Characterizing of growth curves with exponential equations and predicting weaning weights at the age of 6 months through some blood characteristics, milk production in buffalo

Abstract

A sample of 50 Iraqi buffaloes heifers and their dams were used in the study, which was conducted in Baghdad (Al-Dhahab Al-Abyad/Abu Ghraib village area, 20 km west of Baghdad, and Al-Fadhiliya site, 20 km northeast of Baghdad) from the production season of 2021–2022. Following factor adjustment, the study's findings are as follows: The study reveals that an increase in milk supply by one kilogram per day leads to a significant increase in weaning weight for calves, with daily milk production accounting for 18% of their weight at weaning. The study found a positive correlation between weights at a young age and later weights, including weight at weaning, significantly influenced by udder milk production. Weight weaning had a significant association with fat percentage and protein percentage. The study used damsweight at birth to predict animal weights in buffaloes, and weight at weaning and six months of age to approximate real weights. The Brody and Logistic functions were accurate in estimating calves' weight up to six months old, with potential for extension to a year. Growth functions, focusing on sigmoid growth curve, are also available.