RESUMO: Este estudo teve como objetivo avaliar o impacto da silagem de ração total de Megathyrsus maximus colhido com 70 cm de altura e concentrado no momento da silagem ou ração total de capim cortado a 70 cm, composta por Megathyrsus maximus colhido com 70 cm de altura (nos Exp. I e III) e silagem de ração total cortada a 130 cm, composta por Megathyrsus maximus colhido com 130 cm de altura e concentrado no momento da silagem ou ração total de Megathyrsus maximus colhido a 130 cm de altura (nos Exp. II e IV), sobre o metabolismo ruminal, a digestibilidade dos nutrientes, e o desempenho e as características de carcaça de cordeiros confinados. Os resultados mostraram que TMRS70 aumentou o pH ruminal no Exp. I, e TMRS130 exibiu maior digestibilidade do extrato etéreo, concentração de propionato e menor razão acético/propionato e pH ruminal em comparação com TMR130 no Exp. II. Nos Exp. III e IV, não houve efeito significativo sobre o desempenho e a qualidade da carcaça. No entanto, no Exp. IV, TMRS130 levou a uma diminuição no consumo de matéria seca e no ganho médio diário, enquanto cordeiros alimentados com TMR130 mostraram uma maior área de olho de lombo. A ensilagem da ração total poderia ser usada como um método de conservação para gramíneas jovens (70 cm) sem prejudicar o desempenho, metabolismo, carcaças e qualidade da carne. No entanto, recomenda-se mais estudos avaliando a análise econômica da alimentação com ensilagem de ração total (70 cm) em vez de ração totalmente misturada como método de conservação de forragem. RESUMO 7 nos Exp 13 IV , IV) nutrientes confinados TMRS TMRS7 TMRS13 etéreo acéticopropionato acético TMR TMR13 entanto diário lombo (7 carne recomendase recomenda se forragem 1 TMRS1 TMR1 (

ABSTRACT: This study assessed the impact of total mixed ration silage of Megathyrsus maximus harvested with 70 cm composed of Megathyrsus maximus harvested at 70 cm in height and concentrate at the time of silage or total mixed ration of grass cut at 70 cm composed of Megathyrsus maximus harvested with 70 cm in height (in Exp. I and III) and total mixed ration silage cut at 130 cm composed of Megathyrsus maximus harvested 130 cm height and concentrate at the time of silage or total mixed ration of Megathyrsus maximus harvested with 130 cm composed of Megathyrsus maximus harvested at 130 cm height (in Exp. II and IV), on rumen metabolism, nutrient digestibility, and the performance and carcass characteristics of feedlot lambs. The results showed that TMRS70 increased ruminal pH in Exp. I and TMRS130 exhibited higher ether extract digestibility, propionic concentration, and lower acetic to propionic ratio and ruminal pH compared to TMR130 in Exp. II. In Exp. III and IV, there was no significant effect on the performance and quality of the carcass. However, in Exp. IV, TMRS130 led to decreased dry matter intake and average daily gain, while lambs fed with TMR130 showed a higher rib-eye area. Total ration ensilage could be used as a conservation method for young grasses (70 cm) without impairing performance, metabolism, carcasses, and meat quality. However, further research is recommended to evaluate the economic analysis of feeding total ration ensilage (70 cm) instead of total mixed ration as a forage conservation method. ABSTRACT 7 Exp 13 IV , IV) metabolism digestibility TMRS TMRS7 TMRS13 concentration TMR TMR13 However gain ribeye rib eye area (7 carcasses 1 TMRS1 TMR1 (

ABSTRACT: Meat consumption has been declining in favor of a shift towards poultry due to its lower price, health benefits and consumers’ preference. One of the ways to enhance broiler production and quality is to substitute standard maize (SM) with quality protein maize (QPM) in animal diets. QPM is a high lysine maize with improved nutritional and biological values, developed by the selection of a naturally occurring recessive opaque2 mutation, which can reduce the use of costly feed components - synthetic lysine and protein ingredients such as soybean and fishmeal. Different feeding trials with QPM in broiler diets indicated that body weight gain (BWG), feed conversion ratio (FCR), breast meat yield (BMY), and abdominal fat (AF) are the main improved features. Herein, an overview of the effects of QPM on broiler performance and carcass characteristics, as well as the financial effects of its use, is presented. Different effects of QPM were observed, depending, in the main, on the QPM hybrid used in the trial. The possible reasons for the discrepancies and suggestions for overcoming them, focused on the utilization of the full potential of QPM, are discussed. ABSTRACT price consumers preference SM (SM (QPM values opaque mutation fishmeal BWG, BWG , (BWG) FCR, FCR (FCR) BMY, BMY (BMY) AF (AF features Herein characteristics presented observed depending trial them discussed (BWG (FCR (BMY

