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The increasing global demand for food and the strong effect of climate change have forced animal science to advance regarding new methods of selection in search of more efficient animals in production systems. Feed consumption represents more than 70% of the costs of sheep farms, and more efficient animals can increase the farmers' profitability. One of the main measures of feed efficiency is estimated residual feed intake (RFI), created in 1963 by Robert Koch for estimation in cattle and later adapted for sheep. Animals with negative RFI values (RFI-) are more efficient than animals with positive values (RFI+), with influence on the variables of performance, carcass quality and production of enteric gases. The RFI is the most common and accepted metric of the feed efficiency trait for genetic selection, since it is independent of growth traits, unlike the feed conversion ratio. The purpose of this review article was to present updated literature information on the relationship of RFI estimates with performance measures, molecular markers, greenhouse gas production and feed efficiency, the technical aspects and physiological basis of metabolic in sheep.
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Alimentación Animal , Animales , Alimentación Animal/análisis , Crianza de Animales Domésticos/métodos , Ingestión de Alimentos/fisiología , Ovinos/fisiología , Ovinos/crecimiento & desarrollo , Oveja Doméstica/fisiología , Oveja Doméstica/crecimiento & desarrollo , Fenómenos Fisiológicos Nutricionales de los Animales , Gases de Efecto Invernadero/análisisRESUMEN
Muscle mass development depends on increased protein synthesis and reduced muscle protein degradation. Muscle ring-finger protein-1 (MuRF1) plays a key role in controlling muscle atrophy. Its E3 ubiquitin ligase activity recognizes and degrades skeletal muscle proteins through the ubiquitin-proteasome system. The loss of Murf1, which encodes MuRF1, in mice leads to the accumulation of skeletal muscle proteins and alleviation of muscle atrophy. However, the function of Murf1 in agricultural animals remains unclear. Herein, we bred F1 generation Murf1+/- and F2 generation Murf1-/- Duroc pigs from F0 Murf1-/- pigs to investigate the effect of Murf1 knockout on skeletal muscle development. We found that the Murf1+/- pigs retained normal levels of muscle growth and reproduction, and their percentage of lean meat increased by 6% compared to that of the wild type (WT) pigs. Furthermore, the meat color, pH, water-holding capacity, and tenderness of the Murf1+/- pigs were similar to those of the WT pigs. The drip loss rate and intramuscular fat decreased slightly in the Murf1+/- pigs. However, the cross-sectional area of the myofibers in the longissimus dorsi increased in the adult Murf1+/- pigs. The skeletal muscle proteins MYBPC3 and actin, which are targeted by MuRF1, accumulated in the Murf1+/- and Murf1-/- pigs. Our findings show that inhibiting muscle protein degradation in MuRF1-deficient Duroc pigs increases the size of their myofibers and their percentage of lean meat without influencing their growth or pork quality. Our study demonstrates that Murf1 is a target gene for promoting skeletal muscle hypertrophy in pig breeding.
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Músculo Esquelético , Atrofia Muscular , Animales , Ratones , Porcinos , Músculo Esquelético/metabolismo , Atrofia Muscular/metabolismo , Complejo de la Endopetidasa Proteasomal/genética , Complejo de la Endopetidasa Proteasomal/metabolismo , Complejo de la Endopetidasa Proteasomal/farmacología , Hipertrofia/genética , Hipertrofia/metabolismoRESUMEN
The present paper describes the effect of glycyrrhizic acid contained in licorice roots on the quality of pork produced. The study uses advanced research methods as ion-exchange chromatography, inductively coupled plasma mass spectrometry, drying of an average sample of muscle, and pressing method. The paper set out to investigate the effect of glycyrrhizic acid on the pig meat quality after deworming. Of particular concern is the animal body restoration after deworming that results in metabolic disorders. The nutrient content of meat reduces, the output of bones and tendons rises. This is the first report on the use of glycyrrhizic acid to increase the meat quality of pigs after deworming. The findings from this study indicated higher pork quality resulted from a favorable effect of GA on the chemical and amino acid composition of meat. The resulting data demonstrated that glycyrrhizic acid in the piglets' diet had a beneficial effect on the biochemical processes in their body. The main scientific provisions of this paper and its findings have several practical implications for veterinary specialists. They can also be recommended for the educational process. Another possible implication is the development of new drugs, methods, and treatment plans.
