Explore
Communities in English
Advertise on Engormix

Chromium Supplementation

Chromium Supplementation in Cattle Diets

Published: October 26, 2010
By: Dr. Jerry W. Spears (North Carolina State University)
Introduction

In the late 1950's Schwartz and Mertz (1959) reported that trivalent chromium (Cr) was an essential component of a factor in brewer's yeast that corrected impaired glucose metabolism in rats fed certain diets. Subsequent studies demonstrated that Cr functioned as a potentiator of insulin action (Vincent, 2001). Considerable research has been conducted with Cr in human nutrition and an adequate intake of Cr has been established for humans by the Institute of Medicine (DRI, 2001).

Chromium requirements for cattle have been estimated by the National Research Council (NRC). Traditionally, practical diets fed to domestic animals were assumed to provide sufficient Cr to meet animal requirements. However, in the past 15 years a number of studies in cattle and other species have indicated that Cr supplementation of diets can affect animal metabolism and production criteria.

Although considerable research has been conducted with Cr in cattle, only recently has Cr supplementation been allowed in cattle diets. The FDA CVM issued a regulatory discretion letter in July of 2009 which permitted the use of Cr propionate as a source of Cr in cattle diets. Chromium propionate is the only Cr source currently permitted for supplementation to cattle diets in the U.S. It can be added at levels up to 0.50 mg Cr/kg of complete diet.

This paper will discuss responses that have been observed to supplementation with various forms of Cr in dairy and beef cattle. In addition to Cr propionate (CrProp), Cr picolinate (CrPic), Cr methionine (CrMet), Cr amino acid chelate (CrAA), Cr yeast (CrY), Cr nicotinic acid complex (CrNic), and inorganic CrCl have been evaluated experimentally in cattle. It is unclear how different sources of Cr compare in regard to bioavailability.

Chromium and Insulin Action

Glucose tolerance tests have been conducted in cattle to evaluate the effects of Cr on glucose and insulin metabolism. In these studies a glucose solution has been infused intravenously (iv) and circulating concentrations of glucose and insulin measured frequently until they returned to baseline values. The addition of CrPic (Bunting et al., 1994) or CrProp (Sumner et al., 2007) to diets of growing calves has increased glucose clearance rates following glucose infusion without affecting seruminsulin concentrations. Supplementing a milk replacer diet with 0.4 mg Cr/kg of dry matter (DM), from either CrCl3 or a Cr nicotinic acid complex (CrNic) did not affect glucose clearance rate following a glucose infusion in young calves with undeveloped rumens (Kegley et al., 1997a). However, insulin concentrations were lower following glucose administration in calves supplemented with CrCl3, suggesting increased insulin sensitivity in this group.

We recently examined the effect of level of supplemental Cr from CrProp on glucose metabolism in growing heifers. Chromium was supplemented at 0, 3, 6, or 9 mg Cr/head/day. These daily levels corresponded to 0, 0.47, 0.94, and 1.42 mg Cr supplemented/kg diet DM. Serum insulin concentrations and insulin:glucose ratios were much lower in all Cr-supplemented groups the first 15 minutes following glucose infusion (Figure 1). The lower release of insulin and decreased insulin:glucose ratio in Cr-supplemented heifers indicates that their tissues were more sensitive to insulin. Insulin concentrations and insulin:glucose ratios did not differ among heifers supplemented with 0.47, 0.94, and 1.42 mg Cr/kg DM. This suggests that Cr requirements of growing heifers do not exceed 0.47 mg Cr/kg DM.

Chromium Supplementation in Cattle Diets - Image 1

Chromium Supplementation in Cattle Diets - Image 2

Figure 1. Effects of dietary chromium propionate on serum insulin concentrations and insulin:glucose ratios in heifers following a glucose tolerance test

