Data on performance records of 1249 Frieswal daughters of 71 sires over a period of 13 years from 2000-2012 were analyzed to determine the effects of farm, parity, type of calving, period of birth and season of birth on lactation length (LL), 305-day milk yield (305-DY) and calving interval (CI). The age at first calving (AFC) was considered as covariable. The overall least-squares means for AFC, LL, 305-DY and CI were 31.45±0.89 months, 303.31 ± 7.02 days, 2997.01 ± 123.24 kg and 431.19 ± 16.53 days respectively. Period of birth had significant effect on age at first calving. Farm, type of calving and period of birth had significant effect on lactation length. Farm, parity and season of birth had significant effect on 305-day milk yield. Parity, type of calving, period of birth and season of birth had significant effect on calving interval. Heritability estimates for LL and CI were low (0.17 ± 0.10 and 0.11 ± 0.09), while it was high (0.51±0.14) for 305-DY. The phenotypic and genetic correlation between lactation length, 305-day milk yield and calving interval were observed high and positive.
Milk production is one of the most important economic traits in dairy cattle. India continues to be the largest producer of milk in the world. The milk production has increased significantly from the level of 102.6 million tonnes in 2006-07 to 155.5 million tonnes in 2015-16. However, the per capita availability of milk is just around 337 grams per day and there is huge local demand of milk (Anonymous, 2016). In spite of India’s position as the highest producer of milk, productivity of individual animal is low. Considering the large requirement of milk by Indian Army, crossbreeding of local cattle with exotic dairy breeds was introduced in India in 1875 to cater the need of milk by army. Military dairy farms (MDFs) were established in 1891 with the emphasis to develop high yielding crossbred cattle suitable to Indian climate. Project Directorate on Cattle (now CIRC, Central Institute for Research on Cattle), Meerut developed a synthetic breed “Frieswal” (5/8 Holstein Friesian and 3/8 Sahiwal), yielding 4000 kg of milk with 4% butter fat in a lactation of 300 days in collaboration with Ministry of Defence utilizing Military Dairy Farms herds (Anonymous, 2011). The military dairy farms are the largest source of crossbred animals in India and Asia.
Influence of non-genetic factors on various economic traits is required to be evaluated to adjust the data for significant effect of these factors on economic traits. The accurate estimates of genetic and phenotypic parameters viz. heritability, repeatability, genetic and phenotypic correlations amongst different traits are of utmost importance for any breed improvement programme. Identification of the best sires with maximum accuracy is of immense importance for any breed improvement programme, as sires are used extensively in various herds under progeny testing programme. The aim of present study was to evaluate the effects of non-genetic factors and to estimate genetic parameters of production and reproduction traits in Frieswal cattle.
Materials and Methods
Data on a total of 1249 lactations of Frieswal cows maintained at Military Farm, Guwahati, Dimapur and Bengdubi during 2000 to 2012 year of birth were utilized to study the influence of farm, parity, type of calving, period of birth and season of birth on traits viz. lactation length (LL), 305-day milk yield (305-DY), calving interval (CI) and age at first calving (AFC) (considered as covariable). Parity was considered from first to seventh parity; type of calving was divided as normal, retention of placenta (ROP), premature birth and dystokia; period of birth was classified into four periods as 2000-2003, 2004-2006, 2007-2009 and 2010-2012. Seasons were considered to be one of the main environmental factors that affect the performance of cows, as there is a wide variation in meteorological conditions during different seasons of the year. Season of birth was divided into four season viz. summer (March-May), rainy (June-September), autumn (October-November) and winter (December-February). The cows at all farms are bred through artificial insemination with the frozen semen from the Bull Rearing Unit, Frieswal Project, Military Farm, Meerut. The records on various reproduction and production traits of Frieswal cattle were analysed by least-squares (LS) analysis (Harvey, 1990) of fitting constants for the estimation of genetic parameters as well as to examine the simultaneous effects of different genetic and non-genetic factors affecting any trait. The least-squares (LS) model as
The model for Age at First Calving is
= observation in lth cow borned in jth period, ith season with kth type of calving
= overall mean
= effect of ith season of birth (summer, rainy, autumn and winter)
effect of jth period of birth (1 to 4)
= effect of kth type of calving (normal, ROP, premature birth and dystokia)
= random error, assumed to be normally and independently distributed with mean zero and constant variance i.e. NID (0, ).
