The cost of rearing 100 broilers in Kenya can vary depending on various factors such as location, market demand, and availability of resources. However, I can provide you with a general estimate of the costs involved in rearing 100 broilers in Kenya.

1. Day-old chicks: You will need to purchase 100 day-old broiler chicks. The cost per chick can range from KES 100 to KES 150, depending on the breed and the supplier. So, the total cost of purchasing 100 chicks will be around KES 10,000 to KES 15,000.
2. Feed: Broilers require a high protein diet for growth. The cost of feed will depend on the quality and quantity of feed you provide. On average, each broiler will consume about 5-6 kg of feed during the rearing period. The cost of a 50kg bag of broiler feed is approximately KES 2,500 to KES 3,000. So, for 100 broilers, you will need 25-30 bags of feed, which will cost around KES 62,500 to KES 90,000.
3. Housing: You will need to construct a suitable broiler house to provide shelter and protect the birds from predators. The cost of construction will depend on the size and materials used. On average, the cost of constructing a standard broiler house that can accommodate 100 birds is around KES 100,000 to KES 150,000.
4. Vaccination and medication: Broilers require regular vaccination and medication to prevent diseases and maintain their health. The cost of vaccination and medication will depend on the type of vaccine and medicine used. On average, the cost of vaccination and medication for 100 broilers is around KES 10,000 to KES 15,000.
5. Labor and other expenses: You will also need to factor in the cost of labor, electricity, water, and other expenses such as transportation and marketing. The total cost of these expenses will depend on your location and the size of your operation.

In summary, the estimated cost of rearing 100 broilers in Kenya can range from KES 192,500 to KES 273,000, depending on the factors mentioned above.