RESUMEN En dos experimentos se evaluó la adición de AminoGut (AG). En el Experimento 1, se utilizaron 300 pollos Ross 308 en 5 tratamientos con 3 repeticiones de 20 pollos cada una. En el Experimento 2, se emplearon 640 pollos en 4 tratamientos con 5 repeticiones de 32 pollos cada una. Los tratamientos del Exp. 1: T1.- Dieta testigo sorgo + pasta de soya, T2.- Como 1 + 700 ppm de la mezcla de AG/ ton, T3.- Como 1 + 1400 ppm de AG/ ton, T4.- Como 1 + 2100 ppm de AG/ ton, T5.- Como 1 + 2800 ppm de AG/ ton. En el Exp. 2 se eliminó el tratamiento 5. En el Experimento 1, hubo efecto (P<0.05) en comportamiento productivo y peso de la canal, con 700 ppm de AG. En el Experimento 2, mejoró la altura de vellosidades intestinales e hipersensibilidad tardía (P<0.05) con 700 ppm de AG, así como el rendimiento en canal a los 42 días. Se puede concluir que la adición de 700 ppm de AminoGut en dietas para pollos de 1 a 21 días de edad, incrementó los parámetros productivos, longitud de las vellosidades, rendimiento en canal y respuesta inmune.

Abstract In two experiments, the addition of AminoGut (AG) was evaluated. In Experiment 1, 300 Ross 308 broilers were used in five treatments with three repetitions of 20 broilers each. In Experiment 2, 640 broilers were used in four treatments with five repetitions of 32 broilers each. Exp. 1 treatments: T1.- Control diet sorghum + soybean meal, T2.- As 1 + 700 ppm of the mixture of AG/ ton, T3.- As 1 + 1400 ppm of AG/ ton, T4.- As 1 + 2100 ppm of AG/ ton, T5.- As 1 + 2800 ppm of AG/ ton. In Exp. 2, treatment 5 was eliminated. In Experiment 1, there was an effect (P<0.05) on performance and carcass weight, with 700 ppm of AG. In Experiment 2, the height of intestinal villi and late hypersensitivity (P<0.05) improved with 700 ppm of AG, as well as carcass yield at 42 days. It can be concluded that the addition of 700 ppm of AminoGut in diets in broilers from 1 to 21 days of age, increased the performance, villus length, carcass yield and immune response.

ABSTRACT The beef is one of the main sources of nutrients for a balanced diet. In this context, several authors have reported that grass-fed beef presents low levels of intramuscular fat and high levels of polyunsaturated fatty acids. Some studies have noted that forage fatty acid content is variable between species and their varieties, and that can affect fatty acid profile in beef. The aim of this study was to evaluate beef quality from three different types of pastures in southern Chile. A group of 45 Holstein Friesian steers were finished in the spring months with three different types of pastures from temperate rainy climate: Improved pasture (P), Lolium perenne L.-based pasture (LT), and Lolium multiflorum Lam.-based pasture (LM). The steers were separated into groups of 15 for treatment. Nonsignificant differences were found in carcass measurements and P treatment showed a higher intramuscular content than LM treatment (2.26% vs. 1.42%) and greater presence of SFA: 42.4% vs. 40.3% reported in LM treatment. While LM presented a higher n-6 fatty acids: 4.42% related to P treatment: 3.13%. Regardless of the type of pasture, it can be confirmed that meat from pasture systems presents low intramuscular fat and a better ratio of n-6/n-3.

Abstract The objective of this study was to examine the impact of a high-fat finishing diet on the in vivo performance, anatomical and carcass characteristics, and meat quality of adult culled goats. Over a period of 28 days leading up to slaughter, eighteen adult culled goats were subjected to a finishing diet provided in quantities sufficient to meet 3.0 times the nutritional requirements of adult non-dairy maintenance goats. The female goats were divided into two groups: one fed with the baseline diet without fat supplementation (n = 9) and the other fed a diet concentrated supplemented with whole full-fat linseed (n = 9). The diets varied in fat content (2.8% vs. 8.4% DM). The high-fat group exhibited a higher dry matter intake compared to the control group (+37%), along with elevated plasma cholesterol and triglyceride levels. The control group experienced a significant decrease in daily weight gain between the second and final week of the finishing period (-70%), in contrast to the increase observed in the high-fat group (+59%). At slaughter, no differences were noted between the groups in anatomical and carcass characteristics. Additionally, no differences were found between the diets regarding proximate composition, pH, yellow color component, and lightness of loin. The high-fat group exhibited a higher redness of loin. The inclusion of high-fat levels in finishing diets for culled adult goats allows for increased feed intake and performance but does not appear to affect carcass or meat quality.

