RESUMO
In pig breeding, the final product is a crossbred (CB) animal, while selection is performed at the purebred (PB) level using mainly PB data. However, incorporating CB data in genetic evaluations is expected to result in greater genetic progress at the CB level. Currently, there is no optimal way to include CB genotypes into the genomic relationship matrix. This is because, in single-step genomic BLUP, which is the most commonly used method, genomic and pedigree relationships must refer to the same base. This may not be the case when several breeds and CB are included. An alternative to overcome this issue may be to use a genomic relationship matrix (G matrix) that accounts for both linkage disequilibrium (LD) and linkage analysis (LA), called G. The objectives of this study were to further develop the G matrix approach to utilize both PB and CB genotypes simultaneously, to investigate its performance, and the general added value of including CB genotypes in genomic evaluations. Data were available on Dutch Landrace, Large White, and the F1 cross of those breeds. In total, 7 different G matrix compositions (PB alone, PB together, each PB with the CB, all genotypes across breeds, and G) were tested on 3 maternal traits: total number born (TNB), live born (LB), and gestation length (GL). Results show that G gave the greatest prediction accuracy of all the relationship matrices tested for PB prediction, but not for CB prediction. Including CB genotypes in general increased prediction accuracy for all breeds. However, in some cases, these increases in prediction accuracy were not significant (at < 0.05). To conclude, CB genotypes increased prediction accuracy for some of the traits and breeds, but not for all. The G matrix had significantly greater prediction accuracy in PB than the other G matrix with both PB and CB genotypes, except in one case. While for CB, the G matrix with genotypes across all breeds gave the greatest accuracy, though this was not significantly different from G. Computation time was high for G, and research will be needed to reduce its computational costs to make it feasible for use in routine evaluations. The main conclusion is that inclusion of CB genotypes is beneficial for both PB and CB animals.
Assuntos
Ligação Genética , Genômica/métodos , Desequilíbrio de Ligação , Suínos/genética , Animais , Cruzamento , Feminino , Genótipo , Masculino , Linhagem , Fenótipo , Suínos/crescimento & desenvolvimentoRESUMO
Chronic occlusion of saphenous vein aortocoronary bypass grafts is a common problem. Although percutaneous transluminal angioplasty of a saphenous vein with a stenotic lesion is feasible, angioplasty alone of a totally occluded vein graft yields uniformly poor results. Patients with such occlusion are often subjected to repeat aortocoronary bypass surgery. Experience with a new technique that allows angioplasty to be performed in a totally occluded saphenous vein bypass graft is reported. This technique utilizes infusion of prolonged low dose urokinase directly into the proximal portion of the occluded graft. Forty-six consecutive patients with 47 totally occluded grafts were studied. Patients had undergone end to side saphenous vein bypass grafting 1 to 13 (mean 7) years previously. All patients presented with new or worsening angina pectoris with ST-T changes or non-Q wave acute myocardial infarction and all had a totally occluded saphenous vein bypass graft. The new technique entailed the positioning of an angiographic catheter into the stub of the occluded graft and the advancement of an infusion wire into the graft. Patients were returned to the coronary care unit, where urokinase was delivered at a dose of 100,000 to 250,000 U/h. The total dose of urokinase ranged from 0.7 to 9.8 million U over 7.5 to 77 h (mean 31). After therapy, recanalization was seen in 37 (79%) of the 47 grafts. In 20 successfully treated patients, angiography was performed 1 to 24 (mean 11) months after treatment; 13 (65%) of these grafts were patent.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Ponte de Artéria Coronária , Doença das Coronárias/tratamento farmacológico , Oclusão de Enxerto Vascular/tratamento farmacológico , Veia Safena/transplante , Terapia Trombolítica , Ativador de Plasminogênio Tipo Uroquinase/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Angiografia Coronária , Doença das Coronárias/diagnóstico por imagem , Feminino , Seguimentos , Oclusão de Enxerto Vascular/diagnóstico por imagem , Humanos , Infusões Intravenosas/métodos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Resultado do Tratamento , Ativador de Plasminogênio Tipo Uroquinase/administração & dosagem , Grau de Desobstrução VascularRESUMO
