How to scientifically supplement calcium during the confinement rearing of laying ducks
To improve the egg production rate and the marketability of eggs from confined laying ducks, in addition to meeting their needs for protein, energy and other nutrients, scientific calcium supplementation must be carried out in particular. This includes the following aspects:
Choosing a good calcium source Generally, limestone, shells and the like are used as the main source of calcium, but the proportion must be appropriate. The ratio of stone powder to shell powder is preferably 2:3. Adding 1% bone meal gives the best eggshell strength and smoothness.
Timing of calcium supplementation Confined laying ducks generally start laying at around 100 days of age, and 15 weeks of age is the best time to start calcium supplementation. Calcium supplementation should be between that for young ducks and laying ducks, preferably 2.5%, and then gradually increased.
Optimal calcium supplementation amounts for each laying stage The calcium utilization rate of laying ducks is about 65%, and producing one egg requires 4.8-5.12 grams of calcium. Practice has proved that when the laying rate is below 65%, calcium should be 2.5%; when the laying rate is 65%-80%, calcium should be 3%; when the laying rate reaches above 80%, calcium should be 3.2%-3.5%.
Supplementing granular calcium It is best if granular calcium stays in the digestive tract for a long time, so that it can supply calcium evenly during the eggshell formation stage. At the same time, granular calcium has a grinding effect in the stomach similar to that of sand, which can promote the digestion and utilization of feed. Practice has proved that using 50% granular shells together with 50% limestone can give laying ducks good calcium absorption.
The supply of vitamin D in the daily ration should be ensured (liquid cod liver oil or vitamin AD gel capsules can be used), and the calcium-to-phosphorus ratio should be controlled at 5:1-6.5:1, which is beneficial to the absorption and utilization of calcium.