Resumen El objetivo de este estudio fue evaluar el efecto del sexo sobre el peso vivo final, las características de la canal, los rasgos de calidad de la carne y las propiedades sensoriales de una línea específica de cerdos mestizos (Landrace 75% x Yorkshire 25% “Degesa”). En el presente estudio se utilizaron ocho machos castrados (MC) y ocho nulíparas (H) seleccionados al azar. No se observaron diferencias (P˃0.05) entre sexos en cuanto a las características de la canal, el valor de la fuerza de cizallamiento o la longitud del sarcómero. Sin embargo, el grosor de la grasa dorsal, el pH@45, el pH@24, la capacidad de retención de agua, el puntaje de marmoleado y el contenido de grasa intramuscular fueron mayores (P˃0.05) en MC que en H. La carne de MC tuvo menor (P=0.04) luminosidad que la de H, pero similar (P≥0.34) rojez y amarillez. La proporción total de ácidos grasos saturados (AGS), así como los AGS individuales (C16:0 y C18:0) fueron mayores en MC que en H, pero la relación n-6:n-3 fue menor en los machos que en las hembras. En general, la carne de los machos fue mejor calificada que la carne de hembras por el panel entrenado en atributos de sabor, pero el resultado fue opuesto cuando se evaluaron las propiedades de textura. Además, una mayor puntuación general de color, así como los atributos de sabor, se asociaron positivamente con el contenido de grasa intramuscular y la tasa de AG monoinsaturados, pero se asociaron negativamente con la proporción de AG poliinsaturados. En conclusión, los resultados sugieren que la calidad de la carne de cerdos mestizos Degesa mostró marcadas diferencias relacionadas con el sexo y, por lo tanto, podría ser comercializado diferencialmente por sexo en el mercado de carne.

Abstract The objective of this study was to evaluate the effect of sex on final live weight, carcass characteristics meat quality traits and sensory properties of a specific cross breed pig line (Landrace 75% x Yorkshire 25% “Degesa”). Eight randomly selected barrows (CM) and eight gilts (F) were used in the present study. No differences (P˃0.05) between sexes for carcass characteristics, shear-force value or sarcomere length were observed. However, back fat thickness, pH@45, pH@24, water-holding capacity, marbling score and intramuscular fat content were higher (P˃0.05) in CM than in F. Meat from CM had lower (P=0.04) lightness than F but similar (P≥0.34) redness and yellowness. Total saturated fatty acids (SFA) proportion as well as individual SFAs (C16:0 and C18:0) were greater in CM than in F, but n-6:n-3 ratio was lower in males than females. In general, meat from males were better scored than meat from females by the trained panel in flavor attributes but the result was opposed when textural properties were evaluated. In addition, greater overall color score as well as flavor attributes were positively associated with intramuscular fat content and rate of monounsaturated FA but negatively associated with rate polyunsaturated FA proportion. In conclusion, results suggest that pork quality from Degesa crossbred pigs showed marked sex-related differences and therefore, it could be deferentially commercially by sex in the meat market.

Resumen Asegurar la calidad e inocuidad de la carne de animales de abasto es tema de preocupación mundial. De los factores que se deben cuidar están las actividades que generan estrés al animal durante el manejo ante-mortem (transporte, descanso y aturdimiento) y el manejo de la canal post-mortem (maduración y almacenamiento), aunado a las prácticas de higiene en instalaciones y personal. El objetivo del trabajo fue caracterizar unidades de matanza ovina con base a la normatividad mexicana vigente dentro del municipio de Capulhuac de Mirafuentes, Estado de México. Para lo cual, se realizó un análisis de componentes principales (CP), destacando que los que representaron mayor variabilidad en los centros de matanza fueron el precio de las canales y sus productos, lugar de comercialización, volumen de matanza, sexo del animal e inocuidad de las canales, los cuales representaron el 50.4 % de la varianza explicada. Así mismo se realizó un análisis de conglomerados el cual representó la integración de cuatro grupos de descriptores de matanza (P<0.05). Como resultados se encontró que 65 % de animales son faenados en locales comerciales y casas habitación, los cuales no cumplen con la tecnificación descrita en la normatividad; además de que presentan manejos deficientes ante-mortem y post-mortem de animales; también se observó que el 98.3 % de los establecimientos utiliza un método de matanza denominado descabellado, no reportado en la NOM-033-SAG/ZOO/ 2014, aunado al desconocimiento del personal en temas de bienestar animal. Afectando la calidad e inocuidad de la carne y poniendo en riesgo la salud de los consumidores.

