Instructions
Feed your hen a commercially prepared diet. Poultry diets are formulated with consideration for the age and type of hen. Choose an age-appropriate broiler diet for weight gain. The University of Minnesota "Poultry U" publishes a list on its website of reliable suppliers of poultry feed for small flocks.
Blend your own feed using cornmeal or other grains, soybean meal, vegetable oil and nutrient supplements. Be sure to feed calcium supplements like crushed oyster shells, grit for digestion and plenty of water. The University of Florida Agricultural Department publishes a chart on its website that provides the nutritional balance needed for hens. The age-appropriate broiler diet is designed for hen weight gain.
Consider supplementing your hen's diet to make it more flavorful and increase appetite. In small amounts, grasses, alfalfa meal, vegetables, proteins and a broader variety of whole grains might encourage your hen to eat more. Molasses can also be used to supplement the diet -- but use it sparingly, as it can act as a laxative.
Adjust the protein-carbohydrate balance in your feed, or switch to a different protein and carbohydrate source. In some cases, there is a protein-sparing effect with some protein-carbohydrate balances.
Check to be sure there are no environmental influences that are affecting weight gain. Hens need an adequate supply of water and grit to properly process their food. They also need some salt -- but not too much, or it will cause loose droppings. Hens who are always caged may suffer from cage fatigue and require additional nutrition or exercise. Heat or cold stress is also a factor. Extremes of either will inhibit weight gain.
How to Get a Hen to Gain Weight
Hens gain weight the same way people do; they consume more calories than they burn. If they exercise as they gain weight, they will put on muscle. If they are sedentary, they are more likely to add fat. A high-calorie, balanced diet, in combination with light exercise, is the best way to gain weight for person or a hen. University Agricultural Departments have formulated a variety of diets based upon the age, breed and purpose of the chickens.