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This work presents a model based on artificial neural network (ANN) applied to predict water consumption in Brazilian dairy farms. Inputs were simple process data such as number of lactating cows, milk productivity, type of management, among others, with low computational cost and satisfactory data prediction. Data used for ANN training was acquired during two years from 31 farms in semi-confined dairy production. The analysis of the results was based on the following statistical models' indicators: R2 (Coefficient of determination), BIAS (trend coefficient), MAE (mean absolute error), RMSE (Root-mean-square deviation), NRMSE (percentage of the mean of the observations) and RAE (Relative absolute error). After performing the ANN training, the results showed good accuracy to predict water consumption in Brazilian dairy farms, with an average absolute error of 28.4% being obtained. On the other hand, considering the dataset used for ANN validation, an average absolute error of 48% was obtained.

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The objective of this study was to evaluate the influence of different heat-stress-reducing systems, i.e., sprinkler + artificial shade, shower + artificial shade, and artificial shade, on serum mineral, hormonal, hematological, and metabolite profiles, on milk production, and milk composition in lactating cows and pubertal heifers of Holstein and Jersey breeds. For this purpose, 12 animals were used: 3 Holstein cows with an average (mean ± SD) body weight of 600 ± 30 kg, 53 ± 11 months of age, and milk yield of 27 ± 3.5 kg/day; 3 Jersey cows with an average body weight of 370 ± 11 kg, 40 ± 6 months of age, and milk production of 11 ± 1.5 kg/day; 3 Holstein heifers (325 ± 25 kg and 16 ± 0.6 months of age); and 3 Jersey heifers (250 ± 25 kg and 13 ± 0.6 months of age). Animals were used in a replicated 3 × 3 Latin square design with a 3 × 2 × 2 factorial arrangement of treatments that included three treatments (sprinkler + artificial shade, shower + artificial shade, and artificial shade), two breeds (Holstein, Jersey), and two physiological stages (lactating cows, heifers). The experimental treatments influenced (P < 0.05) the concentrations of triiodothyronine, with the shower and shade systems showing greater and similar concentrations (99.5 and 96.3 µg/dL, respectively) when compared with sprinkler treatment (89.2 µg/dL). There was an effect (P < 0.05) of breed on the concentrations of Na + , K + , hemoglobin, hematocrit and mean corpuscular volume levels with the Holsteins having lower levels of Na + , K + , hemoglobin, hematocrit and mean corpuscular volume (101.1, 4.0 ng/mL, 11.2 g/dL, 24.7%, and 42.3 µm3, respectively) than the Jerseys (106.5 and 4.3 ng/mL, 12.4 g/dL, 27.7%, and 46.3 µm3, respectively. Total cholesterol and high-density lipoproteins were influenced by physiological stage (P < 0.05). Concentrations of cholesterol and high-density lipoproteins were higher for cows (94.1, and 56.9 mg/dL, respectively) than for heifers (56.9 and 42,9 mf/dL, respectively). Milk production and fat content were affected (P < 0.05) by breed (P < 0.05), with Holstein cows producing more milk (23.9 kg/day) than Jersey cows (12.0 kg/day), but Jersey cows had higher fat concentration (4.6%) than Holstein cows (3.0%). Therefore, the three different thermal-stress-reducing-systems tested were able to maintain the serum biomarkers within normal physiological ranges. However, the most appropriate thermal-stress-reducing-systems would be a sprinkler systema because it uses less water compared with the shower system.

