Data pertaining to 287 lactations of 125 Surti buffaloes sired by 11 bulls from Buffalo Breeding Farm, Hingoli were considered for the present study. The average age at first calving, lactation milk yield, 305 days lactation milk yield, lactation length, dry period and calving interval were found to be 1373.52±21.76 days, 898.80±25.06 kg, 1180.9±20.01 kg, 254.30±4.75 days, 212.36±11.50 days and 456.09±10.34 days, respectively. The effect of period of birth was significant on AFC, effect of period of calving was significant on LMY, 305 DLMY, LL and CI and effect of season of calving was significant on LMY and 305 DLMY. Parity effect was significant on LMY, 305 DLMY, LL and CI. The heritability estimates for AFC, 305 DLMY, LL, DP and CI were found to be 0.226±0.154, 0.957±0.020, 0.446±0.154, 0.332±0.158 and 0.55±0.131 respectively. Significantly high and positive genetic and phenotypic correlation was observed between 305 DLMY and LL. Similarly highly significant but negative genetic association was observed between AFC and other production traits. At phenotypic level, LL was found highly significant and positively correlated with CI and high and negatively associated with AFC.
India possess the world’s best class buffalo breeds viz. Murrah, Jaffrabadi, Surti, Nagpuri, Niliravi and Bhadawari etc. contributing around 58% of total milk production of the country. Buffalo is one species being seen today as a savior animal to meet increased requirement of human food in coming days. Further the buffalo being proved A2 milk producer is away from the disputed opinion of A1/A2 type beta casein on human health implications. The Surti breed of buffalo has its origin in Surat, Anand, Bharooch and Baroda District of Gujarat but also found in Khandesh and some part of the Vidharbha region in Maharashtra state. The Buffalo Breeding Farm, Hingoli under Maharashtra Livestock Development Board is maintaining the organized herd of this breed. Surti buffalo is well adapted to its native breeding tract but information on its performance related to lactation and production characteristics in the different regions away from its home tract is scanty. This research was undertaken with the view of documentation and conservation.
Material and Methods
Data pertaining to age at first calving, lactation milk yield, 305 days lactation milk yield, lactation length, dry period and calving interval of 287 lactations of 125 Surti buffaloes were collected from the breeding records available at Buffalo Breeding Farm, Hingoli. Abnormal short lactations, records from buffaloes having chronic sickness or suffering from mastitis for a long period and died or sold were not considered. The entire duration was divided into four periods for AFC based on year of birth (POB1 to POB4) and for other lactation traits into three periods based on year of calving (POC1 to POC3). Similarly each of the year was further divided into three seasons viz. summer (February to May), rainy (June to September) and winter (October to January). The data so generated were analyzed using SYSTAT Version 7.0 by SPSS INC and mixed model least squares and maximum likelihood, computer programme, PC-2 as given by Harvey, (1990). The effect of season, period and parity was studied using following model.
Yijkl = m+Pi+Sj+Lk+eijkl
Where, Yijkl was records of buffalo in kth lactation (parity) in jth season and ith period; m was over all mean; Pi was fixed effect of ith period; Sj was fixed effect of jth season; Lk was fixed effect of kth parity and eijkl as random effect of error.
The heritability was estimated by paternal half sib correlation method and its standard errors were obtained as per Swiger et al. (1964). The genotypic and phenotypic correlations were estimated by the analysis of co-variance technique.
Results and Discussion
The least square means for various factors affecting age at first calving, lactation milk yield, 305 days lactation milk yield, lactation length, dry period and calving interval are presented in Table 1. The average age at first calving was found to be 1373.52±21.76 days in Surti buffaloes. The similar estimates were reported in Toda (Karthikeyan et al., 2002), Murrah (Rana et al., 2002 and Gupta et al., 2012) and Surti buffaloes (Charista and Sinniah, 2015). However higher estimates for AFC in Surti (1683.48±34.86 days) by Pathodia et al. (1999); Bhadawari (1540.7±46.6 days) by Singh and Nivasarkar, (2000) and Mehsana buffaloes (1549.62±39.84 days) by Galsar et al. (2016) and lower estimates for AFC in Pandharpuri buffaloes (995±6.33 days) by Patil et al. (1996) were reported.
Table 1: Least square means with SE for AFC, lactation milk yield, 305 days lactation yield, lactation length, dry period and calving interval as affected by period, season and parity
|Effects||Age at first calving||Lactation milk yield (kg)||305 days lactation milk yield (kg)||Lactation length (days)||Dry period (days)||Calving interval|
|No.||Mean with SE||No.||Mean with SE||No.||Mean with SE||No.||Mean with SE||No.||Mean with SE||No.||Mean with SE|
Means with different superscript indicate significant differences (P<0.05)
Such differences might have been due to variable conditions of management. The analysis of variance presented in Table 2 shows that the effect of season of birth was found to be non-significant on age at first calving while the effect of period of birth was significant in Surti buffaloes. The similar findings were reported by Gogai et al. (2002) and Meena et al. (2003) in Surti buffaloes and Sethi et al. (1996) in Murrah buffaloes.
