Age at sexual maturity
The average value and its standard error for age at sexual maturity are presented in Table 1. In the present study, the overall mean for age at sexual maturity was found to be 892.89±43.20 days and its coefficient of variation was 20.53%. Higher than the present findings were reported by
Malik and Ghei (1977) and
Gaur et al., (2003) for Gir heifers being 1096 days and 1149±58 days, respectively. The age at maturity of Sahiwal heifers was mainly controlled by environmental factors. Better management of dams in advanced pregnancy and calves in the early stage may result in early maturity as reported by
Yadava et al., (2010).
Novakovic et al., (2011) explained in their research that the time of sexual maturity depends on numerous genetic and environmental factors like nutrition, climate, rearing, and housing of cows. Scientific management practices might be the cause of lower age to become sexually mature in our herd of study.
Age at first fertile service
The average value and its standard error forage at first fertile service are presented in Table 1. In the present study, the overall mean for age at first fertile service was found to be 1044.79±37.16 days and its coefficient of variation was 13.31%. There is very limited research that exists for determining the average age at which the animal performs first fertile service.
Wu et al., (2012) and
Novakovic et al., (2011) found relatively lower values for age at first fertile service as compared to our result. Higher value for age at first fertile service might result due to the lower availability of higher quality semen straw. Moreover, the herd was introduced newly in high humid area away from their original habitat. So they might take a longer period to overcome their stress level.
Age at first calving
The average value and its standard error for age at first calving are presented in Table 1. In the present study, the overall mean for age at first calving was found to be 1236.79±92.83 days and its coefficient of variation was 28.08%. The average value for age at first calving in the present study is fairly comparable with the report of
Chandrakala and Sinniah (2002) in Sahiwal cows (41±6.9 months). Lower than the present finding has been reported by
Narwaria et al., (2015) and
Wakchaure and Meena (2010) in Sahiwal cows being 1136.14±10.48 days and 1078.09± 21.12 days, respectively.
Kumar et al., (2017) studied in Jersey crossbred heifers and found 1089.36±13.99 days of age at first calving with the coefficient of variation 14.27%. A relatively higher value for age at first calving was reported by
Rehman et al., (2008) in Sahiwal cows (1390±3.9 days) and
Moulick et al., (1972) in Deshi cows (44.5±6.8 months). Lower age of first calving was reported by
Sherwin et al., (2016),
Jadhav et al., (2019) and
Beneberu et al., (2021) for U.K. dairy herds (29.6 months), HF×Gir half breed cows (990.69± 6.53 days) and Jersey Cattle (32.95±0.22 months), respectively.
First service period
The average value and its standard error for the first service period are presented in Table 1. In the present study, the overall mean for the first service period was found to be 153.21±21.60 days and its coefficient of variation was 52.76%. Relatively similar to our research result were reported by
Ahmad (1999) and
Naskar et al., (2005) for Sahiwal cows being 153 days and 137.67±7.87 days, respectively. In another study,
Deshpande et al., (1983) reported 154±5.3 days for Friesian × Sahiwal crossbred cow. Lower than the present finding was reported by
Jadhav et al., (2019) for HF × Gir half bred cow. Relatively higher values were reported by
Narwaria et al., (2015);
Rehman et al., (2008);
Talbott (1997) for Sahiwal cows and by
Wu et al., (2012) for Chinese Holstein cows. Much higher service period was averaged out by
Dandapat et al., (2010) for Sahiwal and crossbred cows (284.50±1.29 and 263.17±6.67 days);
Malik and Ghei (1977) for Gir heifers (317 days). The increased value for service period found in our result could be controlled by minimizing the environmental variation and by providing a proper postpartum cow management system.
First gestation length
The average value and its standard error for the first gestation length are presented in Table 1. In the present study, the overall mean for the first service period was found to be 283.00±1.44 days and its coefficient of variation was 1.90%. Relatively similar to our research results were reported by
Malik and Ghei (1977) for Gir heifers (287 days);
Chandrakala and Sinniah (2002) for Sahiwal cows (279±6 days);
Naskar et al., (2005) for Sahiwal cows (286.67±0.46 days). For Jersey × Local cows, Holstein Friesian × Local and Local cows, the gestation length was 275.74±0.46 days, 275.81±0.53 days and 274.12±0.53 days, respectively as reported by
Hussain et al., (2012).
Das et al., (1990) and
Hussain et al., (2012) explained in their research that the gestation length is affected by different factors like season of calving, lactation order, genetic group and sex of the calf.
First inter-calving period
The average value and its standard error for the first inter calving period is presented in Table 1. In the present study, the overall mean for the first inter calving period was found to be 532.42±51.24 days and its coefficient of variation was 33.34%. Relatively similar values were reported by
Dandapat et al., (2010) for Sahiwal (522.63±27.99 days) and crossbred cattle (500.13±35.35 days). Lower than our research findings were reported by
Chandrakala and Sinniah (2002);
Zafar et al., (2008) and
Narwaria et al., (2015) for Sahiwal cows. Higher than the present findings was obtained by
Malik and Ghei (1977) for Gir heifers (603 days). For Holstein Friesian cows and HF × Gir half breed cows; lower inter calving period were reported by
Froidmont et al., (2013) and
Jadhav et al., (2019), respectively. Higher values found for first inter calving period could be controlled by minimizing the environmental variation and by providing a proper postpartum cow management system.