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Ascariasis , Ácido Glicirrínico , Porcinos , Animales , Ácido Glicirrínico/farmacología , Ácido Glicirrínico/química , Dieta/veterinaria , Músculos , Carne/análisisRESUMEN
The rapidly growing world human population accentuates the need for improved production especially of protein-rich food. Broiler meat production offers opportunity to ensure security of this food. However, the production of modern broilers is not only limited by high feed costs due to dietary use of expensive energy and protein sources but also their meat possesses undesirable quality attributes. This study thus examined the effect of dietary Mucuna pruriens utilis seed meal (MSM) on growth performance, blood profile, carcass traits, and meat quality in finisher broiler chickens. In a completely randomised design (CRD), 320 21-day-old chicks were randomly allocated to 32 pens in which they were allotted 4 dietary treatments with 0, 2.5, 5, and 10% MSM, each with 8 replicate pens of 10 birds, for 28 days. Growth performance, carcass characteristics, internal organs, haemato-biochemistry, and meat quality were measured. Results showed that dietary MSM did not affect (P > 0.05) broiler performance, weights, and lengths of carcass cuts and internal organs, haematology, and meat quality. The only exception was MSM-induced increase in duodenal weight (linear, P < 0.05) and serum phosphorus (quadratic, P = 0.05) in contrast to a decrease in procalcitonin (quadratic, P < 0.01) and serum levels of total protein (linear, P < 0.05; and quadratic, P < 0.01), albumin (quadratic, P < 0.05), and bilirubin (quadratic, P = 0.001). Therefore, MSM could be supplemented up to 10% without compromising performance, carcass traits, internal organs, haemato-biochemistry, and meat quality in finisher broiler diets.
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Pollos , Mucuna , Animales , Alimentación Animal/análisis , Dieta/veterinaria , Suplementos Dietéticos , Carne/análisisRESUMEN
Waterfowl is an important animal-protein source, which has the potential to get a bigger share in the animal production sector. However, waterfowl farming practices and welfare standards are not well established yet. Stocking rate is one of the farming standards that can enhance the productivity, behavior, and well-being of birds; however, rare studies are available in this area. Thus, this article (1) gives an overview of the recent global waterfowls' meat and egg production and their population distribution, (2) reviews the effects of stocking rate on social, feeding, and sexual behaviors, (3) shows the effects of stocking rate on growth performance, carcass weight, and meat quality of ducks and geese, and (4) declares the relationship between the stocking rate and egg production. Conclusively, an optimal stocking rate standard can improve behaviors, productivity (meat-egg), and meat quality. Moreover, using weight (kg)/m2 will help in affording the required space allowance for different ducks and geese under various housing systems. The fish-waterfowl production system could be a promising and sustainable solution for increasing waterfowl production, maintaining the welfare of birds, saving energy, and reducing the water footprint of waterfowl meat. Based on prior research findings, we recommended adopting the stocking rate (SR) standard for specific duck and goose breeds to achieve an optimal production-welfare balance.
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Crianza de Animales Domésticos , Vivienda para Animales , Animales , Patos , Gansos , Carne/análisisRESUMEN
Determining the slaughter weight of pigs is crucial to the profitability of swine production farms. Unfortunately, in developing countries, the basic infrastructure for weight measurement may not always be available, affecting farmers' income. This study presents a machine learning-based approach to determine the dressed weight of pigs using four morphometric dimensions: paunch girth (PG), heart girth (HG), body length and wither height, which can be measured in situ. Different neural network model structures were constructed taking LM, GDX and BR training algorithms, tansigmoid/logsigmoid hidden layer transfer functions and 5-30 hidden layer neurons (HLNs). Results showed that LM training algorithm with logsigmoidal transfer function and 20 HLNs resulted in 99.8% accuracy in determining the pig dressed weight. Further, the number of morphometric parameters as inputs was gradually reduced and it was found that 99% accuracy can still be achieved using just PG and HG, thereby reducing the measurement time.