Table 2 : Analysis of variance (ANOVA) for factors affecting age at first calving, lactation milk yield, 305 days lactation yield, lactation length, dry period and calving interval
|Source of variation||AFC||Source of variation||LMY||305 DLMY||LL||DP||CI|
* P< 0.05,**; P<0.01and NS –Non significant
The average lactational milk yield under the present study was found to be 898.80±25.06 kg. The similar estimate (930±7.52 Kgs) was reported in Purnathadi buffaloes (Baglane et al., 2008), however the higher estimates (1273.17±15.38 kg) by Warade et al. (2005) and (1197kg) by Christa and Sinniah, (2015) were reported in Surti buffaloes. Highly significant effect of period of calving and parity and non-significant effect of season of calving was observed on lactation milk yield. Similar findings were reported by Das et al. (2015) in swamp buffaloes, whereas Patel and Tripathi (1998) reported the significant effect of period and season on lactation milk yield in Surti buffaloes. Periodwise lactation milk yield ranges from 690.08+80.17 kg (P1) to 1310.34+194.43 kg (P3) and the higher lactation yield in later period may be due to culling of low productive animals and selection of high yielders over the time. Lactation milk yield was significantly higher in parity 1stand 2nd as compared to parity 3rd. The overall mean for 305 days lactation milk yield was found to be 1180.9±20.012 kg in close agreement with those reported by the earlier workers in Surti buffaloes as reviewed by Kalyankar and Gujar (2002), however higher 305 days lactation milk yield was reported in Murrah (Parrek and Narang, 2015 and Jhakar et al., 2016) and in buffaloes of Haryana (Kumar et al., 2011). Highly significant effect of season, period and parity on 305 days lactation yield was found in agreement with the similar finding of Patel and Tripathi (1998) in Surti buffaloes. Average 305 days milk yield of period P3 (1830.376±133.48 kg) was significantly higher as compared to other periods P1 and P2.
The least square mean of lactation length was found to be 254.306±4.75 days. The analysis of variance showed significant effect of parity and non-significant effect of period and season on lactation length. In close agreement, Christa and Sinniah, (2015) reported 298, 238 and 287 days lactation length in Murrah, Nili-Ravi and Surti buffaloes respectively in Sri Lanka, while lactation length of 281.17±2.58 days in Mehsana (Galsar et al., 2016); 296.94±4.72 days in Purnathadi (Ambulkar et al., 2002) and 311.68±3.35 days in Murrah buffaloes (Jakhar et al., 2016) were reported. In contrast to the present findings significant effect of season (Patel and Tripathi, 1998) and period (Pathodia and Jain, 2004) were observed on lactation length in Surti buffaloes. The average dry period was found to be 212.36±11.50 days with coefficient of variation 68.75 per cent. Bharat et al. (2004) reported similar finding of 215.46±13.94 days of dry period in Surti and Mehsana buffaloes. However lower estimates for dry period were reported in Surti (Christa and Sinniah, 2015); Mehsana (Galsar et al., 2016); Murrah (Jhakar et al., 2016) and Purnathadi (Baglane et al., 2005). The analysis of variance revealed non-significant effect of season, period and parity on dry period. High coefficient of variation for dry period shows the scope for improvement in this trait through selection or vigorous culling.
The overall mean for calving interval was found to be 456.09±10.34 days. Almost similar estimates with the difference of ±1 month were recorded in Mehsana (Galsar et al., 2016); Murrah (Jhakar et al., 2016); Purnathadi (Baglane et al., 2005) and Murrah, Nili-Ravi and Surti (Christa and Sinniah, 2015) buffaloes. Significant effect of period and parity on calving interval was found in Surti buffaloes. Calving interval ranged from 378.97±34.71 days to 520.91±66.044 days in different periods. Present findings were in agreement with Sethi et al. (1996); Patel and Tripathi (1998) and Singh and Nivasarkar (2000) as reported significant effect of period on CI. The great diversity in average calving interval is evident in Indian buffaloes and the trait could be minimized through post-partum management and the most important is the heat detection, feeding and managemental practices. Reduction in the variability of such trait is also very important for increase in life time production.
Heritability Estimates and Genetic and Phenotypic Correlations
The heritability estimates with standard error for various lactation and production traits were presented in Table 3.
Table 3: Heritabilities (diagonal), Genetic correlation (above diagonal) and phenotypic correlation (below diagonal) for various production and reproduction traits of Surti buffaloes.
|Traits||Age at First Calving||305 DLMY||Lactation length||Dry period||Calving interval|
|Age at first calving||0.226±0.154||-0.839±0.455||-0.652±0.550||>1.00||>1.00|
(Forh2estimates Number of Sires were 11, N=49 and K=3.9796)
Very high estimates of heritability was obtained for 305 days lactation yield amounting to 0.957±0.02 followed by inter-calving period as 0.55±0.131. Moderate estimates of heritability were obtained for age at first calving and dry period amounting to 0.226±0.154 and 0.332±0.158, respectively. In general, all of the estimates had higher magnitude may be due to less no of N or K per sire as compared to those studied by earlier workers viz. Warade et al. (2005), Galsar et al. (2016) and Jhakar et al. (2016). Significantly high and positive genetic and phenotypic correlation was observed between 305 days lactation yield and lactation length. Similarly highly significant but negative genetic association was observed between age at first calving and other production traits. At phenotypic level, lactation length was found highly significant and positively correlated with inter-calving period and High and negatively associated with age at first calving. Trend of genetic and phenotypic correlation is consistent with the observation of Pathodia et al. (1999), Pathodia and Jain (2004), Galsar et al. (2016) and Jhakar et al. (2016). The lactation length and dry period are added together to form inter-calving period, hence relatively traits shows high positive association at phenotypic level which is also reflected in the genetic association. The lactation and production traits of Surti buffaloes suggested that although the habitat of the breed is Gujarat state, the Surti buffaloes have also been suitably well adopted to Maharashtra climate conditions.