Livestock farms in Kenya face pressure to increase productivity amid rising global population. Cattle farming dominates, but small to medium-sized farms struggle with cattle insemination. Currently, visual observation is used for heat detection, with farmers maintaining farm journals. Modern methods utilizing sensors to improve estrus prediction are time-consuming, costly and need constant internet connection. This research proposes a novel approach-the use of an on-controller machine learning algorithm- for estrus prediction in cattle. Motion and temperature data was collected from two zero-grazed multiparous Holstein Friesian cows in Kiambu County, Kenya for 11 months. The data was cleaned and stored. Movement intensity profiles were derived by root-mean-squaring directional accelerometer values and averaging this over time. Validation was performed by observing cow behavior for indicators such as restlessness, mounting, and vulva swelling, with farmer predictions documented in their records. The collected data was then used to train a machine learning algorithm, with several models tested, and a neural network emerged as the best fit. The TensorFlow library facilitated the implementation of the algorithm on a microcontroller, allowing for the development of an animal tag featuring the ML algorithm. Results demonstrated 83.9% sensitivity, 89.0% specificity and 89.5% accuracy in detecting estrus, compared to farmer's visual observation, which had only 37% sensitivity. These findings underscore the potential to integrate machine learning into Precision Livestock Farming for estrus prediction, with prediction occurring directly on the animal tag offline. This integration holds promise for farmers, notably heightened insemination success rates, without necessitating significant financial investment.

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 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.

Resumen Objetivo. Desarrollar un Análisis de Ciclo de Vida (ACV), en granjas ganaderas con manejo rotacional del pastizal según composición botánica. Materiales y métodos: Se compararon granjas lecheras de Cotopaxi, a 2800- 3590 msnm. Granja 1: carga de 1 y 1,2 UA/ha, con 50% de Llantén (Plantago lanceolata), 50% de Trébol blanco (Trifolium repens). Granja 2: Carga de 1 y 1,2 UA/ha, 85 % de Ryegrass (Lolium perenne)-15% Trébol blanco (Trifolium repens). Granja 3: Carga de 1 y 2,1 UA/ha, 33 % de Ryegrass-33% Llantén-34% de Trébol blanco. Se usó fertilización, balanceado y animales Holstein tipos mestizo, neozelandés y norteamericano y reposo del pasto. Resultados: Hubo diferencias en uso de la tierra, coincidente en granjas 1 y 3, en mano de obra familiar. En la Granja 1, el reposo fue 15 a 28 días y FDN de 47,38 a 28,03 y 1,96 a 2,45 Mcal de energía y en 3, valores de Energía Metabolizable de 1,99 a 40 día y 2,11 a 35 días, menos leche/vaca que 3 y superior a 1. En producción de leche/ha, las granjas 1 y 3 superiores con 24 kg vs 19 kg. Esto fue positivo en ACV en esas granjas. Existió potencial para convertir más energía del sistema a productos. Conclusión: En el ACV, se encontró coincidencia con indicadores de sistemas especializados en producción de leche, balances de nitrógeno, energía y sus relaciones con el ambiente y emisiones, aunque se puede recuperar eficiencia con mejoras al manejo y sin insumos extras a la granja.

Abstract Aim. Develop a Life Cycle Analysis (LCA) in livestock farms with rotational management of the pasture according to botanical composition. Materials and methods: Dairy farms from Cotopaxi, at 2800-3590 meters above sea level, were compared. Farm 1: load of 1 and 1.2 AU/ha, with 50% Plantain (Plantago lanceolata), 50% White Clover (Trifolium repens). Farm 2: Load of 1 and 1.2 AU/ha, 85% Ryegrass (Lolium perenne)-15% White clover (Trifolium repens). Farm 3: Load of 1 and 2.1 AU/ha, 33% Ryegrass-33% Plantain-34% White Clover. Fertilization, balancing and crossbred, New Zealand and North American type Holstein animals and grass rest were used. Results: There were differences in land use, coinciding in farms 1 and 3, in family labor. On Farm 1, rest was 15 to 28 days and NDF from 47.38 to 28.03 and 1.96 to 2.45 Mcal of energy and in 3, Metabolizable Energy values from 1.99 to 40 days and 2 .11 to 35 days, less milk/cow than 3 and higher than 1. In milk production/ha, farms 1 and 3 higher with 24 kg vs 19 kg. This was positive for ACV on those farms. There was potential to convert more of the system's energy into products. Conclusion: In the LCA, a coincidence was found with indicators of specialized systems in milk production, nitrogen balances, energy and their relationships with the environment and emissions, although efficiency can be recovered with improvements in management and without extra inputs to the farm.

