ABSTRACT The interaction between pasture and supplementation in dairy production systems constitutes a very important part of the efficiency of dairy. This study evaluated the effect of the herbage mass (HM) on the milk production and solid concentration. Twenty Holstein cows were distributed into two groups, 10 assigned 2200 kg DM ha-1 (low herbage mass, LHM) and 10 with 2800 kg DM ha-1 (medium herbage mass, MHM). Herbage mass was measured above 5 cm. The experiment lasted 8 wk. The variables evaluated were DM intake (DMI), milk production and composition (fat and protein concentration). Effects of treatments on variables were evaluated using a repeated measure analysis over time. The results showed nonsignificant differences in the pasture DMI between LHM and MHM for weeks 1, 2, 3 and 5 (P > 0.05). During week 4, pasture DMI was 3 kg greater for LHM than MHM (P < 0.05). The milk production did not differ between treatments per week, but the average was 2.4 kg greater for LHM compared to MHM (P < 0.05). In conclusion, changes in the pasture availability increased milk production at LHM, but not enough to cause changes in solids concentration. This clearly shows that, LHM can increase milk and solids production.

ABSTRACT An integrative review was conducted to identify which intercrops, composed of grasses from tropical or temperate climates, are most commonly used in ruminant feeding and which result in higher productivity. The review followed a developed and tested protocol according to the PVO strategy to formulate the guiding question. Data were collected from articles published in the electronic databases SCOPUS (Elsevier), Web of Science (Main Collection), and SciELO Citation Index (Web of Science) through a single cross-reference search. It was not carried out temporally, regionally, nor limited to Brazil. Among the selected studies, the genera found were Lolium (26.7%), Avena (26.7%), Brachiaria (20.0%), Cynodon (13.4%), Panicum (6.6%), and Sorghum (6.6%). The technologies adopted in the articles were target height (50.0%), reseeding (33.3%), and defoliation intensity (16.7%). The animal species used were beef cattle, dairy cattle, and goats - 50.0%, 33.3%, and 16.7%, respectively. It was possible to observe that the use of different cultivars yields positive results; this was most evident with the grasses most used in intercropping: ryegrass (Lolium multiflorum Lam) and black oats (Avena strigosa Schreb); which showed higher productivity values compared to monoculture. intercrops climates question Elsevier, Elsevier , (Elsevier) Main Collection, Collection Collection) crossreference cross reference search temporally regionally Brazil studies 26.7%, 267 26.7% 26 7 (26.7%) 20.0%, 200 20.0% 20 0 (20.0%) 13.4%, 134 13.4% 13 4 (13.4%) 6.6%, 66 6.6% 6 (6.6%) 6.6%. . 500 50.0% 50 (50.0%) 333 33.3% 33 3 (33.3%) 16.7%. 167 16.7% 16 (16.7%) cattle respectively results intercropping Lam Schreb Schreb) monoculture (Elsevier 26.7 2 (26.7% 20.0 (20.0% 13.4 1 (13.4% 6.6 (6.6% 50.0 5 (50.0% 33.3 (33.3% 16.7 (16.7% 26. (26.7 20. (20.0 13. (13.4 6. (6.6 50. (50.0 33. (33.3 16. (16.7 (26. (20. (13. (6. (50. (33. (16. (26 (20 (13 (6 (50 (33 (16 (2 (1 ( (5 (3

RESUMO Com o objetivo identificar quais consórcios compostos por gramíneas de clima tropical ou temperado são mais utilizados na alimentação de ruminantes e quais resultam em maior produtividade, foi realizada uma revisão integrativa. A revisão seguiu um protocolo desenvolvido e testado de acordo com a estratégia PVO, para formular a pergunta orientadora. Os dados foram coletados em artigos publicados nas bases de dados eletrônicos SCOPUS (Elsevier), Web of Science (Coleção Principal) e SciELO Citation Index (Web of Science), por meio de uma única busca cruzada de referências. Não foi utilizado corte temporal, regional nem limitado ao Brasil. Entre os estudos selecionados, os gêneros encontrados foram Lolium (26,7%), Avena (26,7%), Brachiaria (20,0%), Cynodon (13,4%), Panicum (6,6%) e Sorghum (6,6%). As tecnologias adotadas nos artigos foram metas de altura (50,0%), ressemeadura (33,3%) e intensidade de desfolhamento (16,7%). As espécies animais utilizadas foram bovinos de corte, bovinos leiteiros e cabras - 50,0%, 33,3% e 16,7%, respectivamente. Foi possível verificar que o uso de diferentes cultivares promove resultados positivos; isso foi mais evidente com as gramíneas mais utilizadas no consórcio: azevém (Lolium multiflorum Lam) e a aveia-preta (Avena strigosa Schreb), que apresentaram valores de produtividade mais altos em comparação ao monocultivo. integrativa PVO orientadora Elsevier, Elsevier , (Elsevier) Coleção Principal Science, Science) referências temporal Brasil selecionados 26,7%, 267 26,7% 26 7 (26,7%) 20,0%, 200 20,0% 20 0 (20,0%) 13,4%, 134 13,4% 13 4 (13,4%) 6,6% 66 6 (6,6% 6,6%. . 500 50,0% 50 (50,0%) 333 33 3 (33,3% 16,7%. 167 16,7% 16 (16,7%) 33,3 respectivamente positivos consórcio Lam aveiapreta aveia preta Schreb, Schreb Schreb) monocultivo (Elsevier 26,7 2 (26,7% 20,0 (20,0% 13,4 1 (13,4% 6,6 (6,6 50,0 5 (50,0% (33,3 16,7 (16,7% 33, 26, (26,7 20, (20,0 13, (13,4 6, (6, 50, (50,0 (33, 16, (16,7 (26, (20, (13, (6 (50, (33 (16, (26 (20 (13 ( (50 (3 (16 (2 (1 (5

