUMO

The aim of this study was to estimate genetic parameters for type traits of hypertrophic Piemontese cows. Seven traditional type trait evaluations (70 to 100 grid scores), 2 body measurements (cm), and 13 linear description traits (1 to 9 grid scores) recorded on 21,757 Piemontese primiparous cows reared in 990 farms were used. Data were analyzed using a multiple-trait (22 traits) animal model with canonical transformation, accounting for a unique design matrix with the following effects: herd-year-classifier, days in milk, age at calving, and the genetic additive cow effect. Heritability estimates of traditional type evaluation traits were low for thorax, rump, feet and legs, and dairyness (≤0.10), intermediate for fleshiness and overall score evaluations (0.13 to 0.15), and medium to high for body size (0.26). Genetic correlations of dairyness with all the other traditional type traits were low (from -0.14 to 0.16), those of feet and legs were moderate (0.19 to 0.44), and the remaining 5 traits were high (≥0.55), with an exception regarding fleshiness and body size (0.28). Medium-high heritability estimates were obtained for withers height (0.31) and trunk length (0.21), with a very high genetic correlation between these traits (0.97). The genetic correlations of body measurements with body size were also very high (about 0.96), high with thorax, rump, and overall score (0.47 to 0.59), and moderate with the other traditional type traits (0.04 to 0.27). Heritability estimates of all linear traits were moderate (0.09 to 0.15), with the exceptions of top line (0.07) and condition score (0.05). Genetic correlations between linear traits were generally low to moderate (from -0.11 to 0.44) with the only exceptions of the 6 fleshiness traits and body condition, which showed very high correlations (0.60 to 0.96). Moreover, skeletal traits as top line, bone thinness, and head scores presented moderate genetic correlations (0.51 to 0.65). Genetic correlations between linear traits and traditional type traits were consistent with the trend observed between type traits. In conclusion, body measurements seem to describe body size better than traditional evaluation or linear descriptors. The genetic correlations among type evaluation and linear description traits suggest the need for a reduction in the number of traits scored, particularly of those relating to muscular development.


Assuntos
Bovinos/genética , Bovinos/fisiologia , Animais , Composição Corporal/genética , Tamanho Corporal/genética , Cruzamento , Feminino , Característica Quantitativa Herdável
14.
Anim Genet ; 36(2): 138-40, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15771724

RESUMO

Growth hormone (GH) exerts its effects on growth and metabolism by interacting with a specific receptor (GHR) on the surface of the target cells. Therefore, GHR has been suggested as candidate gene for traits related to meat production in cattle. The aim of the study was to analyse the polymorphism at position 257 in exon 10 of the GHR gene and investigate relationships with 14 in vivo traits and four meat characteristics in Piemontese animals. The biallelic polymorphism already described was detected using a new PCR procedure. The statistical analysis did not show significant gene substitution effects on growth, size and meat conformation traits. As for meat characteristics, a significant gene substitution of GHR(A) over GHR(G) was observed for drip losses at day 3, with the allele GHR(A) associated with higher values. A significant dominance effect was also observed for this trait. Further investigations in other breeds will be useful for better understanding information on the effect of this GHR polymorphism.


Assuntos
Bovinos/genética , Carne , Fenótipo , Polimorfismo de Nucleotídeo Único , Receptores da Somatotropina/genética , Animais , Primers do DNA , Eletroforese , Frequência do Gene , Padrões de Herança/genética , Itália , Masculino , Modelos Genéticos
15.
J Anim Sci ; 82(12): 3440-6, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15537762

