Fertility Characteristics in Dairy Buffaloes: Probability Modeling

Major objective of present study is to determine probability distributions for reliability analysis of fertility characteristics and prediction of fertility loss in 558 calving events among 162 sample dairy buffaloes. Study variables are Lactation Number (LN) Age-at-First-Calving (AFC) Service Period (SP) Gestation Period (GP) Lactation Length (LL) Dry Period (DP) and Calving Interval (CI). LN(X) follows Poisson distribution showing reproductive benefits as 91.6% at X≤5 lactations. AFC (mean=1744 d=days) has Log-Normal distribution showing survival estimate S(t)=86.6% leading to fertility loss when AFC ≥1500d. Abortions represent failure of gestation with age (mean=1627d) indicating most critical fertility loss. CI (mean=483d) has Log-Normal distribution; SP (mean=183d) & DP (mean=240d) have Weibull distribution; GP (mean=309d) & LL (mean=301d) have Normal distribution. Fertility loss measured by Fertility-Loss-Index (FLI) shows loss of CI > ideal period (400d) or acceptable period (520d). The FLI of ideal CI is 0.72 and FLI of acceptable CI is 0.66 per buffalo. Most critically abortions show FLI of ideal CI is 0.45 and acceptable FLI of acceptable CI is 0.35 per buffalo.