Resumen Introducción. La lechería especializada del trópico alto colombiano presenta elevados costos de producción, emisiones de metano y contaminación por nitrógeno en el suelo y agua, empleo de plaguicidas en las praderas y una producción de leche que aún no alcanza altos estándares de calidad. Lo anterior, requiere un cambio estructural en el modelo de producción con un enfoque de sustentabilidad. Además de otros aspectos, la ganadería sostenible requiere mayor complementariedad y diversidad de especies forrajeras, arbustivas y arbóreas adaptadas a las condiciones de trópico de altura. Objetivo. Recopilar información a través de acción participativa y de innovación rural por los productores y avances de investigación de las especies Axonopus catarinensis y Smallanthus sonchifolius, forrajeras herbáceas con posible potencial productivo y ambiental (en etapa preliminar), para su integración en sistemas silvopastoriles del trópico alto colombiano. Desarrollo. A. catarinensis y S. sonchifolius son especies que podrían ser utilizadas en la alimentación básica y suplementación energética, respectivamente, de vacas lecheras en el trópico alto colombiano. Aunque no existe información científica para estas condiciones, la referencia de algunos productores menciona que estas especies tal vez pueden mejorar la producción y la calidad de la leche con efectos en la economía familiar. Además, pueden contribuir a la generación de productos lácteos con atributos funcionales benéficos, que impacten en la salud humana. Conclusión. A. catarinensis y S. sonchifolius son especies que pueden tener un potencial forrajero y nutricional para incluirse en los sistemas silvopastoriles de producción lechera en el trópico alto colombiano.

Abstract Introduction. Specialized dairy farming in Colombia highlands entails high production costs, methane emissions, nitrogen pollution in soil and water, the use of pesticides in pastures, and milk production that has not yet reached high-quality standards. All of these factors necessitate a structural change in the production model with a sustainability focus. In addition to other aspects, sustainable livestock farming requires greater complementarity and diversity of forage, shrub, and tree species adapted to high-altitude tropical conditions. Objective. To gather information through participatory action and rural innovation by producers and research advancements on the species Axonopus catarinensis and Smallanthus sonchifolius, herbaceous forage species with potential production and environmental benefits (in preliminary stage), for their integration into silvopastoral systems in the Colombian highlands. Development. A. catarinensis and S. sonchifolius are species that could be used in basic diet and energy supplementation, respectively, of dairy cows in the Colombian highlands. While there is no scientific information available for these conditions, some producers' experiences suggest that these species may improve milk production and quality with positive effects on family economics. Additionally, they can contribute to the generation of dairy products with beneficial functional attributes that impact human health. Conclusion. A. catarinensis and S. sonchifolius are species that may have forage and nutritional potential to be included in silvopastoral dairy production systems in the Colombian highlands.

RESUMEN Objetivo: Estimar heredabilidades (h2) de edad al primer parto (AFP), longevidad (L), vida útil (UL) y productividad (P), y las correlaciones fenotípicas y genéticas (rg) entre esos caracteres en vacas Suizo Pardo (SP) y Holstein en el Noroeste de Honduras. Materiales y métodos: El ganado fue criado en condiciones tropicales y manejado intensivamente. El modelo para AFP incluyó el grupo contemporáneo (GC, combinación de hato, año y época de nacimiento) como fijo. Para L, UL y P, el modelo incluyó al GC, grupo de edad al primer parto y su interacción. Los datos se analizaron utilizando el procedimiento de máxima verosimilitud restringida (REML), ajustado a un modelo animal univariado y bivariado. Resultados: Las h2 estimadas para AFP, L, UL y P fueron 0.16, 0.18, 0.25 y 0.09, en vacas SP; y 0.53, 0.49, 0.7 y 0.22 en H, respectivamente. Las rg fueron negativas pero favorables para las vacas SP en un rango de 0.31 a 0.46 entre AFP y los otros rasgos. Sin embargo, para las vacas H, se encontró una rg positiva entre AFP y las demás características que osciló entre 0.49 y 0.96. En ambas razas, las rg entre L, UL y P fueron positivas. Conclusiones: Para los rasgos evaluados, la h2 baja a media para BS sugiere que la mejora genética sería lenta si se aplicará selección independiente esperándose una mejor respuesta para la raza H. Para ambas razas las rg positivas sugieren que se podrían utilizar criterios de selección similares para L, UL y P.