Abstract The objectives were to determine the reproductive response of Holstein heifers in small-scale dairy herds to estrus synchronization protocols based on prostaglandins (PG), estradiol benzoate (EB), and progesterone (P4). Heifers at least 13 mo old (n= 138) were randomly included in one of two synchronization protocols: PG) administration of 500 (g cloprostenol i.m. at d 0 and d 14; and PGPE) similar to PG but with an additional application of 100 mg P4 + 2 mg EB on d 7. The estrus rate of the PG group was similar to that of the PGPE group (84.3 vs 79.4 %; P>0.1). Heifers in PGPE had a higher percentage of estrus between 37-84 h post-treatment vs the PG group (94.2 vs 82.5 %; P=0.05). The conception rate of the PGPE group was higher than that of the PG group (94.4 vs 83.1 %; P=0.05). In the PG group, body development at weaning was lower in heifers that did not show estrus vs those that did (P<0.05). Nonetheless, in the PGPE group, birth weight was lower in heifers that showed estrus than those that did not (P<0.05). In conclusion, heifers in the small-scale dairy system have a good reproductive response to prostaglandin-based estrus synchronization (cloprostenol). The inclusion of EB + P4 into the hormonal synchronization protocol with PG improves conception rate but has a minimal effect on the distribution of the beginning of estrus expression after treatment.

Resumen Los objetivos fueron determinar la respuesta reproductiva de vaquillas Holstein en hatos lecheros de pequeña escala a protocolos de sincronización de estros basado en prostaglandinas (PG) benzoato de estradiol (BE) y progesterona (P4). Vaquillas con al menos 13 meses de edad (n= 138) fueron aleatoriamente incluidas a uno de dos protocolos de sincronización: PG) administración de 500 (g cloprostenol i.m. al día 0 y al día 14; y PGPE) similar a PG pero con una aplicación adicional de 100 mg P4 + 2 mg BE en el día 7. La tasa de estros del grupo PG fue similar al grupo PGPE (84.3 vs 79.4 %; P>0.1). Las vaquillas en PGPE tuvieron mayor porcentaje de estros entre las 37-84 h post tratamiento vs el grupo PG (94.2 vs 82.5 %; P=0.05). La tasa de concepción del grupo PGPE fue mayor vs el grupo PG (94.4 vs 83.1 %; P=0.05). En el grupo PG, el desarrollo corporal al destete fue menor en vaquillas que no mostraron estro vs las que si mostraron (P<0.05). Sin embargo, en el grupo PGPE el peso al nacimiento fue menor en las vaquillas que mostraron estro vs las que no mostraron estro (P<0.05). En conclusión, las vaquillas del sistema lechero de pequeña escala presentan buena respuesta reproductiva a la sincronización de estros basada en prostaglandinas (cloprostenol). La inclusión de BE + P4 al protocolo de sincronización hormonal con PG mejora la tasa de concepción, pero tiene un efecto mínimo en la distribución del inicio de la expresión de los estros después del tratamiento.