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NREP (neuronal regeneration related protein homolog) plays a role in the transformation of neural, muscle, and fibroblast cells and in smooth muscle myogenesis. The NREP gene was selected for detailed study as an expressional and functional candidate gene on the basis of data from the expression microarray, which detected the differences in gene expression between Czech Large White pigs and wild boars in the longissimus lumborum et thoracis and biceps femoris muscle tissues. Quantitative real-time PCR results confirmed that porcine NREP was expressed in both skeletal muscles and significantly overexpressed in Czech Large White pigs compared with wild boars (14.5- and 11.6-fold; p < .05). We identified 9 polymorphic sites in the genomic DNA of NREP. Six of these polymorphisms were in complete linkage disequilibrium, and therefore, only 4 loci were informative. The associations of the HF571253:g.103G>A, HF571253:g.134G>A, HF571253:g.179T>C and HF571253:g.402_409delT polymorphisms with backfat thickness, lean meat content and average daily gain were assessed in Czech Large White pigs. The GG genotypes HF571253:g.103G>A and HF571253:g.134G>A, the TT genotypes HF571253:g.179T>C and 67 HF571253:g.402_409delT genotypes had favourable effects on the studied traits. Our results indicate the possibility of utilizing the variability of the NREP gene in marker-assisted selection in order to improve meat production in pigs.
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Polimorfismo de Nucleótido Simple , Sus scrofa , Animales , Genotipo , Desequilibrio de Ligamiento , Carne , Músculo Esquelético , Sus scrofa/genética , Porcinos/genéticaRESUMEN
We investigated maternal effect on nine body measurement traits (body height, body length, front width (FW), chest width (CW), hind width (HW), chest depth, chest girth (CHG), front cannon circumference (FCC) and rear cannon circumference (RCC)) measured at the end of performance testing and five meat production traits (ages at the start and end of performance testing (D30 and D105), average daily gain (ADG), backfat thickness and loin muscle area) in purebred Duroc pigs. Genetic parameters for each trait were estimated by using six single-trait models with and without common litter environmental effect, maternal genetic effect and direct-maternal genetic correlation. The value of Akaike's information criterion was lowest with the model including direct additive genetic and common litter environmental effects for 10 traits. The estimated proportion of common litter environmental variance to phenotypic variance was approximately ≥0.1 for D30, D105, ADG, FW, CW, HW, CHG, FCC and RCC. Using a model without common litter environmental effect would overestimate the direct heritability of most traits. Standard errors of estimated genetic parameters tended to be larger in models including maternal genetic effect. The results indicate that a compromise could be made for accurate genetic parameter estimation for body measurement traits, as well as meat production traits, in pigs by considering common litter environmental effect.
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Herencia Materna , Carne de Cerdo , Animales , Fenotipo , PorcinosRESUMEN
Cultured meat involves producing meat from animal cells, not from slaughtered animals. This innovation has the potential to revolutionize the meat industry, with wide implications for the environment, health and animal welfare. The main purpose of this paper is to stimulate some economic research on cultured meat. In particular, this paper includes a prospective discussion on the demand and supply of cultured meat. It also discusses some early results on the environmental impacts of cultured meat, emphasizing the promises (e.g., regarding the reduction in land use) but also the uncertainties. It then argues that cultured meat is a moral improvement compared to conventional meat. Finally, it discusses some regulatory issues, and the need for more public support to the innovation.