ABSTRACT Objective: To estimate the heritability (h2) of age at first parturition (AFP), longevity (L), useful life (UL), and productivity (P), as well as the genetic (rg) and phenotypic correlations between those traits in Brown Swiss and Holstein cows in Northwestern Honduras. Materials and methods: Cattle were raised under tropical conditions and intensive management. The model for AFP assessed the effect of contemporary group (herd, year and birth season combination) as fixed. The model used for L, UL and P included the contemporary group, age group at first calving and their interaction. Data were analyzed using restricted maximum likelihood procedure, adjusted to a univariate and to a bivariate animal model. Results: The h2 estimated for AFP, L, UL and P were 0.16, 0.18, 0.25 and 0.09, respectively, in Brown Swiss cows, and 0.53, 0.49, 0.7 and 0.22, respectively in Holstein. Negative but favorable rg among Brown Swiss cow traits ranged from 0.31 to 0.46 between AFP and the other traits. However, for Holsteins cows, positive rg among AFP and the other traits here studied varied from 0.49 to 0.96. In both cattle breeds, rg among L, UL and P, traits were positive. Conclusions: For all traits evaluated low to medium heritability's for BS suggest that a slow genetic improvement could be achieved if independent selection of traits is applied, and better response could be expected for H breed. For both breeds the positive rg among L, UL and P suggest thar similar selection criteria could be used.

RESUMEN En condiciones del trópico colombiano es necesario establecer estrategias de alimentación que permitan aumentar la productividad a bajo costo. El objetivo de esta investigación fue evaluar el efecto de la suplementación con ensilados de totumo, mango, guayabo de monte sobre la digestibilidad in vitro, degradabilidad y parámetros productivos en vacas doble propósito. El estudio fue realizado en la finca La Florida, ubicada, en el municipio de Puerto Boyacá, se usaron 32 vacas (Gyr x Holstein) con peso promedio de 460 ±35 kg en primer tercio de lactación, distribuidas en cuatro (4) grupos de ocho (8) cada uno, conformados de la siguiente manera: T1: grupo control: sin ensilajes; T2: ensilaje de Guayabo de monte; T3: ensilaje de Totumo y T4: ensilaje de Mango común. Todas las vacas permanecieron en pastoreo rotacional con Brachiaria decumbens, agua a voluntad y sal mineralizada. Se analizó el efecto del tratamiento, el tiempo y su interacción, para ello se usó el comando PROC MIXED del software SAS 9.2 (2002), la diferencias entre promedios se realizó mediante prueba de Tukey-Kramer, con nivel de significancia del 5 %. No hubo diferencias (p<0,05) en la producción diaria de leche entre los tratamientos evaluados, sin embargo, el porcentaje de proteína en leche fue mayor (p<0,05) en los tratamientos T2 y T4. EL NUL fue mayor en el T2 y menor en el T4. El consumo de ensilajes fue mayor (p<0,05) en el T4 y la condición corporal mostró ser mejor para los tratamientos T2 y T4, finalmente para los parámetros de degradabilidad y digestibilidad in vitro, los tratamientos T2, T3 y T4 obtuvieron los mayores valores respectivamente. La suplementación de vacas doble propósito con ensilajes de frutos del bosque húmedo tropical mejora la proteína de la leche y la condición corporal de las vacas. Los ensilados estudiados, poseen alta tasa de degradación y digestibilidad In vitro, representando una alternativa de alimentación en los rumiantes.

ABSTRACT In the Colombian tropic, it is necessary to establish feeding strategies that increase productivity and reduce costs. This research aimed to evaluate the effect of totumo, mango, and wild guava silage on in vitro digestibility, degradability, and productive parameters in dual-purpose cows. This study was carried out on a farm located in the municipality of Puerto Boyacá. Thirty-two Gyr x Holstein cows (Body weight = 460 ± 35 kg) in early lactation were enrolled and distributed in four groups of eight individuals: T1: control group: no silage; T2: Wild guava silage; T3: Totumo silage and T4: Mango silage. All the cows remained in a rotational grazing system with Brachiaria decumbens, water, and a salt-based mineral supplement ad libitum. There were no differences (p>0,05) in the daily milk production. However, protein levels in milk were higher (p<0,05) in the T2 and T4 treatments. NUL was more elevated in T2 and lower in T4. Silage consumption was higher (p<0,05) in T4, and the body condition score was higher for T2 and T4. For the degradability and digestibility parameters in vitro, treatments T2, T3, and T4 obtained the highest values. Fruits silage supplementation on dual-purpose cows with silage fruits can increase milk protein levels and body condition score. Those silages have a high rate of degradation and in vitro digestibility, representing a feeding alternative for ruminants.