OBJECTIVES: This multicenter study sought to evaluate the short-term efficacy and safety of prolonged, low dose, direct urokinase infusion in recanalization of chronically occluded saphenous vein bypass grafts in a large sample of patients, as well as to determine the 6-month patency rates for this procedure. BACKGROUND: Patients with chronically occluded aortocoronary vein grafts and uncontrolled angina pectoris have limited options for therapy. Previous work has shown that chronically occluded vein grafts can be recanalized by thrombolysis. METHODS: A coaxial infusion of urokinase (100,000 U/h) was given directly into occluded vein grafts in 107 patients. Balloon angioplasty was performed after lysis was achieved. Patients were discharged with warfarin and aspirin therapy. Six-month clinical follow-up data were obtained, and repeat angiography was encouraged. RESULTS: Initial patency was achieved in 74 patients (69%). Mean duration of infusion was 25.4 h, and mean urokinase dosage was 3.70 million U. Acute adverse events included acute myocardial infarction in 5 patients (5%), enzyme level elevation in 18 (17%), emergency coronary artery bypass graft surgery in 4 (4%), stroke in 3 (3%) and death in 7 (6.5%). Recanalization was unsuccessful in all seven patients who died. Six-month follow-up angiograms were obtained for 40 patients (54%), 16 of whom maintained a patent graft (40%). Angina was present in 13 patients with successful (22%) and 12 with unsuccessful (71%) recanalization at 6-month follow-up. CONCLUSIONS: Chronically occluded aortocoronary vein grafts can be recanalized in approximately 70% of appropriately selected patients. Complications are similar to those observed with repeat operations. Clinical follow-up shows an improvement in angina. This procedure is intended for patients with only one occluded vein graft. Strict adherence to the protocol will improve patency and reduce complications.
Assuntos
Ponte de Artéria Coronária , Oclusão de Enxerto Vascular/tratamento farmacológico , Ativadores de Plasminogênio/administração & dosagem , Veia Safena/transplante , Ativador de Plasminogênio Tipo Uroquinase/administração & dosagem , Grau de Desobstrução Vascular/efeitos dos fármacos , Angioplastia Coronária com Balão , Causas de Morte , Transtornos Cerebrovasculares/etiologia , Angiografia Coronária , Ponte de Artéria Coronária/efeitos adversos , Ponte de Artéria Coronária/mortalidade , Feminino , Seguimentos , Oclusão de Enxerto Vascular/complicações , Oclusão de Enxerto Vascular/mortalidade , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/etiologia , Cooperação do Paciente , Recidiva , Taxa de Sobrevida , Resultado do TratamentoRESUMO
The catecholamine content in blood platelets is considerably higher than that in plasma, and platelet catecholamines must be taken up from plasma, since blood platelets lack enzymes for catecholamine synthesis. However, it is unknown whether platelets take up and store catecholamines during physiological in vivo increments in plasma catecholamines. Previously untreated 50-year-old men (n = 17) with mild to moderate essential hypertension were given a low sodium diet for 2 weeks. Urinary excretion of sodium decreased from 201 +/- 11 (SE) to 24 +/- 5 and 19 +/- 4 mmol/24 hr after 1 and 2 weeks, respectively. During the first week, the blood platelet concentration of norepinephrine increased from 27.2 +/- 2.9 to 39.6 +/- 4.7 pg/mg (p less than 0.005) and venous plasma norepinephrine increased from 3.7 +/- 0.4 to 5.6 +/- 0.5 pg/ml (p less than 0.005), and venous plasma dopamine increased from 26 +/- 4 to 41 +/- 5 pg/ml (p less than 0.05). During the second week, both plasma and platelet norepinephrine and dopamine remained elevated. Platelet epinephrine showed a small increase from baseline to the second week (p less than 0.05), but no concomitant increase in plasma epinephrine occurred. Thus, sodium depletion increases both platelet and plasma catecholamines and blood platelets may take up catecholamines in vivo. Platelet catecholamine content may be an integrated measure of plasma catecholamine concentrations during variations caused by sodium depletion.
