Gyr Cattle
Mostrando 1-12 de 25 artigos, teses e dissertações.
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1. The Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) identification versus biochemical tests: a study with enterobacteria from a dairy cattle environment
Abstract Mastitis adversely affects milk production and in general cows do not regain their full production levels post recovery, leading to considerable economic losses. Moreover the percentage decrease in milk production depends on the specific pathogen that caused the infection and enterobacteria are responsible for this greater reduction. Phenotypic test
Braz. J. Microbiol.. Publicado em: 2017-03
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2. Kinetics of transit and degradation of the fiber from guinea grass silages enriched with waste from soybean pre-cleaning
The objective was to study the kinetics of transit and degradation of the fiber from guinea grass and the waste from soybean pre-cleaning (WSPC), ensiled with different proportions of mass (0, 100, 150, and 200 g WSPC/kg total mass). Four crossbred (Gyr × Holstein), fistulated cattle with an average body mass of 400±50 kg were organized in a 4 × 4 Latin s
R. Bras. Zootec.. Publicado em: 2015-06
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3. Inbreeding on productive and reproductive traits of dairy Gyr cattle
The objective of this study was to estimate genetic parameters and to evaluate the effects of inbreeding on productive and reproductive traits of dairy Gyr cattle. Single-trait animal models were used to estimate genetic parameters and solutions for inbreeding coefficients for milk (milk 305-d), fat (fat 305-d), protein (protein 305-d), lactose (lactose 305-
R. Bras. Zootec.. Publicado em: 2015-05
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4. Carcass characteristics of feedlot-finished Zebu and Caracu cattle
This study analyzes the chemical carcass characteristics and carcass losses in 86 cattle, both castrated and non-castrated, with an average initial weight of 329 kg and an average age of approximately 20 months, including 12 Gyr, 20 Guzerat, 20 Nellore, and 20 Caracu among the herds selected for weight determination at 378 days of age, as well as 14 Nellore
R. Bras. Zootec.. Publicado em: 2014-02
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5. Nutritional performance of cattle grazing on low-quality tropical forage supplemented with nitrogenous compounds and/or starch
The objective of this work was to evaluate the effects of protein and/or starch supplementation on the nutritional performance of cattle grazing on low-quality tropical forage. Five crossbred steers (Holstein × Gyr) with an average body weight (BW) of 397 kg that were fitted with ruminal and abomasal cannulae were used. The animals were kept in individual s
R. Bras. Zootec.. Publicado em: 2013-09
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6. Incorporation of lactations with non-conventional drying-off causes in genetic evaluation of Gyr dairy cattle
Test-day records of milk yields from the first three lactations were used to verify consequences of incorporation of lactation with non-conventional drying-off causes in genetic evaluation of Gyr dairy cattle. The first file (File1) was composed of test-day records of lactations with conventional drying-off causes. In the second file (File2), the test-day re
R. Bras. Zootec.. Publicado em: 2012-09
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7. Zero-inflated Poisson regression models for QTL mapping applied to tick-resistance in a Gyr x Holstein F2 population
Nowadays, an important and interesting alternative in the control of tick-infestation in cattle is to select resistant animals, and identify the respective quantitative trait loci (QTLs) and DNA markers, for posterior use in breeding programs. The number of ticks/animal is characterized as a discrete-counting trait, which could potentially follow Poisson dis
Genetics and Molecular Biology. Publicado em: 28/10/2011
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8. Production indices for dual purpose cattle in central Brazil
This study examined the effects of crossbreeding low genetic potential cows of Bos indicus origin characterized by Gyr crossed with Holstein-Friesian and Simmental bulls to produce animals in a low input dual purpose system. The farm is situated near Brasilia, in the savannah region of Brazil. The climate of the region is classified as Aw by Köppen. Data wa
Revista Brasileira de Zootecnia. Publicado em: 2011-07
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9. Association of bGH and Pit-1 gene variants with milk production traits in dairy Gyr bulls.
The objective of this study was to obtain genetic marker information in the Gyr breed by analyzing bGH and Pit-1 gene polymorphisms and to verify their association with milk production traits. One sample including 40 Gyr bulls were genotyped at two bGH gene restriction sites (bGH- AluI and bGH-MspI) and at one restriction site in the Pit-1 gene (Pit-1 HinfI)
Pesquisa Agropecuária Brasileira. Publicado em: 2011
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10. Quantitative trait loci (QTL) mapping for growth traits on bovine chromosome 14.
Quantitative trait loci (QTL) mapping in livestock allows the identification of genes that determine the genetic variation affecting traits of economic interest. We analyzed the birth weight and weight at 60 days QTL segregating on bovine chromosome BTA14 in a F2 resource population using genotypes produced from seven microsatellite markers. Phenotypes were
Genetics and Molecular Biology. Publicado em: 2011
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11. QTLs for growth traits and growth curve in crossbred dairy cattle / QTLs para características e curva de crescimento em bovinos mestiços leiteiro
This study was conducted to detect quantitative trait loci (QTL) affecting growth traits and growth curve using F2 Holstein x Gyr population. Traits analyzed were birth weight (BW), weaning weights (WW), weight at 205 day (W205), yearling weight (YW), weight at 720 day (W720), average daily gain from birth to weaning weight (ADG0_60), average daily gain from
Publicado em: 2010
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12. Expression profile of genes associated with mastitis in dairy cattle
In order to characterize the expression of genes associated with immune response mechanisms to mastitis, we quantified the relative expression of the IL-2, IL-4, IL-6, IL-8, IL-10, IFN-γ and TNF-α genes in milk cells of healthy cows and cows with clinical mastitis. Total RNA was extracted from milk cells of six Black and White Holstein (BW) cows and six Gy
Genetics and Molecular Biology. Publicado em: 18/09/2009