Resumen El bovino Criollo Mixteco es un recurso genético poco explorado, pero de gran valor por su potencial para ser empleado en sistemas de producción respetables con el entorno y adaptables a las condiciones del mismo. La identificación y caracterización de este recurso local es un punto primordial para su conservación y mejora, es por esto que en el presente estudio se llevó a cabo el análisis de la diversidad y relaciones genéticas de la población de bovinos Criollos Mixtecos de Oaxaca, mediante el empleo de 19 marcadores de ADN microsatélites y 32 poblaciones bovinas de referencia, pertenecientes al consorcio BIOBOVIS de la Red CONBIAND. El número medio de alelos detectados fue de 8.8 ± 2.1 y el número efectivo de alelos estimado fue de 4.5 ± 1.2. La diversidad genética representada por los valores de heterocigosidad esperada (0.7700 ± 0.0682) y observada (0.7170 ± 0.0998), se encontró dentro del rango de estimadores obtenidos en estudios previos con poblaciones bovinas locales empleando marcadores microsatélites. El análisis de la estructura poblacional reveló una influencia predominante de germoplasma ibérico (Bos taurus). Se observa además una estrecha relación entre el Criollo Mixteco y el resto de poblaciones bovinas criollas mexicanas a excepción del Criollo Lechero Tropical.

Abstract The Mixteco Creole cattle is a little explored genetic resource, which, however, has great value due to its potential to be used in production systems that are respectful of the environment and adaptable to its conditions. The identification and characterization of this local resource is essential for its conservation and improvement. For this reason, in the present study it was carried out the analysis of the diversity and genetic relationships of the Mixteco Creole cattle population of Oaxaca, using 19 microsatellite DNA markers and 32 reference cattle populations belonging to the BIOBOVIS consortium of the CONBIAND Network. The mean number of alleles detected was 8.8 ± 2.1 and the estimated effective number of alleles was 4.5 ± 1.2. The genetic diversity represented by the expected (0.7700 ± 0.0682) and observed (0.7170 ± 0.0998) heterozygosity values was within the range of estimators obtained in previous studies with local cattle populations using microsatellite markers. An analysis of the population structure revealed a predominant influence of Iberian germplasm (Bos taurus). There is also a close relationship between the Mixteco Creole and the rest of the Mexican Creole cattle populations, with the exception of the Tropical Dairy Creole.

ABSTRACT: Tropical dairy cattle farming is one the most relevant economic activities for food production; although, currently faces increasing scrutiny from society due to its potential harm to natural resources and the environment. Moreover, some factors are paramount for the evaluation of the sustainability and productive potential of any given tropical dairy farm: soil quality, profitability, and energy efficiency. This study carried out a sustainability analysis in four types of tropical dairy cattle ranches, through three key indicators (economic profitability, energy efficiency and soil quality) and with a comprehensive approach in the Costa region of Oaxaca, Mexico. Therefore, four farms of different sizes (i.e., small, medium, large, and very large) were selected in Costa de Oaxaca, Mexico. The data collection was carried out for daily milk production, the dynamics of farm inputs (introduction or removal) from the production system, alongside with collection of soil samples. The agroecosystems evaluated were economically profitable, and those with greater intensification of their pasture areas display higher profit margins and energy efficiency. In terms of soil quality, there is a regular potential for its rational utilization. ABSTRACT although environment Moreover quality profitability ranches Oaxaca Mexico Therefore i.e., ie i e (i.e. small medium large introduction removal system samples profitable utilization i.e. (i.e i.e

RESUMO: A pecuária leiteira tropical é uma das atividades econômicas mais relevantes para a produção de alimentos, embora atualmente enfrente crescente discussão da sociedade devido ao seu potencial dano aos recursos naturais e ao meio ambiente. Além disso, alguns fatores são primordiais para a avaliação da sustentabilidade e potencial produtivo de qualquer popriedade leiteira tropical: qualidade do solo, rentabilidade e eficiência energética. O objetivo deste estudo foi realizar uma análise de sustentabilidade em quatro tipos de propriedades de gado leiteiro tropical, por meio de três indicadores chave (rentabilidade econômica, eficiência energética e qualidade do solo) e com uma abordagem abrangente na região da Costa de Oaxaca, México. Portanto, quarto propriedades de diferentes tamanhos (isto é, pequenas, médias, grandes e muito grandes) foram selecionadas na Costa de Oaxaca, México. A coleta de dados foi realizada para a produção diária de leite, a dinâmica dos insumos da fazenda (introdução ou retirada) do sistema de produção, juntamente com coleta de amostras de solo. Os agroecossistemas avaliados foram economicamente rentáveis, sendo que aqueles com maior intensificação de suas áreas de pastagens apresentam maiores margens de lucro e eficiência energética. Em termos de qualidade do solo, existe um potencial regular para a sua utilização racional. RESUMO alimentos ambiente disso solo econômica Oaxaca México Portanto isto pequenas médias leite introdução retirada rentáveis racional