Assuntos
Plaquetas/metabolismo , Catecolaminas/sangue , Dieta Hipossódica , Hipertensão/sangue , Pressão Sanguínea , Peso Corporal , Dopamina/sangue , Epinefrina/sangue , Frequência Cardíaca , Humanos , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Norepinefrina/sangue , Plasma/análise , Potássio/metabolismo , Sódio/metabolismoRESUMO
Cardiovascular and sympathoadrenal effects of short-term oral treatment with beta 1-blockade (atenolol, 50 mg, administered two times) and beta 2-blockade (ICI 118,551, 50 mg, administered three times) were compared with placebo during actual flying in subjects with flight phobia (n = 34). beta 1-Blockade lowered resting blood pressure and heart rate and prevented a heart rate response but not a blood pressure response to this psychologic stress. beta 2-Blockade minimally lowered resting heart rate and prevented a heart rate response, but it failed to lower resting blood pressure or blood pressure response to the stress. Plasma epinephrine increased with all three treatments and more with beta 1-blockade than with placebo. Plasma norepinephrine decreased with administration of beta 2-blockade. Thus neither beta 1- nor beta 2-blockade prevents an increase in blood pressure during acute flight phobia stress. Increased plasma epinephrine seems to be the sympathetic variable that is closest related to this increase in blood pressure. Norepinephrine may be less consistently related to the blood pressure rise during flight phobia stress as shown by the decrease in plasma norepinephrine with administration of beta 2-blockade.
Assuntos
Antagonistas Adrenérgicos beta/farmacologia , Medicina Aeroespacial , Atenolol/farmacologia , Transtornos Fóbicos/tratamento farmacológico , Propanolaminas/farmacologia , Sistema Nervoso Simpático/efeitos dos fármacos , Administração Oral , Antagonistas Adrenérgicos beta/administração & dosagem , Adulto , Atenolol/administração & dosagem , Pressão Sanguínea/efeitos dos fármacos , Catecolaminas/sangue , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Propanolaminas/administração & dosagem , Estresse Psicológico/tratamento farmacológicoRESUMO
Plasma renin levels have been used to discriminate between different forms of hypertension, but how to define the normal range of plasma renin levels has not been agreed upon. Sodium depletion stimulates renin release. Evaluation of plasma renin would, therefore seem possible only in relation to sodium balance. Plasma renin concentration and concurrent daily sodium excretion were determined in 33 healthy normotensive subjects (control group) ingesting high, normal and low sodium diets. A well-defined hyperbolic relationship was found between the two variables indicating that the physiologic level of plasma renin concentration depends on the state of sodium balance. An increase in plasma potassium concentration may reduce plasma renin concentration, but this appeared to be overruled by the stimulating effect of sodium depletion. To examine whether beta-adrenergic stimulation contributes to the increase in plasma renin concentration during sodium depletion, the relationship between plasma renin concentration and concurrent sodium excretion was studied during beta-receptor blockade with propranolol. In 20 healthy normotensive subjects in whom beta-receptor blockade was verified by a significant reduction in pulse rate, the same hyperbolic relationship was found between plasma renin concentration and sodium excretion as in the control group showing that sodium depletion stimulates renin release independent of sympathetic nervous activity.
Assuntos
Antagonistas Adrenérgicos beta , Propranolol/farmacologia , Renina/sangue , Sódio/farmacologia , Adulto , Dieta , Feminino , Humanos , Masculino , Potássio/sangue , Potássio/urina , Sódio/urina , Estimulação QuímicaRESUMO
BACKGROUND: In a previous study we found that elevated blood viscosity was linked to the insulin resistance syndrome, and we proposed that high blood viscosity may increase insulin resistance. That study was based on calculated viscosity. OBJECTIVE: To determine whether directly measured whole-blood viscosity was related to the insulin-resistance syndrome in the same way as calculated viscosity had been found to be. METHODS: Healthy young men were examined with the hyperinsulinemic isoglycemic glucose clamp technique, and we related insulin sensitivity (glucose disposal rate) to other metabolic parameters and to blood viscosity. We established a technique for direct measurement of whole-blood viscosity. RESULTS: There were statistically significant negative correlations between glucose disposal rate and whole-blood viscosity at low and high shear rates (r = -0.41, P = 0.007 for both, n = 42). Whole-blood viscosity was correlated positively (n = 15) to serum triglyceride (r = 0.54, P = 0.04) and total cholesterol (r = 0.52, P = 0.05), and negatively with high-density lipoprotein cholesterol (r = -0.53, P = 0.04) concentrations. Insulin sensitivity index was correlated positively to high-density lipoprotein cholesterol (r = 0.54, P = 0.04) and negatively to serum triglyceride (r = -0.69, P = 0.005) and to total cholesterol (r = -0.81, P = 0.0003) concentrations. CONCLUSIONS: The present results demonstrate for the first time that there is a negative relationship between directly measured whole-blood viscosity and insulin sensitivity as a part of the insulin-resistance syndrome. Whole-blood viscosity contributes to the total peripheral resistance, and these results support the hypothesis that insulin resistance has a hemodynamic basis.
