Archivos de Zootecnia最新文献

{"title":"Evaluación de PCR en tiempo real en el diagnóstico de leucosis enzoótica bovina en una raza local de Panamá","authors":"A. Villalobos-Cortés, R. Gonzalez, H. Castillo, M. Jaén","doi":"10.21071/az.v69i267.5356","DOIUrl":"https://doi.org/10.21071/az.v69i267.5356","url":null,"abstract":"The objective of this work was to evaluate the RT-PCR test, to detect the bovine enzootic leukosis virus and compare them with the nPCR and AGID tests in 42 animals of the Guaymi breed from 5 regions of Panama. The AGID test identified the lowest number of positive animals (52%) compared to nPCR (71%) and real-time PCR, RT-PCR (76%). Four animals positive to the AGID test were negative to the nPCR and two animals positive to this same test were negative to RT-PCR. 11 of the 20 AGID negative animals tested positive for nPCR and 12 of the 20 AGID negative animals tested positive for RT-PCR. Regarding molecular tests, of the 12 animals that were negative for the nPCR, five were positive for RT-PCR and 10 animals negative for RT-PCR, 3 were positive for nPCR. The sensitivity of nPCR to AGID was 82% while the specificity was 40%; the concordance test between nPCR and AGID was k = 0.316, considered weak while the sensitivity of RT-PCR with AGID was 91% with a specificity of 40%; the concordance test between the two tests was k = 0.222 also considered weak. The RT-PCR technique is presented as a viable alternative within the group of techniques for the diagnosis of bovine enzootic leukosis virus, particularly in an eventual control program and its eradication in conservation centers of Creole races where it is required to maintain a strict control of animal health.","PeriodicalId":40003,"journal":{"name":"Archivos de Zootecnia","volume":"69 1","pages":"366-370"},"PeriodicalIF":0.0,"publicationDate":"2020-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46576753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parámetros genéticos en la varianza residual de variables de comportamiento en toros de lidia","authors":"J. Domínguez-Viveros","doi":"10.21071/az.v69i267.5354","DOIUrl":"https://doi.org/10.21071/az.v69i267.5354","url":null,"abstract":"The objectives were to analyze the presence of genetic variance in the residual variance of behavior notes in fighting bulls. From a livestock ranch, the conditional residuals were analyzed (RCON; e = y - E[y|a] = y - Xβ - Za) and marginal (RMAR; ξ = y - E[y] = y - Xβ), from the notes of horse tienta (n, 2369), foot tienta (n, 1432), horse bullfight (n, 792) and foot bullfighter (n, 820); in two databases: BD1, logarithmic transformation; BD2, logarithmic transformation eliminating extreme data (x ±2σ). With the MTDFREML software, a multivariate analysis (four notes) was performed within the residual type and for each database; heritability (h²) and genetic correlations (rg) were calculated through variables. The h2 ranged between 0.14 and 0.96, with an average value of 0.58; h2 of RMAR in BD2 presented above estimates (> 0.78). These results show genetic variability in the residual variance and present the possibility of response to selection (environmental channeling) to reduce environmental variance. The selection for residual variance can improve the response to the concepts of resilience, plasticity, robustness and rusticity. The rg were positive, in the range of 0.01 to 0.99 and an average value of 0.79; with these rg there may be a correlated response in the residuals of the four notes.","PeriodicalId":40003,"journal":{"name":"Archivos de Zootecnia","volume":"69 1","pages":"354-358"},"PeriodicalIF":0.0,"publicationDate":"2020-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48996516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mezcla de harinas para ratas. Informe nutricional y bioeficacia de acha (D. iburua & D. exilis) y harina de soja (Glycine max)","authors":"S. D. Sudik, O. S. Ijarotimi, J. O. Agbede, F. A. Igbasan","doi":"10.21071/az.v69i267.5344","DOIUrl":"https://doi.org/10.21071/az.v69i267.5344","url":null,"abstract":"The nutritional potentials of acha as alternative energy source to maize in complementary foods was evaluated with a view to increase the accessibility and affordability of complementary foods by the resource poor mothers. The formulated acha-based complementary foods (D. iburua (DIF); D. exilis (DEF)), maize-based complementary food (MCF) and commercial formula (CFF) were evaluated for chemical compositions and nutritional qualities. Data were statistically analysed. Crude protein (g/100g) and energy values (kcal.) of DEF and DIF were 15.28 - 15.69 and 409.6 - 405.3 respectively, and were comparable to MCF (15.40; 407.9) and commercial formula (CFF) (15.50; 415.0). Essential amino acids of DEF and DIF were 35.64 and 38.76 g/16N respectively. The Na/K and Ca/P molar ratios of DEF and DIF ranged from 0.59 – 0.60 and 1.67 – 1.71 respectively. Phytate, oxalate and tannin concentrations were within tolerable levels. Biological values and protein efficiency ratios of experimental foods were 87.21 - 87.81% and 2.94 - 3.12 respectively, and were higher than maize-based formula (84.32%; 2.02) and commercial formula (86.53%; 2.52). Growth performance of rats fed on experimental were comparable to those fed on commercial formula, but lower in production costs (USD = 0.24) than CFF (USD = 0.90). The acha-based complementary foods were characterized with essential nutrients, ability to support growth and development, affordable and accessible to poor resource mothers; hence, the food samples may be suitable as complementary foods.","PeriodicalId":40003,"journal":{"name":"Archivos de Zootecnia","volume":"20 21","pages":"262-271"},"PeriodicalIF":0.0,"publicationDate":"2020-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41286183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aplicação de marcadores SNP em estudos de diversidade genética em Capra hircus: tendencias, vieses e progressos","authors":"F. Sobrinho, J. O. Moura, G. R. Silva, F. M. Diniz, A. M. Araújo","doi":"10.21071/az.v69i267.5352","DOIUrl":"https://doi.org/10.21071/az.v69i267.5352","url":null,"abstract":"Capra hircus is distributed worldwide due to its extraordinary adaptability and robustness as a source of food, fibers and skin. Genetic markers of single nucleotide polymorphism (SNP) allow the investigation of issues involving evolutionary changes and conservation of population biodiversity. This study aimed to verify the main focus of studies in the world using the marker SNP in Capra hircus (goats). Bibexcel bibliometric research software was used to analyze the publications of Web of ScienceTM until August 2018, which adopted the genetic marker SNP. Of 53,000 registered publications, only 390 employed the SNP markers. The three countries that stood out in publications were China (146 publications), India (64) and Italy (42). Brazil was in eleventh position, with a record of five (05) publications. Several of the keywords were grouped as being semantically equivalent and associated to a specific theme, thus it was possible to identify 23% of the scientific productions associated with the polymorphism of milk proteins, 23% with aspects of reproduction 13% linked to growth and gain of weight; genetic diversity with a percentage of 34%. GWAS studies were cited in 7% of the productions and less than 1% of the studies were associated with adaptation characteristics. The number of publications was related to the technical qualification and laboratory capacity of the country.","PeriodicalId":40003,"journal":{"name":"Archivos de Zootecnia","volume":"69 1","pages":"328-336"},"PeriodicalIF":0.0,"publicationDate":"2020-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46201722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cinética de degradación ruminal in situ de ensilado de rastrojo de maíz (Zea mays) con niveles crecientes de urea","authors":"A. Sanchez, J. Perea, L. Montenegro, I. Espinoza, J. Avellaneda, C. Barba","doi":"10.21071/az.v69i267.5351","DOIUrl":"https://doi.org/10.21071/az.v69i267.5351","url":null,"abstract":"The urea inclusion effect on the nutritional composition and kinetics of in situ ruminal digestion on maize stubble silage was studied. Four treatments were started by adding 0, 1, 2 and 3% urea to a mixture of maize stubble with 10% molasses. 128 microsilos (3 kg/unit and 4 repetitions per treatment) were made. Experimental silages were opened at 7, 14, 21, 28, 35, 42, 49 and 56 days. The content of dry matter (MS), organic matter (OM), crude protein (PB), FND and FAD were determined. In situ degradability was obtained by Mehrez and Orskov method and the degradability of MS and PB by residue analysis with Kjeldhal method. A general linear model was used for data manipulation, using the statistical package SAS (2004), as well as Contrast option and Solver function of Microsoft EXCEL®. 