CATDOLL : CATDOLL: Why are there two types of phosphorus in the feeding standards for pigs and chickens: total phosphorus and available phosphorus?

1. Why are there two types of phosphorus in the feeding standards for pigs and chickens: total phosphorus and available phosphorus?

Three types of phosphorus are mentioned in the animal feeding standards: phytate phosphorus, total phosphorus and available phosphorus.

Plant seeds, that is, various feeds and their processed products, such as bran feeds and meal feeds, contain a large amount of phytic acid phosphorus (inositol hexaphosphate); phytic acid phosphorus can only be absorbed and utilized by animals under the action of phytase. Monogastric animals, calves under 2 months old, and lambs under 3 months old have poor or incomplete microbial flora in the digestive tract, and cannot or rarely secrete phytase, so they cannot decompose (digest) phytic acid phosphorus and the utilization rate is very low.

Since a large part of the phosphorus in grain feed, bran and cake is in the form of phytic phosphorus, although their phosphorus content is high, their utilization rate is very low. For example, the total phosphorus of corn is 0.27%, and the phytic phosphorus is 0.17%; the soybean cake is 0.62% and 0.31% respectively; the bran is 0.51% and 0.37%, etc. Cereal feed accounts for more than 80% of the daily diet of pigs and chickens, and phosphorus accounts for a large part of the total daily diet phosphorus. Therefore, in order to meet the phosphorus needs of pigs and chickens, in recent years, the phosphorus standards for pig and chicken feed have two types of total phosphorus and available phosphorus.

For the convenience of monogastric animal ingredients:

Total phosphorus = phytate phosphorus + non-phytate phosphorus

Non-phytate phosphorus = total phosphorus - phytate phosphorus

Non-phytate phosphorus = available phosphorus = usable phosphorus

For monogastric animals, the utilization rate of phosphorus in various feeds is: 100% of phosphorus in mineral feed; 100% of animal feed; 100% of green and roughage feed; and only 50% of phosphorus in seed feed, bran feed and cake feed is available for pigs and 30% for poultry because phytic acid phosphorus accounts for a considerable proportion.

2. The farm raises chickens and ducks. Chickens account for 58% of the total number, and there are 630 ducks. How many chickens and ducks are there in total?

Chickens account for 58%, and ducks account for 42%. 42% of ducks is 630, so the total number of chickens and ducks in the farm is: 630/42%=1500

So the total number of chickens and ducks in the farm is 1,500.

3. In a farm, chickens account for three-fifths of the total number of chickens, ducks and geese. There are 700 ducks and 200 geese. How many chickens, ducks and geese are there in total?

One minus three-fifths equals two-fifths, seven hundred plus two hundred equals nine hundred, and nine hundred divided by two-fifths equals two thousand two hundred and fifty.

Answer: There are 2,250 chickens, ducks and geese in this farm.