Assuntos
Viscosidade Sanguínea/fisiologia , Resistência à Insulina/fisiologia , Adulto , Pressão Sanguínea , Índice de Massa Corporal , Colesterol/sangue , HDL-Colesterol/sangue , Técnica Clamp de Glucose , Frequência Cardíaca , Hematócrito , Humanos , Masculino , Síndrome , Triglicerídeos/sangueRESUMO
Baseline serum prolactin (PRL) was found to be similar in 35 men with untreated essential hypertension (149 +/- 2/98 +/- 1 mmHg; means +/- s.e.) and 44 healthy normotensive men (126 +/- 1/80 +/- 1 mmHg), all 40 years old. A correlation between baseline PRL and aldosterone was found in the normotensive (r = 0.534, P less than 0.001), but not in the hypertensive group (r = -0.011, NS). Ten subjects from each group received intravenous metoclopramide, a competitive dopamine antagonist, while another 12 normotensive subjects were given saline only, and the effect on PRL, vasopressin (AVP) and catecholamines was followed. An exaggerated PRL response to metoclopramide was observed in the hypertensive group compared with the normotensive (P less than 0.05), and the mean normotensive peak value never exceeded the hypertensive. Plasma noradrenaline increased significantly compared with baseline (P less than 0.05) and the control group (P less than 0.001), concomitant with increased heart rate (P less than 0.05), after the administration of metoclopramide both in the hypertensive and normotensive group. After intravenous injection of metoclopramide, forearm blood flow increased significantly by 50% in the hypertensive (P less than 0.001), and 80% in the normotensive group (P less than 0.001) compared with the control group. Mean blood pressure remained unchanged as did plasma AVP, dopamine and adrenaline. The present study indicates an altered central dopaminergic activity in essential hypertension. Even at rest, endogenous dopamine exerts a modulating effect on noradrenaline release in both hypertensive and normotensive men.
Assuntos
Dopamina/fisiologia , Hipertensão/fisiopatologia , Adulto , Arginina Vasopressina/sangue , Dopamina/sangue , Epinefrina/sangue , Antebraço/irrigação sanguínea , Frequência Cardíaca/efeitos dos fármacos , Humanos , Hipertensão/sangue , Masculino , Metoclopramida/farmacologia , Norepinefrina/sangue , Prolactina/sangue , Prolactina/metabolismo , Fluxo Sanguíneo Regional/efeitos dos fármacosRESUMO
The present study is aimed at studying the effects of selective beta-adrenoceptor blockade on anxiety in subjects with flight phobia. Using an incomplete block design subjects received a beta-1 (atenolol 2 x 50 mg), a beta-2 (ICI 118 551 3 x 50 mg) selective blocking drug, or placebo on three occasions over a 16 h period under double-blind conditions prior to a 1/2 h flight. The same procedure was repeated 4 weeks later. Thirty-four subjects completed this double-blind, two-period crossover study. Self-reporting by the Alderley Park State Anxiety Questionnaire, Global Flight Anxiety and Treatment Preference showed a moderate but significant effect of atenolol in alleviating especially somatic symptoms of flight anxiety in addition to an overall effect in the treatment of this entity (p<0.01). ICI 118 551 was ineffective in alleviating any of the important symptoms of flight phobia. These results may imply that the effect of beta-adrenoceptor blockade in reducing phobic anxiety may be more a result of beta-1 than of beta-2 blockade. Beta-1 adrenoceptor blockade may be an alternative treatment of flight phobia, particularly when the symptoms are of somatic character and when intellectual performance is expected shortly after the flight.