35-days conservation silage (p <0.05) was observed as best treatment. Significant differences for all the variables except OM was evidenced. Urea addition was related to increase in MS and PB and decrease in FND and FAD values (p <0.01). In situ ruminal degradability of DM increased as urea level increased, except in the case of factor c, while for PB differences between treatments were not reflected. Urea addition was related to increase in MS and PB and decrease in FND and FAD values (p <0.01). In situ ruminal degradability of DM increased as urea level increased, except in case of factor c, while differences between treatments for PB were not reflected. Effective degradability was higher in MS, and with greater variability between treatments than in PB, where a more homogeneous behavior was observed. Addition of 3% urea improves the nutritional composition and degradability of maize stubble silage with molasses, making it possible for smallhorders to have an efficient and environmentally acceptable alternative animal feed supplement with this technique.","PeriodicalId":40003,"journal":{"name":"Archivos de Zootecnia","volume":"69 1","pages":"320-326"},"PeriodicalIF":0.0,"publicationDate":"2020-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49086008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Depreciación del caballo Pura Raza Española con la deformación del borde dorsal del cuello","authors":"A. Morales, A. Méndez, J. Pérez","doi":"10.21071/az.v69i267.5358","DOIUrl":"https://doi.org/10.21071/az.v69i267.5358","url":null,"abstract":"The aim of this study was to estimate the depreciation of a Spanish Purebred horse with the deformation of the cresty neck. Were studied a population of 500 Spanish Purebred horses classified in 4 ages: Foals (6 months-4 years), in dressage 4-8 years, adults 8-12 years and mature (12-20 years), belonging to 65 Owners, 10 breeding centers Spanish Purebred horse and a slaughterhouse in Andalucia and Extremadura, Spain. The estimation of the depreciation for 1 year was detected once cresty neck, separately by 3 age groups: horses in dressage 4-8 years, adult horses 8-12 years and mature horses (12-20 Years), using three methods, the straight-line method, the balance reduction method (5%) and the sum-of-the-digits method of the years. In relation to the depreciation of the horse of Spanish Pure Breed with deformation of the cresty neck, estimated for a year, is quite high and proportional to the cost of the horse. In conclusion the depreciation of the Spanish Purebred horse with the deformation of the cresty neck can be presented on average from 6 years of age (approximately 4-8 years), the depreciation calculated by the three straight line methods, Reduction of the balance to 5% and sum of the digits was similar, only presented variation by the age group 4-8 years 95%, 8-12 years 99% and 12-20 years 98% depreciation respectively.","PeriodicalId":40003,"journal":{"name":"Archivos de Zootecnia","volume":"69 1","pages":"378-382"},"PeriodicalIF":0.0,"publicationDate":"2020-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44362895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Produção de pacus e tambacus em tanques-rede na região Sul do Estado de São Paulo","authors":"A. Leonardo, G. R. Lattanzi, G. Bueno, A. E. Baccarin, R. V. R. Neto","doi":"10.21071/az.v69i267.5347","DOIUrl":"https://doi.org/10.21071/az.v69i267.5347","url":null,"abstract":"espanolForam avaliadas as condicoes fisicas e quimicas da agua de uma represa rural utilizada para piscicultura em tanques rede, em Pariquera-Acu, SP. Neste local foram instalados 12 tanques rede de 4 m3, estocados com 300 pacus e 300 tambacus sendo 12,5 kg/m3, durante o periodo de 180 dias. Para determinar a qualidade da agua da represa, foram analisados cinco pontos de coleta mensalmente: abastecimento, area de criacao, dividida em tres pontos (10 cm, 70 cm e 150 cm de profundidade) e efluente. As medias das variaveis analisadas (± desvio padrao) foram: oxigenio dissolvido, 8,97 ± 2,46 mg L-1; temperatura maxima e minima da agua 27,20 ± 2,08 e 21,38 ± 1,34 oC, pH 6,45 ± 0,74, transparencia da agua 96,67 ± 0,70 cm, alcalinidade