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The objective was to evaluate the use of wet brewery residue (WBR) silage additives on carcass characteristics and sheep meat quality. Thirty-two Santa Inês male sheep uncastrated with initial body weight of 22.61 ± 7.2 kg were allocated to a completely randomized design with four treatments: (1) WBR silage without additive (WBRS), (2) WBR silage with milled corn (WBRS + MC), (3) WBR silage with wheat bran (WBRS + WB), and (4) WBR silage with cassava flour (WBRS + CF) and eight replicates. WBRS + WB resulted in lower cold carcass weight than WBRS + CF; however, this reduction was not sufficient to alter the carcass commercial yield or loin-eye area. The leg cut of animals fed WBRS + WB showed less value than those animals fed with WBRS + CS. The meat lightness of WBRS was higher that of WBRS + MC, WBRS + WB, and WBRS + CF. The cooking loss for WBRS + WB was less than those animals fed with WBRS + CS. However, meat protein, meat cholesterol, and shear force were similar among treatments (17.69%, 42.46 mg/100 g of meat, and 2.48 kgf/cm2, respectively). The use of additives in wet brewery residue silage does not improve carcass characteristics or the quality of sheep meat, and it is therefore recommended to use WBR silage without additives.
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Residuos Industriales/análisis , Carne/análisis , Oveja Doméstica/fisiología , Ensilaje/análisis , Animales , Reactores Biológicos , Dieta/veterinaria , Suplementos Dietéticos/análisis , Masculino , Distribución AleatoriaRESUMEN
The challenge of getting machines to understand and interact with natural objects is encountered in important areas such as medicine, agriculture, and, in our case, slaughterhouse automation. Recent breakthroughs have enabled the application of Deep Neural Networks (DNN) directly to point clouds, an efficient and natural representation of 3D objects. The potential of these methods has mostly been demonstrated for classification and segmentation tasks involving rigid man-made objects. We present a method, based on the successful PointNet architecture, for learning to regress correct tool placement from human demonstrations, using virtual reality. Our method is applied to a challenging slaughterhouse cutting task, which requires an understanding of the local geometry including the shape, size, and orientation. We propose an intermediate five-Degree of Freedom (DoF) cutting plane representation, a point and a normal vector, which eases the demonstration and learning process. A live experiment is conducted in order to unveil issues and begin to understand the required accuracy. Eleven cuts are rated by an expert, with 8 / 11 being rated as acceptable. The error on the test set is subsequently reduced through the addition of more training data and improvements to the DNN. The result is a reduction in the average translation from 1.5 cm to 0.8 cm and the orientation error from 4 . 59 to 4 . 48 . The method's generalization capacity is assessed on a similar task from the slaughterhouse and on the very different public LINEMOD dataset for object pose estimation across view points. In both cases, the method shows promising results. Code, datasets, and supplementary materials are available at https://github.com/markpp/PoseFromPointClouds.
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Most infectious diseases in humans originate from animals. In this paper, we explore the role of animal farming and meat consumption in the emergence and amplification of infectious diseases. First, we discuss how meat production increases epidemic risks, either directly through increased contact with wild and farmed animals or indirectly through its impact on the environment (e.g., biodiversity loss, water use, climate change). Traditional food systems such as bushmeat and backyard farming increase the risks of disease transmission from wild animals, while intensive farming amplifies the impact of the disease due to the high density, genetic proximity, increased immunodeficiency, and live transport of farmed animals. Second, we describe the various direct and indirect costs of animal-based infectious diseases, and in particular, how these diseases can negatively impact the economy and the environment. Last, we discuss policies to reduce the social costs of infectious diseases. While existing regulatory frameworks such as the "One Health" approach focus on increasing farms' biosecurity and emergency preparedness, we emphasize the need to better align stakeholders' incentives and to reduce meat consumption. We discuss in particular the implementation of a "zoonotic" Pigouvian tax, and innovations such as insect-based food or cultured meat.