The model for other traits is
= observation in oth individual of ith sire, borned in jth farm during mth period, lth season in kth parity with nth type of calving
= overall mean
= effect of ith sire as random effect
= effect of jth Farm as fixed effect (1 to 3)
effect of mth period of birth (1 to 4)
= effect of lth season as fixed effect (summer, rainy, autumn and winter)
= effect of nth type of calving (normal, ROP, premature birth and dystokia)
= effect of kth parity (1 to 7)
= random error, assumed to be normally and independently distributed with mean zero and constant variance i.e. NID (0, ).
Results and Discussion
The overall least-squares means of AFC (Table 1), LL, 305-DY and CI (Table 2) were observed to be 31.45 ± 0.89 months, 303.31 ± 7.02 days, 2997.01 ± 123.24 kg and 431.19 ± 16.53 days respectively. AFC in comparable range (31.90 ± 0.14 months) was reported by Raheja (1997) for Friesian × Sahiwal cattle. Earlier lower AFC has been reported in Frieswal cattle (Singh et al., 2014; Sumana, 2015). However, higher than the present estimates have also been reported in Jersey X Sahiwal and other crossbred cattle (Mishra and Prasad, 1998; Singh, 2007). Demeke et al. (2004) and Singh et al. (2013) reported an overall mean lactation length of 299 to 304 ± 9 days in crossbred cattle, which can be considered comparable with the present study. Conversely, a longer LL has been reported in Frieswal and Karan-Fries cattle (Singh et al., 2014; Japheth et al., 2015; Sumana, 2015). Lakshmi et al. (2009) estimated a mean 305-day milk yield of 2893.60 ± 0.82 kg in Holstein X Sahiwal cattle. Earlier, lower 305-DY has been observed in Deoni × Holstein Friesian crossbreds (Wondifraw et al., 2013). Higher 305-DY has also been observed earlier in HF crossbred and Karan-Fries cattle (Mathur, 2014; Japheth et al., 2015). Comparable CI (423.05 ± 12.24 to 439.03 ± 5.39 days) has been reported earlier in Frieswal and Karan-Fries cattle (Mathur, 2014; Singh et al., 2014; Japheth et al., 2015; Kumar et al., 2015; Sumana, 2015).
Table 1: Least-squares means (LSM) with standard error (S. E.) for AFC in Frieswal cattle
|Effect||Overall mean(µ)||N||LSM ± S.E.|
|377||31.45 ± 0.89|
|Farm||HD1(Guwahati)||144||31.78 ± 0.94|
|HD2 (Dimapur)||85||31.70 ± 0.98|
|HD3(Bengdubi)||148||30.88 ± 0.93|
|Type of calving||CT1 (Normal)||337||32.73 ± 0.38|
|CT2 (ROP)||33||31.82 ± 0.80|
|CT3 (Premature Birth)||4||28.65 ± 2.21|
|CT4 (Dystokia)||3||32.61 ± 2.53|
|Period of birth||P1(2000-03)||14||31.57b ± 1.43|
|P2 (2004-06)||36||33.81c ± 1.04|
|P3 (2007-09)||149||30.98b ± 0.91|
|P4 (2010-12)||178||29.46a ± 0.90|
|Season of birth||S1 (Summer)||82||32.13 ± 0.98|
|S2 (Rainy)||136||31.29 ± 0.93|
|S3 (Autumn)||60||30.56 ± 1.04|
|S4 (Winter)||99||31.82 ± 0.96|
Table 2: Least-squares means with standard error (S.E.) for lactation length, 305-day milk yield and calving interval in Frieswal cattle
|Effect||Lactation Length||305-day Milk Yield||Calving Interval|
|n||LSM ± S.E.||n||LSM ± S.E.||n||LSM ± S.E.|
|Overall mean(µ)||1249||303.31 ± 7.02||1249||2997.01 ± 123.24||789||431.19 ± 16.53|
|Farm||HD1||542||310.33c ± 7.44||542||2950.28a ± 130.56||354||438.84 ± 17.85|
|HD2||264||303.64b ± 7.66||264||3171.48b ± 134.51||169||430.28 ± 18.11|
|HD3||443||295.97a ± 7.31||443||2869.28a ± 128.26||266||424.46 ± 17.22|
|Parity||PA1||377||302.64 ± 7.11||377||2649.66a ± 124.77||273||463.82d ± 16.00|
|PA2||300||313.15 ± 7.27||300||3112.76b ± 127.66||193||443.89cd ± 16.77|
|PA3||219||305.34 ± 7.55||219||3051.55b ± 132.55||141||417.88ab ± 17.53|
|PA4||170||302.59 ± 7.64||170||3136.51b ± 134.15||89||407.77a ± 18.47|
|PA5||97||299.72 ± 8.38||97||2989.56b ± 147.04||47||394.63a ± 20.56|
|PA6||56||302.78 ± 9.40||56||2993.67b ± 164.98||30||435.79bc ± 23.09|