ABSTRACT This study aimed to describe the epidemiological indexes of mastitis, milk quality and udder hygiene in the Compost Barn system, as well as to search for associations between isolated pathogens from milk with compost characteristics. Three dairy herds participated in the study, and the samples were collected during different periods on each farm. Individual milk samples were collected in duplicate for SCC analysis and microbiological culture. Environmental pathogens caused most cases of clinical mastitis on farm 2, and contagious pathogens caused the most cases on farm 1. Bed moisture was not associated with the incidence of environmental pathogens. Most of the animals remained in good udder hygiene during the study. Poor udder hygiene contributed to the increased incidence of environmental pathogens in one of the farms. A higher number of animals with a hygiene score of ≥ 2 were observed during the warmer and rainfall periods. There was no association between hygiene scores and somatic cell counts. The results suggest that pathogens isolated from milk in animals confined in Compost Barn under tropical climate are like other confinement systems adopted elsewhere. The year period influenced the udder hygiene score, reinforcing the importance of bed management throughout the year. system characteristics culture 1 farms counts elsewhere

RESUMO O objetivo deste estudo foi descrever os índices epidemiológicos da mastite, da qualidade do leite e da higiene do úbere em animais confinados no sistema Compost Barn, bem como buscar associações entre patógenos isolados do leite e características do composto. Três rebanhos leiteiros participaram do estudo e as amostras foram coletadas em diferentes períodos em cada fazenda. Amostras individuais de leite foram coletadas em duplicata para análise de CCS e cultura microbiológica. Patógenos ambientais causaram a maioria dos casos de mastite clínica na fazenda 2, e na fazenda 1 a maioria dos casos foi em decorrência de patógenos contagiosos. Amostras de material da cama foram coletadas em duas fazendas para análise da densidade bacteriana e da umidade. A umidade da cama permaneceu dentro da faixa de controle durante o estudo e não foi associada à incidência de patógenos ambientais. A maioria dos animais permaneceu com boa higiene de úbere durante o estudo. A falta de higiene do úbere contribuiu para o aumento da incidência de patógenos ambientais em uma das fazendas. Durante o período mais quente e mais chuvoso, um número maior de animais com escore de sujidade ≥ 2 foi observado em todos os rebanhos. Não houve associação entre escore de sujidade e contagem de células somáticas em qualquer uma das três fazendas. Os resultados indicam que o perfil de patógenos isolados do leite em animais confinados em Compost Barn sob clima tropical é semelhante a outros sistemas de confinamento adotados em outros lugares. O período do ano influenciou o escore de higiene do úbere, o que reforça a importância do manejo da cama ao longo do ano. composto microbiológica contagiosos chuvoso lugares

Abstract Genomic selection has transformed the livestock industry, enabling early-life selection of animals. Biopsy sampling of pre-implantation embryos has been described since 1968. However, it was only after 2010, with the advancement of molecular biology techniques such as whole genomic amplification and SNP Chips, that next-generation sequencing became commercially available for bovine embryos. It is now possible to make decisions about which embryos to transfer not only based on recipients’ availability or embryo morphology but also on genomic estimates. This technology can be implemented for a wide spectrum of applications in livestock. In this review, we discuss the use of embryo biopsy for genomic selection and share our experience with Gir and Girolando Brazilian breeding programs, as well as future goals for implementing it in Brazilian bovine in vitro embryo production practices. industry earlylife early life animals preimplantation pre implantation 1968 However 2010 Chips nextgeneration next generation recipients estimates review programs practices 196 201 19 20 1 2

Abstract This study assessed the behavior of dairy calves raised in outdoor holding pens covered with different geosynthetics. Twenty crossbred (Girolando, Jersey and Holstein) dairy calves undergoing weaning were used, with an average initial live weight of 40.6 Kg. A completely randomized block design was used, with a 4 x 3 factorial scheme and 5 repetitions. The roofing materials were polyethylene mesh, drainage geocomposite, nonwoven geotextile and woven geotextile, representing the first factor, and assessment times (8 to 11 a.m., 11:15 a.m. to 2 p.m. and 2:15 to 6 p.m.) the second factor. Environmental variables were analyzed, and the following heat stress indices calculated: black globe-humidity index (BGHI) and equivalent temperature. The average BGHI and equivalent temperature were 79 and 26, respectively. Walking behavior differed between treatments (P<0.05) and was more frequent in the woven geotextile treatment. The most frequent behavior observed throughout the day was lying in the shade (53%), demonstrating the importance of providing artificial shading during this stage of life. When compared to polyethylene mesh, the drainage geocomposite and nonwoven geotextile were better suited to providing shade for dairy calves undergoing weaning in tropical regions. geosynthetics Girolando, Girolando (Girolando Holstein used 406 40 40. Kg repetitions mesh factor 8 ( 1 am m 1115 15 11:1 a.m pm p p.m 215 2:1 analyzed calculated globehumidity globe humidity (BGHI 7 26 respectively P<0.05 P005 P 0 05 (P<0.05 treatment 53%, 53 53% , (53%) life regions 111 11: 21 2: P<0.0 P00 (P<0.0 (53% P<0. P0 (P<0. (53 P<0 (P<0 (5 P< (P< (P