RESUMO
OBJECTIVE: To do an analysis of patients with a primary diagnosis of congestive heart failure at discharge before (n = 407) and after (n = 347) the implementation of a comprehensive inpatient and outpatient congestive heart failure program consistent with the guidelines of the Agency for Health Care Policy and Research. STUDY DESIGN: A retrospective analysis of the impact of the congestive heart failure program on length of stay, admission and readmission rates, and costs to both patient and provider. The program, which used a multidisciplinary team approach, included an intensive education program focusing on diet, compliance, and symptom recognition, as well as the use of outpatient infusions. It also incorporated aggressive pharmacologic treatment for patients with advanced congestive heart failure. RESULTS: Our analysis revealed significant decreases in length of stay, admission and readmission rates, and costs to the patient and provider (P < or = .05). The mean cost per admission decreased 17% ($1118), and a substantial 77% ($718,468) net reduction in nonreimbursed (lost) hospital revenue was noted. CONCLUSION: A multidisciplinary, comprehensive congestive heart failure program can improve patient care in a community-hospital setting while significantly reducing costs to both the patient and the institution.
Assuntos
Serviço Hospitalar de Cardiologia/normas , Procedimentos Clínicos , Insuficiência Cardíaca/terapia , Hospitais Comunitários/normas , Serviço Hospitalar de Cardiologia/economia , Serviço Hospitalar de Cardiologia/organização & administração , Insuficiência Cardíaca/economia , Custos Hospitalares/estatística & dados numéricos , Hospitais Comunitários/economia , Hospitais Comunitários/organização & administração , Humanos , Illinois , Tempo de Internação/estatística & dados numéricos , Avaliação de Resultados em Cuidados de Saúde , Admissão do Paciente/estatística & dados numéricos , Equipe de Assistência ao Paciente , Educação de Pacientes como Assunto , Estudos RetrospectivosRESUMO
The influence of HLA matching has been studied in the Norwegian material of 142 living related and 311 cadaveric transplants. Graft survival corresponded closely to the degree of HLA haplotype disparity between donors and recipients. Furthermore, graft survival was less in combinations being incompatible for the serologically defined HLA-A and -B antigens as compared to compatible combinations. A weak MLC response, indicating a possible sharing of the HLA-D determinants between donor and recipient, was also associated with superior graft survival, even in the presence of HLA-A and -B disparity. Matching for HLA-C in addition to HLA-A and -B did not seem to improve graft survival.
Assuntos
Antígenos HLA , Antígenos de Histocompatibilidade , Teste de Histocompatibilidade , Transplante de Rim , Cadáver , Sobrevivência de Enxerto , Humanos , Teste de Cultura Mista de Linfócitos , Transplante HomólogoRESUMO
Continuous measurement of mixed venous oxygen saturation (SvO2) is a beneficial method for evaluating overall dynamic tissue oxygen balance in critically ill patients. Several important factors, however, may influence the accurate analysis of SvO2 data trends. In this review we highlight these factors and support cautious interpretation of SvO2 in conjunction with other available patient data and with strict attention to the clinical value and limitations of the parameter.
Assuntos
Cuidados Críticos/métodos , Cuidados de Enfermagem/métodos , Oximetria , Volume Sanguíneo , Débito Cardíaco , Estudos de Avaliação como Assunto , Hemoglobinas/análise , Humanos , Oxigênio/sangue , Oxigênio/metabolismoRESUMO
In this article, several technical and physiologic factors that might interfere with the accurate interpretation of the pulmonary artery wedge pressure as an indicator of LV preload and extravascular lung water have been reviewed. The purpose of this article is not to belittle the use of the wedge pressure value but, instead, to stress the importance of precise measurement and careful interpretation of this parameter. Every effort must be made by the critical care nurse at the bedside to minimize erroneous data and to optimize the validity of the wedge pressure value in order to prompt appropriate clinical decisions.
