Production and Reproduction Performance of Sahiwal and HF × Sahiwal Cows

Crossbreeding of non-descript cattle with exotic cattle breeds is being practiced as it is the fastest way of increasing milk production of the indigenous low producing cattle. With the several initiatives undertaken by the Government of India for augmenting milk production by crossbreeding, tremendous progress has been achieved so far. As per the Economic survey 2019-20, India stands at the number one position in the World in milk production and the per capita availability of milk increased from 130 g/day in the year 1950-51 to 394 g/day in the year 2018-19 (NDDB, 2020). Holstein Friesian, the world-renowned breed of cattle known for its high milk production is extensively used for crossbreeding in India for more than 100 years. Several crossbred populations with the Friesian inheritance ranging from 35.93% to 93.75% are being maintained at different farms in the country. The increased performance of the crossbreds is due to the superiority of the exotic cattle and hybrid vigour. The present investigation was carried out to study the production and reproduction performance of the Sahiwal and crossbreds (HF × Sahiwal) cows.

Data on 50 purebred Sahiwal cows from the Livestock Farm Complex, College of Veterinary Science, Rajendranagar, Hyderabad and 50 crossbred cows (Holstein Friesian × Sahiwal crosses) maintained at the Military dairy farm, Secunderabad were utilized to study the influence of breed and parity on various production and reproduction traits. Both the farms are located in the same geographical location and so experience similar weather conditions. Both Sahiwal and crossbred herds were provided with standard housing. The animals were given balanced ration comprising of both green and dry fodder. Adequate quantities of concentrates, based on their maintenance and production requirements were given to the milch animals. Regular deworming and vaccination schedules were followed in both the herds. The Sahiwal farm was established in the year 2015 with the main objective of conservation and propagation, while the militarydairy farm, Secunderabad was one of several such breeding farms established by the Government of India indifferent agro-climatic conditions, with a primary objective to supply the milk to the defense forces. In both the farms, selective breeding for higher lactation milk yield was employed. The various production and reproduction traits studied were Total lactation milk yield (TLMY) Lactation length (LL), Peak yield (PY), Age at first service (AFS), Age at first calving (AFC), Gestation period (GP), Service period (SP), Dry period (DP) and Calving interval (Cl). 

Statistical analysis was done using SPSS software, Version 25. Two way analysis of variance was employed to study the effect of genetic group and parity on various production and reproduction traits using the following mathematical model.
 

Y_ijk = µ + G_i+ P_j +e_ijk
 

Where,
Y_ijk = record on nth cow belonging to  jth parity under ith genetic group.
µ = Overall mean.
G_i = Effect of the ith genetic group (i = 1 and 2 for Sahiwal and crossbreds, respectively).
P_j = Effect of jth parity (j = 1 to 4 in Sahiwal and 1to 6 in crossbreds).
e_ijk = random error assumed to be distributed normally and independently with mean zero and variance σ²e.

Significant differences between the means of different breeds and parities were tested by Duncan’s Multiple Range Test (DMRT). Values were considered significant at P≤0.05 and presented as means ± standard errors.

The means of various production and reproduction traits of Sahiwal and HF × Sahiwal cows are presented in Table 1.


 
Production traits
 
The present investigation revealed that the total lactation milk yield was significantly (P≤0.01) affected by breeds with the crossbred cows recording the higher total lactation milk yield (2983.45 ± 78.32 kg) and peak yield (14.92 ± 0.36 kg) as compared to Sahiwal cows. Many authors have reported that crossbred cows have higher total lactation milk yield than the indigenous cows (Dubey and Singh, 2005; Reddy et al., 2015 and Chakravarthi et al., 2017).

The mean total lactation milk yield in Sahiwal (1768.32 kg) was in agreement with the means reported by Kumar and Gandhi (2011) and Reddy et al., (2015). However, Javed et al., (2000), Joshi et al., (2001), Maurya and Saraswat (2002) and Verma et al., (2016), reported higher means, while Rehman and Khan (2012) and Chakravarthi et al., (2017) observed means lower than those obtained in the present investigation. The mean total lactation milk yield in crossbred cows (2983.45 kg) obtained in the present study was almost similar to the means reported by Lakshmi et al., (2010). However, Kumar et al., (2017), Kundu et al., (2018) and Annual Report CIRC, (2019) observed means higher than those obtained in the present investigation. Varying lactation lengths, in addition to the geographical location and the different managemental practices, followed in the respective farms might be the reasons for the differences in the total lactation milk yields.

The mean peak yield in Sahiwal cows in the present investigation was 10.17 kg which was higher than the mean peak yield reported by Sharma et al., (2010), Reddy et al., (2015) and Chakravarthi et al., (2017). The mean (14.92 kg) peak yield in crossbred cows obtained in the present study was in accordance with that reported by Lakshmi et al., (2010), Kumar et al., (2017) and Annual Report CIRC, (2019) in Holstein Friesian × Sahiwal cows.