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Is well known the taurine and zebuine susceptibility to Rhipicephalus microplus. Few are the reports regarding tick population dynamics between the same herd/breed, and because of this, two experiments were performed. In the 1st, the cattle tick population dynamics in dairy nursing calves (reared collective and individually), weaning calves (4-16 months), heifers (17-29 months), cows in lactation and dry cows (≥ 30 months) from the same herd, tick burden and milk production correlation were performed, for two years. R. microplus females (4.5-8.0 mm) counts and the milk production were performed every 28 and 14 days, respectively. In the 2nd experiment, bovines belonging to different categories/age (newborn without previous contact with tick; 12-13 months with tick contact since birth; and 23-24 months with tick contact since birth) were experimentally infested with 30,000 R. microplus larvae, to quantify the number of fully engorged females detached from these animals. In the 1st experiment, when the mean counts of tick were ≥ 30 all animals of the group were treated. Nursing calves showed 3-4 peaks of ticks, animals reared individually showed smaller (p ≤ 0.05) tick burden than those reared collectively. Weaning calves (4-8 months) showed 5 tick peaks/year and higher mean tick burden was found than other categories. On the other hand, animals with 17-29 months of age showed smallest (p ≤ 0.05) tick burden, with 3 tick peaks/year. When the animal become lactating the tick burden increase, and 5 peaks/year occurred, and decrease again in dry cows (p ≤ 0.05) showing 4-5 tick peaks/year. Weaning calves and lactating cows received more acaricide treatments (p ≤ 0.05), 18 and 15, respectively. Nursing calves reared individually, and heifers (21-29 months) were the categories that received two acaricide treatments. The more milk the cow produce, more ticks it has (p ≤ 0.05). In the 2nd experiment, more (p ≤ 0.05) fully engorged females were recovered from younger animals than older ones. So, different tick control strategies need to be adopted in different dairy cattle categories, and the tick burden should be considered, once the effect may be more inherent to the animal rather than the strategy adopted.

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National dairy production is characterized by significant heterogeneity in production techniques and herd and farmer profiles. Our objective was to characterize 18 dairy farms under family farming in Senador Guiomard, Acre State, from January to December 2019. Data were gathered through 255-question semi-structured forms applied to farmers in monthly visits. The data were then stored in Excel® spreadsheets and subjected to descriptive statistics. A joint analysis showed the following characteristics: farmers with low schooling level (89%); farmers of advanced age (61%); non-adoption of good dairy practices (100%); inadequate milk transport (72%); adequate brucellosis vaccination (100%); non-specialized herds (40%); pasture production system (100%); low productivity per area (873 L/ha/year) and per cow (4.0 liters/cow/day); low number of lactating cows (53%); and gross milk income (29,466.65 R$/year) representing 69% of the total gross income. The region studied has positive factors such as market guarantees, proximity to large market centers, reasonable land prices, suitable climate, ease of credit, rural education, and technical assistance. Overall, the farms are managed under a traditional production system, with low use of technology and unsatisfactory zootechnical indexes. However, the region has favorable conditions for dairy farming development.(AU)

A produção nacional leiteira é caracterizada por grande heterogeneidade, tanto nas técnicas de produção, quanto no rebanho e perfil dos produtores. Objetivou-se caracterizar 18 propriedades rurais produtoras de leite em regime de agricultura familiar, no município de Senador Guiomard, Acre, durante o período de janeiro a dezembro de 2019. Para obtenção dos dados, foi aplicado um formulário semiestruturado contando 255 questões e atualizações mensais dos indicadores durante visitas técnicas às propriedades. Os dados foram tabulados em planilhas no software Excel® e submetidos à estatística descritiva. A análise conjunta resultou em baixa escolaridade dos produtores (89%); idade avançada (61%) dos produtores; não realização de boas práticas de ordenha (100%); transporte inadequado do leite (72%); realização de vacina para brucelose satisfatória (100%); rebanho não especializado (40%); sistema de produção a pasto (100%); baixa produtividade por área (873 L/ha/ano) e por vaca (4,0 litros/vaca/dia); baixo índice de vacas em lactação (53%); e renda bruta do leite (29.466,65 R$/ano) representando 69% da renda bruta da atividade. A região estudada apresenta fatores positivos como garantia de mercado, proximidade dos grandes centros, preço da terra, clima, facilidade de créditos, educação rural e assistência técnica. Concluiu-se que as propriedades possuem sistema de produção tradicional com baixo emprego de tecnologia e indicadores zootécnicos insatisfatórios. No entanto, constatou-se que a região apresenta condições favoráveis para o desenvolvimento da produção.(AU)

