Datos reproductivos y productivos de cuatro razas ovinas bajo condiciones de pastoreo en la Reserva 8

El ovino es una especie con una gran capacidad para producir bajos distintas condiciones medio ambientales, la cual ha sido aprovechada a través de programas de cruzamiento y selección para lograr las razas que actualmente están disponibles.EEA BalcarceFil: Papaleo Mazzucco, Juliana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Papaleo Mazzucco, Juliana. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Hozbor, Federico Andrés. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Hozbor, Federico Andrés. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina

Relación de la dieta con el color y la terneza de la carne vacuna.

Para el consumidor de carne vacuna la calidad sensorial es importante al momento de la compra y el consumo. El color depende mayormente de la concentración de mioglobina y el pH, en tanto que la terneza está relacionada con el pH, la composición del colágeno y la degradación miofibrilar. Todos ellos pueden influenciarse por la dieta. La concentración de mioglobina depende del tipo de fibra muscular, cuyo metabolismo está influenciado por la dieta que reciban los animales. Las dietas de baja energía se asocian a fibras rojas, con metabolismo oxidativo y mayor concentración de mioglobina, mientras que las dietas ricas en energía estimulan el desarrollo de fibras glucolíticas. Estas últimas, tienen la capacidad de acumular más glucógeno. El metabolismo de las miofibras también afecta al contenido de enzimas proteolíticas, las fibras oxidativas presentan mayor concentración de calpaínas que las fibras glicolíticas. La estructura del colágeno es influenciada por la dieta de forma indirecta, ya que su efecto está mediado por la tasa de ganancia de peso. Al consumir dietas energéticas los animales incrementan la velocidad de ganancia de peso, lo que disminuye el colágeno total por un efecto de dilución debido al aumento de miofibrillas. Por otro lado, la energía puede retrasar la formación y estabilización de las estructuras del colágeno, con aumento de la fracción soluble. La dieta cumple un rol importante sobre la calidad de la carne, por lo tanto mantener un buen nivel de alimentación permite maximizar la calidad y lograr un producto con atributos sensoriales coincidentes con los requeridos por un gran número de consumidores. The sensorial quality of meat is important when consumers both purchase and eat it. When buying, color is most important, whereas tenderness is significant when eating. The color of the meat mostly depends on the concentration of myoglobin and pH, while tenderness is related to pH, collagen composition and myofibrillar degradation. Muscle fiber metabolism depends on the diet that the animals receive. Low-energy diets are associated with red fibers, oxidative metabolism, and increased myoglobin concentration. High-energy diets stimulate the development of glycolytic fibers, which have the ability to accumulate more glycogen. Myofiber metabolism also affects the content of proteolytic enzymes; oxidative fibers present a higher calpain concentration than glycolytic fibers. Collagen structure is affected by diet indirectly; its effect is mediated by daily weight gain. When consuming energetic diets, animals rapidly increase their weight, which will reduce total collagen by a dilution established by myofibrils increase. Additionally, an energetic diet can delay formation and stabilization of collagen structures, with an increasing soluble proportion. As diet plays an important role in the quality of meat, a good nutritional level allows maximizing quality; as a result, a large number of consumers will have a product with the sensory characteristics requiredThe sensorial quality of meat is important when consumers both purchase and eat it. When buying, color is most important, whereas tenderness is significant when eating. The color of the meat mostly depends on the concentration of myoglobin and pH, while tenderness is related to pH, collagen composition and myofibrillar degradation. Muscle fiber metabolism depends on the diet that the animals receive. Low-energy diets are associated with red fibers, oxidative metabolism, and increased myoglobin concentration. High-energy diets stimulate the development of glycolytic fibers, which have the ability to accumulate more glycogen. Myofiber metabolism also affects the content of proteolytic enzymes; oxidative fibers present a higher calpain concentration than glycolytic fibers. Collagen structure is affected by diet indirectly; its effect is mediated by daily weight gain. When consuming energetic diets, ani-mals rapidly increase their weight, which will reduce total collagen by a dilution established by myofibrils increase. Additionally, an energetic diet can delay formation and stabilization of collagen structures, with an increasing soluble proportion. As diet plays an important role in the quality of meat, a good nutritional level allows maximizing quality; as a result, a large number of consumers will have a product with the sensory characteristics required.EEA BalcarceFil: Della Rosa, María Milagros. Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina.Fil: Papaleo Mazzucco, Juliana. INTA, Estación Experimental Agropecuaria Balcarce, Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Aello, Mario. INTA, Estación Experimental Agropecuaria Balcarce, Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina

Genetic characterisation of PPARG, CEBPA and RXRA, and their influence on meat quality traits in cattle

Background: Peroxisome proliferator-activated receptor gamma (PPARG), CCAAT/enhancer binding protein alpha (CEBPA) and retinoid X receptor alpha (RXRA) are nuclear transcription factors that play important roles in regulation of adipogenesis and fat deposition. The objectives of this study were to characterise the variability of these three candidate genes in a mixed sample panel composed of several cattle breeds with different meat quality, validate single nucleotide polymorphisms (SNPs) in a local crossbred population (Angus - Hereford - Limousin) and evaluate their effects on meat quality traits (backfat thickness, intramuscular fat content and fatty acid composition), supporting the association tests with bioinformatic predictive studies. Results: Globally, nine SNPs were detected in the PPARG and CEBPA genes within our mixed panel, including a novel SNP in the latter. Three of these nine, along with seven other SNPs selected from the Single Nucleotide Polymorphism database (SNPdb), including SNPs in the RXRA gene, were validated in the crossbred population (N = 260). After validation, five of these SNPs were evaluated for genotype effects on fatty acid content and composition. Significant effects were observed on backfat thickness and different fatty acid contents (P < 0.05). Some of these SNPs caused slight differences in mRNA structure stability and/or putative binding sites for proteins. Conclusions: PPARG and CEBPA showed low to moderate variability in our sample panel. Variations in these genes, along with RXRA, may explain part of the genetic variation in fat content and composition. Our results may contribute to knowledge about genetic variation in meat quality traits in cattle and should be evaluated in larger independent populations.Instituto de Genética Veterinari

Genetic variation in FABP4 and evaluation of its effects on beef cattle fat content

FABP4 is a protein primarily expressed in adipocytes and macrophages that plays a key role in fatty acid trafficking and lipid hydrolysis. FABP4 gene polymorphisms have been associated with meat quality traits in cattle, mostly in Asian breeds under feedlot conditions. The objectives of this work were to characterize FABP4 genetic variation in several worldwide cattle breeds and evaluate possible genotype effects on fat content in a pasture-fed crossbred (Angus-Hereford-Limousin) population. We re-sequenced 43 unrelated animals from nine cattle breeds (Angus, Brahman, Creole, Hereford, Holstein, Limousin, Nelore, Shorthorn, and Wagyu) and obtained 22 single nucleotide polymorphisms (SNPs) over 3,164 bp, including four novel polymorphisms. Haplotypes and linkage disequilibrium analyses showed a high variability. Five SNPs were selected to perform validation and association studies in our crossbred population. Four SNPs showed well-balanced allele frequencies (minor frequency &gt; 0.159), and three showed no significant deviations from Hardy-Weinberg proportions. SNPs showed significant effects on backfat thickness and fatty acid composition (P &lt; 0.05). The protein structure of one of the missense SNPs was analyzed to elucidate its possible effect on fat content in our studied population. Our results revealed a possible blockage of the fatty acid binding site by the missense mutation.Instituto de Genética Veterinari

Characterization of the bovine gene LIPE and possible influence on fatty acid composition of meat

