Efeito metafilático do zinco injetável sobre parâmetros metabólicos e oxidativos de ovelhas no pós-parto imediato / Metaphylactic effect of injectable zinc on metabolic and oxidative parameters of sheep in the immediate postpartum

The aim of this study was to evaluate a new source of injectable organic zinc (zinc edetate) on the energy and oxidative profile in sheep during the immediate postpartum period. Twenty-six Texel breed animals were previously identified and divided into two experimental groups: the treated group (TG; n= 13) that comprised the animals that received a subcutaneous (SC) injection of 100 mg of zinc edetate (2 mL) fifteen days before the parturition expected date and the control group (CG; n=13) that comprised the animals that received 2mL of physiological solution at the same date of TG. Blood samples were collected on the parturition day for the assessment of serum fructosamine, cholesterol and triglycerides, insulin-like growth factor type 1 (IGF-1), the oxidative stress index (OSi) and blood zinc concentration. In addition to these parameters, the measurement of zinc was made in food given to the animals. There was no difference in metabolic parameters and OSi between the experimental groups (P>0.05), as well as in blood zinc concentrations (P>0.05). The parenteral zinc edentate does not change the energy and oxidative profile of sheep in immediate postpartum.(AU)

Efeito metafilático do zinco injetável sobre parâmetros metabólicos e oxidativos de ovelhas no pós-parto imediato / Metaphylactic effect of injectable zinc on metabolic and oxidative parameters of sheep in the immediate postpartum

The aim of this study was to evaluate a new source of injectable organic zinc (zinc edetate) on the energy and oxidative profile in sheep during the immediate postpartum period. Twenty-six Texel breed animals were previously identified and divided into two experimental groups: the treated group (TG; n= 13) that comprised the animals that received a subcutaneous (SC) injection of 100 mg of zinc edetate (2 mL) fifteen days before the parturition expected date and the control group (CG; n=13) that comprised the animals that received 2mL of physiological solution at the same date of TG. Blood samples were collected on the parturition day for the assessment of serum fructosamine, cholesterol and triglycerides, insulin-like growth factor type 1 (IGF-1), the oxidative stress index (OSi) and blood zinc concentration. In addition to these parameters, the measurement of zinc was made in food given to the animals. There was no difference in metabolic parameters and OSi between the experimental groups (P>0.05), as well as in blood zinc concentrations (P>0.05). The parenteral zinc edentate does not change the energy and oxidative profile of sheep in immediate postpartum.(AU)

Metabolismo do edetato de zinco em cordeiros e seu efeito metafilático sobre variáveis metabólicas e oxidativas de ovelhas no pós-parto.

A ovinocultura é uma atividade que nos últimos anos passou por uma série de mudanças relacionadas aos sistemas de produção, focando sua busca em manejos eficientes que proporcionem a lucratividade da criação. Dentre os principais entraves na atividade destacam-se os erros nos manejos sanitário e nutricional que são responsáveis diretos pela diminuição da produção, custos com tratamentos e perda de material genético por morte, principalmente de fetos e fêmeas no perirparto. Diante disso, os microminerais utilizados como nutracêuticos podem minimizar estas perdas. Com o objetivo de avaliar o metabolismo de uma nova fonte de zinco injetável, denominada edetato de zinco e seu efeito em parâmetros metabólicos e oxidativos em ovelhas no pós-parto, realizou-se dois estudos experimentais. No primeiro utilizou-se-se 6 cordeiros machos que foram alocados em gaiolas metabólicas individuais. Os animais passaram por um período de 10 dias de adaptação e, posteriormente, foram divididos em dois grupos experimentais. Três animais foram tratados com uma dose de 3mg/kg (2ml) de edetato de zinco por via subcutânea (SC), sendo considerado o grupo tratado (GT), e três receberam a mesma dose de solução de cloreto de sódio a 0,9% pela mesma via, sendo denominado grupo controle (GC). Os animais foram monitorados durante 30 dias para determinação da produção de fezes e de urina e da excreção de zinco. Durante os 7 primeiros dias foram realizadas coletas de amostras de sangue para determinação do zinco sérico. Após este período, as coletas foram realizadas em dias intercalados até 30 dias. Também foram coletas amostras da água e do alimento para determinar a concentração de zinco na dieta. Ao final do estudo os animais foram submetidos à eutanásia com posterior coleta de 5 gramas dos seguintes tecidos: fígado, músculo (Longissimus dorsi), coração e rim, com a finalidade de determinar a concentração de zinco tecidual. Ao final concluiu-se que o edetado de zinco apresentou uma excreção urinária maior que a fecal, assim como foi a principal via de eliminação deste mineral. A aplicação do edetato de zinco não alterou as concentrações de zinco nos tecidos e no sangue dos animais, porém apresentou uma maior absorção e retenção aparentes deste mineral. No segundo estudo, que teve por objetivo avaliar o edetato de zinco sobre variáveis metabólicas e oxidativas em ovelhas no pós-parto imediato, utilizou-se 26 ovelhas da raça Texel, criadas extensivamente, com idade entre 3 e 4 anos, com prenhez confirmada através de ultrassonografia aos 45 dias de gestação e com média de escore corporal 3,0. Foram utilizadas somente ovelhas com gestação simples distribuídas em dois grupos experimentais: grupo tratado (GT; n= 13), animais que receberam 100mg de edetato de zinco SC (2ml) 15 dias antes da data prevista do parto e grupo controle (GC; n= 13), animais que receberam 2ml de cloreto de sódio a 0,9% no mesmo momento experimental. Foram coletadas amostras de sangue 15 dias antes da data prevista do parto e imediatamente após o parto para avaliação do efeito do edetato de zinco. Foram mensurados os teores de Fator de Crescimento Semelhante à Insulina Tipo 1 (IGF-1), de frutosamina, de colesterol, de triglicerídeos, do índice de estresse oxidativo, sendo este obtido através da mensuração do total de antioxidantes e de oxidantes, e dos teores sanguíneos de zinco. Não houve diferença nos parâmetros metabólicos oxidativos entre os grupos experimentais (P>0,05), bem como nas concentrações de zinco sanguíneo (P>0,05). O edetato de zinco não tem ação sobre variáveis metabólicas e oxidativas no pós-parto de ovelhas com reduzido desafio metabólico.

