Effect Of Trace Mineral Source Research Articles

313 Effect of Dietary Trace Mineral Source on Performance, Bones Mineralization and Mineral Status in Fattening Pigs

Abstract Several papers report greater bioavailability of dietary trace mineral fed as organic in pigs compared with inorganic sources. However, only a few studies have tried to assess the variability of the trace mineral bioavailability among different organic sources. Growing barrows (n = 54; initial BW = 28.9 ± 1.3 kg) were used to determine the effects of trace mineral source on growth performance, bones mineralization and mineral status over the entire fattening period (d0-d73). Pigs were blocked by BW and randomly assigned to supplementation of trace minerals as inorganic (ITM) or one of 2 organic sources (OTM): glycine complex (GLY) or amino acids complex (AA). During the two feeding phases (growing: d0-d35; finishing: d35-d73), the experimental diets were supplemented with 5, 35 and 5 mg/kg of Cu, Zn and Mn, respectively. Pigs were fed restricted all through the experimental period. Feed intake was therefore comparable all through the experimental period for all pigs. Growth performance did not differ among the three experimental groups during the growing phase. However, Feed:Gain ratio measured during the finishing period tended to be affected by the dietary treatments (P=0.10). When grouping the GLY and AA pigs, the Feed:Gain ratio measured from d35 to d73 for the OTM pigs was significantly lower compared with ITM pigs (-0.07, P = 0.03). There was no significant effect of the dietary treatment on plasma trace mineral concentrations and alkaline phosphatase activity measured at day 34. At the end of the growing phase, plasma ceruloplasmin activity tended to be greater for the GLY and AA groups in comparison with the ITM pigs (+6.9%, P = 0.06). The zinc deposition in the proximal phalanx was significantly increased when the trace minerals were offered as organic compared with the group ITM (+10.9%, P = 0.06). Zinc content in the liver was greater for the pigs fed the OTM sources compared with the others (+6.0%, P = 0.10). The quantity of copper deposited in the liver did not differ significantly among the 3 trace mineral sources. This study indicates that the total replacement of inorganic Zn, Cu and Mn by organic sources brings benefits in terms of feed efficiency in fattening pigs. A better bioavailability as suggested by greater deposition levels in bone and liver as well as the increased circulating ceruloplasmin activity could explain the improvement of performance during the finishing period. Regardless of the variable considered, no significant differences were noticed between the two organic trace mineral sources.

Effect of trace mineral source on biochemical and hematological parameters, digestibility, and performance in growing lambs.

To study the efficacy of organic trace mineral supplementation on blood parameters, digestibility, and growth as compared to inorganic sources, 18 Zandi male lambs (with initial body weight, 28.5 ±1.4 kg and 110±5 days old) were divided into three groups of six animals in each in a completely randomized design. Lambs in the control group were fed basal diet containing 63 kg/100 kg of concentrate mixture, 22 kg/100 kg of alfalfa hay, and 15 kg/100 kg wheat straw. Animals in the experimental groups were additionally supplemented with trace minerals supplied by sulfates or a diet in which 25.7 ppm Zn, 14.3 ppm Mn, 8.9 ppm Cu from mineral-amino acid complex, and 0.86 ppm Co from Co glucoheptonate replaced with similar amounts of Zn, Mn, Cu, and Co from sulfates. All lambs were kept in individual pens with cemented floor and provision of individual feeding and watering. Lambs fed with either organic or inorganic trace mineral supplement showed higher dry matter intake and growth rate and better feed conversion efficiency (P<0.05) as compared to the control group. Blood glucose, urea nitrogen, cholesterol, and hepatic enzymes were similar among the treatments. Triglycerides (P<0.01) concentration was lower for mineral-supplemented groups. Blood vitamin B12 concentration increased with mineral supplementation and was higher for the lambs fed with organic source of trace elements as compared with those fed with inorganic mineral and the control diet (P=0.04). The results of this study showed that feeding organic trace elements improves growth performance of finishing lambs but did not affect nutrient digestibility and blood parameters.

Impact of trace mineral source on beef replacement heifer growth, reproductive development, and biomarkers of maternal recognition of pregnancy and embryo survival.

