61 Present address: 2 Head and Director-CAFT (vermaak62 @gmail.com), 1 PhD Scholar (yadav08ankita@gmail.com), 3,4 Principal Scientist (putan60@gmail.com, drasitdas @rediffmail.com), Animal Nutrition Division. Normal growth, reproduction and productivity in domestic animals depend upon the nutritional status of the animal. Minerals play crucial role in maintaining the functional and structural integrity of the tissues (McDowell 1995, Underwood and Suttle 1999) and in exploiting the actual genetic potential of the animals. Mineral disorders such as deficiencies and imbalances have significant consequences on animal health and production (McDowell 1995). Mineral deficiency is quite common in livestock and the severity of the deficiency depends upon the type of feed, physiological status of the animals and the agro-climatic conditions of the region.The deficiency of macro and micro minerals may lead to various reproductive failures, such as infertility, delayed puberty, delayed ovulation, lower conception rate and poor conception (Hidiroglou 1979, Boland 2003). To overcome these detrimental effects, mineral supplementations to the livestock are essential (Underwood 1981). Several trace elements act as cofactors and have role in hormone synthesis that may influence biochemical functions associated with reproduction. Minerals such as Cu, Co, Zn, Fe and Mn affect reproduction in ruminants. Copper and zinc are activators of certain enzyme systems that assist in maintaining the activity of hormones in blood (Georgievskii 1982) and are known particularly to have a significant correlation with reproductive hormones such as progesterone and estradiol (Prasad et al. 1989). Copper deficiency leads to reduced insulin concentration, which adversely affects oestrus cyclicity, corpus luteum function and progesterone hormone production (Robinson et al. 2006). An appropriate supplementation of minerals acts as a stimulus for ovarian rebound and initiation of ovarian activity (Markandaya et al . 2002). Molasses based supplements were originally developed as a scarcity feed (Ranjhan et al. 1973, Verma et al. 1995). Later, it was observed that supplementation of urea molasses mineral block can improve the productivity of livestock fed on poor quality of roughages (Mohini and Gupta 1993). Thus, it would be logical to assume that partial replacement of concentrates with molasses based multi-nutrient liquid supplement (MMLS) would be beneficial. There are several reports which indicate that deficiency/ imbalances of trace elements are major determinants of reproductive performance of heifers (Borghese 2005). We hypothesized that supplementation of trace elements through molasses based multi-nutrient liquid supplement (MMLS) would positively influence the serum mineral and hormonal profile of buffalo heifers. Specific objective of this experiment was to study the effect of super dosing of trace minerals through Effect of multi-nutrient liquid supplement on serum minerals and hormone profile in buffalo heifers ANKITA 1 , A K VERMA 2 , PUTAN SINGH 3 and ASIT DAS 4 ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh 243 122 India Received: 14 June 2017; Accepted:13 December 2017 ABSTRACT Eighteen Murrah buffalo heifers (average BW of 290±2.5 kg) were randomly distributed into three groups of six each in an experiment based on randomized block design to investigate the effect of partial replacement of concentrate mixture with molasses based multi-nutrient liquid supplements (MMLS) on serum mineral and reproductive hormonal profile. During 240 d of experimental period, all animals were supplied with green forages (2 kg DM/d) and wheat straw ad libitum. Animals in group T 1 (control) were fed a concentrate mixture (maize 40, wheat bran 40, soyabean meal 17, mineral mixture 2, and salt 1%) to meet their nutrient requirements. However, 20% of the concentrates were replaced with MMLS and MMLS plus in groups T 2 and T 3 , respectively. Blood was collected on d 0, 120 and 240 days of experiment to evaluate serum mineral and reproductive hormonal (progesterone and estradiol) profile. Serum concentrations of Ca, P, Fe and Mn were similar among the groups. Serum concentration of Cu and Zn was higher in groups T 2 and T 3 . Concentrations of progesterone and estradiol were similar among the groups, but showed an increasing trend on day 240. It was concluded that partial replacement of concentrate mixture with MMLS and MMLS plus improved Cu and Zn status without any adverse impact on other minerals and reproductive hormone profile. Key words: Buffalo heifer, Estradiol, Hormones, Minerals, Multi-nutrient liquid supplement, Progesterone Indian Journal of Animal Sciences 88 (4): 453–457, April 2018/Article https://doi.org/10.56093/ijans.v88i4.78813