Título:	Artificial infestation of Boophilus microplus in beef cattle heifers of four genetic groups.
Autor:	SILVA, A. M. ALENCAR, M. M. de REGITANO, L. C. de A. OLIVEIRA, M. C. de S. BARIONI JUNIOR, W.
Afiliación:	ANA MARY DA SILVA, UFSCAR; MAURICIO MELLO DE ALENCAR, CPPSE; LUCIANA CORREIA DE ALMEIDA REGITANO, CPPSE; MARCIA CRISTINA DE SENA OLIVEIRA, CPPSE; WALDOMIRO BARIONI JUNIOR, CPPSE.
Año:	2007
Referencia:	Genetics and Molecular Biology, v. 30, n. 4, p. 1150- 1155, 2007.
Descripción:	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 (> 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.
Thesagro:	Carrapato Cruzamento Gado de Corte Resistência
NAL Thesaurus:	Beef cattle Crossbreds
Palabras clave:	Tick resistance
DOI:	https://doi.org/10.1590/S1415-47572007000600020
Tipo de Material:	Artigo de periódico
Acceso:	openAccess
Aparece en las colecciones:	Artigo em periódico indexado (CPPSE)