Trace minerals are known to play important roles in early embryo development. The study objective was to determine effects of trace mineral source on heifer reproductive performance. Beef heifers (n = 129) were randomly assigned to one of two treatments. From weaning through breeding, all heifers were individually fed a basal diet supplemented with cobalt (Co), copper (Cu), manganese (Mn), and zinc (Zn) either from organic sources (COMP; Cu, Mn, and Zn amino acid complexes and Co glucoheptonate; Availa-4, Zinpro Corporation, Eden Prairie, MN) or inorganic sources (INORG; Cu, Mn, and Zn hydroxychlorides; Intellibond C, M, and Z, Micronutrients, Indianapolis, IN) and Co as CoSO4. Blood samples and a reproductive tract score (RTS) were collected to determine pubertal status. All animals were synchronized and artificially inseminated. Pregnancy status was determined by lymphocyte gene expression, circulating concentrations of pregnancy-associated glycoproteins (PAGs), and by transrectal ultrasonography after artificial insemination. Embryonic loss was defined as when a previously pregnant animal was subsequently diagnosed not pregnant. Data were analyzed using the MIXED procedure in SAS. Puberty (P = 0.44), pelvic area (P = 0.74), RTS (P = 0.49), and estrus expression (P = 0.82) were not influenced by treatment. There was no effect of treatment (P = 0.37) or treatment by time (P = 0.19) on pregnancy, but there was a tendency (P = 0.13) for decreased embryonic loss among COMP heifers (27 ± 6%) compared to INORG heifers (38 ± 6%). There was a treatment by pregnancy status by time interaction (P < 0.01) on circulating PAG concentrations with PAG concentrations tending (P = 0.08) to be greater on day 25 among heifers in the COMP treatment compared to heifers in the INORG group. In summary, source of trace mineral did not affect puberty, RTS, pelvic area, or overall pregnancy success, but feeding complexed trace minerals tended to increase circulating PAG concentrations and embryo survival.

PSIV-17 Effects of Trace Mineral Source and Level on Growth Performance and Carcass Characteristics of Grow-finish Pigs

Abstract Two experiments were conducted to determine the effects of trace mineral source and level for grow-finish pigs. In Exp. 1, 2,168 pigs (initial BW = 23.0 kg) were used in a 117-d trial. There were 5 treatments based on inorganic (sulfates and oxides) or organic (Alltech Bioplex, Lexington, KY) minerals supplemented at different levels as follows: 1) Industry inorganic (120 mg/kg Zn, 100 mg/kg Fe, 40 mg/kg Mn, 10 mg/kg Cu); 2) 100% NRC inorganic (60 mg/kg Zn, 60 mg/kg Fe, 2.2 mg/kg Mn, 4 mg/kg Cu); 3) 33% NRC organic (20 mg/kg Zn, 20 mg/kg Fe, 0.7 mg/kg Mn, 1.3 mg/kg Cu); 4) 66% NRC organic (40 mg/kg Zn, 40 mg/kg Fe, 1.5 mg/kg Mn, 2.6 mg/kg Cu); and 5) 100% NRC organic (60 mg/kg Zn, 60 mg/kg Fe, 2.2 mg/kg Mn, 4 mg/kg Cu). Selenium level was 0.30 mg/kg for all treatments. Treatment 1 had 14 replicates and the other treatments had 18 replicates. Pigs were weighed approximately every three weeks and carcass data was collected at the end of the trial. Data was analyzed with SAS MIXED procedure. There was no evidence for differences (P &amp;gt; 0.10) for overall ADG, ADFI, G:F, and final BW. Pigs fed 66% NRC organic had the highest (P &amp;lt; 0.05) percentage lean and loin depth. In Exp. 2, 1,188 pigs (initial BW = 25.9 kg) were used in a 120-d trial with two treatments: 1) Industry inorganic and 2) 66% NRC organic, with the same mineral levels as Exp. 1 and 24 replicates per treatment. There was no difference (P &amp;gt; 0.10) in growth performance. Similar to Exp. 1, pigs fed 66% NRC organic had higher (P &amp;lt; 0.05) percentage lean and loin depth. In conclusion, lower levels of organic trace minerals resulted in improved carcass characteristics without compromising growth performance.