RESUMO

The aim of the study was to obtain estimates of genetic correlations between direct and maternal calving performance of heifers and cows and beef production traits in Piemontese cattle. Beef production traits were daily gain, live fleshiness, and bone thinness measured on 1,602 young bulls tested at a central station. Live fleshiness (six traits) and bone thinness were subjectively scored by classifiers using a nine-point linear grid. Data on calving performance were calving difficulty scores (five classes from unassisted to embryotomy) routinely recorded in the farms. Calving performance of heifers and cows were considered different traits. A total of 30,763 and 80,474 calving scores in first and later parities, respectively, were used to estimate covariance components with beef traits. Data were analyzed using bivariate linear animal models, including direct genetic effects for calving performance and beef traits and maternal genetic effects only for calving performance. Due to the nature of the data structure, which involved traits measured in different environments and on different animals, covariances were estimated mostly through pedigree information. Genetic correlations of daily gain were positive with direct calving performance (0.43 in heifers and 0.50 in cows) and negative with maternal calving performance (-0.23 and -0.28 for heifers and cows, respectively). Live fleshiness traits were moderately correlated with maternal calving performance in both parities, ranging from 0.06 to 0.33. Correlations between live fleshiness traits and direct calving performance were low to moderate and positive in the first parity, but trivial in later parities. Bone thinness was negatively correlated with direct calving performance (-0.17 and -0.38 in heifers and cows, respectively), but it was positively correlated to maternal calving performance (0.31 and 0.40). Estimated residual correlations were close to zero. Results indicate that, due to the existence of antagonistic relationships between the investigated traits, specific selection strategies need to be studied.


Assuntos
Bovinos/genética , Animais , Composição Corporal/genética , Densidade Óssea/genética , Cruzamento , Bovinos/fisiologia , Feminino , Masculino , Análise Multivariada , Parto/genética , Característica Quantitativa Herdável
16.
Anim Genet ; 33(1): 61-4, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11849139

RESUMO

Growth hormone (GH) and the Pit-1 transcription factor have been shown to be involved in the physiological mechanisms related to growth. The present study was carried out to investigate the possible association of the polymorphism at GH1 and POU1F1 loci with meat production traits in Piemontese cattle. Fourteen traits were considered, expressing growth (weight at 5, 7 and 11 months, daily gain), size [withers height (WH), trunk length (TL), chest girth (CG) at 12 months] and meat conformation [withers width (WW), shoulder muscularity (SM), loin width (LW), loin thickness (LT), thigh muscularity (TM), thigh profile (TP), bone thinness (BT)]. Data were analysed with a mixed model procedure to estimate the allele substitution and the dominance effects. The results did not provide evidence of association of GH1 and POU1F1 polymorphisms with the evaluated traits.


Assuntos
Bovinos/genética , Proteínas de Ligação a DNA/genética , Hormônio do Crescimento/genética , Carne , Fatores de Transcrição/genética , Animais , Frequência do Gene , Itália , Masculino , Polimorfismo Genético , Fator de Transcrição Pit-1
17.
J Anim Sci ; 78(10): 2532-9, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11048917

RESUMO

Estimates of heritabilities and genetic correlations for calving ease over parities were obtained for the Italian Piedmontese population using animal models. Field data were calving records of 50,721 first- and 44,148 second-parity females and 142,869 records of 38,213 cows of second or later parity. Calving ability was scored in five categories and analyzed using either a univariate or a bivariate linear model, treating performance over parities as different traits. The bivariate model was used to investigate the genetic relationship between first- and second- or between first- and third-parity calving ability. All models included direct and maternal genetic effects, which were assumed to be mutually correlated. (Co)variance components were estimated using restricted maximum likelihood procedures. In the univariate analyses, the heritability for direct effects was .19 +/- .01, .10 +/- .01, and .08 +/- .004 for first, second, and second and later parities, respectively. The heritability for maternal effects was .09 +/- .01, .11 +/- .01, and .05 +/- .01, respectively. All genetic correlations between direct and maternal effects were negative, ranging from -.55 to -.43. Approximated standard errors of genetic correlations between direct and maternal effects ranged from .041 to .062. For multiparous cows, the fraction of total variance due to the permanent environment was greater than the maternal heritability. With bivariate models, direct heritability for first parity was smaller than the corresponding univariate estimate, ranging from .18 to .14. Maternal heritabilities were slightly higher than the corresponding univariate estimates. Genetic correlation between first and second parity was .998 +/- .00 for direct effects and .913 +/- .01 for maternal effects. When the bivariate model analyzed first- and third-parity calving ability, genetic correlation was .907 +/- .02 for direct effects and .979 +/- .01 for maternal effects. Residual correlations were low in all bivariate analyses, ranging from .13 for analysis of first and second parity to .07 for analysis of first and third parity. In conclusion, estimates of genetic correlations for calving ease in different parities obtained in this study were very high, but variance components and heritabilities were clearly heterogeneous over parities.


Assuntos
Bovinos/genética , Trabalho de Parto/genética , Paridade/genética , Animais , Bovinos/classificação , Feminino , Masculino , Modelos Biológicos , Gravidez
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