There has been interest in the effect of Cr on insulin sensitivity in transition dairy cows because insulin resistance occurs in late gestation and continues during early lactation in both dairy (Sano et al., 1993) and beef cows (Sano et al., 1991). Subiyatno et al. (1996) found that supplementation of 0.5 mg Cr/kg diet, from CrAA, appeared to increase insulin sensitivity in primiparous dairy cows but not in multiparous cows at approximately 14 days prepartum. This was based on reduced insulin release and lower insulin:glucose ratios following iv glucose administration. Hayirli et al. (2001)supplemented multiparous cows with varying concentrations of CrMet from 21 days prepartum until 28 days postpartum, and conducted glucose tolerance tests at approximately 10 days prepartum and 28 days postpartum. Chromium supplementation did not affect glucose clearance or serum insulin concentrations prepartum. In postpartum cows, peak glucose concentrations and serum insulin concentrations were lower following iv glucose infusion in cows supplemented with 3.7 or 7.7 mg Cr/day compared with controls (Hayirli et al., 2001). Multiparous beef cows provided CrPic in a free choice mineral had lower insulin release following glucose infusion than control cows at approximately 30 days prepartum and 30 day postpartum (Stahlhut et al., 2006a). The lower serum insulin concentrations occurred without a change in glucose clearance indicating increased insulin sensitivity.

Dairy Cattle

Feed Intake and Milk Production

It is well documented that the transition period from 21 days prepartum to approximately 21 days postpartum is a critical period in regard to health and subsequent milk production of high producing dairy cows (Drackley, 1999). Most of the Cr supplementation studies with dairy cows have involved supplementation during the transition period. Supplementation of Cr prepartum has increased prepartum intake in some studies (Hayirli et al., 2001; Sadri et al., 2009) but not in others (Yang et al., 1996; Besong, 1996; Smith et al., 2005; McNamara and Valdez, 2005). Supplementation of 0,3.9, 8.3 and 16.5 mg Cr/day from CrMet resulted in a linear increase in prepartum DM intake (Hayirli et al., 2001). Sadri et al. (2009) reported that supplementation with CrMet (approximately 10 mg Cr/day) increased prepartum DM intake when barley was used as the grain source but not when corn served as the prepartum grain source.

Supplementation of 0.5 mg Cr/kg diet from CrAA increased milk yield in primiparous dairy cows in two separate experiments (Table 1; Yang et al., 1996). Chromium was supplemented during both experiments from 6 weeks prepartum to 16 weeks postpartum.
Chromium Supplementation in Cattle Diets - Image 3


Besong (1996) supplemented multiparous and primiparous cows with 0 or 0.8 mg r/kg diet, as CrPic, from 30 days prepartum to 8 weeks postpartum. Performance results were not presented by parity in this study but parity was included in the statistical model. Chromium supplementation increased average milk yield from 31.1 to 33.4 kg/day. Feed intake was higher in Cr-supplemented cows during weeks 2, 3, 4, 5, and 6 of lactation.

Multiparous cows supplemented with CrMet from 21 days prepartum through early lactation had higher DM intake and milk production during the first 28 days in milk (Table 2; Hayirli et al., 2001; Smith et al., 2005). Sadri et al. (2009) reported that grain source used in the pre and postpartum diets affected responses to supplemental CrMet. Chromium supplementation, at a level of approximately 10 mg/day, increased DM intake and milk production during the first 28 days in milk when barley was used as the grain source in the total mixed ration (TMR). Feed intake and milk production were not affected by Cr addition when corn was used in the TMR. Yang et al. (1996) observed no DM intake or milk production response to Cr supplementation with CrAA in multiparous cows. However, in these same experiments Cr supplementation improved milk yield in primiparous cows. Estimated net energy for lactation (1.59 Mcal/kg DM) was lower in the lactation diets used by Yang et al. (1996) compared to other studies (1.67 to 1.74 Mcal/kg DM) with multiparous cows fed harvested feeds. It is unclear if feed intake and milk production responses to supplemental Cr are affected by dietary energy level. However, Cr supplementation from either CrPic (Peterson, 2000) or CrMet (Bryan et al., 2004) did not affected milk production in grazing dairy cows where forage was the major source of energy.

Chromium Supplementation in Cattle Diets - Image 4

Supplementing with Cr during the transition period may increase feed intake and milk production later in lactation even if Cr supplementation is discontinued. McNamara and Valdez (2005) supplemented dairy cows with CrProp from 21 days prepartum until 35 days postpartum. After CrProp was removed from the diet on day 35, DM intake and milk production continued to be monitored through 90 days in milk (Figure 2). Numerical increases in DM intake and milk yield were observed in Cr-supplemented cows the first 35 days of lactation. However, differences in intake and milk production between control and Cr-supplemented cows were greater from days 36-90 of lactation even though Cr was no longer being supplemented.

