ABSTRACT Single nucleotide polymorphisms are variations of a single nucleotide base pair and can be associated to phenotypic characteristics. This study aimed to determine the association of CAPN1 and CAST gene polymorphisms with the tenderness of Creole cattle meat from the Amazonas region, Peru. The texture profile (adhesiveness, cohesiveness, Warner-Bratzler shear force, elasticity, gumminess, and chewiness) of 100 animals was determined in 100 g of Longissimus dorsi et lumborum muscle. Allelic frequencies, genotypic frequencies, and Hardy-Weinberg equilibrium (HWE) of calpain (CAPN-316, CAPN-530) and calpastatin (CAST-2959) gene polymorphisms were studied. Allelic and genotypic frequencies were calculated, as well as the Hardy-Weinberg equilibrium with the Chi-square test. The texture profile of each group of samples corresponding to a polymorphism was compared with the Duncan’s test and the t-test for independent samples (p < 0.05). Genotypic frequencies were 78 % GG and 22 % CC for CAPN-316; 68 % GG, 5 % GA, and 27 % AA for CAPN-530; and 74 % AA, 18 % AG, and 8 % GG for CAST-2959. The CAPN-316, CAPN-530, and CAST-2959 polymorphisms were not in Hardy-Weinberg equilibrium. The CC genotype of CAPN-316 marker influences meat tenderness on day 21 of meat aging. In contrast, the GG genotype of CAST-2959 marker affects meat tenderness at days 14 and 21 of meat aging concerning the other genotypes. characteristics CAPN region Peru adhesiveness, adhesiveness (adhesiveness cohesiveness WarnerBratzler Warner Bratzler force elasticity gumminess chewiness 10 muscle HardyWeinberg Hardy Weinberg HWE (HWE CAPN316, CAPN316 316, 316 (CAPN-316 CAPN530 530 CAPN-530 CAST2959 2959 (CAST-2959 studied calculated Chisquare Chi square Duncans Duncan s ttest t p 0.05. 005 0.05 . 0 05 0.05) 7 2 6 GA 1 AG CAST2959. 2959. CAPN530, 530, CAST-295 CAPN-31 contrast genotypes CAPN31 31 (CAPN-31 CAPN53 53 CAPN-53 CAST295 295 (CAST-295 00 0.0 CAST-29 CAPN-3 CAPN3 3 (CAPN-3 CAPN5 CAPN-5 CAST29 29 (CAST-29 0. CAST-2 CAPN- (CAPN- CAST2 (CAST-2 CAST- (CAPN (CAST- (CAST

Abstract The agronomic parameters of Tithonia diversifolia were evaluated by the effect of four cutting heights (AC) from the ground (AC1: 0 cm, AC2: 10 cm, AC3: 20 cm, AC4: 30 cm); with four replicates each, by 55 days. Shoots/tiller, leaves/shoot and leaves/tiller were higher (p<0.05) in AC1. However, the number of leaves/bush and shoots/bush were higher (p<0.05) in AC2, AC3 and AC4. The green forage weight (FV)/tiller was higher (p<0.05) in AC1; although, the weight of FV/mat was higher in AC2, AC3 and AC4, showing a higher (p<0.05) yield (kg/m2) in FV and dry matter for AC2, AC3 and AC4. The higher number of leaves/shoot (p<0.05) in AC2 than AC4 could improve the productivity of T. diversifolia, suggesting AC2 as adequate AC.

Resumen Se evaluaron los parámetros agronómicos de Tithonia diversifolia por efecto de cuatro alturas de corte (AC) desde el suelo (AC1: 0 cm, AC2: 10 cm, AC3: 20 cm, AC4: 30cm), con cuatro replicas cada una, durante 55 días. Los brotes/macollo, hojas/brote y hojas/macollo fueron mayores (p<0.05) en AC1. Sin embargo, el número de hojas/mata y brotes/mata fueron mayores (p<0.05) en AC2, AC3 y AC4. El peso de forraje verde (FV)/macollo fue mayor (p<0.05) en AC1; aunque el peso de FV/mata fue mayor en AC2, AC3 y AC4, mostrando un mayor (p<0.05) rendimiento (kg/m2) en FV y materia seca para AC2, AC3 y AC4. El mayor número de hojas/brote (p<0.05) en AC2 que AC4 podría mejorar la productividad de T. diversifolia, sugiriendo a AC2 como adecuada AC.

ABSTRACT The aim of this study was to determine the influence of a co-culture system with cumulus oophorus cells on the quality of bovine embryos produced in vitro, based on their viability. Ovaries from crossbred bovine slaughtered at the Chachapoyas Municipal Benefit Centre, Amazonas, Peru, were used. Oocytes aspirated from 2-6 mm follicles were matured in TCM-199 medium for 24 hours, in a humidified atmosphere with 6% CO and 38.5 °C. The maturation state was determined by the nuclear stage through aceto-orcein staining. The mature oocytes were fertilized in vitro with frozen semen from Angus bulls for 18 hours. The presumed zygotes were randomly distributed for development in one group in medium with co-culture and another in medium without co-culture (control). The embryonic quality was determined based on the enzymatic activity and DNA damage of the embryos on the seventh day of culture, using the fluorochromes fluorescein diacetate (FDA) and propidium iodide (PI), respectively. No significant association was found in the number of embryos produced in vitro, but there was a significant difference in embryonic viability in favour of the system with co-culture (p<0.05). The use of co-cultures with cumulus oophurus cells improves viability and, therefore, embryonic quality, without influencing the rate of embryo production in vitro.