|PA7||30||296.96 ± 11.05||30||3045.37b ± 194.05||16||454.57cd ± 27.75|
|Calving type||CT1||1111||295.00a ± 2.56||1111||3263.88 ± 44.97||702||394.89a ± 6.49|
|CT2||123||312.84b ± 4.86||123||3238.23 ± 85.41||78||421.18a ± 11.57|
|CT3||10||305.01ab ± 15.37||10||2691.83 ± 269.93||5||404.60a ± 40.89|
|CT4||5||300.40ab ± 21.55||5||2794.11 ± 378.35||4||504.09b ± 45.64|
|Period of birth||P1||97||339.97c ± 11.94||97||3391.16 ± 209.58||80||495.47d ± 25.64|
|P2||211||296.57b ± 8.62||211||2904.18 ± 151.34||162||442.88c ± 20.46|
|P3||617||287.84a ± 8.21||617||2901.85 ± 144.22||416||400.86b ± 19.55|
|P4||324||288.87a ± 8.99||324||2790.86 ± 157.89||131||385.57a ± 21.81|
|Season of birth||S1||281||301.61 ± 7.69||281||3029.05bc ± 135.05||177||425.80ab ± 18.22|
|S2||456||303.53 ± 7.28||456||3110.43c ± 127.90||290||435.13bc ± 17.23|
|S3||219||301.56 ± 7.82||219||2965.30ab ± 137.24||149||411.88a ± 18.46|
|S4||293||306.54 ± 7.67||293||2883.28a ± 134.65||173||451.96c ± 18.29|
Means with different superscripts within the factors differ significantly (P<0.05)
Effect of Farm
Least-squares analysis of variance revealed that effect of farm was highly significant on LL (P<0.01) (Table 4). The longest LL was observed for Guwahati MDF i.e., 310.33 ± 7.44 days followed by 303.64 ± 7.66 days for Dimapur and 295.97 ± 7.31 days for Bengdubi MDF. Sumana (2015) also observed highly significant effect of farm on LL in Frieswal cattle. Farm effect was found to be highly significant on 305-DY (P<0.01) in the present study. The highest 305-DY, 3171.48 ± 134.51 kg was obtained at Dimapur MDF, followed by 2950.28 ± 130.56 kg at Guwahati and 2869.28 ± 128.26 kg at Bengdubi MDF. Significant effect of farm on 305-DY was also reported in HF crossbred cattle (Mathur, 2014). Farm had no significant (P≥0.05) effect on AFC and CI (Table 3). However, Das et al. (2016) reported significant effect of farm on AFC in Friesian crossbred dairy cattle. While, Haile et al. (2009) observed significant effect of farm on CI in Holstein crossbred.
Table 3: Least-squares analysis of variance for AFC in Frieswal cattle
|Source of Variation||d. f.||AFC|
|Type of calving||3||27.73||0.2103|
|Period of birth||3||192.12**||0.00|
|Season of birth||3||32.44||0.1515|
** = Significant (P < 0.01)
Table 4: Least-squares analysis of variance for lactation length, 305-day milk yield and calving interval in Frieswal cattle
|Source of Variation||d. f.||Lactation Length||305-day Milk Yield||Calving Interval|
|Type of calving||3||10441.16**||0.0022||1266681.80||0.1174||27113.30**||0.01|
|Period of birth||3||11734.67**||0.001||1262993.06||0.1182||38771.48**||0.0012|
|Season of birth||3||1158.32||0.6521||1752266.53*||0.0435||27779.47**||0.0089|
|Regression of AFC||1||6027.04||0.0908||2330127.72||0.0582||29.52||0.9486|
*= Significant (P < 0.05) and **= Significant (P < 0.01)
Effect of Parity
Effect of parity was highly significant (P<0.01) on 305-DY in the present investigation. Fourth parity had the highest 305-DY of 3136.51 ± 134.15 kg while first parity had the lowest 305-DY of 2649.66 ± 124.77 kg. Wondifraw et al. (2013) and Narwaria et al. (2015) also observed highly significant effect of parity on 305-DY. Parity also had highly significant effect (P<0.01) on CI in the present study. First parity had the longest CI of 463.82 ± 16.00 days, while fifth parity had the shortest CI of 394.63 ± 20.56 days. Kumar et al. (2015), Japheth et al. (2015) and Narwaria et al. (2015) also reported significant effect of parity on CI in Frieswal, Karan-Fries and Sahiwal cattle, respectively. A non-significant effect of parity on LL was observed in the present study. Singh et al. (2014) also reported a non-significant effect of parity on LL in HF x Sahiwal cattle.