Abstract Ensuring the quality and safety of meat from slaughter animals is a matter of global concern. Among the factors that must be taken care of are the activities that generate stress to the animal during antemortem handling (transport, rest, and stunning), postmortem carcass handling (aging and storage), and hygiene practices in facilities and staff. This work aimed to characterize sheep slaughter units within the municipality of Capulhuac de Mirafuentes, State of Mexico, based on current Mexican regulations. For this, a principal component (PC) analysis was carried out, highlighting that those that represented the highest variability in the slaughter centers were the price of the carcasses and their products, place of marketing, slaughter volume, sex of the animal, and safety of the carcasses, which represented 50.4 % of the explained variance. A cluster analysis was also carried out, which represented the integration of four groups of slaughter descriptors (P<0.05). As a result, it was found that 65 % of animals are slaughtered in commercial premises and houses that do not comply with the technification described in the regulations; they also present deficient antemortem and postmortem handling of animals; it was also observed that 98.3 % of the establishments use a slaughter method called “descabellado” (pithing), not reported in NOM-033-SAG/ZOO/2014, coupled with the lack of knowledge of the staff on animal welfare issues. This affects the quality and safety of meat and puts consumers’ health at risk.

The decomposition of a body, and the associated gaseous and liquid discharges emanating from it, attract gravid female blow flies which lay their eggs in or on the body. After the eggs have hatched, the emerging larvae start feeding on the body. As decomposition progresses, the blow fly larvae often migrate away, typically in a random manner in search of favourable conditions for pupation. In this paper, we report on a rarely described phenomenon of unidirectional mass migration of blow fly larvae and postulate on the factors which may drive this process. A decomposition trial utilising a 60-kg pig carcass, deployed in the summer months in Table Mountain National Park, Cape Town, South Africa, was conducted in 2022. On the fifth day of the trial, simultaneous unidirectional mass dispersal of blow fly larvae was observed. The larvae moved downhill in a southeasterly direction, following the flow of decomposition fluids oozing out from the pig carcass. The 'larval migration stream' had a length of approximately 1.5 m with a width of 40 cm, tapering to 17 cm at the terminal point. The larval migration stream consisted of the larvae of Chrysomya albiceps and Chrysomya chloropyga. This study demonstrates the importance of understanding the timing and pattern of dispersal of post-feeding blow fly larvae in each geographical region. This is crucial as the minimum post-mortem interval can be miscalculated if older immature insects dispersing from the corpse are not considered and collected during crime scene investigations. SIGNIFICANCE: • Understanding the timing and pattern of dispersal of blow fly larvae from decomposing vertebrate remains in each geographical region is important in time-since-death estimations when using entomological evidence. • In the summer season of the Western Cape Province, Chrysomya albiceps and Chrysomya chloropyga are among the blow fly species of forensic importance as they deposit their eggs on vertebrate remains. • When a decomposing body is found within the Table Mountain region, we suggest that crime scene investigators should examine the downhill area of the scene for larval/pupal entomological evidence that can assist in time and season of death estimations.

RESUMEN El objetivo del estudio fue evaluar el comportamiento productivo de cuyes en crecimiento, alimentados con forraje verde de alfalfa y un suplemento artesanal ampliamente difundido en el Valle del Mantaro, Perú, elaborado a base a subproducto de trigo, maíz amarillo integral y torta de soya en la proporción base de 3:2:1, comparado con cuatro alimentos comerciales, en términos de incremento de peso (IP), conversión alimenticia (CA), rendimiento de carcasa (RC) y mérito económico. Se utilizaron 60 cuyes machos y hembras de línea colorada de 18 ± 3 días de edad con pesos de 318 ± 35 g. Fueron distribuidos en cinco jaulas metálicas de cuatro niveles cada uno. Se utilizó un Diseño de Bloques Completos al azar considerando al sexo como bloque. El efecto logrado por el suplemento artesanal sobre IP, CA y RC fue similar a lo conseguido por dos productos comerciales, pero superior a los otros dos; sin embargó, evidenció un mejor retorno económico en términos de margen de utilidad unitaria y rentabilidad relativa, debido al menor costo de alimentación registrado. Se concluye que el suplemento alimenticio artesanal es apropiado para ser usado en el engorde de cuyes debido a su fácil elaboración y eficacia para conseguir una adecuada respuesta productiva y mayor retribución económica.