Assuntos
Monitorização Fisiológica/métodos , Pressão Propulsora Pulmonar , Cateterismo de Swan-Ganz , Humanos , Monitorização Fisiológica/enfermagem , Circulação PulmonarRESUMO
Chronic heart failure (CHF) is a clinical syndrome characterized by left ventricular dysfunction secondary to the loss of functional cardiac contractile cells following some type of myocardial damage. In response to this cell loss, several hemodynamic and neurohormonal compensatory mechanisms are activated, which can become deleterious over time. Direct-acting vasodilators, however, can produce favorable hemodynamic effects in this setting by reducing ventricular wall stress. Furthermore, diuretics can promote the excretion of sodium and water, thereby relieving hypervolemia and circulatory congestion. This article examines the role of these two classes of agents in the pharmacologic management of CHF.
Assuntos
Diuréticos/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Vasodilatadores/uso terapêutico , Doença Crônica , Insuficiência Cardíaca/enfermagem , Insuficiência Cardíaca/fisiopatologia , HumanosRESUMO
A baby boy who had been born with a large myelomeningocele had a ventriculoperitoneal shunt inserted at the age of 6 months. Two months later it was revised, after which he developed satisfactorily both mentally and physically. He presented at the age of 13 months because the epithelialisation of the myelomeningocele was both fragile and incomplete. Enough soft tissue was obtained to cover the defect, which was 13 x 10 cm, by the use of two 600 ml expanders placed subcutaneously one on either side of the deformity.
Assuntos
Meningomielocele/cirurgia , Expansão de Tecido , Humanos , Lactente , Masculino , Dispositivos para Expansão de Tecidos , Derivação VentriculoperitonealRESUMO
The influence of HLA matching has been studied in a Norwegian material of 147 living related first transplants, 281 cadaveric first transplants and 48 cadaveric second transplants. Graft survival corresponded closely to HLA antigen disparity and degree of MLC response in combinations transplanted with kidneys from living related donors. In patients transplanted with cadaveric grafts. HLA identical and compatible grafts performed significantly better than imcompatible grafts. Matching for HLA-C in addition to HLA-A and -B did not seem to improve graft survival.
Assuntos
Sobrevivência de Enxerto , Antígenos HLA , Teste de Histocompatibilidade , Transplante de Rim , Cadáver , Humanos , Transplante HomólogoRESUMO
The objective of our study was to investigate the heritabilities and genetic correlations between traits from a linear exterior assessment system and osteochondrosis (OC) measured by computed tomography (CT), and in addition, to study the genetic trend in a population where the conformation traits have been included in the breeding goal. The data material consisted of phenotypes from a total of 4571 Norsvin Landrace test boars. At the end of the test period, all boars were subjected to a detailed exterior assessment system. Within 10 days of the assessment, the boars were CT scanned for measuring OC. The total score of osteochondrosis (OCT), used in this study, is the sum of phenotypes from the assessment on the medial and lateral condyles at the distal end of both the humerus and the femur of the right and the left leg of the boar based on images from CT. The exterior assessment traits included in the study were; 'front leg knee' (FKNE), 'front leg pasterns' (FPAS), 'front leg stance' (FSTA), 'front leg twisted pasterns' (FFLK), 'hind leg stance', 'hind leg pasterns' (HPAS), 'hind leg standing under' (HSTU), 'hind leg small inner toe', 'dipped back', 'arched back' (ARCH) and 'waddling hindquarters' (WADL). The estimation of (co)variance components and breeding values were performed using bivariate animal genetic models. Breeding values for HSTU, HPAS, FPAS, WADL and OCT traits were additional outputs from the same bivariate analyses. The lowest heritability was found for FFLK (h 2 FFLK=0.05), whereas FPAS was estimated to have the highest heritability (h 2 FPAS=0.36), and OCT demonstrating a heritability of 0.29. Significant genetic correlations were found between several traits; the strongest correlation was between FSTA and FFLK (0.94), which was followed by the correlation between FPAS and FKNE (0.69). The traits ARCH and FSTA had significant genetic correlations to OCT, whereas all other genetic correlations between OCT and the conformation traits were low and not significantly different from 0. Our study shows positive genetic trends for the conformation traits included in the breeding goal. In general, low genetic correlations between conformation traits and OC were observed in our study.
