Influence of pregnancy and lactation on diurnal and seasonal changes in lactic acid and pyruvic acid levels and in values of pH, pCO2 and pO2 in the mare blood.

The research article focuses on how pregnancies and lactation affect the daily and seasonal changes in lactic acid, pyruvic acid levels, and some gaseous values in mare blood.

Objectives and Scope of the Research

• The research set out to study the diurnal (day time) changes in levels of lactic acid (LA), pyruvic acid (PA) and gaseous values (pH, pO2, and pCO2) in the blood of barren, pregnant, and lactating mares over a period of three years.

Method and Procedure

• Blood samples were taken from these mares every 4 hours for one whole day each month, throughout three consecutive years.
• The lighting was kept natural, and all the mares were fed and maintained under the same conditions to ensure consistency.

Key Findings

• The study showed that barren mares have a noticeable diurnal rhythm in LA, PA, pO2, and pCO2 levels. This implies that these levels fluctuate predictably over a 24-hour period.
• Pregnancy and lactation had shown to mask these diurnal rhythms, except for the LA level during lactation, albeit with a phase delay of 3-4 hours.
• Similarly, barren mares also displayed clear seasonal cyclicity in LA, PA, and pCO2 values, which signifies a recurring pattern of these values over different seasons of the year.
• However, pregnancy impacted this seasonal cyclicity by eradicating cyclicity in LA level and inducing a shift of peak timings (acrophases) and lowering the maximum values (amplitudes) in PA and pCO2 values.
• No seasonal cycles were observed in pO2 tensions. This means the levels of oxygen remained relatively constant throughout the different seasons of the year.
• Neither were diurnal rhythms nor seasonal cycles observed in the pH values throughout the study years. This indicates that the acidity or alkalinity level of the blood was relatively stable throughout the day and over different seasons.

Conclusion

• In conclusion, the study shows that pregnancy and lactation can significantly influence diurnal and seasonal changes in certain acid and gas levels in the blood of mares. This might have implications for health care and management for pregnant and lactating mares.