RESUMEN El estudio tuvo como objetivo determinar la influencia de un sistema de co-cultivo con células del cumulus oophorus sobre la calidad de embriones bovinos producidos in vitro en función a su viabilidad. Se utilizaron ovarios de bovinos hembra cruzadas, sacrificadas en el Centro de Beneficio Municipal de Chachapoyas, Amazonas, Perú. Los ovocitos aspirados de folículos de 2-6 mm fueron madurados en medio TCM-199 por 24 horas, en una atmósfera humidificada con 6% de CO2 y a 38.5 °C. El estado de maduración fue determinado mediante el estadio nuclear a través de tinción aceto- orceína. Los ovocitos maduros se fertilizaron in vitro con semen congelado de toros Angus durante 18 horas. Los presuntos cigotos fueron distribuidos aleatoriamente para su desarrollo en un grupo en medio con co-cultivo y otro en medio sin co-cultivo (control). Se determinó la calidad embrionaria en función a la actividad enzimática y daño al ADN de los embriones al séptimo día del cultivo, mediante los fluorocromos diacetato de fluoresceína (FDA) y yoduro de propidio (PI), respectivamente. No se encontró asociación significativa en la cantidad de embriones producidos in vitro, pero hubo diferencia significativa en viabilidad embrionaria a favor del sistema con co-cultivo (p<0.05). El uso de co-cultivos con células de cumulus oophurus mejora la viabilidad y, por lo tanto, la calidad embrionaria, sin influir en la tasa de producción de embriones in vitro.

La morfología espermática es esencial en la evaluación de la calidad seminal e importante para la predicción de la fertilidad de machos reproductores. El objetivo del presente estudio fue comparar los parámetros morfométricos de espermatozoides de alpaca, obtenidos por tres métodos de extracción de semen, la recuperación del conducto deferente (DCD), electroeyaculación (EE) y aspiración vaginal (AV). La colección se realizó de 3 animales por cada método. Se determinó la movilidad, concentración, vitalidad, funcionalidad de membrana y parámetros de morfometría espermática, con un equipo de análisis computarizado de semen - ISAS® CASA - Morph. Para los parámetros morfométricos, las muestras de semen se procesaron con un kit de tinción Hemacolor® y se observaron en un microscopio de contraste de fases. Por cada muestra, se capturaron al menos 200 espermatozoides al azar, con resolución de imágenes de 0.08 μm por píxel en los ejes horizontal y vertical. La motilidad total fue de 16.27±11.96%, 14.68±11.21% y 12.44±7.27%, la concentración espermática de 247±186.70 x 10(6)EPZ/mL, 67.92±67.92 x 10(6)EPZ/mL y 100.32±56.13 x 10(6)EPZ/mL, la vitalidad fue 62.86±15.92%, 63±15.21% y 70.16±14.33% en espermatozoides colectados por DCD, EE y AV respectivamente. En cuanto a los parámetros morfométricos se encontró una longitud de 5.49±0.43 µm, 5.53±0.41µm y 5.75±0.53µm, área 14.30±2.0µm², 15.05±1.77µm² y 15.88±2.0µm², perímetro de 16.10±1.31µm, 17.11±1.20µm y 17.41±1.43µm, ancho de 3.22±0.27µm, 3.30±0.32µm y 3.33±0.25 µm y el porcentaje de acrosoma de 52.22±7.82%, 49.52±7.47% y 47.44±5.77% en espermatozoides colectados por DCD, EE y AV respectivamente. La comparación de los parámetros morfométricos entre método de colecta y animal se realizó mediante un diseño de bloques alzar. Los parámetros morfométricos del tamaño y forma de la cabeza de espermatozoide, y pieza intermedia mostraron diferencias estadísticas significativas (p<0.01) entre métodos de colección y entre animal. En conclusión, los parámetros morfométricos del espermatozoide de alpaca son influidos por el método de colección, y muestran variación entre animales.

Sperm morphology is essential in evaluating seminal quality and important for fertility prediction in breeding males. The aim of this study was to compare the morphometric parameters of alpaca sperm, collected using three methods of semen extraction, recovery of the vas deferens (DCD), electro ejaculation (EE) and vaginal aspiration (VA). The collection was made of 3 animals by each method. The mobility, concentration, vitality, membrane functionality and sperm morphometry parameters were determined in a computerized semen analysis kit - ISAS® CASA - Morph. For morphometric parameters, semen samples were processed with a Hemacolor® staining kit and viewed under a phase-contrast microscope. For each sample, at least 200 sperm were captured at random, with an image resolution of 0.08 µm per pixel on the horizontal and vertical axes. The comparison of the morphometric parameters between the collection method and the animal was carried out using a random block design. Total motility was 16.27±11.96%, 14.68±11.21% and 12.44±7.27%; the sperm concentration of 247±186.70x10(6)EPZ/mL, 67.92±67.92x10(6)EPZ/mL and 100.32±56.13x10(6)EPZ/mL, the vitality was 62.86 ±15.92%, 63±15.21% and 70.16±14.33% in sperm collected by DCD, EE and AV respectively. Regarding the morphometric parameters, a length of 5.49±0.43µm, 5.53±0.41µm and 5.75±0.53µm was found, area 14.30±2.00 µm², 15.05±1.77 µm² and 15.88±2.00 µm², perimeter of 16.10±1.31µm, 17.11±1.20µm and 17.41 ± 1.43, width of 3.22±0.27µm, 3.30±0.32µm and 3.33±0.25µm and the acrosome percentage of 52.22±7.82µm, 49.52±7.47µm and 47.44±5.77µm in sperm collected by DCD, EE and AV respectively. The morphometric parameters of the size and shape of the sperm head and the intermediate piece showed significant statistical differences (p <0.01) between the collection methods and between the animals. In conclusion, the morphometric parameters of alpaca spermatozoa were influenced by collection method, and show variations between animals.