139 Ruminal microbiota mineral requirements to optimize performance on different diets

Abstract This presentation will discuss mineral requirements of ruminal microorganisms, and the effect of trace mineral source on ruminal fermentation. Sulfur and phosphorus are required in relatively large amounts by ruminal microorganisms, and dietary deficiencies of these minerals have been related to impaired ruminal fermentation. A number of trace minerals are required in low concentrations by ruminal microorganisms. With the except of cobalt (Co) minimal trace mineral requirements of the host ruminant appear to be considerably greater than that needed for rumen microbial requirements. It is well known that certain bacteria can synthesize vitamin B12 from inorganic Co. Some bacteria require vitamin B12 as a growth factor, and adequate dietary Co is needed to allow sufficient ruminal B12 synthesis to meet their requirement. Vitamin B12 is needed as a cofactor for ruminal microorganisms to convert succinate to propionate. Dietary Co deficiency results in decreased ruminal propionate in ruminants fed high concentrate diets, and decreased fiber digestion in ruminants fed high fiber diets. Attempts have been made to use high concentrations of certain trace minerals to favorably manipulate ruminal fermentation. For example, attempts have been made to increase rumen protein bypass by feeding high dietary zinc (Zn). However, studies have indicated that high concentrations of copper (Cu), Zn, and iron reduce cellulose digestion in vitro. Recent studies have indicated lower fiber digestibility in cattle supplemented with sulfate sources of Cu, Zn, and manganese compared with those fed similar concentrations from hydroxy or certain organic sources. Additional research is needed to elucidate the mechanism(s) whereby trace mineral sources affect fiber digestibility differently.

393 Awardee Talk: Effect of trace mineral source on rumen fermentation and trace mineral distribution in the rumen

Abstract The role that Cu and Zn play in rumen microbial fermentation is not well understood. Microorganisms use small proportions of dietary Cu and Zn for catalytic, structural, and stabilizing functions. In order for microorganisms to acquire Cu and Zn, the elements must be soluble in the rumen environment. Data would indicate that practical diets fed to ruminants without Cu and Zn supplementation are able to meet the microbial Cu and Zn requirements. Therefore, rumen solubility of supplemental Cu and Zn can impact rumen microbial fermentation characteristics. Numerous factors can impact rumen solubility of minerals, such as the pH of the rumen, the concentration of dietary antagonists (Mo, Fe, S, fiber, etc.), and mineral source. Earlier research has indicated that high soluble concentrations of Cu and Zn in the rumen environment can become toxic to certain rumen microorganisms and decrease fiber digestion. Recent research from our laboratory has indicated that hydroxy trace mineral (HTM) forms of Cu and Zn are relatively insoluble in the rumen and that a greater proportion of HTM remained loosely bound to the insoluble fraction within the rumen when compared to sulfate trace mineral (STM) sources of Cu and Zn. We have also reported that supplemental sources of Cu and Zn that are highly soluble in the rumen environment (STM) can decrease fiber digestion, reduce total VFA concentrations, and can become more tightly bound to rumen solid digesta than HTM sources of Cu and Zn. The stronger binding of STM relative to HTM to the solid rumen digesta fraction may reduce absorption in the small intestine. Future research investigating the flow and passage rate of different trace mineral sources through the abomasum into the duodenum and duodenal absorption efficiency of Cu and Zn from different TM sources is needed.

383 Effect of trace mineral source on heifer reproductive performance

Abstract Trace minerals are known to play important roles in early embryo development. The study objective was to determine effects of trace mineral source on heifer reproductive performance. Over two years, beef heifers (n = 130) were randomly assigned to two pens and two treatments, within each pen, based on breed, age, and BW. From weaning through the breeding season, all heifers were individually fed a basal diet of grass hay, corn silage, and a supplement pellet (soybean hulls, dried distiller’s grains plus solubles, minerals, vitamins and monensin). Cobalt, Cu, Mn, and Zn were supplemented with either complexed sources (Availa-4) or inorganic sources (Cu, Mn, and Zn hydroxychlorides; Intellibond C, M, and Z) and Co as CoSO4. Blood samples were collected bi-weekly, and a reproductive tract score (RTS) was collected 30 d prior to breeding to determine pubertal status. All animals were synchronized and artificially inseminated (AI). Pregnancy status was determined by lymphocyte gene expression on d 17, 19, and 21; by circulating concentrations of pregnancy associated glycoproteins (PAGs) on d 22, 23, 24, 25, 26, 27, and 28; and by transrectal ultrasonography on d 30 and 60 after AI. Embryonic loss was defined as when a previously pregnant animal was subsequently diagnosed not pregnant. Data were analyzed using the MIXED procedure in SAS. Puberty (P = 0.44), pelvic area (P = 0.74), RTS (P = 0.49), and estrus expression (P = 0.82) were not influenced by treatment. There was no effect of treatment (P = 0.37) or treatment by time (P = 0.19) on pregnancy, but there was a weak tendency (P = 0.13) for decreased embryonic loss among heifers supplemented with complexed trace minerals (27±6%) compared to inorganic minerals (38±6%). In summary, source of trace mineral did not affect puberty, RTS, pelvic area, or overall pregnancy success, but feeding complexed trace minerals tended to increase embryo survival from d 17 to 60.