Effect of Type of Calving
The distribution of records under different categories of type of calving was highly skewed as almost 90% records belonged to the normal birth while abnormal birth constituted only 10%. The overall effect of type of calving on LL was observed to be highly significant (P<0.01) but there were significant difference in LL only among normal calving and ROP type of calving. Normal calving had the lowest LL of 295.00 ± 2.56 days, while all abnormal calving (dystokia, premature birth and retention of placenta) had significantly higher LL ranging from 300.40 ± 21.55 days (dystokia) to 312.84 ± 4.86 days (retention of placenta). Actually, most of authors reported that abnormal calving had shorter LL but in present study it was found that controversial effect of abnormal calving, which strengthen the LL may be due to long term and repeated hormonal therapy after abnormal calving especially in ROP, Premature birth. Effect of type of calving on CI was found to be highly significant (P<0.01) in Frieswal cattle in the present study. Normal calving had the shortest CI of 394.89 ± 6.49 days, whereas, all other abnormal calvings had significantly longer CI ranging from 404.60 ± 40.89 to 504.09 ± 45.64 days. On AFC and 305-DY, the effect of type of calving was observed to be non-significant (P≥0.05) in the present study. Studies on the effects of type of calving is apparently lacking in the literature.
Effect of Period of Birth
There were unequal numbers of records under different period of birth. Cows born during 2000 to 2003 and 2004 to 2006 (P1 and P2) had lower number of records in comparison to cows born during 2007 to 2009 and 2010 to 2012 (P3 and P4) due to unavailability of records of that period. Period had highly significant effect (P<0.01) on AFC in present study, may be due to during different period of time different managemental practices were adopted viz. feeding practices to heifers, early insemination etc. The highest AFC of 33.81 ± 1.04 months was observed for cows born during 2004 to 2006, followed by 31.57 ± 1.43 months for cows born during 2000 to 2003, 30.98 ± 0.91 months for cows born during 2007 to 2009 and 29.46 ± 0.90 months for cows born during 2010 to 2012. Effect of period of birth was also found to be significant on AFC by Japheth et al. (2015) in Karan-Fries cattle. Period of birth had also significant effect on LL (P<0.01) in the present study, may be due to during different period of time different managemental practices were adopted viz. milking up to late lactation (milking in late pregnancy) Vs. early drying off, which affects the lactation length in cows. Longest LL was observed in the cows born during 2000 to 2003 birth period (339.97 ± 11.94 days), whereas shortest LL was seen in cows born during 2007 to 2009 (287.84 ± 8.21 days). Narwaria et al. (2015) reported significant effect of period of birth on LL in crossbred cattle. Effect of period of birth on CI was highly significant (P<0.01) in the present study. The shortest CI (385.57 ± 21.81 days) was shown by cows born during 2010-2012, followed by 2007-2009 (400.86 ± 19.55), 2004-2006 (442.88 ± 20.46) and 2000-2012 birth period (495.47 ± 25.64 days). Kumar et al. (2015) also reported significant effect of period of birth on CI in Frieswal cattle. Effect of period of birth was found to be non-significant on 305-DY in the present study (P≥0.01). Fadellmoula (2007) also reported non-significant effect of period of birth on 305-DY in crossbred cattle.
