The records of 457 Surti buffaloes with 1346 lactations sired by 35 sires maintained at Livestock Research Station, Navsari Agricultural University, Navsari born during 1987 to 2012 were collected and analysed to examine the effect of non-genetic factors viz. season and period of birth on age at first calving. The average age at first calving in Surti buffaloes was found to be 1333.96 ± 19.53 days. The analysis of variance revealed highly significant effect of period of birth but non-significant effect of season of birth on age at first calving. No effect of season of birth on age at first calving indicated breed characteristics to acclimatize with environment. Age at first calving showed a significant rise during Period-2 (1993 to 1998) and Period-3 (1999 to 2004) and subsequent decline in Period-4 (2004-2012) indicates improvement of managemental practices over the periods of the farm.
In India, the majority of small and marginal farmers are more dependent on buffaloes than cattle for their livelihood as they also serve as an insurance against the risk of crop failure due to natural calamities (Dhanda, 2004). FAO (2000) has termed the buffalo as an important but ‘an asset undervalued’. Buffalo is a triple purpose animal, being suitable for milk, meat and draught. The Surti buffalo is a reputed breed of buffalo with its origin in charotar region of central Gujarat.
High production efficiency in livestock production is an economically desirable attribute that targets ultimately for genetic up gradation. In fact, the economy of dairy industry mainly rely upon the performance parameters of dairy animals, therefore, it becomes more relevant to tackle out the means for ameliorating the performance efficiencies by developing certain guidelines for selection (Dangar and Vataliya, 2014). First calving marks the beginning of an animal’s productive life. Age at first calving is closely related to generation interval and, therefore, influences response to selection. Thus, segregation of factors like season and years and their effect on trait like age at first calving will enable the breeder in assessing the effectiveness of selection programme and managemental conditions over time. This will help in designing more appropriate breeding strategies to maximize genetic gain and also suggest amendments in managemental standards if desired. Therefore the present investigation was planned with a view to study the non genetic factors affecting age at first calving in Surti buffaloes.
Materials and Methods
In order to achieve the objective, the data pertinent to production traits on 457 Surti buffaloes with 1346 lactation which were born during 1987 to 2012 and progeny of 35 sires maintained at Livestock Research Station, Navsari Agricultural University, Navsari, Gujarat, India were considered. The duration of 1987 to 2012 was divided into 4 periods; PB1 (1987 to 1992), PB2 (1993 to 1998), PB3 (1999 to 2004) and PB4 (2005 to 2012). The three seasons were delineated as winter (November-February), summer (March- June) and monsoon (July-October) on the basis of geo-climatic conditions prevailing in the region. Records of buffaloes with some specific or non-specific diseases, reproductive disorder and physical injury were excluded from the present investigation. For analysis Harvey (1990) software was used following LSMLMW mix model:
Yijkl = µ + Ai + Bj + Ck + eijkl
Yijkl = record of lth buffalo born in ith period, jth season and kth parity
µ = population mean
Ai = fixed effect of jth season where i = 1, 2 and 3.
Bj = fixed effect of ith period where j = 1, 2, 3 and 4.
Ck = effect of parity of calving where k=1, 2, 3, 4 and above.
eijkl = random error which is assumed to be normally independently distributed with zero mean and constant variance (NID, 0, σ2).
Duncan’s Multiple Range Test (DMRT) as modified by Kramer (1957) was used for testing differences among least squares means.
Results and Discussion
Least squares mean for AFC was found to be 1333.96 ± 19.53 days which is presented in Table 2. Higher AFC as compared to the finding of the present study has been reported by Pathodiya et al. (1999), Warade et al. (2005) and Gogoi et al. (2002) in Surti buffaloes while lower values have been reported by Pandya et al. (2013) in the Surti buffaloes of the same farm for different period. Higher AFC as compared to present study has also been reported in Murrah buffalo by Jain and Tailor et al. (1992), Gogoi et al. (2002) and Chaikhun et al. (2013); in Nili-Ravi buffalo by Hussain et al. (2006) and Bashir et al. (2015); combinedly in Surti, Murrah, Nili-Ravi and their crossbred buffalo by Charlini and Sinniah (2015) and in Jaffrabadi buffalo by Sharma et al. (2016) while in Mehsana buffalo by Prajapati et al. (2017). Lower AFC as compared to present study has also been reported in Murrah buffalo by Dutt et al. (2001), Yadav et al. (2007), Newale (2010) and Gupta et al. (2012). However the findings pertaining to AFC reported by Patil et al. (2012) and Jamuna et al. (2015) in Murrah buffaloes are comparable with the finding of the present study.
AFC, being lowly genetic based trait is largely governed by management and other environmental factors on the farm. The AFC is also a reflection of the nutrition and management provided to the animal during early age. The differences in AFC between herds studied are likely due to management and genetic difference with other herds. The lower AFC in comparison to previous reports in Surti and other Indian buffalo breeds indicates good management practices followed in the farm.
Effect of Season of Birth
Season of birth has no significant (P>0.05) effect on AFC which indicate that all seasons have similar influence on it (Table 1).
Table 1: Analysis of variance for age at first calving in Surti buffalo
* = Significant (P<0.05), ** = Highly Significant (P<0.01)
Similar observations were also reported by Patel and Tripathi (1995) and Shashidhara et al. (1999) in Surti buffalo. Contrary to the present finding, Pandya et al. (2013) reported highly significant (P<0.01) effect of season of birth on AFC in Surti buffaloes and in Mehsana buffalo by Prajapati et al. (2017). They observed that animals born in monsoon and summer season had significantly lower AFC. Dutt et al. (2001), Penchev et al. (2014) and Jamuna et al. (2015) reported significant effect of season of birth on AFC in Murrah buffalo. The seasonal influence on AFC is mainly due to nutritional availability during post natal period which can be reduced by efficient nutritional management on the farm.
Effect of Period of Birth
In present study, period of birth had highly significant (P<0.01) effect on AFC in Surti buffalo (Table 1). It was observed that animals born in period of birth 4 (2005-2012) had significantly lowest AFC (1215.85 ± 68.74 days) than other periods of birth (Table 2).
Table 2: Season and period of birth wise least square means and standard error for age at first calving in Surti buffaloes
|Factors||N||Least Square Means and Standard Error of AFC (Days)|
|μ||457||1333.96 ± 19.53|
|SB1||115||1353.98 ± 24.61|
|SB2||38||1307.55 ± 37.68|
|SB3||304||1340.33 ± 18.16|
|PB1||100||1292.79b ± 56.96|
|PB2||145||1410.42a ± 44.72|
|PB3||127||1416.76a ± 38.39|
|PB4||85||1215.85c ± 68.74|
Mean of a trait bearing different superscript within factor differ significantly (P<0.01)
Similar to present study, Shashidhara et al. (1999) as well as Patel and Tripathi (1995) reported that AFC was significantly affected by period of birth in Surti buffaloes and in Mehsana buffalo by Prajapati et al. (2017). Sharma et al. (2016) reported highly significant effect of period of birth on AFC in Jaffrabadi buffalo. Dutt et al. (2001) also reported significant effect of period of birth on AFC. However contrary to the present study was reported by Jamuna et al. (2015) in Murrah buffalo. Influence of period of birth on AFC is likely due to differential availability of fodder, environmental factors and managemental practices affecting growth of the animals.
Conclusion can be made based on this study, there was no influence of season of birth on age at first calving indicates Surti buffalo breed’s characteristic to acclimatize with environment. Significant rise in age at first calving during 1993 – 2004 (Period 2&3) and the review managemental practices followed during these periods might have resulted in lowest AFC during Period 4 (2004 to 2012).