Effect of trace mineral source on mineral status and performance of beef steers fed low- or high-sulfur diets.

A 2 × 2 factorial assessed the effect of trace mineral (TM) sources fed within low- or high-S diets on the mineral status and performance of cattle. Angus crossbred steers ( = 48; 6/pen) were blocked by BW (316 ± 16.6 kg), assigned to low-S (0.27%; LS) or high-S (0.54%; HS; added as CaSO) diets, and supplemented TM at 10 mg Cu, 30 mg Zn, and 20 mg Mn/kg DM from hydroxy (HYD; IntelliBond; Micronutrients USA LLC, Indianapolis, IN) or inorganic (sulfates; ING) sources ( = 12 steers/treatment). Steers were fed corn silage and corn-based diets via GrowSafe bunks in the growing period (GP; 84 d) and finishing period (FP; 77 d), respectively. Plasma and liver were collected at trial initiation and end of GP and FP for mineral concentrations. End of GP and FP red blood cell lysate superoxide dismutase (SOD) and Mn-SOD activity and liver glutathione concentrations were measured. Data were used as a 2 × 2 factorial using Proc Mixed of SAS (SAS Inst. Inc., Cary, NC) with initial plasma and liver status analyzed as covariates. High S decreased ( < 0.01) liver Cu and tended ( ≤ 0.10) to decrease plasma Cu concentrations. Liver Cu concentrations were lower in HYD than ING in the FP ( < 0.01). High S decreased ( = 0.04) GP plasma Zn concentrations and tended to decrease ( = 0.10) GP liver Zn. There were GP ( = 0.05) and FP ( = 0.02) S × TM effects for liver Mn concentrations where GP LS-HYD was greater than all other treatments, whereas FP LS-HYD was lower than HS-HYD and LS-ING and FP HS-ING was less than LS-ING. Glutathione, SOD, and Mn-SOD were not different ( ≥ 0.13) in the GP, but S × TM tended to affect FP Mn-SOD ( = 0.10), where LS-HYD tended to be lower than LS-ING. Oxidized glutathione in FP tended to be lower ( = 0.06) for HYD than ING. In the GP, there were S × TM effects on performance where LS-HYD had greater ADG and G:F ( ≤ 0.05) than HS-HYD, whereas LS and HS-ING were intermediate. For FP performance S × TM effects were noted where LS-HYD and HS-ING tended ( = 0.10) to gain more than HS-HYD and HS-HYD had lower G:F ( = 0.04) than HS-ING. There were no effects of S × TM on final BW, DMI, or ADG ( ≥ 0.11); however, HS-HYD had lower G:F than other treatments overall ( = 0.05). High S decreased back fat and yield grade ( = 0.03), and rib eye area was smaller for HYD than ING ( = 0.02). In this study HS decreased markers of Cu and Zn status, and differential effects of HYD vs. ING minerals were noted across dietary phases, although all steers maintained adequate TM status.