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This study aimed to evaluate the ingestive behavior and body surface temperature of F1 Holstein × Zebu cows that were non-lactating in the final third of gestation and managed in two pastoral environments. Forty F1 Holstein × Zebu cows divided into two pastoral environments were evaluated: signal grass (Urochloa decumbens cv. Basilisk) deferred at the beginning of regrowth and pasture of xaraés grass (Urochloa brizantha cv. Xaraés) in vegetative growth in four periods during the day (morning, afternoon, night and dawn), following the completely randomized design in a factorial scheme. Each cow is the experimental unit. The total grazing time was 32.22% higher in the signal grass than xaraés grass (averageof 479.50 minutes). There was an interaction between the pastoral environments and the times of day on the black globe temperature and humidity index (BGHI). In the pasture of signal grass, the BGHI was 19.07% higher in the morning and afternoon periods than the average (68.95) verified during the night and dawn. F1 Holstein × Zebu cows grazing time in the final third of gestation is influenced by the pasture condition and not by the climate since they feed in a high BGHI environment.(AU)

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This study aimed to evaluate the ingestive behavior and body surface temperature of F1 Holstein × Zebu cows that were non-lactating in the final third of gestation and managed in two pastoral environments. Forty F1 Holstein × Zebu cows divided into two pastoral environments were evaluated: signal grass (Urochloa decumbens cv. Basilisk) deferred at the beginning of regrowth and pasture of xaraés grass (Urochloa brizantha cv. Xaraés) in vegetative growth in four periods during the day (morning, afternoon, night and dawn), following the completely randomized design in a factorial scheme. Each cow is the experimental unit. The total grazing time was 32.22% higher in the signal grass than xaraés grass (averageof 479.50 minutes). There was an interaction between the pastoral environments and the times of day on the black globe temperature and humidity index (BGHI). In the pasture of signal grass, the BGHI was 19.07% higher in the morning and afternoon periods than the average (68.95) verified during the night and dawn. F1 Holstein × Zebu cows grazing time in the final third of gestation is influenced by the pasture condition and not by the climate since they feed in a high BGHI environment.

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This study aimed to evaluate the ingestive behavior and body surface temperature of F1 Holstein × Zebu cows that were non-lactating in the final third of gestation and managed in two pastoral environments. Forty F1 Holstein × Zebu cows divided into two pastoral environments were evaluated: signal grass (Urochloa decumbens cv. Basilisk) deferred at the beginning of regrowth and pasture of xaraés grass (Urochloa brizantha cv. Xaraés) in vegetative growth in four periods during the day (morning, afternoon, night and dawn), following the completely randomized design in a factorial scheme. Each cow is the experimental unit. The total grazing time was 32.22% higher in the signal grass than xaraés grass (averageof 479.50 minutes). There was an interaction between the pastoral environments and the times of day on the black globe temperature and humidity index (BGHI). In the pasture of signal grass, the BGHI was 19.07% higher in the morning and afternoon periods than the average (68.95) verified during the night and dawn. F1 Holstein × Zebu cows grazing time in the final third of gestation is influenced by the pasture condition and not by the climate since they feed in a high BGHI environment.(AU)