ABSTRACT The aim of this study was to evaluate the productive performance of growing guinea pigs, fed with green alfalfa forage and an artisanal supplement widely spread in the Mantaro Valley, Peru, made from wheat byproduct, whole yellow corn and soy cake in the base ratio of 3:2:1, compared to four commercial feeds, in terms of weight gain (BWG), feed conversion (FC), carcass yield (CY), and economic merit. In total, 60 male and female red-line guinea pigs, 18 ± 3 days old and weighing 318 ± 35 g, were used. They were distributed in five metal cages with four levels each. A randomized Complete Block Design was used considering sex as a block. The effect achieved by the artisanal supplement on BWG, FC and CY were similar to that achieved by two commercial products, but superior to the other two; however, it showed a better economic return in terms of unit profit margin and relative profitability due to the lower food cost recorded. It is concluded that the artisanal formulation is appropriate to be used in the fattening of guinea pigs due to its easy preparation and effectiveness in achieving an adequate productive response and greater economic remuneration.

Abstract A determination of how the amount of allotted feedlot living space influences both production indicators as well as carcass and meat quality traits obtained from Holstein steers was performed by forming two treatment groups, T14: 65 steers/pen (14 m2/head of space allowances) and T16: 57 steers/pen (16 m2/head of space allowances), with five replications each treatment. The average arrival weight 238 ± 0.74 kg. During the fattening period the cattle was feed twice a day with commercial diets. The steers were slaughtered after a 261-d period. At the moment of the first reimplant a greater average body weight was found in T16 vs T14 (384.25 vs 378.38 kg; P<0.05) and the difference continued until day 261 (612.35 vs 595.54 kg; P<0.05); regarding ADG, hot carcass weight and cold carcass weight the result were: 1.50 vs 1.46 kg (P<0.05), of ADG kg/d; 367.34 vs 360.35 kg (P<0.05) and 366.68 vs 358.78 kg (P<0.05). No difference between treatments were found in dorsal fat, marbling, pH and meat color. The results suggest that an increase from 14 m2/animal to 16 m2/animal improves the production results as well as the hot and cold carcass weight, with no effect on the quality traits of the carcass and beef.

Resumen Se determinó cómo la cantidad de espacio vital asignado en el corral de engorda, influye tanto en los indicadores de producción como en los rasgos de calidad de la canal y la carne obtenidas de novillos Holstein mediante la formación de dos grupos de tratamiento, T14: 65 novillos/corral (14 m2/cabeza de espacio permitido) y T16: 57 novillos/corral (16 m2/cabeza de espacio permitido), con cinco repeticiones en cada tratamiento. El peso promedio de llegada fue de 238 ± 0.74 kg. Durante el período de engorda el ganado se alimentó dos veces al día con dietas comerciales. Los novillos se sacrificaron después de un período de 261 días. En el momento del primer reimplante se encontró un mayor peso corporal promedio en T16 vs T14 (384.25 vs 378.38 kg; P<0.05) y la diferencia se mantuvo hasta el día 261 (612.35 vs 595.54 kg; P<0.05); en cuanto a la GDP, el peso de la canal caliente y el peso de la canal fría, los resultados fueron: 1.50 vs 1.46 kg (P<0.05), de GDP kg/día; 367.34 vs 360.35 kg (P<0.05) y 366.68 vs 358.78 kg (P<0.05). No se encontraron diferencias entre los tratamientos en la grasa dorsal, el marmoleado, el pH y el color de la carne. Los resultados sugieren que un aumento de 14 m2/animal a 16 m2/animal mejora los resultados productivos, así como el peso de la canal caliente y fría, sin afectar a los rasgos de calidad de la canal y la carne.

