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Carvalho,Caio Victor Damasceno; Bittencourt,Thereza Cristina Calmon de. |
Abstract:The objective of this work was to define the traits that should be included as breeding objectives for Nellore cattle, according to simulations with a bio-economic model for rearing systems. The economic values (EVs) of the traits were calculated as the differences between the profits due to an increased performance of 1% in each trait, with the others traits remaining constant. To determine the impact of each selection on the revenue system, two scenarios were simulated based on the traits being selected. In the first scenario, the adopted selection criteria were: weaning weight (WW), weaning rate (WR), yearling weight (YW), and mature cow weight (MCW). In the second scenario, the cumulative productivity (CP) of dams was used as an indirect... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Beef cattle; Bio-economic model; Economic value; Market fluctuation; Selection criteria.. |
Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2015000900814 |
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Loiola,Marcus Vinícius Galvão; Bittencourt,Rodrigo Freitas; Rodrigues,Alexandra Soares; Ferraz,Priscila Assis; Lima,Marcos Chalhoub Coelho; Carvalho,Caio Victor Damasceno; Ribeiro Filho,Antonio de Lisboa. |
Abstract: The objective of this work was to evaluate the effects of supplementation with melengestrol acetate (MGA), after timed artificial insemination (TAI), on the conception rate of Nellore cows, according to cyclicity during the protocol, estrus expression between intravaginal device withdrawal and insemination, and diameter of the largest follicle at the time of insemination, in order to identify predictors of the use of MGA. Multiparous lactating cows (577) were subjected to a hormonal protocol for ovulation synchronization. On day -2 of the protocol, the animals were painted with a marker on the base of their tail. On day 0, they were evaluated for estrus expression; the preovulatory follicle diameter (POFD) was measured by ultrasonography, and the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Anestrous; Bovine; Fertility; Insemination; Melengestrol acetate. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2018000100105 |
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