Sheep rearing is an activity that in the last years has undergone several changes related to the production systems, focusing its search in efficient managements that provide the creation profitability. Among the main obstacles in the activity, the errors in sanitary and nutritional management are directly responsible for the decrease in production, the costs with treatments and the loss of genetic material by death, mainly of fetuses and females in peripartum. There fore microminerals used as nutraceuticals can minimize these losses. In order to evaluate the metabolism of a new source of injectable zinc, called zinc edetate and its effect on metabolic and oxidative parameters in postpartum ewes, two experimental studies were performed. In the first one, six male lambs were used and housed in individual metabolic cages. The animals went through a period of 10 days of adaptation and later were divided into two experimental groups. Three animals received a dose of 3mg/kg (2ml) of zinc edetate subcutaneous (SC), being considered the treated group (GT), and other three animals received the same dose of 0.9% sodium chloride solution by the same route, being denominated control group (CG). After the adaptation period the animals were monitored for 30 days to determine the production of faeces and urine and the zinc excretion was measured. During the first 7 days, blood samples were collected for the determination of serum zinc. After this initial period, the blood collections were performed on interspersed days up to 30 days. Water and food samples were also collected to determine the diet concentration of zinc. At the end of the study, the animals were submitted to euthanasia, where 5 grams each of liver, muscle (Longissimus dorsi), heart and kidney were collected in order to determine the concentration of tissue zinc. At the end of the experiment, it was concluded that the zinc edetate presented a greater urinary excretion than the fecal one, as well as being the main route of elimination of this mineral. The use of zinc edetate did not alter the concentrations of this mineral in the tissues and blood of the animals, but presented a higher apparent absorption and retention of this mineral. In the second study, which aimed to evaluate zinc edetate on metabolic and oxidative variables in ewes in the immediate postpartum period, 26 Texel ewes, raised extensively, aged 3 to 4 years, with pregnancy confirmed by ultrasonography at 45 days of gestation, and with mean body score 3.0 were used. Only sheep with simple gestation distributed in two experimental groups were used in the study: the animals in the treated group (GT; n = 13) received 100mg of zinc edetate SC (2mL) 15 days before the expected delivery date and the group control (CG; = 13) received 2mL of 0.9% sodium chloride solution SC at the same date as GT. Blood samples were collected 15 days before the expected delivery date and immediately after delivery for evaluation of the effect of zinc edetate. The 20mL of blood sample was collected in a silicone tube without anticoagulant. The levels of insulin-like growth factor (IGF-1), fructosamine, cholesterol, triglycerides, and oxidative stress index were obtained by measuring the total antioxidants and oxidants, and the blood levels of zinc. There was no difference in oxidative metabolic parameters between the experimental groups (P> 0.05) as well as in blood zinc concentrations (P> 0.05). Zinc edetate had no action on metabolic and oxidative variables in the postpartum period of sheep with reduced metabolic challenge.