Effect of trace mineral source on mineral status and performance of beef steers fed low- or high-sulfur diets

Effect of trace mineral source on mineral status and performance of beef steers fed low- or high-sulfur diets

0737 The effect of trace mineral source and fiber source on total-tract nutrient digestion

0737 The effect of trace mineral source and fiber source on total-tract nutrient digestion

067 Effect of trace mineral source on postweaning Bos Taurus beef bull sexual development

067 Effect of trace mineral source on postweaning Bos Taurus beef bull sexual development

The effect of trace mineral source and concentration on ruminal digestion and mineral solubility

The objective of this experiment was to compare the effect of sources of sulfate trace mineral (STM) and hydroxy trace mineral (HTM) at different inclusions on digestibility of dry matter (DM) and neutral detergent fiber and solubility of Cu, Mn, and Zn in the rumen and abomasum of cattle. Five ruminally cannulated steers were used in a 5×5 Latin square design and individually fed a corn silage–based diet on an ad libitum basis. The 5 dietary treatments were as follows: control: no supplemental Cu, Mn, or Zn, analyzed to contain 7.4mg of Cu, 30.8mg of Mn, and 32.1mg of Zn per kilogram of diet DM (CON); low sulfate: 5mg of Cu/kg of DM supplemented from CuSO4, 15mg of Mn/kg of DM from MnSO4, and 30mg of Zn/kg of DM from ZnSO4; low HTM: 5mg of Cu/kg of DM supplemented from basic copper chloride (IntelliBond C; Micronutrients Inc., Indianapolis, IN), 15mg of Mn/kg of DM from manganese hydroxychloride (IntelliBond M; Micronutrients Inc.), and 30mg of Zn/kg of DM from zinc hydroxychloride (IntelliBond Z; Micronutrients Inc.); high sulfate: 25mg of Cu/kg of DM supplemented from CuSO4, 60mg of Mn/kg of DM from MnSO4, and 120mg of Zn/kg of DM from ZnSO4; and high HTM: 25mg of Cu/kg of DM supplemented from basic copper chloride, 60mg of Mn/kg of DM from manganese hydroxychloride, and 120mg of Zn/kg of DM from zinc hydroxychloride. Periods lasted for 12d, with 10d of diet adaptation. Dacron bags containing the CON total mixed ration were inserted on d 11 at 0h and were removed at 6, 12, 24, and 36h after insertion. Dry matter and neutral detergent fiber disappearances and rumen and simulated abomasal trace mineral solubilities were evaluated. Dietary treatment did not affect DM intake. Dry matter disappearance was lesser in supplemental TM treatments and greater in CON than the STM treatments, although the CON and HTM treatments did not differ. Neutral detergent fiber disappearance was not affected by treatment. Ruminally soluble Cu and Mn concentrations were least in CON and were lesser in HTM-containing treatments compared with STM treatments. However, in the abomasum, solubilities of Cu and Mn were similar across trace mineral sources. Ruminal and simulated abomasal soluble Zn was greater in the HTM treatments than in CON and STM, driven by the greater solubility of the high HTM treatment. Under the conditions of this study, supplementing trace minerals as STM decreased DM digestibility, whereas HTM did not affect DM digestibility. Additionally, Cu and Mn from HTM sources were relatively insoluble in the rumen but had similar solubility as STM at the pH found in the abomasum, suggesting that these minerals should be available for absorption in the intestine.

Effect of trace mineral source on reproduction and milk production in Holstein cows

<h2>ABSTRACT</h2> A lactation study was conducted to evaluate the effect of increasing the proportion of inorganic versus organic trace minerals (polysaccharides and amino-acid chelates) on reproductive performance and milk production of multiparous and primiparous Holstein cows. Trace minerals evaluated were copper (Cu), manganese (Mn), and zinc (Zn). All minerals were supplemented to meet the NRC (1989) recommended level (10, 40, and 40 mg/kg of Cu, Mn, and Zn, respectively) in diet DM. A total of 101 cows were randomly assigned by expected calving date to 1 of 4 trace mineral treatments: 1) 100% from inorganic sulfate (SULF); 2) 67% SULF:33% polysaccharide complex (SULF-POLY); 3) 67% SULF:33% specific amino-acid complex (SULF-AA); and 4) 100% polysaccharide complex (POLY). Treatments were implemented the day of calving. Number of days open was reduced (P < 0.05) for all cows receiving the POLY versus SULF treatments. Cows receiving the POLY treatment were also more likely (P = 0.008) to become pregnant from the first service than were cows receiving the other treatments. Milk production and composition were not affected by supplements fed. Under the conditions of this study, reproductive performance of cows fed a trace-mineral supplement composed of 100% polysaccharide complexed trace minerals was enhanced versus sulfate, sulfate and polysaccharide, or sulfate and amino acid complexed supplements.