ABSTRACT The aim of this study was to evaluate the efficiency of artificial insemination (AI) services in Holstein x Brahman cows under a heat induction programme. Three experiments were carried out. In Exp. 1, a retrospective analysis of the efficiency of AI insemination of 41 000 cows treated with the combination of progesterone and oestradiol benzoate or equine chorionic gonadotropin (eCG) was carried out. In Exp. 2 it was evaluated 863 cows inseminated after heat induced with progesterone and oestradiol benzoate to know the physiological events that occur before and after service in herds with a high incidence of anoestrus. Gynaecological examinations and determination of progesterone in milk were performed. The purpose of Exp. 3 was to improve the effectiveness of AI services for cows in postpartum anoestrus treated with progesterone and oestradiol benzoate combined with a technique to identify and induce the return to service of females that did not conceive. Only 30% of the cows exceeded 40% conception. The best results were obtained when using eCG (47% vs 29%). The problems associated with the low conception rate were unfertilized oestrus, embryonic mortality and anoestrus after breeding (Exp. 2). The return to service induction technique increased (p<0.001) the conception rate of the second induced service and the percentage of accumulated pregnancy in the treated group compared to the control (69.0 and 32.0%, respectively) (Exp. 3).

RESUMEN El trabajo tuvo como objetivo evaluar la eficiencia de los servicios de inseminación artificial (IA) en vacas Holstein x Brahman bajo programa de inducción del celo, Se realizaron tres experimentos. En el Exp. 1 se efectuó un análisis retrospectivo de la eficiencia de la inseminación artificial de 41 000 vacas tratadas con la combinación de progesterona y benzoato de estradiol o gonadotropina coriónica equina (eCG). En el Exp. 2 se trabajó con 863 vacas inseminadas de celo inducido con progesterona y benzoato de estradiol para conocer los eventos fisiológicos que ocurren antes y después del servicio en rebaños con alta incidencia de anestro. Se hicieron exámenes ginecológicos y determinación de progesterona en leche. El Exp. 3 tuvo como fin mejorar la eficacia de los servicios de IA de vacas en anestro posparto tratadas con progesterona y benzoato de estradiol combinado con una técnica para identificar e inducir el retorno al servicio de las hembras que no llegasen a concebir. Solo 30% de las vacas superaron el 40% de concepción. Los mejores resultados se obtuvieron al utilizar la eCG (47% vs 29%). Los problemas asociados a la baja tasa de concepción fueron los celos no fertilizados, la mortalidad embrionaria y el anestro posterior al servicio (Exp. 2). La técnica de inducción del retorno al servicio aumentó (p<0.001) la tasa de concepción del segundo servicio inducido y el porcentaje de preñez acumulada en el grupo tratado respecto al testigo (69.0 y 32.0%, respectivamente) (Exp. 3).

ABSTRACT The chemical characteristics of Cenchrus clandestinus grass, nutritional base in dairy production systems, demand the energy supplementation. Corn grain is the most used food for this purpose, but considering its demand and prices, the aim of this study was to evaluate its partial replacement by alternative non-fibrous carbohydrates sources on methane emissions, energy and nitrogen balance and productive performance of dairy cows. Sixteen multiparous Holstein cows were fed Cenchrus clandestinus plus one of four concentrate supplements formulated with corn (Zea mays) or a partial replacement of corn with sorghum (Sorghum vulgare), cassava (Manihot esculenta) or citrus pulp (Citrus sp). Inclusion of these ingredients did not affect dry matter intake, dry matter digestibility, enteric methane emissions, energy and nitrogen balance, milk yield or composition. The results allow to conclude that these ingredients can partially replace corn in the diet of lactating dairy cows.

RESUMEN Las características químicas del pasto Cenchrus clandestinus, base alimenticia en los sistemas de producción lechera, hacen necesaria la suplementación energética. El grano de maíz es el alimento más empleado para este propósito, pero dada su demanda y precio, el objetivo de este trabajo fue evaluar su reemplazo parcial por otras fuentes de carbohidratos no fibrosos sobre la emisión de metano, el balance energético-nitrogenado y el desempeño productivo de vacas lecheras. Dieciséis vacas Holstein recibieron Cenchrus clandestinus y uno de cuatro concentrados formulados con maíz (Zea mays) y sorgo (Sorghum vulgare), yuca (Manihot esculenta) o pulpa cítrica (Citrus sp) en reemplazo parcial del maíz. La inclusión de estos ingredientes no alteró el consumo de materia seca ni su digestibilidad, producción de metano, balance energético-nitrogenado, producción de leche o su composición. Los resultados permiten concluir que esos ingredientes pueden reemplazar parcialmente al maíz en la dieta de vacas lecheras.