Chromium Supplementation in Cattle Diets - Image 5

Chromium Supplementation in Cattle Diets - Image 6


Figure 2. Effects of supplementing chromium propionate from 21 days pre until 35 days postpartum on DM intake and milk production. Adapted from McNamara and Valdez (2005).

Studies in humans and rodents suggest that stress increases Cr requirements. Recently, Cr has been evaluated in lactating dairy cows under heat stress conditions. In Saudi Arabia, supplementation of dairy cows in mid lactation with CrY (4 mg Cr/day) increased DM intake by 1.6 kg/day and milk production by 3.3 kg/day (Al-Saiady et al., 2004). Supplementation of heat-stressed dairy cows with CrPic during early lactation in China also increased DM intake and milk production (AnQiang et al., 2009).

Reproduction

Limited research indicates that Cr supplementation may improve reproduction in dairy cattle. Chromium supplementation reduced the number of open cows in one of two experiments with primiparous dairy cows (Table 1) but not in multiparous cows (Yang et al., 1996). Pregnancy rate tended to be higher in intensively grazed dairy cows supplemented with CrMet than in controls (Bryan et al., 2004).

Immunity and Health

Studies in periparturient dairy cows indicate that Cr supplementation of practical diets may affect cell-mediated and humoral immune responses. Lymphocytes from cows supplemented with 0.5 mg Cr/kg diet, from CrAA, had increased blastogenic responses to concavalin A stimulation (Burton et al., 1993). Furthermore, Cr supplementation prevented the decrease in blastogenic response that was observed in control cows 2 weeks prepartum. Chromium supplementation also improved primary and secondary antibody response to ovalbumin administration but not antibody response to human erythrocytes (Burton et al., 1993). The primary injection of ovalbumin and human erythrocytes was given 2 weeks prepartum and the secondary injection was administered 2 weeks postpartum. Supplementation with 5 mg Cr/day increased antibody responses following vaccination with tetanus toxin in dairy cows (Faldyna et al., 2003). Neutrophil function has not been affected by dietary Cr (Chang et al., 1996; Faldyna et al., 2003).

Studies examining the effects of dietary Cr on health in dairy cows are limited. Supplementing 3.5 mg Cr/day (from CrPic) during the last 9 weeks of pregnancy reduced the incidence of retained placenta, in a dairy herd with a high incidence of retained placenta, from 56 to 16% (Villalobos-F et al., 1997). Chromium supplementation (CrAA) prepartum and during the first 16 weeks of lactation did not affect mammary gland health status (Chang et al., 1996).

Chromium may affect incidence of ketosis by enhancing insulin sensitivity. Insulin is an anabolic hormone that promotes lipogenesis and inhibits lipolysis. Supplementation of dairy cows with CrMet has reduced circulating nonesterified fatty acids (NEFA) concentrations at 7 to 10 days prepartum in some studies (Bryan et al., 2004; Hayirli et al., 2001) but not in others (Smith et al., 2008). Dairy cows supplemented with CrPic had lower plasma concentrations of β- hydroxybutyate than controls at 3 and 30 days postpartum (Besong, 1996). Liver triglyceride concentration were also lower in Cr-supplemented cows at 30 days postpartum (Besong, 1996). Chromium supplementation has not affected clinical cases of ketosis in lactation studies that have reported health-related disorders (Chang et al., 1996; Yang et al., 1996; Smith et al., 2005).

Beef Cattle

Health and Performance of Stressed Calves

Research at the University of Guelph in the 1990's suggesting that Cr supplementation could affect performance and morbidity in stressed calves generated considerable interest in Cr in ruminant nutrition. A summary of Cr studies with calves that had been stressed, due to transportation and other factors associated with shipping (weaning, feed restriction, etc), is presented in Table 3. Performance and morbidity results shown represent data from the first 28 days after arrival in the feedlot. Chromium supplementation in the form of CrY or CrAA reduced incidence of morbidity following transportation in some studies (Moonsie-Shageer and Mowat, 1993; Mowat et al., 1993), but not in other trials (Chang and Mowat, 1992; Chang et al., 1995; Mathison and Engstrom, 1995). As expected, performance of calves during the receiving phase also has been improved by Cr in studies where Cr supplementation reduced morbidity (Moonsie-Shageer and Mowat, 1993; Mowat et al., 1993). Chromium supplementation has tended to increase gain in some studies (Chang and Mowat, 1992; Wright et al., 1994) where morbidity was not affected by Cr.