The Impact of Trace Mineral Source, Water Quality, and Short-Term Choline Supplementation on Performance and Carcass Characteristics of Finishing Steers

ABSTRACT A total of 288 yearling steers (315.2 ± 3.7 kg) were used to determine the effects of trace mineral source, water quality, and short-term choline supplementation on feedlot performance and carcass characteristics. Trace mineral treatments consisted of 1) a control, namely, 15 mg Cu/kg DM, 20 mg Mn/kg DM, and 45 mg Zn/kg DM supplemental trace minerals in inorganic form; and 2) organic (proteinate form) iso-concentrations to the inorganic trace minerals composed of 50% organic and 50% inorganic trace minerals. Water treatments consisted of 1) a blend of reverse-osmosis (RO) water and well water (1,072.4 mg sulfate/L) and 2) well water (2,377.5 mg sulfate/L). At 29 d before slaughter, 4 pens of steers per trace mineral × water treatment combination were supplemented with choline at a rate of 20 g of rumen-protected choline/steer daily, and the remaining 4 pens served as the controls (no supplemental rumenprotected choline). There were no effects of trace mineral source, water quality, or interactions with feeding period for BW, ADG, DMI, or G:F. Initial and final BW, ADG, DMI, and G:F were similar across trace mineral and water treatments. Choline supplementation for only the last 29 d on feed did not affect performance. Morbidity, mortality, and percentage of retreated cattle were similar across trace mineral and water treatments. There was a trace mineral × water quality interaction (P

Effects of Trace Mineral Source and Growth Implants on Trace Mineral Status of Growing and Finishing Feedlot Steers

Three hundred and seventy-three steers (approximately 7 mo of age and 247±19.4 kg) were utilized to determine the effects of trace mineral (TM) source and growth implants on trace mineral status. Steers were blocked by ranch, post-weaning treatment within ranch, stratified by initial body weight, and randomly assigned to one of 36 pens (9-12 head/pen). Treatment consisted of: i) control (no supplemental Cu, Zn, Mn, and Co), ii) inorganic trace minerals, and iii) organic trace minerals. Six pens of steers per treatment received a growth implant at the beginning of the experiment and were re-implanted during the finishing phase. The remaining steers received no growth implants. Steers were fed a corn silage-based growing diet for 56 d then were gradually switched to a high concentrate finishing diet. Treatments during the finishing phase consisted of: i) control (no supplemental Zn); ii) inorganic Zn (30 mg of Zn/kg DM from ZnSO 4 ); and iii) organic Zn (iso-amounts of organic Zn). By the end of the growing and finishing phases, implanted steers had greater (p<0.01) plasma Cu concentrations than non-implanted steers. During the growing phase, liver Cu concentrations (p<0.01) and plasma Zn concentrations (p<0.02) were greater in steers supplemented with TM compared to control steers. Steers supplemented with inorganic minerals had greater liver Cu concentrations than steers supplemented with organic minerals at the beginning (p<0.01) and end (p = 0.02) of the growing phase. During both the growing (p = 0.02) and finishing phases (p = 0.05), non-implanted control steers had greater plasma Cu concentrations than non-implanted steers supplemented with TM, whereas, implanted control steers had similar plasma Cu concentrations than implanted steers supplemented with TM. Non-implanted steers that received inorganic TM had lower plasma Cu concentrations (p = 0.03) during the growing phase and ceruloplasmin activity (p<0.04) during the finishing phase than non-implanted steers that received organic TM, whereas, implanted steers supplemented with either organic or inorganic TM had similar plasma Cu concentrations.