ABSTRACT The effect of four harvest ages (90, 120, 150 and 180 days) on the aerial biomass yield and chemical composition of rapeseed was evaluated, as well as its use as a hay supplement for dairy cows grazing at an altitude of 3279 m. Forage yield and its chemical composition were evaluated in 16 plots, 4 per treatment, according to a randomized complete block design. The harvested rapeseed biomass was hayed and chopped to 1 cm in length, supplied daily at a rate of 3 kg per cow. Sixteen crossbred and multiparous Holstein cows were distributed in four treatments that consisted of hays made according to harvest age. Milk production per cow was recorded for six weeks. Total solids, fat, protein, and lactose were determined in the last week of the study. As rapeseed age increased, forage biomass and neutral detergent fiber (NDF) increased, and crude protein concentration decreased; however, milk production and its milk components were not affected by the supplementation of the four types of hay, except for rapeseed hay harvested at 90 days of age, which increased the milk protein content.

RESUMEN Se evaluó el efecto de cuatro edades de cosecha (90, 120, 150 y 180 días) sobre el rendimiento de biomasa aérea y composición química de la colza, así como su uso como suplemento henificado para vacas lecheras en pastoreo a 3279 msnm. El rendimiento forrajero y la composición química se evalúo en 16 parcelas, 4 por tratamiento, de acuerdo con un diseño de bloques completos al azar. La biomasa de colza cosechada fue henificada y picada a 1 cm de longitud, suministrada diariamente a razón de 3 kg por vaca. Dieciséis vacas Holstein cruzadas y multíparas se distribuyeron en cuatro tratamientos que consistieron en henos elaborados de acuerdo con la edad de cosecha. La producción de leche por vaca se registró durante seis semanas. Los sólidos totales, grasa, proteína y lactosa se determinaron en la última semana del estudio. A medida que la edad de la colza fue mayor se incrementó la biomasa forrajera y la fibra detergente neutra (FDN), y disminuyó la concentración de proteína cruda; sin embargo, la producción de leche y sus componentes lácteos no se vieron afectados por la suplementación de los cuatro tipos de heno, con excepción del heno de colza cosechada a 90 días de edad, que incrementó el contenido de proteína láctea.

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 The work aims to analyze the associations of polymorphic variants of the PRL and BLG genes with resistance and susceptibility to mastitis in Holstein cows. The experimental study consisted of the selection of biomaterial samples from 250 heads of Holstein cows aged 3 years divided into two groups (healthy and with a confirmed diagnosis of mastitis). The determination of animal genotypes was carried out using polymerase chain reaction and restriction fragment length polymorphism. The study of the nature of the association of polymorphic variants of the PRL and BLG gene with resistance/increased risk of mastitis established a significant deviation from the theoretically expected distribution of bBLG-HaeIII genotypes in the group of animals suffering from mastitis (the value of χ2 was 0.24). The bBLG-HaeIIIBB genotype can act as a marker of an increased risk of developing mastitis in Holstein cows; its frequency in the group of sick animals exceeds the frequency in the control group by more than 2 times (44.0 compared to 17.0%, respectively). The bBLG-HaeIIIAB genotype is significantly associated with mastitis resistance in Holstein cows; its frequency is 2 times lower than in the control group (28.0 compared to 54.0%). 25 healthy mastitis. . mastitis) polymorphism resistanceincreased bBLGHaeIII bBLG HaeIII χ 0.24. 024 0.24 0 24 0.24) bBLGHaeIIIBB HaeIIIBB 44.0 440 44 (44. 170 17 17.0% respectively. respectively respectively) bBLGHaeIIIAB HaeIIIAB 28.0 280 28 (28. 54.0%. 540 54.0% 54 54.0%) 02 0.2 44. 4 (44 1 17.0 28. (28 54.0 5 0. (4 17. (2 54. (

