RESUMO
The number of dermal mast cells in several European and Zebu cattle breeds was determined and correlated with the tick load. Breeds included European registered and non-registered Holstein, Brown-Swiss and Jersey cows, Zebu (Nelore and Gyr) and crossbred cows with either high or low tick infestations. Animals were naturally infested with Rhipicephalus (Boophilus) microplus and evaluated at regular time intervals for tick attachment and feeding. Ear biopsies were taken and processed according to routine histology for mast cell countings carried out on both the upper and deep dermis. The average cell counts were then correlated with the number of engorged ticks attached to host. Nelore cows presented the largest mast cells countings/mm2 (139.42; P 0.05), while surprisingly Gyr showed similar number of cells (61.73) as the Holstein (48.76) and Brown-Swiss (67.31) ones. Jersey cows presented the smallest cell countings (29.32) despite their greater resistance to tick infestation as compared to Holstein and Brown-Swiss. There was a negative correlation (r= -0.21, P 0.01) between the number of cells in the upper dermis and tick counts when all data (n= 155) were analyzed in a single correlation plane, irrespective of the breed. These results confirm the important role played by mast cells in bovine resistance to the cattle tick R. microplus.
RESUMO
Utilizing three types of pollen trap (bottom, front and intermediate level) installed in hives with Africanized honey bees, at the Tropical Apiculture Center, in Pindamonhangaba, São PauLo State (2257S, 4227W; 560m elevation) between January, 1992 and December, 1994, it was coilected and weigbhed, in a daily basis, the pollen intercepted. Interaction between month and type of pollen trap did not occur (p = 0.5285). Daily amount of pollen collected from the intermediate level model was bigger (p 0.05) than those collected from the other models. Daily averages of pollen collectea during each month can be expressed by the equation: Y = 55.2241-6.0611X+0.4013X (R2 = 0.99), where Y stands by daily collected pollen amount (gram) and X stands by the respective month.
Utilizando três modelos de coletores de pólen (coletor de fundo, frontal e de nível intermediário) em colmeias de abelhas africanizadas pertencentes ao Centro de Apicultura Tropical, em Pindamonhangaba, SP (Latitude 22º 57 S, Longitude 45 27 W e Altitude 560m), durante o período de janeiro 1992 a dezembro de 1994, foi coletado e pesado, diariamente (com exceção dos dias de chuva), o pólen interceptado. Não houve interação (p = 0,5285) entre mês e modelo de coletor; a média das quantidades diárias de pólen interceptado através dos coletores intermediários foi maior (p 0,05) que a dos demais modelos de coletores. As médias das quantidades diárias de pólen coletado nos diferentes 12 meses do ano podem ser representadas pela equação: Y = 55.2241- 6,0611X+0,4013X (R2 = 0,99), onde Y é a quantidade de pólen coletado por dia (em g) e X é o mês.
RESUMO
Utilizing three types of pollen trap (bottom, front and intermediate level) installed in hives with Africanized honey bees, at the Tropical Apiculture Center, in Pindamonhangaba, São PauLo State (2257S, 4227W; 560m elevation) between January, 1992 and December, 1994, it was coilected and weigbhed, in a daily basis, the pollen intercepted. Interaction between month and type of pollen trap did not occur (p = 0.5285). Daily amount of pollen collected from the intermediate level model was bigger (p 0.05) than those collected from the other models. Daily averages of pollen collectea during each month can be expressed by the equation: Y = 55.2241-6.0611X+0.4013X (R2 = 0.99), where Y stands by daily collected pollen amount (gram) and X stands by the respective month.
Utilizando três modelos de coletores de pólen (coletor de fundo, frontal e de nível intermediário) em colmeias de abelhas africanizadas pertencentes ao Centro de Apicultura Tropical, em Pindamonhangaba, SP (Latitude 22º 57 S, Longitude 45 27 W e Altitude 560m), durante o período de janeiro 1992 a dezembro de 1994, foi coletado e pesado, diariamente (com exceção dos dias de chuva), o pólen interceptado. Não houve interação (p = 0,5285) entre mês e modelo de coletor; a média das quantidades diárias de pólen interceptado através dos coletores intermediários foi maior (p 0,05) que a dos demais modelos de coletores. As médias das quantidades diárias de pólen coletado nos diferentes 12 meses do ano podem ser representadas pela equação: Y = 55.2241- 6,0611X+0,4013X (R2 = 0,99), onde Y é a quantidade de pólen coletado por dia (em g) e X é o mês.