The Effects of Trace Mineral Source on Performance and Health of Newly Received Steers and the Impact of Cobalt Concentration on Performance and Lipid Metabolism During the Finishing Phase

<h2>ABSTRACT</h2> Two hundred sixteen Angus crossbred steers (230kg ± 3.6) purchased from sale barns were utilized to determine the impact of trace mineral source and concentration on performance, tissue metabolites, and lipid metabolism. Treatments during the 27-d receiving phase consisted of 1) inorganic trace mineral (125mg CuSO₄/d per head, 360mg ZnSO₄/d per head, 200mg MnSO₄/d per head, and 12.5mg CoCO₃/d per head) or 2) organic trace mineral (iso-amounts of Cu, Zn, Mn amino acid complexes, and Co glucoheptonate). On d 0 and 27, blood samples were collected from 3 steers per pen (pen = experimental unit). On d 28, steers were transitioned to a high concentrate finishing diet containing different concentrations of Co. Treatments during the finishing phase consisted of 1) control (no supplemental Co); 2) 0.10mg Co/kg DM from cobalt glucoheptonate; and 3) 1.0mg Co/kg DM from cobalt glucoheptonate. The same 3 steers per pen were bled on d 84 and 224 of the finishing phase. During the receiving phase, red blood cell superoxide dismutase activity was greater (P < 0.03) for organic- vs. inorganic-supplemented steers. During the finishing phase, overall ADG tended (P < 0.06) to be greater for steers receiving 1.0mg Co/kg DM. Steers receiving 1.0mg Co/kg DM had greater YG (P < 0.04) and back fat thickness (P < 0.04) than steers receiving 0.10mg Co/kg DM. Serum, liver, and LM B₁₂ concentrations increased (P < 0.04) as dietary Co concentration increased.

Effect of Trace Mineral Source on Lactation Performance, Claw Integrity, and Fertility of Dairy Cattle

Two hundred fifty multiparous and primiparous cows were assigned to a study at approximately 70 d prepartum to determine the effect of trace mineral source on lactation performance, claw integrity, and fertility. Cows received treatments from 3wk prepartum through wk 35 postpartum. Treatments consisted of 1) all supplemental Zn, Mn, Cu, and Co provided in sulfate form (Sulfate) and 2) 360mg of Zn, 200mg of Mn, 125mg of Cu, and 12mg of Co supplied daily by Sulfate minerals replaced with similar amounts of minerals supplied by Availa-4 (CTM). Individuals involved with daily animal care or data recording, or both, were blinded to treatment assignments. Cows from all treatments were housed in common pens, and treatments were dispensed to cows via a computerized feeder. All claws of cows were examined before treatment administration and at 16 and 36wk postpartum by personnel trained in identifying claw lesions. Cows fed the CTM diet tended to produce more milk and energy-corrected milk than cows fed the Sulfate diet. Cows fed the CTM diet also produced more milk protein and solids (fat + protein) than cows fed the Sulfate diet. Replacing Sulfate minerals with those supplied by CTM decreased incidence of sole ulcers at wk 36 postpartum and tended to decrease incidence of interdigital dermatitis at wk 16 and 36 postpartum. Severity of heel erosion tended to be less for cows fed CTM than cows receiving the Sulfate diet. Despite first service conception rates tending to be greater for cows fed the Sulfate diet, there was no effect of treatment on rate of conception. A greater percentage of cows fed the Sulfate diet tended to be culled from the herd before wk 36 postpartum than cows fed the CTM diet. Replacing Sulfate minerals with CTM resulted in improved lactation performance and claw integrity.

Effect of Replacing Dietary Inorganic Forms of Zinc, Manganese, and Copper with Complexed Sources on Lactation and Reproductive Performance of Dairy Cows

ABSTRACT One hundred eighty multiparous Holstein cows (90 cows/treatment) were blocked according to calving date and randomly assigned to a study to determine the effect of trace mineral source on performance. Treatments were 1) all trace minerals supplied by inorganic sources or 2) inorganic minerals (360 mg Zn/d, 200 mg Mn/d, and 125 mg Cu/d) replaced with amino acid complexes of Zn, Mn, and Cu (CTM, Availa-4, Zinpro Corporation). Neither level nor source of Co supplementation differed between dietary treatments. Cobalt was supplemented as Co carbonate to supply 12 and 23 mg Co/d to dry and lactating cows, respectively. Cows received their respective treatments from 60 d prior to calving through 200 d oflactation. Replacing inorganic trace minerals with CTM tended to increase (P = 0.06) milk protein yield (1.09 vs. 1.05 kg/d) and tended to decrease (P = 0.15) linear SCC. There was no effect oftreatment on milk yield and yields of 3.5% fat-corrected milk and energy corrected milk. Feeding CTM increased (P = 0.005) BCS (2.97 vs. 2.86), decreased (P = 0.02) culling rate (13.3 vs. 25.6%) and tended (P = 0.07) to increase incidence of retained placentas (13.3 vs. 6.7%). Feeding CTM also tended to decrease (P = 0.15) incidence of metritis (14.4 vs. 16.7%) and to increase (P = 0.15) first service conception rate (21.9 vs. 19.1%). Replacing inorganic trace minerals with those supplied by CTM tended to improve lactation performance and reduced culling rates.

Effects of Trace Mineral Source and Feeding Method on the Productivity of Grazing Braford Cows

Braford cows (n = 160) were used to evaluate the effects of trace mineral source and feeding method on cow herd productivity over 3yr. In yr 1, cows were stratified by age and randomly allocated to one of eight groups (n = 20 cows per group). Cows were allotted to 8 of 16 bahiagrass pastures (8.0ha each, one empty pasture between groups) and were rotated each week. Cow groups remained intact throughout the study with the exception of culled cows, which were replaced with 3-yr-old pregnant heifers. Cows were offered 2.27kg of liquid molasses daily from early November until mid April. One mature Braford bull was placed into each cow group starting in early January, where the bull remained for 90 d. Bulls were rotated through cow groups each week. Two main factors were randomly applied to groups in a 2 × 2 factorial arrangement (two groups per treatment): 1) trace mineral source (inorganic vs organic) and 2) mineral feeding method (free-choice vs control-fed in a molasses supplement). Cow BW, body condition score (BCS), pregnancy rate, calving interval, and calf BW at weaning were obtained. Mineral intake was measured each week in pastures where mineral source was provided for ad libitum intake. In yr 1 and 2, liver biopsy collections were conducted for the determination of mineral status at the start and end of winter supplementation on the same six randomly chosen cows. Cows assigned to free-choice treatments consumed 23% less (P<0.001) mineral compared with control-fed cows, resulting in a greater (P<0.05) decrease in liver Zn (yr 1) and liver Cu (yr 2) concentration compared with control-fed cows. Mineral source and feeding method had no effect on cow BW, cow BCS, and calf BW at weaning. Young cows (3 and 4yr of age) consuming organic minerals had a greater pregnancy rate during yr 2 (P<0.05) and 3 (P=0.15) and a lesser (P<0.05) calving interval in yr 1 and 3, compared with cows consuming inorganic minerals. The supplementation of organic minerals (Cu, Zn, Mn, and Co) appears to increase the reproductive performance of young, but not mature, grazing Braford beef cows consuming molasses-based supplements.

Effects of Feeding Complexed Zinc, Manganese, Copper, and Cobalt to Late Gestation and Lactating Dairy Cows on Claw Integrity, Reproduction, and Lactation Performance

Three hundred multiparous Holstein cows (150 cows per treatment) were blocked according to calving date and randomly assigned to a study to determine the effect of trace mineral source on incidence and severity of claw lesions, reproduction, and lactation performance of dairy cattle. Treatments were 1) all trace minerals supplied by sulfates(ITM)or 2) 360mg Zn from Zn amino acid complex, 200mg Mn from Mn amino acid complex, 125mg Cu from Cu amino acid complex, and 12mg Co from Co glucoheptonate per day(CTM;Availa®; Zinpro Corporation, Eden Prairie, MN) replacing an equivalent amount of Zn, Mn, Cu, and Co from sulfates. Cows received assigned treatments from 21 d prior to calving through 250 d of lactation. Cows fed CTM produced 1.2kg more (P < 0.05) milk, energy-corrected milk, and 3.5% fat-corrected milk than cows supplemented with ITM. The CTM treatment reduced (P < 0.05) days open by 22 d and tended to increase (P < 0.15) percentage of cows pregnant by 150 d in milk (54.8% vs 42.7%) and first service conception rate (27.4% vs 18.4%). Cows fed CTM tended to have a lesser incidence (P < 0.15) of claw disorders than cows fed inorganic trace minerals at 75 d postpartum (23.6% vs 34.1%) and numerically lower incidence at 250 d postpartum (10.0% vs 17.7%). The CTM treatment increased yield of milk, decreased days open, and tended to increase first service conception rates, increase percentage of cows pregnant at 150 d in milk, and decrease claw disorders at 75 d postpartum.