articles about anestrus
Reproductive performance of gilts and weaned sows grouped at different days after insemination
Heat stress affects the sows' reproductive cycle
From their respective academic and on-farm perspectives, Josep Gasa and Josep Casanovas comment on a recent study regarding the effect of heat stress on sows: Which weeks does it affect the farrowing rate the most? What about the weaning-to-first-service interval? Are there differences depending on parity?
Clinical case: Gilts not coming into heat
Since 2017 the number of gilts coming into heat (with standing reflex) has gradually fallen to levels less than 50-60% of the gilts ready to be inseminated...
Anestrus in multiparous sows
When multiparous sows are affected, not as many need to be culled as in the case of gilts (which we saw in the last article). Generally sows will eventually show signs of heat, but with a considerable delay compared to a normal heat.
Anestrus in gilts
Lack of estrus in gilts is a common cause for culling, which increases the need for gilts and the cost of gilts. Let's take a look a what causes anestrus:
Analysis of steroids in gilt saliva to identify biomarkers of the period of receptivity
Factors for improving reproductive performance of sows and herd productivity in commercial breeding herds
Use of altrenogest on pig farm
The shorter and lower dose regime saves money but there is an increased risk of follicular cyst development, which may occur at doses below 13mg/day.
Thompson’s tip: Provide cover for summer infertility
Anoestrus upon weaning
Short weaning to service interval isn’t always a synonym for good management, since we have to take into consideration not only average number of days, but also the effect on the percentage of distribution after returns.
Hormone management (II)
When the sow is pregnant, the corpus luteum remains and continues to produce progesterone. While the levels of progesterone are high the sow does not become in heat and maintains gestation.