Quantitative and qualitative assessment of milk production after pharmaceutical induction of lactation in the mare.

This research involves a study to stimulate lactation in mares that are not pregnant, with the end goal being to evaluate the quantity and quality of the milk produced. A combination of hormonal and pharmaceutical treatments were used, with milk production and its components being analyzed.

Methods

• The study was conducted over two years, with five mares under treatment and five as a control group in the first year. In the second year, twelve mares were observed.
• Treatment included the administration of a vaginal pessary (composed of 500mg altrenogest and 50mg estradiol benzoate) for a week. In the second week, another similar sponge was given along with Sulpiride in oil, dosed at 50mg/100kg body weight (BW), twice daily.
• Once 1 litre of milk was obtained, the pharmaceutical treatment was ceased. All milk was manually extracted.
• In the second year, the same treatment was followed, but in addition to Sulpiride, some mares also received Domperidone. Milking was done using a machine, and oxytocin injections were used just a minute before the start of milking.

Measurements and Findings

• Measurement parameters included milk immunoglobulin G (IgG) contents, milk yield, and plasma prolactin concentration. IgG is a type of antibody that is highly present in colostrum and helps provide immunity to the foal.
• In the first year, all treated mares started lactating within 1-5 days of Sulpiride treatment and produced on average 0.88 litre per 500kg BW per day. The IgG contents increased in all mares, ranging from 14 to 92 g/L.
• There was a noticeable increase in plasma prolactin levels during the Sulpiride treatment: it ranged from 27.7ng/mL before treatment to 289ng/mL during treatment.
• In the second year, similar results were observed, although the daily milk production was significantly higher. Using Sulpiride, mares produced, on average, 3.13 litres per 500kg BW per day, and while using Domperidone, this increased to 3.45 litres. The peak IgG concentrations ranged from 4.2 to 106.7 g/L.

Conclusion

• The study concluded that lactation can be successfully induced in mares within two weeks, and some mares produce high-quality colostrum.
• The increased production of Prolactin hormone via the given pharmaceuticals played a significant role in lactation induction.
• However, the lactation induction protocol used in mares is still far from that in high-producing dairy animals due to hormonal, physiological, and anatomical differences between species.