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The aim of this study was to evaluate the effect of sex on carcass yield and meat quality of guinea pig (Cavia porcellus). Twenty animals (10 males and 10 females) Criollos, with initial body weight of 286 ± 4.26 g and 2 months of age were distributed in a completely randomized design. The guinea pigs fed a diet based on vegetables and concentrate in a roughage:concentrate ratio of 80:20. After 60 days, animals were slaughtered and their carcasses and meat were evaluated. Males had higher slaughter weight, total weight gain, hot carcass weight, cold carcass weight, cold carcass yield, meat weight, meat yield, leg weight, loin + flank weight and front weight (P < 0.05). Females showed higher carcass chilling loss, liver yield, cooking loss and protein and ash content in meat (P < 0.05). The use of male guinea pigs for meat production provides higher yields of carcasses, meat and commercial cuts, and lower losses during carcass chilling and meat cooking.
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Insulin-like growth factor 2 (IGF2) is an important growth factor, which promotes growth and development in mammals during fetal and postnatal stages. Using CRISPR-Cas9 system, we generated multiple founder pigs containing 12 different mutant alleles around a regulatory element within the intron 3 of IGF2 gene. Crossing two male founders passed four mutant alleles onto F1 generation, and these mutations abolished repressor ZBED6 binding and rendered this regulatory element nonfunctional. Both founders and F1 animals showed significantly faster growth, without affecting meat quality. These results indicated that editing IGF2 intron 3-3072 site using CRISPR-Cas9 technology improved meat production in Bama pigs. This is the first demonstration that editing non-coding region can improve economic traits in livestock.
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Sistemas CRISPR-Cas , Edición Génica/métodos , Factor II del Crecimiento Similar a la Insulina/genética , Intrones , Secuencias Reguladoras de Ácidos Nucleicos , Porcinos/genética , Alelos , Crianza de Animales Domésticos/métodos , Animales , Cruzamiento/métodos , Femenino , Genotipo , Masculino , Carne/análisis , Mutación , FenotipoRESUMEN
Myostatin, also known as growth differentiation factor 8, a member of the transforming growth factor-beta super-family, is a negative regulator of muscle development. Myostatin acts at key points during pre- and post-natal life of amniotes that ultimately determine the overall muscle mass of an animal. Mutations have already demonstrated the impact of attenuating myostatin activity on muscle development. A number of large animals, including cattle, sheep, dogs and humans, display the 'double muscled' phenotype due to mutations in the myostatin gene. Here, we firstly give an overview of the molecular pathways regulated by myostatin that control muscle development. Then we describe the natural mutations and their associated phenotypes as well as the physiological influence of altering myostatin expression in livestock animals (cattle, sheep, goat, horse, pig, rabbit and chicken). Knowledge of null alleles and polymorphisms in the myostatin gene are of great interest in the animal breeding field, and it could be utilized to improve meat production in livestock animals.
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Ganado/genética , Desarrollo de Músculos/genética , Miostatina/genética , Animales , Cruzamiento , Mutación , Fenotipo , Polimorfismo Genético , Transducción de SeñalRESUMEN
Small ruminant production is one of the main sources of meat in Algeria and plays a vital role in the country's food security. Algeria's small ruminant industry has the potential to improve the living standards of farmers and households, as well as to increase animal protein availability to the public, and as a consequence to alleviate poverty and improve health. This review describes the main infectious diseases that have an impact on small ruminant production in Algeria. It also discusses the adopted control measures for these diseases. The epidemiological status of small ruminant diseases in Algeria is striking and the main infectious diseases threatening its small ruminant industry are peste des petits ruminants, bluetongue, foot and mouth disease, sheep pox/goat pox, brucellosis and Rift Valley fever. Therefore, the establishment of early warning systems and the proper implementation of control measures are needed in order to prevent, control and/or eradicate these diseases that have a significant impact on Algeria's economy.