Though the effect of the breed was found to be non-significant on the lactation, the mean lactation length in crossbred cows was found to be higher (324.71 days) than in Sahiwal cows (304.41 days).  The results obtained were within the wide range (235 to 348.25 days) as observed from published literature on Sahiwal and HF crossbred cows (Rehman and Khan, 2012 and Reddy et al., 2015). The crossbreds, in the present investigation, recorded higher peak yield (4.75 kg more than Sahiwal), lactation length (20.3 days longer than Sahiwal) and consequently, the elevated TLMY (1215.13 kg higher than Sahiwal).

The analysis revealed significant (P<0.01) influence of parity on total lactation milk yield with the mean increasing from first to third parity, followed by an irregular trend in the later parities. The highest and lowest total lactation milk yields were recorded for the cows in parities three (2681.42kg) and first (2215.50kg), respectively. A perusal of the published literature also revealed a significant effect of parity on total lactation milk yield in Sahiwal cows (Kumar and Gandhi, 2011, Rehman and Khan, 2012 and Singh et al., 2016) and in HF crosses (Lakshmi et al., 2010, Kakati et al., 2017 and Kundu et al., 2018). The consistent increase in total lactation milk yield up to the third lactation might be due to the development occurring in the body, particularly in the mammary glands due to pregnancy and lactation. The irregular trend observed beyond the fourth lactation in the present study could be attributed to the small sample size and also due to the variations in climatic and environmental factors to which the cows were exposed during different parities.
 
Reproduction traits
 
The overall mean gestation period, service period, dry period and calving interval obtained in the present study were 276.52 ± 1.72, 181.84 ± 11.77, 147.24 ± 8.11  and 421.92 ± 10.22 days respectively. The dry period was significantly (P<0.01) affected by breed, while parity had a non-significant effect on the gestation period, service period, dry period and calving interval.

The mean gestation period in Sahiwal was 277.71 days which was lower than the mean obtained by Reddy et al., (2015), while the mean gestation period in crossbred cows was 275.34 days which was similar to the mean reported by Lakshmi (2007) in HF × Sahiwal cows of the military dairy farm, Secunderabad. Parity was found to be non-significant on the gestation period. Lakshmi (2007) also found a non-significant effect of parity on the gestation period.

The mean service period was 182.60 and 181.09 days in Sahiwal and crossbred cows respectively. Published literature revealed that the service period ranged from 123.73 to 205 days in Sahiwal cows (Naskar et al., 2005 and Reddy et al., 2015) and from 148.24 to 183.28 days in HF × Sahiwal cows (Lakshmi, 2007 and Kumar et al., 2015). Parity was found to be non-significant on the service period in the present study probably because of the small sample size. However, Lakshmi, (2007) reported a significant effect of parity on the service period with the lowest and highest means obtained for cows in parities 12 and 1, respectively which was due to differences in the environmental and managemental practices over different parities.

The mean dry period in Sahiwal cows was 167.47 days which was within the wide range (133.58 to 176.79 days) as observed from the published literature on Sahiwal cows (Naskar et al., 2005 and Reddy et al., 2015). The mean dry period of 127.01 days obtained in the present study corroborated with the findings of Lakshmi (2007) in HF × Sahiwal cows. However, lower means were obtained by Singh et al., (2014) and Kumar et al., (2015) in crossbred cows. In the present investigation, parity was found to be non-significant on the dry period but significant effect of parity was observed by Lakshmi (2007) and Singh et al., (2014) in HF × Sahiwal cows.

The mean calving interval in Sahiwal was 430.23 days which was more than the mean obtained by Naskar et al., (2005), while the mean calving interval in crossbred cows was 413.61 days which was less than the mean reported by Lakshmi (2007), Singh et al., (2014), Kumar et al., (2015), Kakati et al., (2017) and Annual report, CIRC, (2019) in HF × Sahiwal cows. Parity was found to be non-significant on the calving interval while Lakshmi (2007) and Kakati et al., (2017) reported a significant effect of parity on calving interval, which was attributed to the variations in the age of the cows and also the various climatic factors faced by the cows in different parities.

The mean age at first service and age at first calving were 641.34 ± 17.24 and 947.26 ± 19.67 days, respectively in crossbred cows, while these means could not be estimated in Sahiwal cows due to paucity of records. Lakshmi (2007) also reported similar means for AFS and Kundu et al., (2018) for AFC in HF × Sahiwal cows.

In the present investigation, the effect of breed was found to be significant on total lactation milk yield and peak yield, which are important traits of economic importance in dairy cows. The crossbreds recorded higher Total lactation milk yield (TLMY) and Peak yield (PY). It was also found that the crossbreds had lower service periods, dry periods and calving intervals than the indigenous Sahiwal cows.

The authors gratefully acknowledge the Director, Military Dairy Farm, Secunderabad and PV Narsimha Rao Telangana Veterinary University for providing the facilities to carry out the research work on Crossbred and Sahiwal cows.