Abstract The objective was to know the population structure of Holstein animals in the family dairy system, to identify possible origins of the genetic material, to know the degree of inbreeding and to identify possible traces of selection in the genome, which allow glimpses of the traits that have been improved over the years. The study included 270 animals genotyped with the GGP-50K® chip. After genotype quality control, 43,548 autosomal SNPs were included. To know the population structure, analyses of mixtures and principal components (PCs) were performed. To know genomic inbreeding and detect traces of selection, information on runs of homozygosity (ROH) was used. Mixture analysis was performed with the Admixture software, and PC, ROH and inbreeding analyses were performed with SVS-v7.6.8. Mixture analysis showed evidence of six components, all linked to Holstein bulls families with different country of origin. The PCs did not show stratification of the population by herd. The mean inbreeding coefficient was 0.59 ± 0.53 %. In the regions of the genome with ROHs most frequent in the population (≥20 animals), numerous associations, QTLs and genes related to milk production and composition, fertility parameters, susceptibility to diseases, body conformation, feed efficiency and some characteristics of carcass composition have been reported. The results reflect the existence of a wide genetic diversity in this population and the possibility of carrying out genetic improvement work through selection without affecting inbreeding levels.

Resumen El objetivo fue conocer la estructura poblacional de los animales Holstein del sistema de lechería familiar, identificar posibles orígenes del material genético, conocer el grado de consanguinidad e identificar posibles huellas de selección en el genoma, que permitan vislumbrar las características que se han mejorado a través de los años. El estudio incluyó 270 animales genotipados con el chip GGP-50K®. Después del control de calidad de genotipos, se incluyeron 43,548 SNP autosómicos. Para conocer la estructura poblacional se realizaron análisis de mezclas y componentes principales (CP). Para conocer la consanguinidad genómica y detectar huellas de selección, se usó información de corridas de homocigosidad (ROH). El análisis de mezclas se realizó con el software Admixture, y los de CP, ROH y consanguinidad se realizaron con SVS-v7.6.8. El análisis de mezclas mostró evidencia de seis componentes, todos ligados a familias de sementales Holstein con diferente país de origen. Los CP no evidenciaron estratificación de la población por hato. El coeficiente de consanguinidad promedio fue de 0.59 ± 0.53 %. En las regiones del genoma con ROH más frecuentes en la población (≥20 animales), se han reportado numerosas asociaciones, QTL y genes relacionados con producción y composición de la leche, parámetros de fertilidad, susceptibilidad a enfermedades, conformación corporal, eficiencia alimenticia y algunas características de composición de la canal. Los resultados reflejan la existencia de una amplia diversidad genética en esta población y la posibilidad de realizar trabajos de mejoramiento genético a través de selección sin afectar los niveles de consanguinidad.

Abstract The objective was to evaluate the effect of various castration protocols through a meta-analysis of indicators of daily feed intake, feed conversion, daily weight gain, slaughter weight, hot carcass weight, and carcass yield. 179 publications from three electronic sources (Scopus, PubMed, and Web of Science) were reviewed over a 24-year period, out of which the 26 studies that met the inclusion criteria were selected. The effect was analyzed with six comparisons: C1=surgical castration vs whole; C2=standard immunocastration vs whole; C3= standard immunocastration vs surgical castration; C4= alternative immunocastration vs whole; C5= alternative immunocastration vs surgical castration, and C6= alternative immunocastration vs standard immunocastration. Averages were estimated for feed intake (kg) (0.23, 0.23, -0.05, 0.32, 0.11, -0.09), feed conversion (kg:kg) (0.27, 0.05, -0.16, 0.11, 0.11, 0.11, -0.19), daily weight gain (g) (-9. 54, 39.08, 40.70, 107.63, -53.0, 69.14), carcass weight (kg) (-9.54, 39.08, 40.70, 107.63, -53.0, 69.14), and hot carcass weight (kg) (1.23, 0.85, 0.46, 1.03, 1.02, -0.42) respectively. The indicators of feed consumption, feed conversion, daily weight gain, slaughter weight, and hot carcass weight proved different (P<0.05); only the carcass yield variable exhibited no difference (P>0.05). The conclusion is that immunocastration improves performance in production and carcass indicators; surgical castration improves carcass yield; whole pigs have better feed conversion, and standard and alternative immunocastration differ in their response in terms of production and carcass measurement indicators.