Assuntos
Predisposição Genética para Doença , Osteocondrose/veterinária , Doenças dos Suínos/genética , Animais , Osso e Ossos/diagnóstico por imagem , Cruzamento , Membro Anterior/anatomia & histologia , Membro Anterior/diagnóstico por imagem , Membro Posterior/anatomia & histologia , Membro Posterior/diagnóstico por imagem , Masculino , Osteocondrose/genética , Suínos , Tomografia Computadorizada por Raios XRESUMO
In this study, computed tomography (CT) technology was used to measure body composition on live pigs for breeding purposes. Norwegian Landrace (L; n = 3835) and Duroc (D; n = 3139) boars, selection candidates to be elite boars in a breeding programme, were CT-scanned between August 2008 and August 2010 as part of an ongoing testing programme at Norsvin's boar test station. Genetic parameters in the growth rate of muscle (MG), carcass fat (FG), bone (BG) and non-carcass tissue (NCG), from birth to â¼100 kg live weight, were calculated from CT data. Genetic correlations between growth of different body tissues scanned using CT, lean meat percentage (LMP) calculated from CT and more traditional production traits such as the average daily gain (ADG) from birth to 25 kg (ADG1), the ADG from 25 kg to 100 kg (ADG2) and the feed conversion ratio (FCR) from 25 kg to 100 kg were also estimated from data on the same boars. Genetic parameters were estimated based on multi-trait animal models using the average information-restricted maximum likelihood (AI-REML) methodology. The heritability estimates (s.e. = 0.04 to 0.05) for the various traits for Landrace and Duroc were as follows: MG (0.19 and 0.43), FG (0.53 and 0.59), BG (0.37 and 0.58), NCG (0.38 and 0.50), LMP (0.50 and 0.57), ADG1 (0.25 and 0.48), ADG2 (0.41 and 0.42) and FCR (0.29 and 0.42). Genetic correlations for MG with LMP were 0.55 and 0.68, and genetic correlations between MG and ADG2 were -0.06 and 0.07 for Landrace and Duroc, respectively. LMP and ADG2 were clearly unfavourably genetically correlated (L: -0.75 and D: -0.54). These results showed the difficulty in jointly improving LMP and ADG2. ADG2 was unfavourably correlated with FG (L: 0.84 and D: 0.72), thus indicating to a large extent that selection for increased growth implies selection for fatness under an ad libitum feeding regime. Selection for MG is not expected to increase ADG2, but will yield faster growth of the desired tissues and a better carcass quality. Hence, we consider MG to be a better biological trait in selection for improved productivity and carcass quality. CT is a powerful instrument in conjunction with breeding, as it combines the high accuracy of CT data with measurements taken from the selection candidates. CT also allows the selection of new traits such as real body composition, and in particular, the actual MG on living animals.
Assuntos
Tecido Adiposo/crescimento & desenvolvimento , Desenvolvimento Ósseo/genética , Músculo Esquelético/crescimento & desenvolvimento , Suínos/crescimento & desenvolvimento , Suínos/genética , Tomografia Computadorizada Espiral/veterinária , Tecido Adiposo/diagnóstico por imagem , Animais , Composição Corporal/genética , Osso e Ossos/diagnóstico por imagem , Cruzamento , Feminino , Análise dos Mínimos Quadrados , Masculino , Modelos Genéticos , Músculo Esquelético/diagnóstico por imagem , Linhagem , Característica Quantitativa HerdávelRESUMO
Subcutaneous fat from Norwegian Landrace (n=3230) and Duroc (n=1769) pigs was sampled to investigate the sources of variation and genetic parameters of various fatty acids, fat moisture percentage and fat colour, with the lean meat percentage (LMP) also included as a trait representing the leanness of the pig. The pigs were from half-sib groups of station-tested boars included in the Norwegian pig breeding scheme. They were fed ad libitum to obtain an average of 113 kg live weight. Near-infrared spectroscopy (NIRS) was applied for prediction of the fatty acids and fat moisture percentage, and Minolta was used for the fat colour measurements. Heritabilities and