Chromium Supplementation in Cattle Diets - Image 7
The effects of dietary Cr on physiological response of calves to an experimental disease challenge have also been evaluated. Chromium supplementation was provided for 49 to 75 days before disease challenge in these studies. Calves supplemented with 0.4 mg Cr/kg diet (as either CrNic or CrCl3) tended to have lower body temperatures at certain time points after intranasal inoculation with infectious bovine rhinotracheitis virus (IBRV) followed by Pasteurella haemolytica intratracheally 5 days later (Kegley et al., 1996). Supplementing calves with 0.4 mg Cr/kg diet, as CrNic, for 56 days before transportation did not affect body temperature or feed intake responses to an IBRV challenge (Kegley et al., 1997b). Rectal temperature responses also were not affected by CrY supplementation in calves inoculated with IBRV (Arthington et al., 1997).

Stress results in elevated blood concentrations of cortisol which is known to depress immune functions. Chromium supplementation in cattle decreased serum cortisol concentrations in some studies with stressed cattle (Chang and Mowat, 1992; Moonsie-Shageer and Mowat, 1993; Kegley et al., 1996), but not in others (Kegley and Spears, 1995; Kegley et al., 1997b). When serial blood samples were obtained from jugular-cannulated calves at 4-hour intervals for 6 days, Cr supplementation from CrY did not affect serum cortisol concentrations following inoculation with IBRV (Arthington et al., 1997).

Reproduction

Chromium has affected reproduction in beef cows grazing pastures. Providing CrPic in a free choice mineral improved pregnancy rate in beef cows (Stahlhut et al., 2006b). The improvement in reproduction was due to increased pregnancy rate in cows 5 years of age or younger (Table 4). Chromium did not affect pregnancy rate in beef cows 6 years of age or older. The improved pregnancy rate was associated with much lower plasma NEFA concentrations at approximately 21 and 79 days postpartum in Cr-supplemented cows (Stahlhut et al., 2006a). Chromium supplementation reduced postpartum body weight loss in 2 and 3-year old cows but not in older cows (Stahlhut et al., 2006b). Supplementation of CrY in a free choice mineral reduced the interval from calving to first estrus and tended to improve pregnancy rate in primiparous Zebu beef cows in Brazil (Aragon et al., 2001). Body weight gain was also greater in Cr-supplemented cows from parturition until their calves were weaned (Aragon et al., 2001). Reproductive responses to Cr may relate to its ability to increase insulin sensitivity. Insulin administration improved ovulation rate in energy-deprived heifers (Harrison and Randel, 1986).


Chromium Supplementation in Cattle Diets - Image 8
Chromium in Feedstuffs

Variation among studies in response to Cr supplementation may relate to differences in Cr content or bioavailability from feedstuffs. Little is known regarding Cr concentrations in practical feedstuffs and even less is known regarding bioavailability of Cr from common feedstuffs. In many Cr studies with cattle the Cr content of the control diets have not been reported. Chromium analysis of diets is challenging due to the low levels of Cr normally present and problems with Cr contamination of feed samples during collection and preparation of samples for analysis (NRC, 2005). We have found most complete diets to contain less than 1 mg Cr/ kg diet DM.

References

Al-Saiady, M.Y., M.A. Al-Shaikh, S.I. Al-Mufarrej, T.A. Al-Showeimi, H.H. Mogawer and A. Dirrar. 2004. Effect of chelated chromium supplementation on lactation performance and blood parameters of Holstein cows under heat stress. Anim. Feed Sci. Technol. 117:223-233.

AnQiang, L., W. ZhiSheng and Z. AnGuo. 2009. Effect of chromium picolinate supplementation on early lactation performance, rectal temperatures, respiration rates and plasma biochemical response of Holstein cows under heat stress. Pakistan J. Nutr. 8:940-945.

Aragon, V.E.F., D.S. Graca, A.L. Norte, G.S. Santiago and O.J. Paula. 2001. Supplemental high chromium yeast and reproductive performance of grazing primiparous zebu cows. Arq. Bras. Med. Vet. Zootec. 53:624-628.

Arthington, J.D., L.R. Corah, J.E. Minton, T.H. Elsasser and F. Blecha. 1997. Supplemental dietary chromium does not influence ACTH, cortisol, or immune responses in young calves inoculated with bovine herpesvirus-1. J. Anim. Sci. 75:217-223.