Resumo O trabalho avaliou o comportamento de bezerras leiteiras, criadas em bezerreiros de modelo tropical, contendo diferentes geossintéticos como material de cobertura. Foram avaliadas 20 fêmeas Girolando, Jersey e Holandesa com peso inicial médio de 40,6 Kg durante a fase de aleitamento. O delineamento experimental foi de blocos casualizados completos, em arranjo fatorial 4 x 3 com 5 repetições. Os materiais de cobertura foram: malha de polietileno, geocomposto drenante, geotêxtil não-tecido e geotêxtil tecido foram o primeiro fator e os períodos do dia (08 às 11, 11:15 às 14 e 14:15 às 18 horas) foram o segundo fator. Foram avaliadas as variáveis ambientais e calculados os índices de conforto térmico: índice de temperatura do globo negro e umidade e índice de temperatura equivalente. As médias do índice de temperatura do globo negro e índice de temperatura equivalente foram 79 e 26, respectivamente. O comportamento andando diferiu entre tratamentos (P<0,05), sendo mais frequente no tratamento geotêxtil tecido. A frequência comportamental mais observada ao longo do dia foi deitada à sombra (53%) deixando evidente a importância da disponibilização de sombreamento artificial para essa fase de vida. Os materiais de cobertura geossintéticos Geodrenante e Geotêxtil não-tecido, comparados à malha de polietileno, foram os mais apropriados para a utilização como sombreamento em regiões de clima tropical para bezerras em fase de aleitamento. leiteiras 2 Girolando 406 40 6 40, aleitamento completos repetições polietileno drenante nãotecido não 08 (0 11 1115 15 11:1 1 1415 14:1 horas térmico 7 26 respectivamente P<0,05, P005 P P<0,05 , 0 05 (P<0,05) 53% 53 (53% vida nãotecido, tecido, ( 111 11: 141 14: P00 P<0,0 (P<0,05 (53 P0 P<0, (P<0,0 (5 P<0 (P<0, P< (P<0 (P< (P

ABSTRACT Introduction: Brucellosis is a zoonosis in Cuba. Preventing this disease is possible through intervention strategies aimed at changing predisposing behaviors to the infection. This research analyzes clinical and epidemiological aspects of reported cases of human brucellosis in three Cuban provinces located in the western, central, and eastern regions of the country to provide information to medical doctors and health decision-makers. Methods: A retrospective, descriptive study was conducted between January 2013 and June 2016. The clinical-epidemiological surveys of 65 reported cases of human brucellosis from three Cuban provinces were analyzed. The variables studied were: age, sex, symptoms, occupation, direct contact with animal reservoirs, and consumption of unpasteurized dairy products or half-cooked meat. Descriptive statistical measures such as absolute frequency and percentage were used for the analysis. Results: Male sex (66%), age between 25 and 54 years (66.1%), and direct contact with animal reservoirs of Brucella spp. (78.5%) prevailed among the individuals reported with human brucellosis. General malaise (58.5%), joint pain (56.9%), and fever (55.4%) were the prevailing symptoms. Conclusion: The outcomes of the clinical-epidemiological variables described were similar to those previously reported in Cuba and in other countries where the disease is endemic. It suggests the need to increase the strategies for the prevention, surveillance and control of human brucellosis in Cuba.

RESUMEN Fundamentos: La brucelosis es una zoonosis presente en Cuba. Su prevención es posible mediante la aplicación de estrategias de intervención encaminadas a cambiar las conductas que predisponen para la adquisición de la infección. Con la finalidad de aportar información a médicos de asistencia y decisores de salud, en esta investigación se analizan aspectos clínicos y epidemiológicos de casos notificados con brucelosis humana en tres provincias cubanas que se ubican en las regiones del occidente, centro y oriente del país. Métodos: Se realizó un estudio retrospectivo y descriptivo entre enero de 2013 y junio de 2016. Se analizaron 65 encuestas clínico-epidemiológicas de casos notificados con brucelosis humana, procedentes de tres provincias cubanas. Las variables que se exploraron fueron: edad, sexo, síntomas clínicos, ocupación, contacto directo con reservorios animales, consumo de lácteos no pasteurizados e ingestión de carne semicruda; para su análisis se utilizaron medidas de estadística descriptiva como frecuencias absolutas y porcentajes. Resultados: Entre los individuos notificados con brucelosis humana sobresalió el sexo masculino (66 %), las edades entre 25 y 54 años (66,1 %), el contacto directo con reservorios animales de Brucella spp. (78,5 %) y, como síntomas predominantes, el malestar general (58,5 %), los dolores articulares (56,9 %) y la fiebre (55,4 %). Conclusión: Las variables clínico-epidemiológicas descritas muestran comportamientos similares a los reportados en periodos anteriores en Cuba y en otros países donde la enfermedad es endémica, lo que sugiere la necesidad de incrementar las estrategias para la prevención, vigilancia y control de la brucelosis humana en Cuba.