LIPE is an intracellular neutral lipase, which is capable of hydrolyzing a variety of esters and plays a key role in the mobilization of fatty acids from diacylglycerols. The objectives of this study were to characterize the genetic polymorphism of bovine LIPE gene and to evaluate the possible association between three SNPs in the coding regions of this gene with the fatty acid composition of meat in a cattle population. Forty-three unrelated animals from different cattle breeds were re-sequenced and 21 SNPs were detected over approximately 2600. bp, five of these SNPs were novel. Three SNPs were selected, on the basis of evolutionary conservation, to perform validation and association studies in a crossbred cattle population. Our results may suggest a possible association of SNP1 with contents of oleic acid and total monounsaturated fatty acids (p < 0.01), and SNP2 and SNP3 with Heneicosylic acid content (p < 0.01), may be helpful to improve the quality of meat and improve health.Instituto de Genética Veterinari

Precocidad sexual de corderas Texel, Corriedate, Highlander y Poll Dorset en el Sudeste de Buenos Aires

La provincia de Buenos Aires posee el 17% del total de ovinos de la Argentina. La mayoría de las majadas están constituidas por razas de doble propósito (carne y lana) y se crían predominantemente en forma extensiva sobre campo natural. Tradicionalmente, el primer servicio se realiza en el segundo otoño de vida de las borregas, cuando tienen 18-20 meses de edad. Sin embargo, en la actualidad existen razas que permiten adelantar el primer servicio al primer otoño de vida, cuando las corderas tienen 7-9 meses de vida. El objetivo del presente trabajo fue comparar el desempeño reproductivo de 4 razas ovinas servidas a los 8-9 meses de edad para evaluar su precocidad sexualEEA BalcarceFil: Gual, Ignacio. Universidad Nacional de mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Hozbor Federico A. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Papaleo Mazzucco, Juliana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Jaimes, Florencia. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Dininno, José Sergio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Nieto, Carlos Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Burges, Julio Cesar. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentin

Characterization of the bovine gene LIPE and possible influence on fatty acid composition of meat

LIPE is an intracellular neutral lipase, which is capable of hydrolyzing a variety of esters and plays a key role in the mobilization of fatty acids from diacylglycerols. The objectives of this study were to characterize the genetic polymorphism of bovine LIPE gene and to evaluate the possible association between three SNPs in the coding regions of this gene with the fatty acid composition of meat in a cattle population. Forty-three unrelated animals from different cattle breeds were re-sequenced and 21 SNPs were detected over approximately 2600. bp, five of these SNPs were novel. Three SNPs were selected, on the basis of evolutionary conservation, to perform validation and association studies in a crossbred cattle population. Our results may suggest a possible association of SNP1 with contents of oleic acid and total monounsaturated fatty acids (p < 0.01), and SNP2 and SNP3 with Heneicosylic acid content (p < 0.01), may be helpful to improve the quality of meat and improve health.Instituto de Genética Veterinari