Le secteur de l'élevage de petits ruminants constitue l'une des principales sources d'approvisionnement de viande en Algérie et joue un rôle vital pour la sécurité alimentaire du pays. Le secteur des petits ruminants en Algérie a les capacités potentielles d'améliorer le niveau de vie des éleveurs et des ménages tout en augmentant l'offre de protéines d'origine animale disponibles pour les consommateurs, permettant par là même d'alléger la pauvreté et d'améliorer la santé publique. L'auteur décrit les principales maladies infectieuses affectant le secteur des petits ruminants en Algérie. Il examine également les mesures mises en oeuvre pour lutter contre ces maladies. Le statut épidémiologique des maladies des petits ruminants en Algérie est frappant ; les principales maladies infectieuses menaçant le secteur des petits ruminants sont : la peste des petits ruminants, la fièvre catarrhale ovine, la fièvre aphteuse, la clavelée et la variole caprine, la brucellose et la fièvre de la vallée du Rift. Par conséquent, il est nécessaire de mettre en place des systèmes d'alerte précoce et de veiller à la mise en oeuvre appropriée des mesures de contrôle afin de prévenir, de contrôler et/ou d'éradiquer ces maladies, dont l'impact sur l'économie algérienne est considérable.
Dado que los pequeños rumiantes son en Argelia una de las principales fuentes de carne, este sector productivo cumple una función capital para la seguridad alimentaria del país. La industria argelina de los pequeños rumiantes ofrece, en potencia, la perspectiva de mejorar los niveles de vida de productores y familias, poner a disposición de la población una mayor cantidad de proteínas animales y, en consecuencia, aliviar la pobreza y mejorar los niveles de salud del país. Tras enumerar las principales enfermedades infecciosas que repercuten en la producción argelina de pequeños rumiantes, el autor examina también las medidas instituidas para combatir esas enfermedades. La situación epidemiológica de las enfermedades de los pequeños rumiantes en Argelia resulta llamativa. Las principales enfermedades infecciosas que amenazan la producción del sector son: peste de pequeños rumiantes, lengua azul, fiebre aftosa, viruela ovina/ caprina, brucelosis y fiebre del Valle del Rift. Por ello, a fin de prevenir, controlar y/o erradicar estas enfermedades, que inciden notablemente en la economía de Argelia, es necesario instaurar sistemas de alerta rápida y aplicar debidamente medidas de lucha.
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Enfermedades de los Animales/epidemiología , Enfermedades de las Cabras/epidemiología , Enfermedades de las Ovejas/epidemiología , Argelia/epidemiología , Enfermedades de los Animales/microbiología , Enfermedades de los Animales/parasitología , Animales , Enfermedades de las Cabras/microbiología , Enfermedades de las Cabras/parasitología , Cabras , Ovinos , Enfermedades de las Ovejas/microbiología , Enfermedades de las Ovejas/parasitologíaRESUMEN
A profit function for a typical commercial farm of intensive guinea pig production was designed. The simulated farm contained 86 cages with a ratio of 7:1 females/males, with continuous mating. Kits were weaned at 15 days of age and slaughtered for meat production at 90 days of age. The absolute (EW) and relative economic weights of the main traits were calculated. The highest EW were kits produced per kindling (US$25), kits weaned per kindling (US$22), kits born alive per kindling (US$20), and the number of kindlings per female and year (US$12). Profit, returns, and costs per female and year were US$15, 68, and 53, respectively. Returns came from the production of young guinea pigs and discarded reproductive adults for meat production, 90 and 10% of the total returns. The highest costs were feeding and labor, 44 and 23% of the total cost. The EW and profit did not substantially change when simulating variations of ±20% in the prices of kilograms of fattening feed and kilograms of live weight of guinea pig, showing their robustness to future variations in market prices or to variations in prices between countries. The results obtained highlight the importance of the feeding costs in the guinea pig meat production.
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Crianza de Animales Domésticos/economía , Cobayas , Carne/economía , Animales , Comercio , Costos y Análisis de Costo , Femenino , Masculino , Modelos EconómicosRESUMEN
Although Australians on average consume large quantities of meat, their attitudes to farm animal welfare are poorly understood. We know little about how farm animal production is discussed in Australian households or how children learn about the origins of meat. This study consisted of an online survey completed by 225 primary carers throughout Australia recruited through social media. Findings include that conversations about the origin of meat were generally stimulated by meal preparation within the home rather than visits to agricultural shows or similar activities. Parents preferred to initiate conversations with children about meat production before they were 5 years of age. Urban parents were more likely than rural parents to reveal that they were conflicted about eating meat and would be more empathetic to children who chose to stop eating meat. Rural parents were more likely than urban parents to feel that children should eat what they are given and that talking about meat is not a major issue. Both groups felt that it was important that children should know where their food comes from. The findings of this study suggest that parental attitudes to meat production and consumption influence conversations about meat origins with children.
