How much is appropriate to introduce 500 pigs at a time?

What would you do if you made an introduction plan for a new pig farm with a scale of 1000? You may think it's simple. First, set the utilization target of sows. If the utilization rate is 85%, then the number of imported sows = 1000/0.85, 1 176, and then1/76/5 = 235, and one batch is caught every month.

Perhaps most pig farms do this, which is also taught in classic textbooks, but in practice, I feel more and more that the utilization rate of reserve sows is not as high as I thought. Sometimes, in order to complete the weekly breeding task, even some sows with weak reserve ability participate in breeding, which often leads to a high elimination rate of first-born sows, and most pig farms also have the so-called "second child syndrome" phenomenon.

What's wrong with designing the import scheme like this? I think the mistake is that there was no concept of "reservoir" when designing and introducing reserve sows from the beginning, which led to the goal of "lack of money" every week. It has been expected that the sow can estrus 53 times a week as scheduled, but once the sow estrus is not ideal, it can only be adjusted urgently by hormones, and even the sow will mate strongly.