Resumo O trabalho tem como objetivo analisar as associações de variantes polimórficas dos genes PRL e BLG com resistência e suscetibilidade à mastite em vacas holandesas. O estudo experimental consistiu na seleção de amostras de biomateriais de 250 cabeças de vacas holandesas com 3 anos de idade divididas em dois grupos (saudáveis e com diagnóstico confirmado de mastite). A determinação dos genótipos dos animais foi realizada utilizando reação em cadeia da polimerase e polimorfismo de comprimento de fragmentos de restrição. O estudo da natureza da associação de variantes polimórficas do gene PRL e BLG com resistência/risco aumentado de mastite estabeleceu um desvio significativo da distribuição teoricamente esperada dos genótipos bBLG-HaeIII no grupo de animais que sofrem de mastite (o valor de χ2 foi 0,24). O genótipo bBLG-HaeIIIBB pode atuar como marcador de risco aumentado de desenvolvimento de mastite em vacas holandesas; sua frequência no grupo de animais doentes excede a frequência no grupo controle em mais de duas vezes (44,0% contra 17,0%, respectivamente). O genótipo bBLG-HaeIIIAB está significativamente associado à resistência à mastite em vacas holandesas; sua frequência é duas vezes menor que no grupo controle (28,0% contra 54,0%). 25 saudáveis mastite. . mastite) restrição resistênciarisco bBLGHaeIII bBLG HaeIII o χ 0,24. 024 0,24 0 24 0,24) bBLGHaeIIIBB HaeIIIBB 44,0% 440 44 (44,0 170 17 17,0% respectivamente. respectivamente respectivamente) bBLGHaeIIIAB HaeIIIAB 28,0% 280 28 (28,0 54,0%. 540 54,0% 54 54,0%) 2 02 0,2 44,0 4 (44, 1 17,0 28,0 (28, 54,0 5 0, 44, (44 17, 28, (28 54, (4 (2 (

ABSTRACT: This study evaluated the probability of pregnancy and associated factors for two times artificial inseminations (AI), 8 or 10 hours after automated activity monitoring (AAM) alarm on the first postpartum AI of 1,054 Holstein dairy cows. The estrus was synchronized by prostaglandin or estradiol-progesterone program. Stepwise logistic regression was performed to analyze the probability of pregnancy, and associated factors (activity, estrus intensity, parity, peripartum health, retained placenta, postpartum vaginal discharge, and season). The highest pregnancy rates were obtained with multiparous animals, inseminated ten hours after the AAM alarm, in the fall or winter season, with a high activity peak and estrus intensity (P < 0.05). Peripartum diseases, retained placenta, and postpartum vaginal discharge negatively influenced the pregnancy rate, regardless of parity. Thus, the optimization of AAM models by including on-farm measures like parity, peripartum health history, and environmental conditions may favor the correct identification of estrus and improve the AAM alarm regarding the ideal moment for AI, increasing the reproductive performance in dairy cows. ABSTRACT , (AI) 1 (AAM 1054 054 1,05 cows estradiolprogesterone estradiol progesterone program activity, (activity parity placenta season. season . season) animals P 0.05. 005 0.05 0 05 0.05) diseases rate Thus onfarm farm history (AI 105 1,0 00 0.0 1, 0.