total 19,26 ± 9,40 mg CaCO3 L-1, condutividade eletrica 49,38 ± 3,60 μS cm-1, nitrogenio amoniacal total 0,002 ± 0,004 mg L-1, fosforo total dissolvido 0,01 ± 0,01 mg L-1, e indice de estado trofico (IET) calculado foi de 49,3 ± 7,3. Concluimos que a criacao de pacu e de tambacu em tanque rede nao comprometeu a qualidade da agua do reservatorio rural. Entretanto as boas praticas de manejo zootecnico e o monitoramento ambiental devem ser realizados para o desenvolvimento de uma aquicultura sustentavel. EnglishThe study aimed to evaluate physical and chemical water conditions of a rural reservoir utilized for cage fish culture in Pariquera-Acu, SP. In this place 12 cages of 4 m3 were installed and stocked with 300 pacus e 300 tambacus per 12,5 kg/m3, during the period of 180 days. To determine reservoir water quality five points of collection were analyzed every month: water supply, fish rearing area divided into three depths (10 cm, 70 cm and 150 cm) and effluent. Averages of analyzed parameters ± standard deviation were: dissolved oxygen, 6.83 ± 0.7 mg O2D L-1; maximum and minimum temperature, 27,20 ± 2,08 and 21,38 ± 1,34 oC, respectively; hydrogenionic potential, 6,45 ± 0,74; transparency, cm; total alkalinity, 19,26 ± 9,40 mg CaCO3 L-1; electric conductivity, 49,38 ± 3,60 μS cm-1; total ammonia, 0,002 ± 0,004 mg L-1, total dissolved phosphorus 0,01 ± 0,01 mg L-1.Calculated Trophic Estate Index was 49,3 ± 7,3 . We conclude that pacus e tambacus cage culture did not compromise the water quality of rural reservoir. However animal production good practices and environmental monitoring should be followed for a sustainable fish culture.","PeriodicalId":40003,"journal":{"name":"Archivos de Zootecnia","volume":"69 1","pages":"288-292"},"PeriodicalIF":0.0,"publicationDate":"2020-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44994482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Caracterización morfológica de cabras indígenas en el área de Laghouat en Argelia.","authors":"M. Laouadi, S. Tennah, Nassim Moula, Nicolas Antoine-Moussiaux, Nacerredine Kafidi","doi":"10.21071/az.v69i267.5345","DOIUrl":"https://doi.org/10.21071/az.v69i267.5345","url":null,"abstract":"espanolEl objetivo de este estudio es caracterizar fenotipicamente dos razas de cabras indigenas en el area de Laghouat (Argelia), y evaluar el efecto de la edad y el sexo sobre las caracteristicas biometricas morfologicas. Se analizaron un total de 312 animales: 58 hembras de raza Mekatia y 254 de raza Arabia (44 machos y 210 hembras). Los resultados muestran que la raza Mekatia se caracteriza por el pelo corto (96.55%) mientras que Arabia muestra un pelo largo (100% para los machos, 92.38% para las hembras). La mayor parte de los animales de ambas razas eran multicolores (≥3 colores). Las orejas semi-pendulares fueron las mas representadas en Mekatia (48.28%) mientras que en Arabia, las orejas pendulares fueron las dominantes (79.55% y 75.72% en machos y en hembras, respectivamente). Sobre los rasgos cuantitativos, ambas razas se clasifican como grandes. El efecto de la edad se muestra para mas de la mitad de las mediciones con un aumento general del tamano del animal con la edad (p EnglishThis study aims to characterize phenotypically two indigenous goat breeds in Laghouat area (Algeria) and to evaluate effect of age and sex on morph-biometrics characteristics. A total of 312 animals were investigated : 58 females of Mekatia breed and 254 of Arabia breed (44 males and 210 females). The results show that Mekatia breed is characterized by short hair type (96.55%) whereas Arabia breed by long hair type (100% for males, 92.38% for females). The majority of both breeds were multi-coloured (≥3 colors). The semi-pendulous ears were the most represented in Mekatia (48.28%) while in Arabia, the pendulous ears were the dominant (79.55% and 75.72% for males and females respectively). About quantitative traits, both breeds are classified as large. The age effect is shown for more half of measurements with an overall increase of animal size with age (p˂0.05). A significant sexual dimorphism (p˂0.05) is shown for all measurements except two characters (ear length and ischia width). The results of this study can be a basis for the description and standardization of goat breeds, Mekatia and Arabia, in the region of Laghouat in