Besong, S. A. 1996. Influence of supplemental chromium picolinate on the concentrations of hepatic triglyceride and blood metabolites in dairy cattle. Ph.D. Dissertation, University of Kentucky, Lexington, KY.

Bryan, M.A., M.T. Socha and D.J. Tomlinson. 2004. Supplementing intensively grazed late-gestation and early- lactation dairy cattle with chromium. J. Dairy Sci. 87:4269-4277.

Bunting, L.D., J.M. Fernandez, D.L. Thompson and L.L. Southern. 1994. Influence of chromium picolinate on glucose usage and metabolic criteria in growing Holestein calves. J. Anim. Sci. 72:1591-1599.

Burton, J.L., B.A. Mallard and D.N. Mowat. 1993. Effects of supplemental chromium on immune responses of periparturient and early lactation dairy cows. J. Anim. Sci. 71:1532-1539.

Chang, X. and D.N. Mowat. 1992. Supplemental chromium for stressed and growing feeder calves. J. Anim. Sci. 70:559-565.

Chang, X., D.N. Mowat and B.A. Mallard. 1995. Supplemental chromium and niacin for stressed feeder calves. Can. J. Anim. Sci. 75:351-358.

Chang, X., B.A. Mallard and D.N. Mowat. 1996. Effects of chromium on health status, blood neutrophil phagocytosis and in vitro lymphocyte blastogenesis of dairy cows. Vet. Immunol. Immunopathol. 52:37-52. DRI. 2001. Dietary Reference Intakes. National Academy Press, Washington, DC.

Drackley, J.K. 1999. Biology of dairy cows during the transition period: the final frontier? J. Dairy Sci. 82:2259-2273.

Faldyna, M., A. Pechova and J. Krejci. 2003. Chromium supplementation enhances antibody response to vaccination with tetanus toxin in cattle. J. Vet. Med. (Series B) 50:326-331.

Harrison, L.M. and R.D. Randel. 1986. Influence of insulin and energy intake on ovulation rate, luteinizing hormone and progesterone in beef heifers. J. Anim. Sci. 63:1228-1235.

Hayirli, A., D.R. Bremmer, S.J. Bertics, M.T. Socha and R.R. Grummer. 2001. Effect of chromium supplementation on production and metabolic parameters in periparturient dairy cows. J. Dairy Sci. 84:1218-1230.

Kegley, E.B. and J.W. Spears. 1995. Immune response, glucose metabolism, and performance of stressed feeder calves fed inorganic or organic chromium. J. Anim. Sci. 73:2721-2726.

Kegley, E.B., J.W. Spears and T.T. Brown. 1996. Immune response and disease resistance of calves fed chromium nicotinic acid complex or chromium chloride. J. Dairy Sci. 79:1278-1283.

Kegley, E.B., J.W. Spears and J.H. Eisemann. 1997a. Performance and glucose metabolism in calves fed a chromium-nicotinic acid complex or chromium chloride. J. Dairy Sci. 80:1744-1750.

Kegley, E.B., J.W. Spears and T.T. Brown. 1997b. Effect of shipping and chromium supplementation on performance, immune response, and disease resistance of steers. J. Anim. Sci. 75:1956-1964.

Mathison, G.W. and D.F. Engstrom. 1995. Chromium and protein supplements for growing-finishing beef steers fed barley-based diets. Can. J. Anim. Sci. 75:549-558.

McNamara, J.P. and F. Valdez. 2005. Adipose tissue metabolism and production responses to calcium propionate and chromium propionate. J. Dairy Sci. 88:2498-2507.

Moonsie-Shageer, S. and D.N. Mowat. 1993. Effect of level of supplemental chromium on performance, serum constituents, and immune status of stressed feeder calves. J. Anim. Sci. 71:232-238.

Mowat, D. N., X. Chang and W.Z. Yang. 1993. Chelated chromium for stressed feeder calves. Can. J. Anim. Sci. 73:49-55.

NRC. 2005. Mineral Tolerance of Animals. National Academies Press, Washington, DC.

Peterson, S. W. 2000. Effects of chromium picolinate on milk production and plasma insulin concentration in dairy cows. Proc. New Zealand Soc, Anim. Prod. 60:307-310.