RESUMO: O objetivo deste estudo foi avaliar a probabilidade de prenhez e fatores associados para dois horários de inseminação artificial (IA), oito ou 10 horas após o alarme de monitoramento automatizado de atividades (AAM), na primeira IA pós-parto em 1.054 vacas leiteiras da raça Holandês. O estro foi sincronizado por protocolos a base de prostaglandina ou estradiol-progesterona. Regressão logística stepwise foi realizada para analisar a probabilidade de prenhez e fatores associados (atividade, intensidade do estro, paridade, saúde no periparto, placenta retida, descarga vaginal pós-parto e estação do ano). As maiores taxas de prenhez foram obtidas em multíparas, inseminadas 10 horas após o alarme do AAM, no outono ou inverno, com pico de atividade elevado e intensidade de estro (P < 0,05). Doenças no periparto, placenta retida e descarga vaginal pós-parto influenciaram negativamente a taxa de prenhez, independentemente da paridade. Assim, a otimização dos modelos de AAM, incluindo medidas rotineiras da fazenda como paridade, histórico de saúde no periparto e condições ambientais, podem favorecer a identificação correta do estro e melhorar o alarme do AAM em relação ao momento ideal para a IA, aumentando o desempenho reprodutivo nas vacas leiteiras. RESUMO , (IA) 1 (AAM) pósparto pós parto 1054 054 1.05 Holandês estradiolprogesterona. estradiolprogesterona estradiol progesterona. progesterona estradiol-progesterona atividade, (atividade paridade ano. ano . ano) multíparas inverno P 0,05. 005 0,05 0 05 0,05) Assim ambientais (IA (AAM 105 1.0 00 0,0 1. 0,

ABSTRACT: Protocols to artificially induce cows and heifers into lactation are effective and commercially available in Brazil. However, these protocols demand long hormonal treatments, which is debatable since little research has been done in the subject. To further understand artificial induction to lactation (AIL) protocols, we conducted two experiments. In experiment 1, our objective was to better characterize steroidal profile during an AIL protocol and assess the estradiol (E2) and progesterone (P4) serum profiles of Jersey cows (n=6) subjected to a conventional protocol. In experiment 2, we aimed to compare milk production and serum E2 concentrations of Holstein heifers induced into lactation by the standard AIL protocol (15 injections of E2 and 8 P4 injections) and by a short protocol in which the number of E2 injections and, consequently, the overall dosage of E2, were reduced (8 injections of E2 and 8 P4 injections). We hypothesized that a short AIL protocol (8 days) would be as efficient as the long standard protocol of 15 days. Our hypothesis was confirmed, since we demonstrated that a shorter protocol was able to induce lactation in Holstein heifers without hindering milk production. ABSTRACT Brazil However treatments subject (AIL experiments 1 E (E2 P (P4 n=6 n6 n 6 (n=6 2 (1 consequently ( injections. . days confirmed (E (P n= (n= (n

RESUMO: Protocolos que induzem à lactação artificial em vacas e novilhas são eficazes e estão comercialmente disponíveis no Brasil. No entanto, esses protocolos demandam longos tratamentos hormonais, o que é discutível visto que poucas pesquisas foram feitas sobre o assunto. Para entender melhor os protocolos de indução artificial à lactação (IAL), realizamos dois experimentos. Foi testada a hipótese de que um protocolo curto (oito dias) de IAL é tão eficiente quanto o protocolo padrão de 15 dias. No experimento 1 objetivou-se caracterizar o perfil esteroidal durante um protocolo de IAL e avaliou-se os perfis séricos de estradiol (E2) e progesterona (P4) de vacas Jersey (n=6) submetidas a um protocolo convencional. No experimento 2 foram comparadas a produção de leite e as concentrações séricas de E2 de novilhas holandesas induzidas à lactação pelo protocolo padrão de IAL (15 injeções de E2 e 8 injeções de P4) e por um protocolo curto, no qual o número de injeções de E2 e, consequentemente, a dosagem geral de E2 foram reduzidas (oito injeções de E2 e oito injeções de P4). A hipótese foi confirmada, demonstrado que um protocolo mais curto induziu a lactação em novilhas holandesas sem prejudicar a produção de leite. RESUMO Brasil entanto hormonais assunto IAL, , (IAL) experimentos dias objetivouse objetivou se avaliouse avaliou E (E2 P4 P (P4 n=6 n6 n 6 (n=6 convencional (1 consequentemente P4. . confirmada (IAL (E (P n= (n= ( (n

