Gilson Pereira de Oliveira

Comportamento da Haematobia irritans em fazendas com diferentes manejos de bovinos

Haematobia irritans parasitical dynamics was studied in three farms rearing crossbred beef cattle, under different management systems, in the region of Sao Carlos, Sao Paulo State. In the farms was not utilized any specific treatment against horn flies. The experiment consisted in counting fortnightly the number of flies on the dorso-lombar area of the animals, from October, 1992 to October, 1994. Each farm used a different parasite control: T1- Ribeirao Bonito Farm, anthihelminthic treatment, with injectable levamizole (Ripercol L); ticks treated with pour on pyrethroid compound (Ectoplus); and berne, treated with trichlorphon (Neguvon) plus used motor oil, applied topically; T2- Sao Carlos Farm, antihelminthic treatmen with injectable levamizole (Ripercol L); ticks treated with formamidine (Triatox) in immersion bath; and berne treated with pour on fenthion (Tiguvon); and T3- Santa Eudoxia Farm, no parasitism treatments. The number of horn flies (MC) was analised in the scale √(MC + 0,5) in a statistical model that included, besides the mean, the effects of treatments, year, month, period and the double interactions. In the scale MC, all the effects differed from each other (P < 0.01). During the months in which the temperature was higher (October to March) average parasite load was of 15.7±36.4 flies, while temperature was lower (April to August) it was of 6.8 ± 23.6 flies. The average parasite load differed (P < 0.01) among years (92 = 4.8 ± 7.8; 93 = 8.8 ± 20.0; 94 = 16.6 ± 43.8) and among farms (T1= 3.1 ± 9.7; T2= 2.2 ± 13.7 e T3=26.0 ± 44.5), indicating that horn fly behaviour is irregular and noncyclic. The efficiency of 81.1% and 86.3% was observed for treatment T1 and T2, respectivelly, when compared to treatment T3.

Doramectin e levamizole no controle dos helmintos de bovinos no início da estação seca

Sixty cattle from Canchim breed with 15 months were mantained in a Bracharia decumbens Stapf pasture were randomly alloted into three balanced treatments designed to the control of gastro-intestinal nematodes (T1: control group; T2: 1ml/50kg BW of Doramectin, corresponding to 200mg/kg; and T3: Levamizole 1ml/40kg BW, equivalent to 3,75 mg of the active principle per kg of body weight). The administration was proceeded through the parenteral via, subcutaneously and the verminotic infeccion took place naturally. The experiment was carried out at the Canchim Farm, head office of the Animal Prodution Research Center of Embrapa (CPPSE) located in Sao Carlos, Sao Paulo State, Brazil, from April/95 to June/95. It has been determined body weight, eggs per gram (EPG) and mean corpuscular volume (MCV), over six periods (P) as follows: 0, 14, 28, 42, 56 and 70 days after drug administration. The mathematical model for statistical analysis included effects of treatment (T) and period, as well T x P interaction. From day 14 on, Doramectin presented the least EPG (P 0.05) between each other from day 42 on. Treated animals showed similar weight gains (P>0.05) up to day 42. Control group animals had a reduction in the weight gain (P 0.05) over the experimental period. In the other hand, control group showed lower calves (P<0.05) since day 28.