Sadri, H., G.R. Ghorbani, H. R. Rahmani, A.H. Samie, M. Khurvash and R. M. Bruckmaier. 2009. Chromium supplementation and substitution of barley grain with corn: Effects on performance and lactation in periparturient dairy cows. J. Dairy Sci. 92:5411-5418.

Sano, H., M. Nakai, T. Kondo and Y. Terashima. 1991. Insulin responsiveness to glucose and tissue responsiveness to insulin in lactating, pregnant, and nonpregnant, nonlactating beef cows. J. Anim. Sci. 69:1122-1127.

Sano, H., S. Narahara, T. Kondo, A. Takahashi and Y. Terashima. 1993. Insulin responsiveness to glucose and tissue responsiveness to insulin during lactation in dairy cows. Domest. Anim. Endocrinol. 10:191-197.

Schwarz, K. and W. Mertz. 1959. Chromium (III) and the glucose tolerance factor. Arch. Biochem. Biophys. 85:292-295.

Smith, K.L., M.R. Waldron, J.K. Drackley, M.T. Socha and T.R. Overton. 2005. Performance of dairy cows as affected by prepartum dietary carbohydrate source and supplementation with chromium throughout the transition period. J. Dairy Sci. 88:255-263.

Smith, K.L., M.R. Waldron, L.C. Ruzzi, J. K. Drackley, M.T Socha and T.R. Overton. 2008. Metabolism of dairy cows as affected by prepartum dietary carbohydrate source and supplementation with chromium throughout the periparturient period. J Dairy Sci. 91:2011-2020.

Stahlhut, H.S., C.S. Whisnant, K.E. Lloyd, E.J. Baird, L.R. Legleiter, S.L. Hansen and J.W. Spears. 2006a. Effect of chromium supplementation and copper status on glucose and lipid metabolism in Angus and Simmental beef cows. Anim. Feed Sci. Technol. 128:253-265.

Stahlhut, H.S., C.S. Whisnant and J.W. Spears. 2006b. Effect of chromium supplementation and copper status on performance and reproduction of beef cows. Anim. Feed Sci. Technol. 128:266-275.

Subiyatno, A., D.N. Mowat and W.Z. Yang. 1996. Metabolite and hormonal responses to glucose or propionate infusions in periparturient dairy cows supplemented with chromium. J. Dairy Sci. 79:1436-1445.

Sumner, J.M., F. Valdez and J.P. McNamara. 2007. Effects of chromium propionate on response to an intravenous glucose tolerance test in growing Holstein heifers. J. Dairy Sci. 90:3467-3474.

Villalobos-F, J.A., C. Romero-R, M.R. Tarrago-C and A. Rosado. 1997. Supplementation with chromium picolinate reduces the incidence of placental retention in dairy cows. Can. J. Anim. Sci. 77:329-330.

Vincent, J.B. 2001. The bioinorganic chemistry of chromium (III). Polyhedron 20:1-26.

Wright, A.J., D.N. Mowat and B.A. Mallard. 1994. Supplemental chromium and bovine respiratory disease vaccines for stressed feeder calves. Can. J. Anim. Sci. 74:287-295.

Yang, W.Z., D.N. Mowat, A. Subiyatno and R.M. Liptrap. 1996. Effects of chromium supplementation on early lactation performance of Holstein cows. Can. J. Anim. Sci. 76:221-230.
Related topics
Authors:
Jerry Spears
North Carolina State University - NCSU
Follow
Join to be able to comment.
Once you join Engormix, you will be able to participate in all content and forums.
* Required information
Would you like to discuss another topic? Create a new post to engage with experts in the community.
Create a post
Ali Imran
2 de noviembre de 2010

A very good and interesting article about Chromium Supplementation in Dairy Cattle. In our country common farmers or even progressive farmers are not fully aware about the need of micro elements especially in pre partum phase and they only give attention to two main macro elements ca:p. I think such article will help a farmer/reader to study and learn the chemistry and importance of Micro elements .

Arshaq Ramzee
2 de noviembre de 2010

An excellent paper about Chromium Supplementation in Dairy Cattle Diets, author has explained in detail, effect of Chromium on various aspects of production cycle.

Dr Nelson Sam
27 de octubre de 2010

Dear sir,
It is a good article in the field of new mineral nutrition for dairy cattle.
With kind regards,
Dr.S.Nelson

Join Engormix and be part of the largest agribusiness social network in the world.
LoginRegister