2019) Determination of carcase yield, sensory and acceptance of meat from male and female pigs with dietary supplementation of oregano essential oils ABSTRACTThe aim was to determine the dietary supplementation of oregano essential oil (OEO) to male and female pigs on carcase performance, sensory characteristics and consumer acceptability of meat. A total of 48 pigs (Landrace  Yorkshire) of 18.5 ± 5.4 kg live weight were randomly allotted into one of four experimental diet groups each containing 12 pigs. Each group was fed a commercial diet supplemented with 0 ppm (control), 1000 ppm, 2000 ppm or 3000 ppm OEO. No difference (p>.05) by OEO supplementation nor by gender was observed in average daily gain (0.56 kg/d), daily feed intake (2.5 kg/d), slaughter weight (94.1 kg), and cold carcase weight (71.4 kg). Pigs receiving 2000 ppm OEO had higher (p<.05) cold carcase yield (77.4%) than the other treatments and it was higher in females (76.9%) than in males (74.3%). Pigs with 1000 and 2000 ppm OEO showed higher carcase length and carcase width. Loin yield was higher (p<.05) in pigs fed 2000 ppm (28.8%) and leg yield of pigs fed all level of OEO was lower (p<.05) than the control group. Females showed better values of carcase performance. Meat from pigs receiving 2000 ppm OEO was evaluated by the trained panellists as the best in colour and it also showed the highest consumer acceptability of colour, flavour, texture and overall liking. The supplementation of 2000 ppm OEO in pig diets is suggested to achieve good carcase performance and consumer acceptability. HIGHLIGHTS

Los objetivos fueron analizar la estructura y variabilidad genética del bisonte americano con marcadores genéticos de tipo SNP. Se muestrearon 174 bisontes y se analizaron 42,366 SNP distribuidos en los 29 cromosomas. Se estimó la heterocigosis esperada (He) y observada (Ho), contenido de información polimórfica (CIP), índice de fijación (FIS), índice de Shannon (IS), desequilibrio de ligamiento y relación de parentesco (Rij; %), así como el tamaño efectivo de población (Ne). Se realizó un análisis de estructura genética para inferir cuántas líneas o genomas (k) definen la población. Se identificó y seleccionó un panel con 2,135 SNP polimórficos, con un promedio de 74 SNP por cromosoma. En el proceso de exclusión,  84.5 % fueron monomórficos,  8.5 % con porcentaje de usables menor a 90 %, 6.3 % con frecuencia del alelo menor inferior a 0.01 y 0.70 % por desequilibrio Hardy-Weinberg (P<0.05). Las estimaciones de IS, Ho, He, FIS y CIP fueron de 0.30, 0.187, 0.182, -0.029 y 0.152, respectivamente. Se generaron 15,051 estimaciones de Rij, el valor promedio de éstas fue 7.6 %, y el 45.1 % de ellas fue igual a cero. El Ne fue de 12.5, señalando un posible incremento de consanguinidad por generación de 4 %. Se identificaron tres líneas genéticas, con proporciones de 0.730, 0.157 y 0.113; dado el origen de la población, se asocian a selección natural o deriva genética. La variabilidad genética, así como los niveles de la Rij, se deben de considerar en esquemas de conservación.

En la ganadería de lidia, la selección está en función del desempeño del toro durante la lidia. Posición de la cabeza (PC) y de las manos (PM), recorrido del toro (RE) y modo de finalizar (FI) la embestida define el desempeño del toro, y pueden ser considerados como criterios de selección. El objetivo fue estimar heredabilidades (h2) y correlaciones genéticas (rg) para PC, PM, FI y RE; y construir dos índices de selección: IS1 con valores relativos de un análisis factorial, IS2 con valores relativos a partir de la desviación estándar de cada rasgo. Se calculó la respuesta a la selección (RS) y exactitud (EX) de cada IS. El número de observaciones (valor promedio ± desviación estándar) para PC, PM, RE y FI fue 984 (5.46 ± 1.4), 978 (2.93 ± 1.1), 981 (3.15 ± 0.7) y 785 (2.88 ± 1.1), respectivamente; con escalas de uno a siete para PC, y de uno a cinco para el resto de las variables. Para h2 y rg se realizó un análisis multivariado con el software MTDFREML. La h2 fue de 0.20 ± 0.06, 0.15 ± 0.05, 0.13 ± 0.03 y 0.17 ± 0.05 para PC, RE, PM y FI, respectivamente; todas las rg fueron positivas, de 0.57 a 0.94, con valor promedio de 0.753. IS1 = 0.068*PC + 0.048*RE - 0.012*PM + 0.088*FI; con EX de 0.46 y RS de 0.325. IS2 = 0.231*PC + 0.249*RE - 0.038*PM + 0.298*FI; con EX de 0.45 y RS de 1.15.

This study analyzed the Sardo Negro breed pedigree (41,521 animals registered from 1958 to 2019) to determine its structure, evolution, and genetic variability (GV). The population genetic parameters evaluated were effective number of founders (fe) and ancestors (fa), pedigree integrity, additive genetic relationship (AGR); number of complete generations (NCG), maximum generations traced (NMGT), and equivalent complete generations (NECG); effective population size (Ne), inbreeding coefficient (F), and generation interval (GI). The average GI was 7.45 years. A total of 7,804 founders and 4,856 ancestors were identified for a fe of 185 and a fa of 97. The average and maximum values of NCG, NECG, and NMGT were 1.6 and 5.0, 2.5 and 6.5, 4.3 and 12, with Ne estimates of 15.9, 25.9, and 69.0, respectively. The increase in F, linked to Ne, ranged from 0.72% to 3.1% per generation. The average values for F and AGR were 3.6% and 1.0%, respectively. The proportion of inbred individuals was 32.0%, with F values ranging from 0.01 to 62.2% and an average of 11.3%. The rate of inbred population was 1.3% per year. The annual rate of AGR was 0.04%. For the continuity and projection of the breed, the evolution of F as a function of Ne and the possible implications of the selection schemes must be considered. The genetic variability sustained over time results from the Ne.

This study aimed to evaluate the lactation curve of female Murrah buffaloes, using mixed nonlinear models (NLM), across three lactation periods (180 d, 210 d, and 240 d). A total of 5334 data on daily milk production (kg) were analyzed. The data were collected every seven days in the interval of one to 250 days of lactation, corresponding to 221 lactations and 145 females, with calvings from 2017 to 2019. The data came from a herd located in the Centro municipality, Tabasco, Mexico. Five NLM were evaluated: Wood (WOD), Wiltmink (WIL), Cobby (COB), Brody (BRO), Sikka (SIK). The best fit model was selected based on the mean prediction error, mean absolute percentage error (MAPE), prediction error variance, coefficient of determination (R 2 ), concordance correlation coefficient (CCC), Akaike (AIC) and Bayesian (BIC) information criteria. A regression analysis was performed between the observed and predicted values. All the NLM had a R 2 above 0.91. They tend to underestimate the predictions, without residual autocorrelation. The MAPE showed an average value of 23.5%. The best fit model was WOD, followed by SIK and BRO. For WIL and COB, the mixed model did not improve the fitting. The shortest lactation period showed the best fit, followed by the 210 d and 240 d periods. The relationship between observed:predicted values fluctuated from 0.65 to 1.00, with an average value of 0.94. The use of NLM transcended in the AIC and BIC. The evaluated models showed goodness of fit, with good predictability, but low values in accuracy and precision of prediction.