Impact of Propolis on Milk Yield, Composition and Somatic Cell Count of Cow Breeds at Dairy Farm of Banaras Hindu University, Varanasi, India

Propolis has several pharmacological properties and safe alternatives to antibiotics. This study aims to address the impact of methanol extract of Indian propolis (MEIP) on milk yields and composition of six breeds and cross-breeds of cows. Bioactive compounds extracted from the raw propolis. 24 lactating cows were selected from six different types of breeds viz. Sahiwal, Haryana, Holstein Frisian × Sahiwal, Holstein Frisian Χ Haryana, Jersey × Sahiwal and Jersey × Haryana. They were randomly divided into four treatments with 6 replicates each and fed according to NRC (2001) with 0, 10, 20, 30ml MEIP/cow/day. The result showed that MEIP influenced the milk yield and composition of cows. The milk composition (%) was better (P<0.05) and the somatic cell count was lower in MEIP20 and MEIP30 compared to control and MEIP10. The response was greater in Sahiwal cows. The lowest (P<0.05) somatic cell count was observed in the Holstein Friesian × Sahiwal crossbred cows. The study concluded that the supplementation with MEIP, improved milk yield, milk composition and somatic cells count in other breeds except Holstein Friesian.

Livestock provided 16% to the input of small rural families, and contributes to two-thirds of their livelihood. About 8.8 % of the population in India gained employment opportunity and increased income by selling milk (Dash 2017). In spite of India having the largest dairy flock in the world, it still faces a production shortfall because of demand from the growing population as well as indigenous cows having low productivity. Dairy production in the country is still depending on traditional methods by subsistence farming where the milk is produced by small livestock farmers holding two or three lactating cows or buffaloes or both. Chronic deficiency in the feed resource; green fodder, dry fodder and concentrate supplements is one of the continuing challenge for decades. Many strategies are followed for enhancing milk production in the past. Antibiotic supplements were tried successfully but, discontinued on the context of food safety to consumers due to presence of their residues in milk. Plant extracts such as saponins, tannins, and polyphenolics are considered to be safe natural alternatives those are having antimicrobial and enhance productivity properties (Wallace 2004). It improves rumen-microbial fermentation, based on their source and concentration in diets (Narvaez et al. 2013). One of the natural alternatives to antibiotics is Propolis (bee glue) which is produced by bees as they collect the resinous material from the buds of plants and mix it with salivary, enzymatic secretions and beeswax (Castaldo and Capasso 2002). Propolis has antioxidant and antimicrobial properties (Marcucci et al. 2001;Shimizu et al. 2004). The present study aims to examine the effectiveness of the methanol extract of Indian propolis on cow milk yield and composition, and clarifies the role of breeding at the dairy farm of Banaras Hindu University, Varanasi, India.

Geographical location
The raw propolis was collected manually from Bulandshahr district, Uttar Pradesh situated 28.4° south and 28.0° north latitudes and between 77.0° and 78.0° east longitudes. Propolis was collected during the period December 2016 to March 2017. The experiment was conducted at the dairy farm, Department of Animal Husbandry and Dairying, Institute of Agricultural Sciences, Banaras Hindu University, in Varanasi (23045' N to 28030' N and 80045' E to 84030' E, mean sea level 128.93 m, mean annual rainfall 110 cm).

Extraction of Bioactive compounds from Propolis
The crude propolis was kept dry at -30˚C for 24 h followed by grinding into a fine powder. Bioactive compounds from the fine powder was soaked in 97% methanol in a tightly closed container at room temperature for 14 d, and shaken twice per day. At the end, methanol was filtered through Whatman filter paper no. 41 (Whatman no. 41). The methanol extract was kept at room temperature (20 ˚C) until use.

Animals and experimental details
The study was carried for 12 months from March 2017. The breed and cross-bred cows of six different breed, i.e., Sahiwal (S), Haryana (H), Holstein Frisian × Sahiwal (HFS), Holstein Frisian × Haryana (HFH), Jersey × Sahiwal (JS) and Jersey × Haryana (JH) were randomly divided into 4 groups of 6 in each, based on milk production, lactation stage and body weight.
The cows were housed in well ventilated individual pen having facility for feeding, and cleaned twice a day. Cows were fed according to NRC (2001) for maintenance and milk production.

Effect of propolis on milk yield, composition and somatic cell count
Significant differences (P<0.05) were observed in milk yield, composition and somatic cell count but no significant effect (P>0.05) was found in total solids% and pH in treatment groups MEIP 10 ,

Effect of propolis and breed on milk composition and somatic cell count
The effect of propolis supplementation had significant (P<0.05) effect on milk composition and somatic cell count. However, the milk composition was higher (P<0.05) and the somatic cell count was lower (P<0.05) in MEIP 20 and MEIP 30 than control and MEIP 10 , Affect on milk composition was significant (P<0.