ABSTRACT: This study evaluated the vaccine-induced serological response after administering four commercial formulations containing Bovine Viral Diarrhea Virus (BVDV) type-1, BVDV-2, and Bovine Herpesvirus type 1 (BoHV-1) to young heifers with circulating maternal antibody titers. The study also determined the anamnestic response to vaccinations after the complete metabolization of maternal antibodies when the calves reached six months. Eighty-seven Holstein heifers were selected and randomly distributed into four experimental groups based on the vaccine administered. The four vaccine-based experimental groups were as follows: vaccine A (n = 22), vaccine B (n = 22), vaccine C (n = 24), and vaccine D (n = 19), given on the 60th, 90th, and 180th day of life, respectively. Virus-neutralization (VN) tests were performed at baseline (day 60) and 30 days after administering the second (day 120) and third doses (day 210). We analyzed the effect of vaccine group (P ≤ 0.001), day of vaccination (P ≤ 0.001), and group versus vaccine day interaction (P ≤ 0.001) for antibody titers produced against BVDV-1, BVDV-2, and BoHV-1 using the PROC MIXED method (Statistical Analysis System -SAS 9.4). Antibody titers against BVDV-1, BVDV-2, and BoHV-1 were similar at baseline and on day 60 of life. The mean antibody titers were constant and persisted against BVDV-1 in heifers immunized with vaccines A and C. Heifers immunized with vaccine A alone had a similar effect against BVDV-2. Regarding BoHV-1, the antibody titers decreased between days 60 and 210 in groups B, C, and D. The antibody titer for heifers in group A also decreased between days 60 and day 120, and an intense increase in titers was observed on day 210. After being immunized with formulations B, C, and D, the frequency of animals with titers above protective levels for BVDV-1, BVDV-2, and BoHV-1 was very low or null. Indicators of anamnestic response were observed in heifers vaccinated with formulation A only. Therefore, it can be concluded that passive immunity negatively interferes with antibody production after vaccination. ABSTRACT vaccineinduced induced BVDV (BVDV type1, type1 1, type-1 BVDV2, BVDV2 2, 2 BVDV-2 BoHV1 BoHV (BoHV-1 months Eightyseven Eighty seven administered vaccinebased follows n 22, 22 , 22) 24, 24 24) 19, 19 19) 60th th 90th life respectively Virusneutralization neutralization VN (VN 3 120 . 210) P 0.001, 0001 0.001 0 001 BVDV1, BVDV1 BoHV- Statistical SAS 9.4. 94 9.4 9 4 9.4) 6 BVDV- BVDV2. 2. BoHV1, 21 null only Therefore type- (BoHV- 12 000 0.00 00 9. (BoHV 0.0 0.

RESUMO: O objetivo desse estudo foi avaliar a resposta sorológica induzida após vacinação com quatro formulações comerciais contendo o BVDV-1, BVDV-2 e BoHV-1 em novilhas jovens com títulos de anticorpos maternos circulantes, assim como analisar uma possível resposta anamnéstica em vacinações, após a completa metabolização dos anticorpos maternais aos seis meses de idade. Foram selecionadas 87 novilhas Holandesas, distribuídas aleatoriamente em quatro grupos experimentais de acordo com as vacinas: vacina A (n = 22), vacina B (n = 22), vacina C (n = 24) e vacina D (n = 19), aplicadas aos dias 60, 90 e 180 de vida. Testes de vírus-neutralização (VN) foram realizados no momento basal (D60) e 30 dias após a aplicação da 2ª dose (D120) e 3ª dose (D210). Observou-se efeito do grupo (P ≤ 0,001), dia da vacinação (P ≤ 0,001), e interação grupo versus dia (P ≤ 0,001) para os títulos de anticorpos produzidos contra o BVDV-1, BVDV-2 e BoHV-1, por meio do comando PROC MIXED (Statistical Analysis System, versão 9,4). Os títulos de anticorpos contra o BVDV-1, BVDV-2 e BoHV-1 eram semelhantes no momento basal aos 60 dias de vida. Os títulos médios de anticorpos foram constantes e persistentes contra o BVDV-1 nas novilhas imunizadas com as vacinas A e C, porém apenas a vacina A teve este mesmo perfil contra o BVDV-2. Em relação ao BoHV-1, os grupos B, C e D apresentaram queda nos títulos de anticorpos do D60 ao D210, enquanto as novilhas do grupo A apresentaram queda do D60 ao D120, com aumento intenso dos títulos no D210. A frequência de animais com títulos acima dos protetores contra o BVDV-1, BVDV-2 e BoHV-1 foram muito baixos ou nulos após as vacinações nos animais imunizados com as formulações B, C e D. Sugere-se que a imunidade passiva interferiu negativamente na indução de anticorpos pelas vacinas, observando-se indicadores de resposta anamnéstica apenas para as novilhas vacinadas com a formulação A. RESUMO BVDV1, BVDV1 BVDV 1, 1 BVDV2 2 BVDV- BoHV1 BoHV BoHV- circulantes idade 8 Holandesas n 22, 22 , 22) 24 19, 19 19) 9 18 vida vírusneutralização vírus neutralização VN (VN (D60 3 ª D120 (D120 D210 . (D210) Observouse Observou se P 0,001, 0001 0,001 0 001 BoHV1, Statistical System 9,4. 94 9,4 4 9,4) 6 BVDV2. 2. D6 Sugerese Sugere observandose observando (D6 D12 (D12 D21 (D210 000 0,00 00 9, (D D1 (D1 D2 (D21 0,0 (D2 0,

