A study of Lusitano mare lactation curve with Wood’s model.

The study researches lactation curves in Lusitano mares using Wood’s model, with a focus on milk yield and milk composition changes throughout the lactation period, finding consistency between their milking patterns and those of other horse breeds.

Research Method

• The study used milk yield and composition data from seven Lusitano mares, each with a weight range from 450 to 580 kg, and parity (the number of times a mare has given birth) ranging from 2 to 9.
• Each mare was subjected to five yield measurements and eight composition measurements.
• The duration of the study was 180 days.

Lactation Curve Model

• Wood’s lactation model was used to study and describe the lactation curves for milk fat, protein, and lactose.
• The data was fitted to an algebraic model through a nonlinear regression procedure which resulted in an accurate prediction for milk yield and major constituents.
• The model resulted in an R(a)(2) of 0.89 for milk yield, and ranged from 0.89 to 0.95 for the major constituents, indicating high predictability.

Findings

• The average values for the concentration of major milk components across the lactation period were: 5.9 g/kg of fat, 18.4 g/kg of protein, and 60.8 g/kg of lactose.
• The yields of protein and lactose in the milk were similar in their shape to the milk yield curve.
• Protein yield peaked at 307 g on the tenth day, while lactose peaked at 816 g on the 45th day.
• The fat yield curve took a different shape compared to milk, protein, and lactose yields.
• Milk fat and protein (g/kg) decreased, while lactose (g/kg) increased during the 180-day lactation period.
• Total production of the major milk constituents throughout the lactation period was estimated to be 12.0 kg for fat, 36.1 kg for protein, and 124 kg for lactose.

Conclusion

• The lactation curve patterns discovered in Lusitano mares were found to be comparable in shape and values to those of other horse breeds.
• This data provides important insights for estimating milk yield and understanding the variation of milk components at different lactation stages, which is crucial for nursing and dairy mares, notably for determining the best weaning time and informing decisions on foal supplementation.