Algeria.","PeriodicalId":40003,"journal":{"name":"Archivos de Zootecnia","volume":"69 1","pages":"272-279"},"PeriodicalIF":0.0,"publicationDate":"2020-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44656363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pigmentantes naturais em dietas de codornas japonesas a base de arroz integral descascado e não polido","authors":"Martha Lopes Schuch de Castro, S. Silva, C. Bavaresco, R. C. Dias, E. Gopinger, E. G. Xavier, Débora Cristina Nichelle Lopes, V. Roll, F. Rutz, J. Schafhauser","doi":"10.21071/az.v69i267.5346","DOIUrl":"https://doi.org/10.21071/az.v69i267.5346","url":null,"abstract":"espanolDesenvolveu-se um experimento a fim de verificar o efeito da inclusao de pigmentos naturais, feno de alfafa (FA), colorifico de urucum (U) e beterraba (B), em uma dieta a base de arroz integral descascado e nao-polido e farelo de soja sobre a coloracao das gemas dos ovos de codornas. Foram utilizadas 100 codornas japonesas com 70 dias de idade. Os tratamentos foram T1: dieta controle (arroz integral descascado e nao-polido em substituicao total ao milho); T2: T1 + de 4% FA; T3: T1 + de 8% FA; T4: T1 + de 12% FA; T5: T1 + 4% de U; T6: T1 + 8% de U; T7: T1 +12% de U; T8: T1 + 4% de B; T9: T1 + 8% de B; e T10: T1 + 12% de B. Ao final de 15 dias foram verificadas as coloracoes das gemas dos ovos com colorimetro. O feno de alfafa promoveu diminuicao da luminosidade e a cor variou do verde ao amarelado. Houve tambem aumento da saturacao da cor com o aumento dos niveis de feno de alfafa na dieta (P EnglishA trial was conducted to evaluate the inclusion of natural pigments, alfalfa meal (FA), annatto (U) and sugar beet (B) in a diet based on peeled and unpolished whole rice and soybean meal. A total of 100 70-day-old Japanese quails were used. Treatments were T1: control diet (peeled and unpolished whole rice in full replacement of corn); T2: T1 + 4% FA; T3: T1 + 8% FA; T4: T1 + 12% FA; T5: T1 + 4% U; T6: T1 + 8% U; T7: T1 + 12% U; T8: T1 + 4% B; T9: T1 + 8% B; and T10: T1 + 12% B. After 15 days of trial yolk colour was measured with a colorimeter. Alfalfa meal decreased brightness and the colour ranged from green to yellowish. Additionally, colour saturation was augmented with increased levels of alfalfa meal in the diets (P","PeriodicalId":40003,"journal":{"name":"Archivos de Zootecnia","volume":"69 1","pages":"280-287"},"PeriodicalIF":0.0,"publicationDate":"2020-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42448830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Produção e análise marginal em vacas de leite submetidas a níveis de ureia na dieta à base de silagem de sorgo","authors":"R. H. Alves, H. S. Júnior, E. O. C. Santana, F. Mendes, G. A. Filho, P. T. Viana, L.A.P. Raduns, Bruno Weiss","doi":"10.21071/az.v69i267.5349","DOIUrl":"https://doi.org/10.21071/az.v69i267.5349","url":null,"abstract":"The objective of this study was to evaluate productive, nutritional and economic traits of dairy cows fed sorghum silage diets with urea levels. Five ¾ Holstein × ¼ Gir lactating dairy cows in the middle third of lactation, at an average age of 60 months and average body weight of 518 kg ± 52 kg, were allocated to five treatments in a 5 × 5 Latin square experimental design. Treatments (U-50, U-75, U-100, U-125 and U-150) consisted of different urea levels in the concentrate (5.7, 8.6, 11.4, 14.3 and 17.1 g urea/kg concentrate, respectively). The significance level of 0.5 was adopted. Urea levels did not influence the feed intake, digestibility, or metabolic parameters of dairy cows. No significant differences were observed for 3.5% fat-corrected milk yield. Milk composition was not significantly affected. Gross revenue from the sale of milk was not significantly affected, averaging BRL 28.65. Marginal rate of return did not differ significantly. The different urea levels did not influence the dairy cows’ milk yield. In conclusion, urea can be included in the concentrate of sorghum silage diets for dairy cows at the levels of 5.7 to 17.1 g/kg of concentrate without compromising production performance.","PeriodicalId":40003,"journal":{"name":"Archivos de Zootecnia","volume":"69 1","pages":"300-309"},"PeriodicalIF":0.0,"publicationDate":"2020-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47812408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}