ABSTRACT This study aimed to determine the effectiveness of topical HoofCare® in the treatment of digital dermatitis (DD) in dairy cows. Thirty-six high-yielding Holstein cows with DD in at least one limb were included and randomly divided into two groups, making 42 limbs. The alternating treatment group consisted of 21 limbs treated for three alternating days every 48h, and the continuous treatment group consisted of 21 limbs treated every 24h for five days. The cows underwent lameness examination, thermographic analysis, and qualitative and quantitative analysis of the lesions on D0 (time of identification of the lesion and prior to treatment), D4 (fourth day of treatment), and D10 (five days after the end of treatment). The data were compared between different time points and groups. There was no significant difference between the groups for the variables evaluated. However, both groups presented a reduction in the degree of lameness around the lesion, in the local temperature, and regression from the active to the inactive stage of the lesions. Thus, this short-term study demonstrates the suggestive efficacy of HoofCare® in treating DD and recommends conducting further long-term studies. HoofCare (DD Thirtysix Thirty six highyielding high yielding 4 2 48h h examination D treatment, , treatment) fourth D1 treatment. . evaluated However temperature Thus shortterm short term longterm long studies

RESUMO Este estudo teve como objetivo determinar a eficácia do HoofCare® tópico no tratamento da dermatite digital (DD) em vacas leiteiras. Trinta e seis vacas Holandesas de alto rendimento, com DD em pelo menos um dos membros, foram incluídas e divididas aleatoriamente em dois grupos, totalizando 42 membros. O grupo de tratamento alternado consistiu de 21 membros tratados por três dias alternados, a cada 48 horas, e o grupo de tratamento contínuo consistiu de 21 membros tratados a cada 24 horas, por cinco dias. As vacas foram submetidas ao exame de claudicação, à análise termográfica, à análise qualitativa e quantitativa das lesões no D0 (momento da identificação da lesão e antes do tratamento), no D4 (quarto dia de tratamento) e no D10 (cinco dias após o término do tratamento). Os dados foram comparados entre diferentes momentos e grupos. Não houve diferença significativa entre os grupos para as variáveis avaliadas. Entretanto, ambos os grupos apresentaram redução no grau de claudicação, na área da lesão, na temperatura local e regressão do estágio ativo para o inativo das lesões. Assim, este estudo de curto prazo demonstra sugestiva eficácia do HoofCare® no tratamento da DD e recomenda a realização de mais estudos de longo prazo. HoofCare (DD leiteiras rendimento 4 2 alternados horas claudicação termográfica D momento tratamento, , quarto D1 tratamento. . avaliadas Entretanto Assim