Resumen La información espectral ha sido utilizada ampliamente en el estudio de las condiciones nutricionales y en el desarrollo de diversos cultivos empleados en el ámbito agrícola, pero existe un vacío de investigación en especies forrajeras para condiciones tropicales. El presente estudio contempló la comparación de información multi e hiperespectral correspondientes al cultivo de pasto Estrella Africana (Cynodon nlemfuensis) dedicado a la alimentación de ganadería lechera usando espectroscopia de campo e información satelital de Sentinel-2. Se determinó que existe una heterogeneidad de la firma espectral del cultivo, debido al patrón aleatorio de alimentación por parte del ganado y la variación de las condiciones ambientales. Se generaron zonas con distintas alturas del cultivo, influyendo directamente en los valores de reflectancia, índice de área foliar e índices de vegetación. Se compararon los índices espectrales calculados con información de campo y satelital, obteniéndose valores de R2 de 0,725 para el caso del NDVI y de 0,446 para el SAVI. La presente investigación es de gran relevancia ya que sienta la línea base del uso de información espectral para el estudio de pastos dedicados a la alimentación de ganado lechero a partir de sensores remotos y espectrorradiometría de campo.

Abstract Spectral information has been widely applied to study the growth and nutritional conditions of different crops used in the agricultural field; however, there is a research gap regarding forage crops in tropical conditions. This study compared the multi and hyperspectral information of the African star pasture crop (Cynodon nlemfuensis) for dairy cattle feeding using field spectroscopy and satellite information of Sentinel-2. This study determined spectral signature heterogeneity of this crop due to the randomness of the feeding pattern of the cattle and the continuous change of the environmental conditions. Different crop heights in the sampling areas affected the reflectance values, leaf area index and vegetation indices directly. For the NDVI and SAVI, R2 values of 0,725 and 0,446 were achieved for spectral indices between field and satellite data. This research is relevant because it lays the baseline for the use of spectral information regarding the analysis of tropical pastures employed in dairy cattle feeding using remote sensing and a field spectroradiometer.

Resumen Introducción. Utilizar ensilaje de avena forrajera (Avena sativa L.) en la ganadería de leche en épocas deficitarias de alimento, permite mitigar pérdidas de biomasa por sequía en el trópico alto colombiano. Objetivos. 1) Determinar el rendimiento en materia seca (RMS) de cinco genotipos de avena forrajera y la estabilidad fenotípica y la calidad bromatológica de su ensilaje, y 2) evaluar la inclusión de ensilaje del genotipo AV25-T en dietas para ganado lechero. Materiales y métodos. Se realizaron en el trópico alto colombiano dos experimentos: 1) prueba de evaluación agronómica (octubre de 2016 a febrero de 2017) en un diseño de bloques completos al azar con cinco genotipos, ocho localidades y cuatro repeticiones; se determinó el rendimiento en materia seca (RMS) y en ensilaje los contenidos de proteína, fibra en detergente neutro (FDN) y nutrientes totales digestibles (NTD) y 2) estudio de respuesta animal (enero 2018) con la inclusión del genotipo AV25-T en dietas, en un diseño Crossover simple con dos factores: animal (5) y dietas (3); las dietas fueron: D1: solo pradera; D2: 35 % de ensilaje AV25-T + pastoreo y D3: 65 % de ensilaje AV25-T + pastoreo. Se determinó en la leche la producción, la proteína, la grasa y los sólidos totales, y en el animal el cambio de peso. Resultados. AV25-T presentó adaptación con el mayor RMS. La inclusión de ensilaje de AV25-T en la dieta animal, mostró un cambio significativo en el peso del animal (0,1 y 0,25 kg con D2 y D3), el rendimiento de leche (27,2 - 29,7 L/vaca/día con D3 y D2) y el contenido de grasa (3,2 - 3,9 % con D3 y D2), sin detrimento en proteína y sólidos totales. Conclusión. El uso del ensilaje de avena forrajera AV25-T permitió en vacas lecheras Holstein incrementos en el peso animal, el rendimiento de leche y el contenido grasa sin afectar la proteína y los sólidos totales.