genetic correlations were estimated with a multi-trait animal model using average information-restricted maximum likelihood (AI-REML) methodology. Fat from Landrace pigs had considerably more monounsaturated fatty acids, polyunsaturated fatty acids (PUFAs) and fat moisture, as well as less saturated fatty acids (SFAs) than fat from Duroc pigs. The heritability estimates (s.e. 0.03 to 0.08) for the various fatty acids were as follows: Palmitic, C16:0 (0.39 and 0.51 for Landrace and Duroc pigs, respectively); Palmitoleic, C16:1n-7 (0.41 and 0.50); Steric, C18:0 (0.46 and 0.54); Oleic, C18:1n-9 (0.67 and 0.57); Linoleic, C18:2n-6 (0.44 and 0.46); α-linolenic, C18:3n-3 (0.37 and 0.25) and n-6/n-3 ratio (0.06 and 0.01). The other fat quality traits revealed the following heritabilities: fat moisture (0.28 and 0.33), colour values in subcutaneous fat: L* (whiteness; 0.22 and 0.21), a* (redness; 0.13 and 0.24) and b* (yellowness; 0.07 and 0.17) and LMP (0.46 and 0.47). LMP showed high positive genetic correlations to PUFA (C18:2n-6 and C18:3n-3), which implies that selecting leaner pigs changes the fatty acid composition and deteriorates the quality of fat. Higher concentrations of PUFA are not beneficial as the ratio of n-6 and n-3 fatty acids becomes unfavourably high. Owing to the high genetic correlation between C18:2n-6 and C18:3n-3 and a low heritability for this ratio, the latter is difficult to change through selection. However, a small reduction in the ratio should be expected if selection aims at reducing the level of C18:2n-6. Selection for more C18:1n-9 is possible in view of the genetic parameters, which are favourable for eating quality, technological quality and human nutrition. The NIRS technology and the high heritabilities found in this study make it possible to implement fat quality traits to achieve the breeding goal in the selection of a lean pig with better fat quality.
RESUMO
This study was conducted to evaluate the potential of near-infrared (NIR) spectroscopy (NIRS) technology for prediction of the chemical composition (moisture content and fatty acid composition) of fat from fast-growing, lean slaughter pig samples coming from breeding programmes. NIRS method I: a total of 77 samples of intact subcutaneous fat from pigs were analysed with the FOSS FoodScan NIR spectrophotometer (850 to 1050 nm) and then used to predict the moisture content by using partial least squares (PLS) regression methods. The best equation obtained has a coefficient of determination for cross-validation (CV; R(2)(cv)) and a root mean square error of a CV (RMSECV) of 0.88 and 1.18%, respectively. The equation was further validated with (n = 15) providing values of 0.83 and 0.42% for the coefficient of determination for validation (R(2)(val)) and root mean square error of prediction (RMSEP), respectively. NIRS method II: in this case, samples of melted subcutaneous fat were analysed in an FOSS XDS NIR rapid content analyser (400 to 2500 nm). Equations based on modified PLS regression methods showed that NIRS technology could predict the fatty acid groups, the main fatty acids and the iodine value accurately with R(2)(cv), RMSECV, R(2)(val) and RMSEP of 0.98, 0.38%, 0.95 and 0.49%, respectively (saturated fatty acids), 0.94, 0.45%, 0.97 and 0.65%, respectively (monounsaturated fatty acids), 0.97, 0.28%, 0.99 and 0.34%, respectively (polyunsaturated fatty acids), 0.76, 0.61%, 0.84 and 0.87%, respectively (palmitic acid, C16:0), 0.75, 0.16%, 0.89 and 0.10%, respectively (palmitoleic acid, C16:1n-7), 0.93, 0.41%, 0.96 and 0.64%, respectively (steric acid, C18:0), 0.90, 0.51%, 0.94 and 0.44%, respectively (oleic acid, C18:1n-9), 0.97, 0.25%, 0.98 and 0.29% (linoleic acid, C18:2n-6), 0.68, 0.09%, 0.57 and 0.16% (α-linolenic acid, C18:3n-3) and 0.97, 0.57, 0.97 and 1.22, respectively (iodine value, calculated). The magnitude of this error showed quite good accuracy using these rapid methods in prediction of the moisture and fatty acid composition of fat from pigs involved in breeding schemes.