The present study was carried out on at ERS-NDRI, institute’s adopted village (Muratipur) of Nadia district, West Bengal which has hot humid climate. The latitude and longitude position being 22°56'30"N and 88°32'04"E, respectively.

Methodology followed for field experimentation of Alpha-tocopherol was as follows:

In Muratipur village of Nadia district, 191 respondents were surveyed who were keeping dairy cows for their livelihood. Most of them were marginal or small farmers with two or three dairy animals. Respondents were surveyed for udder health management practices which are represented in table (1) and management practices as shown in table (2) followed by dairy farmers.

Out of 191 surveyed respondents, dairy cows (n=19) of different farmers which were in last trimester of gestation were selected for field experimentation based on their parity, level of production, BCS, age and body weight. Keeping in mind, the poor economic background of dairy farmers, Alpha-tocopherol of feed grade was procured (₹ 1.4/ gram) for supplementing @ 1 g/d/cow to those selected cows from 30 days pre to 60 days post partum period in two different treatment groups than control group. Surveyed milk samples reflected poor udder health. pH was higher (>6.8) and electrical conductivity (EC) was (>5.57mS/cm) in subclinical mastitic milk samples. Batavani et al. (2007) and Boas et al. (2016) stated that these conditions to be the indicative tests of subclinical mastitis case. Furthermore, Norberg et al. (2004) suggested EC to be effective parameter for predicting udder health status of dairy cows. In addition to this, animals were in poor body condition (<3 BCS) on 1 to 6 scale (Singh and Kumari, 2019)

Competent and trained research assistants used to supply the pre packaged 1 g Alpha-tocopherol to the selected dairy cows during the targeted days of dry as well as lactation period to feed them. Following which the udder health parameters were measured in the NDRI- ERS, Livestock Production Management section (LPM section) laboratory under aseptic conditions and body condition scores were measured on fortnight basis. However, these fortnight evaluations were utilized for parameters on monthly basis.

This experimentation was conducted during the year 2018 to 2019 on 19 Jersey crossbred cows having similar initial body condition score (BCS), body weight and parity and observations were taken during dry period (30 days pre calving), during calving and post-partum up to 5 months of lactation period. Based on BCS and body weight during drying off time (after completion of full lactation) animals were randomly divided into 3 different comparable group i.e. group-1 as T1 and group-2 as T2 and control group. T1 comprised 7 animals supplemented with Alphatocopherol @ 1 g/ cow/ day for 30 days pre- partum and 30 days post- partum period; In T2, 6 cows were supplemented with Alpha-tocopherol @ 1 g/ cow/ day for 30 days pre-partum and 60 days post- partum period, and in control group traditional feeding management was done without Alphatocopherol supplementation. Chatterjee et al. (2004) suggested a dose of 1000 IU/cow/day to be used in dairy animal feeding 30 days before and 30 days after calving. Farmers of this region are mostly small and marginal (Garai et al, 2017), keeping in view of this situation we procured Alpha-tocopherol @ ₹ 1.4/g to be fed to the dairy cows of farmers to which they can afford. Vitamin E dry powder (a-Tocopheryl acetate 50%, containing 500mg Vitamin E acetate per gram) manufactured by MERCK Limited, Usgaon, Ponda, Goa- 403407 was used in this experiment. Alpha-tocopherol was added to concentrate mixture pre-partum and during milking time to make sure that the animals had received complete amount of Alphatocopherol.

All groups of animals were provided (traditional feeding management practice) with ad libitum green and dry fodders during dry period. During postpartum period provided with concentrate mixture (@3 kg/cow/day) as a part of management practice along with ad libitum green and dry fodders. The DCP and TDN contents of concentrate mixture were 14 % and 68 % respectively. Animals were stall fed with provision of separate manger and watering facility (Singh et al, 2020e). However, all animals were observed as apparently healthy before and during the conduct of field trial. Housing and other management practices were similar to all groups.

Body condition score (BCS) of animals were assigned using visual plus palpation technique. This method grades the status of cow’s body condition on a six-point scale (16). The score 1 reflects very thin and 6 reflects very fat condition of the animal. For assessing the body condition of animals, anatomical regions (critical points) were taken into account meticulously as standardized (ultrasonography method) by Paul et al. (2019) for Jersey crossbred dairy cows of tropical lower Gangetic region.

From every animal, about 70 ml of milk samples were collected from whole milk bucket after complete milking of individual animals in sterilized glass bottles at fortnight intervals. Udder health status (sub-clinical mastitis) was detected by EC and pH of milk samples as per the method followed by (Singh et al, 2020a).

Overall difference between the mean BCS as shown in table (3) and graphically shown in figure (1) during dry period in control, T1 and T2 groups was found nonsignificant. However, there was significantly (P<0.01) marked difference between control and treatment groups but, T1 and T2 groups differed non significantly after 5 months of lactation period. There was trend of reduction in the body condition of cows, post calving, of each group but, loss in body condition was more pronounced and sharp in control group as compared to treatment groups. Similar pattern of reduction in BCS during initial lactation period was shown by Singh et al. (2020a). This may be due to the inability of control group animals to cope with maintenance and lactation needs of alpha tocopherol. However, the mechanism behind this is a researchable issue. Increased incidence of health problems arises in dairy cattle as a consequence of accelerated BCS drop during the transition period (Kim and Suh, 2003). More body loss and body condition loss leading to negative energy balance post partum are known to reveal adverse effects in high milk yielders (Cutullic, 2010; Friggens et al., 2007). Vitamin E deficiencies are frequently observed during the periparturient period (Smith et al, 1997; Singh et al., 2020f) which may be one of the causes for sub clinical mastitis. Decreased body condition loss during lactation period from optimum range reflects negative energy balance of dairy animals as shown by lesser production of milk and also the milk quality is reduced. Supplementation of Vitamin E at > 1000 IU/ day during the dry period of dairy cow was found to reduce the cases of mastitis (Weiss et al., 1997).

Means with different superscripts differ significantly (P < 0.01) from each other row wise.