Resumen El objetivo fue evaluar el efecto de los diferentes protocolos de castración por medio del meta-análisis de los indicadores del consumo diario de alimento, conversión alimenticia, ganancia diaria de peso, peso al rastro, peso de la canal caliente y rendimiento de la canal. Se revisaron 179 publicaciones de tres fuentes electrónicas (Scopus, PubMed, Web of Science) en un periodo de 24 años, de las cuales se seleccionaron los 26 estudios que cumplieron con los criterios de inclusión. El efecto se analizó con seis comparaciones: C1=castración quirúrgica vs enteros; C2=inmunocastración estándar vs enteros; C3= inmunocastración estándar vs castración quirúrgica; C4= inmunocastración alternativa vs enteros; C5= inmunocastración alternativa vs castrados quirúrgicamente; y C6= inmunocastración alternativa vs inmunocastración estándar. Las medias obtenidas fueron de consumo de alimento (kg) (0.23, 0.23, -0.05, 0.32, 0.11, -0.09), de conversión alimenticia (kg:kg) (0.27, 0.05, -0.16, 0.11, 0.11, -0.19), ganancia diaria de peso (g) (-9.54, 39.08, 40.70, 107.63, -53.0, 69.14), peso de la canal (kg) (-9.54, 39.08, 40.70, 107.63, -53.0, 69.14), y peso de la canal en caliente (kg) (1.23, 0.85, 0.46, 1.03,1.02, -0.42) respectivamente. Los indicadores de consumo de alimento, conversión alimenticia, ganancia diaria de peso, peso al rastro y peso de la canal caliente fueron diferentes (P<0.05); solo la variable de rendimiento de la canal no mostró diferencia (P>0.05). Se concluye que, la inmunocastración mejora el desempeño en indicadores productivos y de la canal, la castración quirúrgica mejora el rendimiento de la canal, los cerdos enteros tienen mejor conversión alimenticia, y la inmunocastración estándar y alternativa difieren en su respuesta en indicadores de producción y medición de la canal.

Resumen Las carcasas animales en entornos naturales son una fuente de alimento para diversos organismos, como hongos, bacterias e insectos. Los insectos también utilizan este recurso efímero para la oviposición y el desarrollo de sus crías, siendo los inmaduros responsables del mayor consumo del recurso. Por lo tanto, el objetivo fue conocer la fauna de insectos necrófagos asociados a una carcasa de vaca Bos taurus Linnaeus encontrada en el municipio de São Raimundo das Mangabeiras, Maranhão, Brasil. Los insectos se muestrearon con la ayuda de pinzas y redes entomológicas durante ocho días, y los inmaduros se llevaron al Laboratorio de Entomología y Vectores (LEV) y posteriormente se criaron a temperatura ambiente. Se obtuvo un total de 1.149 especímenes, siendo 141 adultos y 1.017 inmaduros. Entre los adultos, destacaron las especies Chrysomya albiceps (Widemann), Necrobia rufipes (Fabricius) y Dermestes maculatus (De Geer). En cuanto a los inmaduros, todos los insectos que emergieron fueron de la especie C. albiceps. Además, se reporta el primer registro de Chrysomya putoria (Widemann), Cochliomyia hominivorax (Coquerel) y Hemertia illucens (Linnaeus) visitando una carcasa bovina en la región neotropical. Nuestros resultados revelan una colonización tardía de C. albiceps en etapas avanzadas, confirmando la importancia de la investigación con carcasas en el contexto de la entomología forense.

Abstract Animal carcasses in natural environments are a food source for various organisms, such as fungi, bacteria, and insects. Insects also utilize this ephemeral resource for oviposition and development of their offspring, with the immatures being responsible for the greatest consumption of the resource. Thus, the aim of this study was to characterize the fauna of necrophagous insects associated with a cow carcass Bos taurus Linnaeus found in the municipality of São Raimundo das Mangabeiras, Maranhão, Brazil. Insects were sampled using forceps and entomological nets for eight days, with the immatures being taken to the Laboratory of Entomology and Vectors (LEV) and subsequently reared at room temperature. A total of 1,149 specimens were sampled, comprising 141 adults and 1,017 immatures. Among the adults, the species Chrysomya albiceps (Widemann), Necrobia rufipes (Fabricius), and Dermestes maculatus (De Geer) were prominent. Regarding immatures, all insects that emerged were of the species C. albiceps. Additionally, we report the first record of Chrysomya putoria (Widemann), Cochliomyia hominivorax (Coquerel), and Hemertia illucens (Linnaeus) visiting bovine carcasses in the Neotropical region. The results reveal a late colonization of C. albiceps in advanced stages, confirming the importance of research with carcasses in the context of forensic entomology.

