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Energy & Protein Requirements for Wool, Meat and Egg production

Energy and Protein Requirement of Sheep for wool production


  1. The dependence of wool growth rate on the energy intake of the sheep is due in part to the association between energy intake and the synthesis of microbial protein. With restricted energy consumption, wool growth slows, fiber diameter is reduced, and weak spots (breaks) develop in the wool fiber.
  2. The major sources of energy in a sheep’s diet are pasture and browse, hay, silage, and grains. Sheep and goats often lack nutrients, however, due to poor-quality pastures and roughage or inadequate amounts of feed. Because of this, energy is the most common limiting factor in small ruminant nutrition.
  3. As a thumb rule a non-pregnant, non-lactating ewe requires 10 gm TDN per kg live weight for maintenance and wool production. Energy requirement for Wool Production is 127 ME Kcal per kg metabolic weight per day.


  1. The wool fibre consists almost entirely protein and wool keratin. To grow in one year, a fleece containing 3 kg protein, the sheep would need to deposit a daily average of about 8 g protein. 5 g of DCP per kg metabolic weight has been recommended as the requirement for maintenance. Optimum nitrogen-sulphur ratio in the diet of wool producing sheep was found to be 5:1.
  2. Wool is very rich in cystine and methionine. Wool protein contains a high proportion of the high-sulphur amino acids cystine. Hence, Sulphur containing amino acids play a major role in wool growth. The supply of sulphur containing amino acids cystein, cystine and methionine often limits wool growth, and the supply of lysine is also reported to be important.
  3. Protein supplements, such as oilseed meals (cottonseed meal, soybean meal) or commercially blended supplements should be fed to meet nutrient requirements. Sheep can convert nonprotein nitrogen (such as urea, ammonium phosphate, and biuret) into protein in the rumen. Methionine is 1st limiting AA in microbial protein. When NPN substances are used in sheep ration, the N:S ratio should be maintained as 10:1.

Energy and Protein requirements for Egg and Meat production

The maintenance energy requirement is affected by body size, environmental temperature and level of activity. In order to calculate energy requirements a knowledge of the calorie requirement per unit body size (surface area), growth rate, and egg mass output must be known.

It can be noted that the maintenance energy requirement is around 80% of total energy intake.

Meat Production

  1. Nutrient requirements are higher than the chickens being raised for egg production. In case of layer rate of growth is not important as they obtain a body weight of 1.5 kg in 20 weeks. The same weight is obtained in just 5-6 weeks in case of broiler.
  2. The major energy sources in poultry diets are cereal grains, such as wheat and corn, which have a high starch content. Concentrated sources of energy, including fats and oils, are usually provided to obtain optimum growth and performance.

Sources of protein

  1. Protein is a vital nutrient for poultry and all other classes of animals. In virtue of its amino acid constituents, protein plays a significant role in growth, immunity, adaptation to the environment, and in many other biological functions
  2. There are many protein sources that are commonly used in poultry diets. Some sources are from plant origin (e.g. soybean meal, cottonseed meal, alfalfa meal, and sunflower meal), and others are from animal origin (e.g. fish meal and meat and poultry products).


Egg Production (Egg Laying Chickens)

  1. Chicks are given relatively high levels of energy, protein and the vitamins and minerals for the starter period. Layer pullet diets have lower energy and protein levels than chick diets.
  2. Feed intake will increase to a steady level of 100-105 grams per day. An average egg of around 65g requires approximately 140kcal of metabolized energy for its production. 
  3. Protein required to produce a 65g egg (containing 7.8g of protein) should be around 7.8÷.55 (suggested efficiency of dietary protein utilization for egg production) = 14.2g.
  4. Further, 8.15g of protein intake per day is required to meet maintenance protein requirement. Considering egg production and maintenance the protein requirement would be 14.2 + 8.15 = 22.4g/h/d. This should be sufficient for a hen to lay a 65g egg every day.

Growing period nutrition recommendations

Examples of layer diets (at 100 grams per day intake level)

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