Perfil oxidativo e leucometria de ovelhas de corte acometidas por mastite crônica / White cell count and oxidative profile in sheep affected by chronic mastitis

O objetivo deste estudo foi avaliar o perfil oxidativo e o leucometria de ovelhas de corte com mastite crônica. Para isso foram utilizados 30 animais em lactação, os quais foram divididos em dois grupos de 15 animais: grupo positivo - animais que exibiram sinais clínicos de mastite e grupo negativo - ovelhas sem sinais de alteração na glândula mamária e/ou no leite. Para realização do California Mastitis Test (CMT) e exame microbiológico foram coletadas amostras de leite e para determinar o total de leucócitos, o índice de estresse oxidativo (OSI) e o óxido nítrico foram coletadas amostras de sangue. Sessenta por cento das ovelhas com mastite apresentaram CMT positivo. Não houve diferença entre os grupos nos valores de leucócitos, de OSI e no óxido nítrico. Em decorrência da redução do processo inflamatório, ovelhas com mastite crônica não apresentam alterações no perfil oxidativo e no total de leucócitos.

In this study 30 lactating sheep were used to evaluate the oxidative profile and leucocytes of animals with chronic mastitis. Groups, containing 15 animals each, were divided into: group of positive animals presenting clinical signs of mastitis, and control group containing animals which did not present alterations in the mammal gland or in the milk. Milk samples were collected and the California Mastitis Test (CMT) and microbiologic examination were performed. In addition, the total of leukocytes, total antioxidant capacity (TAC), total oxidant status (TOS) and nitric oxide were measured through blood analyses. Sixty percent of the animals with mastitis presented CMT positive. There was no difference in the values of leukocytes, OSI and nitric oxide between groups. Sheep with chronic mastitis did not present alterations in the oxidative profile and total leukocytes, due to the reduction of the inflammation

Oxidative stress by Haemonchus contortus in lambs: Influence of treatment with zinc edetate.

The aim of the present study was to assess the effects of zinc edetate on the oxidative stress of lambs infected by Haemonchus contortus. Twenty-four lambs were allocated into four groups: Group I--uninfected animals; Group II--uninfected animals treated subcutaneously with zinc edetate; Group III--animals infected by H. contortus and Group IV--animals infected and treated. The oxidative stress index (OSI) and the eggs per gram of feces (EPG) were assessed after 10, 17, 24, 31 and 38 days post-infection. Based on the EPG and the quantity of adult H. contortus, the infection did not differ between groups III and IV. Zinc edetate reduced the OSI in Group IV in relation to Group I after 24 days post-infection, and in relation to group III after 31 days post-infection. Treatment with zinc edetate could help reduce the oxidative stress induced by H. contortus in lambs.

Copper and selenium: auxiliary measure to control infection by Haemonchus contortus in lambs.

The aim of this study was to evaluate the effects of selenium and copper on oxidative stress and its performance in lambs experimentally infected with Haemonchus contortus. Twenty-eight five-months old lambs were experimentally infected by the oral route with 5000 third-stage infective larvae and allocated into four groups, i.e., untreated animals, animals treated intramuscularly with sodium selenite (0.2 mg kg(-1)), animals treated subcutaneously with copper (3.5 mg kg(-1)), and animals treated with sodium selenite (IM; 0.2 mg kg(-1)) and copper (SC; 3.5 mg kg(-1)). These animals received oat hay (Avena sativa) and commercial concentrate, totaling 15% of crude protein, 30% being derived from oat hay and 70% of the concentrate. Lipid peroxidation, antioxidant enzymes, eggs per gram of feces (EPG) and body weight were assessed on the day of infection and after 20, 40, 60 and 80 days post-infection. The number of H. contortus adults was assessed at the end of the experiment. The selenium associated or not with copper reduced the effects of oxidative stress caused by infection. The groups supplemented with copper had increased body weight, and the combination of these two minerals reduced the EPG and number of H. contortus adults in lambs. The use of selenium associated with copper may help the control of infection by H. contortus.