Abstract Introduction. The use of forage oat silage (Avena sativa L.) in dairy cattle in times of feed deficit, allows mitigating biomass losses due to drought in the Colombian high tropics. Objectives. 1) To determine the dry matter yield (DMY) of five forage oat genotypes and the phenotypic stability and the bromatological quality of their silage, and 2) to evaluate the inclusion of the AV25-T genotype silage in diets for dairy cattle. Materials and methods. In the Colombian high tropics two experiments were performed: 1) agronomic evaluation test (October 2017 and February 2018) in a randomized complete block design with five genotypes, eight locations, and four replicates; dry matter yield (DMY) and protein, neutral detergent fiber (NDF) and total digestible nutrients (TDN) contents in silage were determined, and 2) animal response study (January 2018) with the inclusion of the AV25-T genotype in diets, in a simple crossover design with two factors: animal (5) and diets (3); the diets were: D1: only meadow; D2: 35 % AV25-T silage + grazing, and D3: 65 % AV25-T silage + grazing. Milk yield, protein, fat, total solids, were determined in the milk, and weight change was determined in the animals. Results. AV25-T presented adaptation with the highest DMY. The inclusion of AV25-T silage in the animal diet showed a significant change in animal weight (0.1 and 0.25 kg with D2 and D3), milk yield (27.2 - 29.7 L/cow/day with D3 and D2), and the fat content (3.2 - 3.9 % with D3 and D2), without detriment in protein and total solids. Conclusion. The use of AV25-T forage oats in silage allowed increases in animal weight, milk yield, and fat content in Holstein dairy cows without affecting protein and total solids in milk.

Resumen El objetivo fue determinar el efecto de la edad al primer parto sobre la longevidad, el número de días productivos y la producción de leche durante toda la vida de las vacas Holstein y Pardo Suizo en la sabana tropical de Honduras. La información se recolectó de tres granjas lecheras con vacas Holstein (n= 1,391) y cuatro granjas con vacas Pardo Suizo (n= 480), nacidas entre 1993 y 2013, manejadas bajo sistemas intensivos. El modelo estadístico que describió las variables de interés incluyó el efecto de la granja, el grupo de edad al primer parto, el período de nacimiento, la estación de nacimiento y la interacción granja x período y el error residual. Se encontraron efectos de la granja, período, el grupo de edad al primer parto y la interacción granja x período en las variables de respuesta. Un efecto favorable de las vacas que tuvieron su primer parto a una edad más temprana en el número de días de producción y la producción de leche durante toda la vida, y un aumento en la longevidad, tanto en vacas Holstein como en vacas Pardo Suizo (P<0.05). En conclusión, las vacas que parieron a una edad temprana tuvieron más días productivos en la granja y produjeron más leche durante su vida productiva. Por lo tanto, hacer que las novillas paran a una edad temprana podría ser una estrategia de manejo para aumentar la productividad en la granja. Sin embargo, se debe tener en cuenta el peso al primer parto y los aspectos fisiológicos del animal.

Abstract The aim was to determine the effect of age at first calving on longevity, lifetime number of productive days and lifetime milk yield of Holstein and Brown Swiss cows in the tropical savanna of Honduras. The information was collected from three dairy farms with Holstein (n = 1,391) and four farms with Brown Swiss cows (n = 480), born from 1993 to 2013, managed under intensive systems. The statistical model that described the variables of interest included the effect of farm, group of age at first calving, period of birth, season of birth and the interaction farm x period and the residual error. Effects of farm, period group of age at first calving and interaction of farm x period were found on the response variables. A favorable effect of the cows that had their first calving at an earlier age on lifetime number of days in production and lifetime milk yield, and an increase in longevity, in both Holstein and Brown Swiss cows (P<0.05). In conclusion, cows that calved at an early age had more productive days in the farm and produced more milk during their productive life. Therefore, make the heifers to calf at an early age could be a management strategy to increase productivity in the farm. However, the weight at first calving and physiological aspects of the animal should be taken into consideration.

ABSTRACT: There is limited information regarding both nitrogen (N) and energy partitioning of dairy cows grazing well–managed tropical pastures. The objective of this study was to investigate the N and energy partitioning of mid–lactation dairy cows on rotationally grazed elephant grass using two pre–grazing targets: 95 % or maximum canopy light interception (LI95% or LIMax) during regrowth. The study used 26 Holstein × Jersey dairy cows arranged in a randomized complete block design with three 40–day periods of sampling. Grazing at LI95% increased organic matter and crude protein intake by 20 % (p ≤ 0.05) which resulted in a 9 % increase in fat corrected milk yield (p ≤ 0.05) relative to LIMax. Cows grazing at LI95% had greater concentration of total volatile fatty acids, butyrate and valerate (p ≤ 0.05), and smaller acetate (p ≤ 0.05) than those grazing at LIMax. Intake of net energy for lactation (NEL) and NEL secreted in milk were greater (p ≤ 0.05), while partitioning of NEL towards maintenance tended to be greater (p = 0.07) for cows grazing at LI95% than those grazing at LIMax. Milk urea nitrogen and both urine and fecal N excretion were greater for cows grazing at LI95% (p ≤ 0.05), but N excretion intensity was lower than in cows grazing at LIMax (p ≤ 0.05). Strategic grazing management using the LI95% pre–grazing target increases N losses through both urine and feces; however, it reduces N excretion intensity of dairy cows by 9 %.