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Crianza de Animales Domésticos/métodos , Bienestar del Animal , Carnivoría , Preferencias Alimentarias , Industria para Empaquetado de Carne/métodos , Relaciones Padres-Hijo , Crianza de Animales Domésticos/educación , Crianza de Animales Domésticos/ética , Crianza de Animales Domésticos/tendencias , Bienestar del Animal/ética , Bienestar del Animal/tendencias , Animales , Australia , Carnivoría/ética , Carnivoría/psicología , Niño , Preescolar , Culinaria , Dieta Vegetariana/ética , Dieta Vegetariana/psicología , Femenino , Preferencias Alimentarias/ética , Preferencias Alimentarias/psicología , Humanos , Internet , Masculino , Comidas , Industria para Empaquetado de Carne/educación , Industria para Empaquetado de Carne/ética , Industria para Empaquetado de Carne/tendencias , Padres , Autoinforme , SocializaciónRESUMEN
A shortcut to identify DNA markers associated with economic traits is to use a candidate gene approach that is still useful in livestock species in which molecular tools and resources are not advanced or not well developed. Mutations in the growth hormone receptor (GHR) gene associated with production traits have been already described in several livestock species. For this reason GHR could be an interesting candidate gene in the rabbit. In this study we re-sequenced all exons and non-coding regions of the rabbit GHR gene in a panel of 10 different rabbits and identified 10 single nucleotide polymorphisms (SNPs). One of them (g.63453192C>G or c.106C>G), located in exon 3 was a missense mutation (p.L36V) substituting an amino acid in a highly conserved position across all mammals. This mutation was genotyped in 297 performance tested rabbits of a meat male line and association analysis showed that the investigated SNP was associated with weight at 70 days (P < 0.05). The most frequent genotype (GG) was in animals with higher weight at this age, suggesting that the high directional selection pressure toward this trait since the constitution of the genotyped line might have contributed to shape allele frequencies at this polymorphic site.
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Peso Corporal/genética , Carne/normas , Polimorfismo de Nucleótido Simple/genética , Receptores de Somatotropina/genética , Secuencia de Aminoácidos , Animales , Femenino , Estudios de Asociación Genética , Masculino , Conejos , Receptores de Somatotropina/química , Alineación de SecuenciaRESUMEN
In this study, we investigated whether a selection programme based on boar genetic evaluation obtained with a classical BLUP animal model can change allele frequencies in a pig population. All Italian Large White boars born from 1992 to 2012 with estimated breeding value reliability >0.85 (n = 200) were selected among all boars of this breed. Boars were genotyped with markers in major genes (IGF2 intron3-g.3072G>A, MC4R p.D298N, VRTN PRE1 insertion, PRKAG3 p.I199V and FTO g.276T>G). Genotyping data were analysed grouping boars in eight classes according to their year of birth. To evaluate the influence of time on allele frequencies of the genotyped markers, multinomial logistic regression models were computed. Four of five polymorphic sites (IGF2, MC4R, VRTN and FTO) showed significant (p < 0.01) changes in allele frequencies over time due to a progressive and continuous increase of one allele (associated with higher lean meat content, higher average daily gain and favourable feed: gain ratio) and, consequently, decrease of the other one, following the directional selection of the selection programme of this pig breed. The retrospective analysis that was carried out in Italian Large White boars suggests that selection based on methodologies assuming the infinitesimal model is able to modify in a quite short period of time allele frequencies in major genes, increasing the frequency of alleles explaining a relevant (non-infinitesimal) fraction of the overall genetic variability for production traits.