Data/hora: 10/06/2024 10:00:00

Provedor de dados: | 74
País: | Brazil
Título: | Artificial infestation of Boophilus microplus in beef cattle heifers of four genetic groups
Autores: | Silva,Ana Mary da; Alencar,Maurício Mello de; Regitano,Luciana Correia de Almeida; Oliveira,Márcia Cristina de Sena; Barioni Júnior,Waldomiro.
Data: | 2007-01-01
Ano: | 2007
Palavras-chave: | Beef cattle; Crossbred; Tick resistance.
Resumo: | Resistance of beef cattle heifers to the cattle tick Boophilus microplus was evaluated by artificial infestation of 66 beef cattle heifers of the following genetic groups: 16 Nelore (NE), 18 Canchim x Nelore (CN), 16 Angus x Nelore (AN) and 16 Simmental x Nelore (SN). The animals, with a mean age of 16.5 months, were maintained with no chemical tick control in a Brachiaria decumbens pasture. Four artificial infestations with 20,000 B. microplus larvae were carried out 14 days apart and from day 18 to day 22 of each infestation the number of engorged female ticks (&gt; 4.5 mm) was counted on the left side of each heifer. Data were analyzed as the percentage of return (PR = percentage of ticks counted relative to the number infested), transformed to (PR)¼, and as log10 (Cij + 1), in which Cij is the number of ticks in each infestation, using the least squares method with a model that included the effects of genetic group (GG), animal within GG (error a), infestation number (I), GG x I and the residual (error b). Results indicated a significant GG x I interaction, because AN and SN heifers had a higher percentage of return than CN and NE heifers, while CN heifers showed a higher percentage of return than the NE heifers only in infestations 3 and 4. Transformed percentages of return were NE = 0.35 ± 0.06, AN = 0.89 ± 0.06, CN = 0.54 ± 0.05 and SN = 0.85 ± 0.06.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572007000600020
Editor: | Sociedade Brasileira de Genética
Relação: | 10.1590/S1415-47572007000600020
Formato: | text/html
Fonte: | Genetics and Molecular Biology  v.30 n.4 2007
Fonte: | info:eu-repo/semantics/openAccess