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The qualities of food, mainly of animal origin, have always been of concern to consumers. It is known that the composition of animals' diets can influence the composition of the foods produced, such as milk. Thus, the objective of this study was to evaluate diets with cactus pear in combination with different forages for F1 Holstein/Zebu cows on the chemical composition and fatty acid profile of milk. Two simultaneous 4 × 4 Latin squares were used in the experimental design. Four experimental diets were used: Diet 1, sorghum silage as the only roughage; Diet 2, sorghum silage combined with cactus pear in a proportion of 50% of the roughage (dry matter basis); Diet 3, elephant grass (Pennisetum purpureum cv. Roxo) as the only roughage; and Diet 4, elephant grass combined with cactus pear in a proportion of 50% of the roughage. The roughage:concentrate ratio was 75:25. The milk urea nitrogen was higher (16.08 mg/dL) in the milk of cows fed the diet with only elephant grass than that of milk from the other diet groups. The other analyzed variables of the chemical composition of milk were not influenced by the diets. However, there was a change in the sum of the saturated and monounsaturated fatty acids. The content of C16:0 fatty acid was higher and that of C18:0 was lower in the milk of cows fed the cactus pear diets than in that of cows fed the other diets. Higher levels of oleic acid were observed in the milk of cows fed with diets containing elephant grass than those in the milk of the cows in the sorghum forage groups. Conjugated linoleic acid (CLA) was higher in the milk of cows fed cactus pear than in that of the other cows. The combination of cactus pear with elephant grass or sorghum silage in the diet did not alter the chemical composition of milk. However, it influenced the fatty acid profile.

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The aim of this study was to employ the principal component technique to physiological data and environmental thermohygrometric variables correlated with detection of clinical and subclinical mastitis in dairy cattle. A total of 24 lactating Girolando cows with different clinical conditions were selected (healthy, and with clinical or subclinical mastitis). The following physiological variables were recorded: udder surface temperature, ST (°C); eyeball temperature, ET (°C); rectum temperature, RT (°C); respiratory frequency, RF (mov. min-1). Thermohygrometric variables included air temperature, AirT (°C), and relative humidity, RU (%). ST was determined by means of thermal images, with four images per animal, on these quarters: front left side (FL), front right side (FR), rear right side (RR) and rear left side (RL), totaling 96 images. Exploratory data analysis was run through multivariate statistical technique with the employment of principal components, comprehending nine variables: ST on the FL, FR, RL and RR quarters; ET, RT; RF, AirT and RU. The representative quarters of the animals with clinical and subclinical mastitis showed udder temperatures 8.55 and 2.46° C higher than those of healthy animals, respectively. The ETs of the animals with subclinical and clinical mastitis were, respectively, 7.9 and 8.0% higher than those of healthy animals. Rectum temperatures were 2.9% (subclinical mastitis) and 5.5% (clinical mastitis) higher compared to those of healthy animals. Respiratory frequencies were 40.3% (subclinical mastitis) and 61.6% (clinical mastitis) higher compared to those of healthy animals. The first component explained 91% of the total variance for the variables analyzed. The principal component technique allowed verifying the variables correlated with the animals' clinical condition and the degree of dependence between the study variables.

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The aim of this study was to employ the principal component technique to physiological data and environmental thermohygrometric variables correlated with detection of clinical and subclinical mastitis in dairy cattle. A total of 24 lactating Girolando cows with different clinical conditions were selected (healthy, and with clinical or subclinical mastitis). The following physiological variables were recorded: udder surface temperature, ST (°C); eyeball temperature, ET (°C); rectum temperature, RT (°C); respiratory frequency, RF (mov. min-1). Thermohygrometric variables included air temperature, AirT (°C), and relative humidity, RU (%). ST was determined by means of thermal images, with four images per animal, on these quarters: front left side (FL), front right side (FR), rear right side (RR) and rear left side (RL), totaling 96 images. Exploratory data analysis was run through multivariate statistical technique with the employment of principal components, comprehending nine variables: ST on the FL, FR, RL and RR quarters; ET, RT; RF, AirT and RU. The representative quarters of the animals with clinical and subclinical mastitis showed udder temperatures 8.55 and 2.46° C higher than those of healthy animals, respectively. The ETs of the animals with subclinical and clinical mastitis were, respectively, 7.9 and 8.0% higher than those of healthy animals. Rectum temperatures were 2.9% (subclinical mastitis) and 5.5% (clinical mastitis) higher compared to those of healthy animals. Respiratory frequencies were 40.3% (subclinical mastitis) and 61.6% (clinical mastitis) higher compared to those of healthy animals. The first component explained 91% of the total variance for the variables analyzed. The principal component technique allowed verifying the variables correlated with the animals' clinical condition and the degree of dependence between the study variables.(AU)

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