Spring is the busiest time for Arkansas' 33,000 beef cattle producers. The majority of calves are born in the spring, which means cattle producers should gather the cow herd to vaccinate the calves. The most important disease to vaccinate calves against is blackleg. Blackleg, which can cause sudden death, affects cattle worldwide. Blackleg usually doesn't occur until summer, but calves should be vaccinated in the spring to protect them when summer arrives. Blackleg may be more prevalent on farms where producers have recently dug a waterline through a pasture or done some type of excavation. It may also be noted in flooded areas. Another springtime chore is deworming cattle. The effects of internal parasites on cattle vary with the severity of infection, age and stress level of the animal. In general, younger animals under stress are more likely to show signs of parasites. Mature cows acquire a degree of immunity to parasites which reside in the lower gastrointestinal tract. Losses in animal productivity because of parasites can occur. These can include reduced milk production, weight gain and conception rates. Spring is also the time to begin preparing for hay season. The mechanics of hay production begin with a caution to check and service all equipment thoroughly before haying season. It's impossible to calculate the tons of hay damaged annually because of poorly maintained equipment that breaks down during harvest. The cost of growing, cutting, baling, storing and feeding is substantial. Cost estimates range from $40-$80 a ton. It's critical to harvest the highest quality hay and package hay so the beef herd can take advantage of the nutrient value of the hay. No single factor affects the quality of hay as much as the maturity of the forage. As plants mature, the proportion of less digestible stem is increased compared to the more desirable leaf material. In Arkansas, nearly all hay is produced from improved pasture species that, for the most part, are grown on fertilized soils. With timely cuttings, hay quality can be high enough so that additional protein or energy supplementation will not be needed during this winter's feeding period. Some producers in Cooperative Extension's Arkansas beef improvement program found their hay was of sufficient quality that additional supplements (other than vitamins and minerals) weren't needed. Therefore, management decisions in the spring can affect management decisions for this fall and winter.