Effect of Season of Birth
Cows born during monsoon or rainy season (June to September) had highest number of records in comparison to other seasons i.e., summer, autumn and winter. Effect of season of birth was found to be significant on 305-DY (P<0.05) in the present study. Cows born during monsoon season had the highest 305-DY (3110.43 ± 127.90 kg), whereas lowest 305-DY was observed for cows born during winter season (2883.28 ± 134.65 kg). Narwaria et al. (2015) also reported highly significant effect of season of birth on 305-DY in different crossbred cattle. Highly significant effect (P<0.01) of season of birth was found on CI; Winter born cows had the longest CI of 451.96 ± 18.29 days; while autumn born cows had the shortest CI of 411.88 ± 18.46 days. Singh et al. (2014), Kumar et al. (2015) and Narwaria et al. (2015) also observed significant effect of season of birth on CI in HF crossbred cattle. Season of birth had no significant effect on AFC and LL (P≥0.05) in the present study. Non-significant effect of season of birth on AFC was also reported by Singh et al. (2014) in Frieswal cattle. Wondifraw et al. (2013) and Singh et al. (2014) also reported non-significant effect of season of birth on LL in the crossbred cattle.
Estimates of Genetic Parameters
Heritability estimate of various traits are presented in Table 5.
Table 5: Estimates of heritability (along diagonal), genetic (rg) (above diagonal) and phenotypic (rp) (below diagonal) correlations among lactation length, 305-day milk yield and calving interval of Frieswal cattle
|Traits||Lactation Length||305-day milk yield||Calving Interval|
|Lactation length||0.17 ± 0.10||0.663 ± 0.23||0.783 ± 0.30|
|305-day milk yield||0.44||0.51 ± 0.14||0.452 ± 0.38|
|Calving interval||0.64||0.21||0.11 ± 0.09|
Heritability estimate for LL was 0.17 ± 0.10 in the present investigation. Komatwar et al. (2009) estimated heritability of LL as 0.15 ± 0.001 in Friesian X Sahiwal cattle. A high heritability estimation of 0.51 ± 0.14 was observed for 305-DY in present study. Normally, heritability of milk yield falls in the range of 0.20 to 0.40. The over estimation of heritability could be due to the variation in the genetic potential of sires and their unequal distribution among the farms. Lakshmi et al. (2010) observed a medium estimate of 0.20 ± 0.08 for heritability of 305-DY of in Frieswal cattle. Mudgal et al. (1990) also reported high heritability estimate of 305-DY (0.48 ± 0.05) in Friesian X Red Sindhi cattle. Low estimate of heritability of 0.11 ± 0.09 was found for CI in the present study. Vinothraj et al. (2016) also observed a medium heritability of 0.22 ± 0.10 for CI in Jersey X Red Sindhi herd. In contrast, Mathur (2014) estimated low heritability of 0.016 ± 0.006 for CI in Frieswal cattle. CI is a reproduction trait having low heritability. Calving interval is influenced more by environmental factors and sufficient improvement in the trait could be brought about by management interventions.
Phenotypic and Genetic Correlations
In the present study, a positive genetic and phenotypic correlations were observed between LL and 305-DY (??= 0.663 ± 0.23, ??= 0.44) and between LL and CI (??= 0.783 ± 0.30, ??= 0.64). A positive genetic and phenotypic correlations were obtained between 305-DY and CI (??= 0.452 ± 0.38, ??= 0.21). Positive correlations between LL and 305 or less days milk yield were also reported in crossbred cattle by Narwaria et al. (2015). Eid et al. (2012) reported that total lactation milk yield had positive phenotypic correlations with daily milk yield and LL in Friesian cattle. Sumuna (2015) estimated positive genetic and phenotypic correlations of CI with LL (??= 0.87 ± 0.14, ??= 0.66), SLPY (??= 0.164 ± 0.24, ??= 0.13) in Frieswal cattle. Positive genetic correlation between the traits implies that selection for improvement in one trait would automatically improve the other traits as a correlated response to selection. However, LL and CI should be optimum and need not to be raised to improve standard lactation yield.
Study on Frieswal cattle maintained at Military Farm, Guwahati, Dimapur and Bengdubi revealed that AFC was affected only by period of birth but not by farm, type of calving and season of calving. LL was affected by farm, type of calving and period of birth. 305-DY was affected by farm, parity and season of birth. CI was affected by parity, type of calving, period of birth and season of birth. Heritability estimates for LL and CI were low, while it was high for 305-DY. The phenotypic and genotypic correlation between LL, 305-DY and CI were observed high and positive.
We are thankful to Director of Military Farm, Head Quarter, Eastern Command for providing and tracking of all the data on Frieswal cattle.