SUMMARY: The cattle in the Pantanal region show a notable influence from Bos indicus breeds and their crossbreeds. However, a comprehensive biometric assessment of the reproductive system in these animals is currently lacking. This study evaluated the effects of breed, age, carcass weight, and estrous cycle phase on female reproductive system morphometry. A total of 124 healthy, non-pregnant reproductive tracts (83 Nelore and 41 Crossbred) were collected at a slaughterhouse. Neither the volume and weight of the ovaries nor the majority of uterine dimensions were affected by breed. Compared to heifers, cows showed longer uterine horns, a larger external caudal diameter of the uterine horns and body, and a greater external cranial diameter and internal caudal diameter of the cervix. The carcass weight (below vs. within commercial weight) affected the length of the uterine horns, uterine body, and cervix. Ovaries with a corpus luteum presented higher volume and weight than those with only follicles. Although the uterine measurements in the luteal phase were increased, the cycle stage did not affect the uterine morphometry. The average number of cervical rings was 5.0, independent of weight or breed. Crossbred animals presented a higher first cervical ring. Age didn´t influence the number, height, or distance between cervical rings. Deviation from the normal alignment of the cervix was recorded in 14.29 % of the animals, with a higher occurrence among Nelore cattle; deviation from the median axis was the most common (30%). This study emphasizes various parameters influencing the morphometry of the female reproductive system in Nelore cattle and their crosses, which could be crucial for implementing reproductive biotechnology techniques better suited to the morphological characteristics of zebu breeds.

RESUMEN: El ganado de la región del Pantanal muestra una notable influencia de las razas Bos indicus y sus cruces. Sin embargo, actualmente falta una evaluación biométrica exhaustiva del sistema reproductivo de estos animales. Este estudio evaluó los efectos de la raza, la edad, el peso de la canal y la fase del ciclo estral sobre la morfometría del sistema reproductivo de la hembra. En un matadero se recogieron un total de 124 tractos reproductivos sanos y no preñados (83 Nelore y 41 cruzados). Ni el volumen ni el peso de los ovarios ni la mayoría de las dimensiones del útero se vieron afectados por la raza. En comparación con las novillas, las vacas mostraron cuernos uterinos más largos, un diámetro caudal externo más grande de los cuernos y del cuerpo uterino, y un diámetro craneal externo y un diámetro caudal interno más grandes del cuello uterino. El peso de la canal (por debajo versus dentro del peso comercial) afectó la longitud de los cuernos uterinos, el cuerpo uterino y el cuello uterino. Los ovarios con cuerpo lúteo presentaron mayor volumen y peso que aquellos con solo folículos. Aunque las medidas uterinas en la fase lútea aumentaron, la etapa del ciclo no afectó la morfometría uterina. El número promedio de anillos cervicales fue de 5,0, independientemente del peso o la raza. Los animales mestizos presentaron un primer anillo cervical más alto. La edad no influyó en el número, altura o distancia entre anillos cervicales. La desviación de la alineación normal del cuello uterino se registró en el 14,29 % de los animales, con mayor ocurrencia en el ganado Nelore; la desviación del eje de la mediana fue la más común (30%). Este estudio enfatiza varios parámetros que influyen en la morfometría del sistema reproductor de las hembras en el ganado Nelore y sus cruces, lo que podría ser crucial para implementar técnicas de biotecnología reproductiva más adecuadas a las características morfológicas de las razas cebú.

ABSTRACT The effect of a partial substitute of fish meal by biofloc meal on the growth and survival of fry Nile tilapia Oreochromis niloticus was evaluated over nine weeks. Two biofloc meals were obtained by drying them in two processes: A) sun exposure and B) convection oven. A randomized design of eight isonitrogenous (40%) and isoenergetic (17 kJ g-1) diets was used, where 5, 10, 15, and 20% of the fish meal was substituted for the two biofloc meals. The nutritional study was conducted in a recirculating aquaculture system with Nile tilapia fry (initial weight: 0.64 ± 0.16 g). The survival range was similar in all treatments and higher than 97%. Tilapia fed with the treatments A5, A10, B5, and B10 of substitution of biofloc meal showed similar and significantly better final weight, individual weight gain, specific growth rate, and condition factor than A15, A20, B15, and B20 treatments; as well as efficiency of use of the feed: protein efficiency ratio, carcass nitrogen deposition, apparent nitrogen utilization, and apparent digestibility. Therefore, these results suggest that biofloc meal is possible in diets for tilapia, thus reducing the need for fishmeal as the main source of protein in the diet.