Efecto de la maduración sobre la calidad de la carne en novillos brangus

Tesis para obtener el grado de Magister Scientiae en Producción Animal. presentada en la Facultad de Ciencias Agrarias de la Universidad Nacional de Mar del Plata, en Septiembre de 2008.Se utilizaron 193 terneros de destete de raza Brangus, provistos por seis cabañas pertenecientes a la Asociación Argentina de Brangus, engordados sobre pasturas permanentes en el oeste de la provincia de Buenos Aires y faenados a lo largo de 6 fechas (F) al alcanzar 6 mm de espesor de grasa dorsal ecográfico, resultando en un promedio de peso vivo de 457 kg. En la res se registró la evolución del pH y temperatura durante las primeras 24 horas post-mortem. Se extrajeron tres bifes (costillas 11ª a 13ª) de cada media res izquierda, los que se envasaron al vacío y asignaron al azar a tres tratamientos de maduración post-mortem (T) a 2-5 ºC: 1, 7 y 14 días. En laboratorio se determinó el pH final (pHu), la resistencia al corte (Rc), las coordenadas de color L*a*b* y las pérdidas por descongelación (Pd) y cocción (Pc). Las coordenadas L* y a* mejoraron con la maduración. Se detectó interacción entre F y T para pHu, Pd, Pc, Rc y b*. Para las primeras tres características la interacción se produjo por cambios en el ordenamiento en las medias de T entre fechas. En cambio, para Rc y b* la interacción se dio por cambios en la magnitud de la diferencia entre medias de T. Se observó que los valores de Rc disminuyeron y los de b* aumentaron con la maduración. La técnica de descongelación afectó a Rc, b*, Pd y Pc. Se detectó efecto fenotípico de padre sobre Rc y L*. Se concluye que, para la muestra de la raza Brangus estudiada, la maduración mejora el color, la terneza y la jugosidad, siendo 14 días de almacenamiento la duración más favorable. Por otra parte, los resultados sugieren que podría haber un componente genético dentro de la variación fenotípica en Rc y L*, lo que debe ser estudiado.One hundred and ninety-three weaning Brangus calves coming from six pedigree breeding herds belonging to the Argentine Brangus Association were used. Calves were fattened on pastures in a commercial farm located in the west of Buenos Aires province and slaughtered along six dates (D) with a mean live-weight of 457 kg, when they reached 6mm of ultrasound back-fat thickness. Carcass pH and temperature were measured between 1h and 24h post-mortem. Three steaks corresponding to the left half-carcass 11th to 13th rib were obtained, vacuum packed and randomly assigned to three treatments (T) of post-mortem ageing length at 2-5ºC: 1, 7 and 14d. At the meat laboratory the following measurements were recorded: ph ultimate (pHu), Warner- Bratzler shear force (WB), L*, a* and b* colour parameters and thawing (Tl) and cooking (Cl) losses of meat. Increasing ageing length significantly improved L* and a*. A significant D*T interaction was detected for pHu, Tl, Cl, b* and WB. For the first three variables the interaction was explained by treatment means ranking differently in the different slaughter dates, whereas for b* and WB means ranking didn’t change, increasing and diminishing, respectively, with increasing ageing length. An important effect of thawing technique on WB, b*, Tl and Cl was observed. The inclusion of the sire of steer random effect in the model of analyses revealed significance for WB and L*. It is concluded that in the Brangus breed sample studied, ageing is useful to improve meat colour, juiciness and tenderness, with 14d-length being best among the treatments studied. Results also suggest that a genetic component may exist within the phenotypic variation of meat tenderness and brightness, which must be further studied.EEA BalcarceFil: Papaleo Mazzucco, Juliana. Instituto Nacional de Tecnología Agropecuaria (INTA) Estación Experimental Agropecuaria Balcarce; Argentin

Desempeño productivo de ovejas y corderos de la Reserva 8, Balcarce. Periodo 2008-2019.

La Unidad Ganadera “Reserva 8” de la EEA Balcarce tiene una historia ovina de más de 50 años, comenzando como un campo productivo para luego pasar a ser un campo experimental. En todos esos años se trabajó con diversidad de razas ovinas puras y en cruzamientos. El objetivo de este trabajo es evaluar la evolución de los pesos de corderos y ovejas desde el nacimiento hasta el destete en 4 razas puras, tomando los registros de los últimos 10 años.EEA BalcarceFil: Papaleo Mazzucco, Juliana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Hozbor Federico A. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentin

Datos reproductivos de cuatro razas ovinas bajo condiciones de pastoreo en la Reserva 8, Balcarce. Comunicación

La Unidad Ganadera “Reserva 8” de la EEA Balcarce tiene una historia ovina de más de 50 años, comenzó como un campo productivo que luego pasó a ser un campo experimental. En todos estos años se trabajó con diversidad de razas ovinas puras y cruzamientos. El objetivo de este trabajo es comparar parámetros reproductivos de cuatro razas, tomando los registros de los últimos 10 años.EEA BalcarceFil: Papaleo Mazzucco, Juliana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Ledesma, Alba Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible Balcarce; ArgentinaFil: Hozbor Federico Andrés. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentin