ABSTRACT
Our objective was to investigate the effects of intravenous (IV) or intrauterine (IU) lipopolysaccharide (LPS) challenge at 5 or 40 d postpartum (DPP) on clinical signs, systemic and uterine inflammation, dry matter intake (DMI), and milk yield (MY). Holstein cows at 5 DPP (n = 23) or at 40 DPP (n = 24) were blocked by parity and randomly assigned to one of 3 treatments: 1) IV-LPS [0.0625 µg/kg BW (5 DPP) or 0.1 µg/kg BW (40 DPP) over 1h], 2) IU-LPS [100 µg (5 DPP) or 300 µg (40 DPP) in 20 mL saline], or 3) 20 mL saline IU (IU-SAL; same for 5 and 40 DPP). The proportion of polymorphonuclear (PMN) cells was measured by endometrial cytology at d -1, 1, 4, and 7 relative to treatment. Blood haptoglobin (Hp), serum-amyloid A (SAA), and LPS-binding protein (LBP), DMI, and MY were measured from d -1 through 7. Data were analyzed separately for each DPP group in multivariable linear regression models accounting for repeated measures. For both DPP groups, there were increases in rectal temperature, heart and respiratory rates, and a decrease in rumination rate following IV-LPS, but not following IU-LPS. At 5 DPP, endometrial PMN proportion was similar in IU-LPS and IU-SAL. Serum Hp was unaffected by LPS challenge, SAA was greater in IV-LPS from 12 to 24 h after challenge, and LBP was greater in IV-LPS from 8 to 24 h. At 40 DPP, PMN was greater in IU-LPS (37 ± 4%) than in IU-SAL (15 ± 4%) 1 d after LPS challenge. Serum Hp was greater from 24 to 72 h after challenge in IV-LPS than in the other groups, SAA was greater in IV-LPS from 6 to 48 h, and LBP was greater in IV-LPS from 8 to 24 h. At both 5 and 40 DPP, treatment did not affect DMI, but MY was lesser in IV-LPS cows at 12 and 24 h than in IU-SAL or IU-LPS. The IV-LPS challenge resulted in more pronounced changes in clinical signs and acute phase protein (APP) concentrations than IU-LPS or IU-SAL at 40 DPP, but more subtle or inconsistent changes at 5 DPP. These may be due to the different doses of LPS used at 5 and 40 DPP or possibly due to the high variation in baseline clinical signs and APP observed in all groups at 5 DPP. The IU-LPS increased uterine PMN 1 d after challenge at 40 DPP, but not at 5 DPP. At each time, IU-LPS did not produce changes in clinical signs or markers of systemic inflammation.
ABSTRACT
Our objectives were to evaluate the effects of complete replacement of supplementary inorganic salts of trace minerals (ITM; cobalt (Co), copper (Cu), manganese (Mn), zinc (Zn) sulfates and sodium (Na) selenite) by organic trace minerals (OTM; Co, Cu, Mn, Zn proteinates, and selenized yeast) in both pre- and postpartum diets on trace minerals (TM) concentrations in body fluids and liver, antioxidant and inflammation biomarkers in blood, and postpartum health of dairy cows. Pregnant cows were blocked by parity and body condition score and randomly assigned to ITM (n = 136) or OTM (n = 137) 45 d before expected calving. Both groups received the same pre- and postpartum diets except for the source of supplementary TM. The day of calving was considered study d 0 and blood was collected on d -45, -21, -14, -10, -7, -3, 0, 3, 7, 10, 14, 23, 65, and 105 for analyses of TM and biomarkers. Concentrations of TM were also investigated in the liver (d 105), milk (d 7, 23, 65, 105), urine (d -21, 21, 65, 105), ruminal fluid and feces (d -21, 21, 65). Incidence of clinical and subclinical health conditions were evaluated. Complete replacement of ITM by OTM resulted in greater concentration of selenium (Se) in serum (0.084 vs. 0.086 µg/mL; P < 0.01), milk (0.24 vs. 0.31 µg/g; P < 0.01), and ruminal fluid (0.54 vs. 0.58 µg/g; P = 0.06), and reduced concentration of Se in urine (1.54 vs. 1.23 µg/g; P<0.01). For concentration of Co in serum, an interaction between treatment and time was detected (P < 0.01). Cows supplemented with OTM had greater concentrations of Co on d -7 and 0 (0.30 vs. 0.33 ng/mL; P < 0.01) but lower concentrations of Co on d 23, 65, and 105 (0.34 vs. 0.31 ng/mL; P < 0.05), in addition to reduced concentration of Co in feces (1.08 vs. 0.99 µg/g; P = 0.04) and, for multiparous only, in urine (0.019 vs. 0.014 µg/g; P < 0.01). Cows supplemented with OTM had lower postpartum concentrations of glutamate dehydrogenase (20.8 vs. 17.8 U/L; P < 0.05) and higher albumin on d -10 (36.0 vs. 36.7 g/L; P = 0.04) and 23 (36.9 vs. 37.6 g/L; P = 0.03) relative to calving. Primiparous cows fed OTM had lower concentration of ceruloplasmin in plasma (55 vs. 51 mg/L; P ≤ 0.05). Cows supplemented with OTM had less incidence of lameness (14% vs. 7%; P = 0.05), elevated nonesterified fatty acids (NEFA) (61% vs. 44%; P < 0.01), and multiple metabolic problems (35% vs. 20%; P < 0.01). Despite the lack of differences in Cu, Mn, and Zn concentrations and antioxidant capacity, complete replacement of ITM by OTM altered concentrations of Se and Co, supported liver and hoof health, and reduced the risk of postpartum elevated NEFA.
Trace minerals (TM) are important for oxidative balance and immunity of cows. Different forms of TM are available for dietary supplementation of dairy cows. We tested whether replacing inorganic salts of TM by organic sources of TM in both pre- and postpartum diets improve TM concentration in body fluids and liver, antioxidant capacity in blood, and postpartum health of dairy cows. Despite the lack of difference in antioxidant capacity and in concentrations of Cu, Mn, and Zn, the complete replacement of inorganic salts by organic sources altered concentrations of Se and Co in circulation, and reduced the concentration of biomarkers associated with inflammation and liver damage, and the risk of lameness and postpartum metabolic problems.
