The effect of injectable trace mineral (selenium, copper, zinc, and manganese) on health and production of lactating Holstein cows

The objective of this study was to evaluate the effect of subcutaneous supplementation of 300 mg of zinc, 50 mg of manganese, 25 mg of selenium, and 75 mg of copper (Multimin North America, Inc., Fort Collins, Co) at 230 days of gestation, 260 days of gestation, and 35 days postpartum, on health, milk production and reproduction of lactating Holstein cows. A randomized field trial was conducted on 3 large commercial dairy farms located near Ithaca, New York and 1416 cows were enrolled. Subcutaneous TMS significantly decreased linear Somatic Cell Count (SCC) scores as compared to control cows. The interaction of parity (1, 2, > 2) and treatment group (Control vs. TMS) was significant; the effect of treatment on linear score increased as parity group increased and the greatest reduction in linear scores was observed in parity > 2 cows treated with TMS. Control cows had 1.31 times higher odds of subclinical mastitis than TMS cows. The main effect of treatment on clinical mastitis was not significant, however; the interaction of treatment and parity was significant with a reduction of 39% in the cumulative incidence of clinical mastitis observed for multiparous cows treated with TMS. Additionally, control cows had 1.69 and 1.30 increased odds of having stillbirth parturitions and endometritis, respectively. INTRODUCTION Trace minerals play an important role in dairy cows’ immune function (Spears, 2000), fertility (Wilde, 2006) and growth (Wikse et al., 1992). Zn forms a structural component of over 300 enzymes (Spears, 2000; Andrieu, 2008) and Zn deficiency impairs immunity and reduces disease resistance (Shankar and Prasad, 1998). Manganese (Mn) is an important part of enzymes that are involved in immune system, reproduction, lipid and carbohydrate metabolism, bone growth, nervous function, and anti-oxidant defense (Andrieu, 2008). A recent study has shown that lactating cows need a Mn intake of 1.6 times higher and dry cows need a Mn intake of 2.7 times higher than the intake suggested by the NRC, to meet estimated fecal losses of Mn (Weiss and Socha, 2005). Copper (Cu) is also a component of several enzymes important for antioxidant resistance, cellular respiration, bone formation, immune function, carbohydrate and lipid metabolism and cardiac function (Andrieu, 2008) and it seems to play an important role on udder health (Scaletti et al., 2003). Selenium (Se) is also an essential component of enzymes of the antioxidant system (Spears and Weiss, 2008). Se deficiency impairs the anti-oxidant and immune system, and consequently disease resistance (Grasso et al., 1990; Hogan et al., 1990; Spears, 2000). Additionally, serum concentration of Se seems to be associated with udder health (Erskine, 1987; Weiss, 1990); and its synergistic action with vitamin E has for long been established (Smith, et al., 1984). The transition period (usually defined as the period from three weeks before to three weeks after calving) is extremely challenging for the dairy cow that goes through physiological stress, preparing for and recovering from parturition (Drackley, 1999) dramatically altering her metabolism to supply the mammary gland with nutrients necessary for milk synthesis (Bauman and Currie, 1980; Goff et al., 2002) and dealing with reduced dry matter intake, negative energy balance (Roche et al., 2009) and oxidative stress (Sordillo and Aitken, 2009). Nockels et al. (1993) reported that calves under stress reduced their trace mineral retention ability. Given the fact that the transition period is a stressful period for the cow, a similar reduction in trace mineral retention ability could also happen in transition cows. Moreover, either the act of parturition or the beginning of lactation have been found to be related with a decrease in plasma minerals levels, such as calcium (Ca) and zinc (Zn) (Goff et al., 2002), suggesting that other mineral levels could also be affected during the same period. Hence, it is possible that transition cows may have increased trace minerals needs that a diet formulated to meet the current NRC recommendations for Holstein cows may not satisfy, especially since dietary mineral supplements may not be absorbed properly due to interactions with other nutrients at the ruminal level (Suttle, 1986, Goonerate et al., 1989) or due to modifications in the rumen, while antagonists located in drinking water may also have a negative effect on the efficiency of trace minerals absorption from the digestive tract (Spears, 2003). Dietary sulfur seems to reduce the bioavailability of Se and Cu; moreover, high dietary iron reduces Cu bioavailability (Spears, 2003). Additionally, high dietary Ca and phosphorus may reduce Mn absorption in ruminants (Spears, 2003). An injectable trace mineral solution could potentially provide an alternative way of extra trace mineral supplementation during the transition period. Some positive effects of such supplementation on cows’ reproductive traits have already been shown (Harrison et al. 1984, Sales et al. 2011). However, studies regarding the effect of injectable trace minerals supplementation during the transition period, on health and milk production traits remain, to the best of our knowledge, scarce. Thus, the objective of this study was to evaluate the effect of subcutaneous supplementation of a trace mineral supplement containing Zn, Mn, Se, and Cu (Multimin North Figure 1: Least square means of linear scores by month of lactation for primiparous cows. The dark gray line represents the controls and the light gray lines represent the trace mineral supplemented cows. The first, second and third figures represent parities 1, 2, and 3 respectively 1 1.5 2 1 2 3 4 5 Le as t s qu ar e m ea ns o f