Our study confirmed an increased prevalence of VC in HD patients and selected age and calcium phosphate product as the most predictive parameters. These findings support careful monitoring of calcium metabolism beginning at the early stages of end-stage renal failure to reduce the risk of heart disease.

The objectives of the current experiment were to characterize the correlation among total serum Ca, nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), and haptoglobin concentrations and daily rumination time (DRT) and activity of periparturient cows and to determine the association between periparturient events and peripartum DRT and activity. Holstein animals (nulliparous = 77, parous = 219) were enrolled in the experiment approximately 21 d before expected calving date. Cows were fitted with individual Heat Rumination Long Distance collars (HRLD, SCR Engineers Ltd., Netanya, Israel) from enrollment until approximately 21 ± 3 d postpartum. Blood samples collected weekly from enrollment to 21 d postpartum were used to determine concentrations of NEFA, BHBA, and haptoglobin. Blood samples collected within 72 h after calving were used to determine total serum Ca concentration. Subclinical ketosis was characterized by BHBA > 1,000 µmol/L in any sample, and subclinical hypocalcemia was characterized by Ca < 8.55 ng/dL within 72 h after calving. Cows were examined 1, 7 ± 3, and 14 ± 3 d postpartum for diagnosis of retained fetal membrane and metritis. Total Ca (r = 0.15), NEFA (r = -0.27), and haptoglobin (r = -0.18) concentrations were weakly correlated with DRT. Concentration of BHBA (r = -0.14) was weakly correlated with activity. Postpartum DRT was reduced among cows that delivered twins compared with cows that delivered singletons (437.9 ± 4.8 vs. 385.9 ± 17.1 min/d). Prepartum (465.8 ± 4.1 vs 430.8 ± 14.9 arbitrary units) and postpartum (536.5 ± 5.5 vs. 480.3 ± 19.4 arbitrary units) activity were reduced among cows that delivered twins compared with cows that delivered singletons. Delivery of stillborn calves was associated with reduced DRT prepartum (478.0 ± 5.9 vs. 417.0 ± 23.4 min/d) and postpartum (437.2 ± 4.8 vs. 386.5 ± 19.3 min/d). On the other hand, cows delivering stillborn calves had increased activity prepartum compared with cows delivering live calves (499.3 ± 16.2 vs. 461.3 ± 4.1 arbitrary unit). Occurrence of retained fetal membrane tended to and was associated with reduced prepartum (444.3 ± 11.0 vs. 466.5 ± 4.3 arbitrary unit) and postpartum (488.2 ± 14.5 vs. 538.8 ± 5.7 arbitrary unit) activity, respectively. Cows diagnosed with metritis had reduced postpartum DRT (415.9 ± 10.1 vs. 441.0 ± 5.2 min/d) and activity (512.5 ± 11.5 vs. 539.2 ± 6.0 arbitrary unit). Postpartum activity was reduced among cows that were diagnosed with subclinical ketosis (502.20 ± 16.5 vs. 536.6 ± 6.2 arbitrary unit). Although differences in DRT and activity between populations of cows that developed periparturient diseases and healthy cows were observed, further experiments are necessary to determine how DRT and activity data may be used to precociously diagnose individuals that will develop such periparturient diseases.

a b s t r a c tThis experiment compared insulin resistance parameters, milk production, and reproductive outcomes in: (1) lactating dairy cows consuming adequate or excessive energy, and (2) lactating dairy cows consuming excessive energy and receiving or not Cr-propionate supplementation. Seventeen primiparous and multiparous, non-pregnant, lactating Holstein cows (initial days in milk ¼ 76 72) were assigned on d 0 to: (1) concentrate intake to meet their requirements of net energy for lactation (NE L ) without Cr supplementation (MAN; n ¼5), (2) concentrate intake to exceed their NE L requirements without Cr supplementation (HIGH; n ¼ 6), and (3) HIGH with 2.5 g/d of Cr propionate (HIGHCR; n ¼ 6). Throughout the experiment (d 0 to 210), cows were offered corn silage for ad libitum consumption, and individually received a corn-based concentrate twice daily. Concentrate intake was formulated to allow diets to provide 100% of daily NE L requirements of MAN, and 160% of daily NE L requirements of HIGH and HIGHCR cows. Cow BW, BCS, and milk production were recorded weekly. Blood samples were collected weekly, prior to and at 2 and 4 h after the morning concentrate feeding. Six glucose tolerance tests (GTT) were performed, every 42 d, by infusing cows with 0.5 g of glucose/kg of BW. Follicle aspiration for in vitro embryo production was performed via transvaginal ovum pick-up 2 d after each GTT. Increase in BCS from d 0 to 210 was greater (P r0.04) in HIGH and HIGHCR vs. MAN. Milk production was similar (P ¼0.92) between treatments. Within weekly samples, serum non-esterified fatty acids concentration were greater (P r0.05) for MAN vs. HIGH and HIGHCR. Serum insulin concentrations and insulin:glucose ratio were often greater (Pr 0.05) for HIGH, intermediate for HIGHCR, and lesser for MAN (treatment  day interaction, Po 0.01). During the GTT, serum insulin concentrations and insulin:glucose ratio were greater (P r0.05) for HIGH compared with HIGHCR and MAN from 10 to 60 min relative to the time of glucose infusion. Proportion of embryo produced per oocyte collected was greater (Pr 0.02) for MAN vs. HIGH and HIGHCR, and similar (P ¼0.59) between HIGH and HIGHCR. In conclusion, lactating cows consuming excessive concentrate and NE L experienced increased insulin resistance and reduced proportion of embryo produced per oocyte collected compared with cows consuming adequate amounts of energy, whereas Cr-propionate supplementation was effective in alleviating insulin resistance caused by excessive NE L intake.

This experiment compared performance and physiological responses of the offspring from cows supplemented with Ca salts of PUFA or SFA + MUFA during late gestation. Ninety-six multiparous, nonlactating, pregnant Angus × Hereford cows were ranked by BW, BCS, and age and divided into 24 groups of 4 cows/group at the end of their second trimester of gestation (d -7). Cows conceived during the same estrus synchronization + AI protocol, with semen from a single sire; hence, gestation length was 195 d for all cows at the beginning of the experiment (d 0). Groups were randomly assigned to receive (DM basis) 405 g/cow daily of soybean meal in addition to 1) 190 g/cow daily of Ca salts of PUFA based on eicosapentaenoic, docosahexaenoic, and linoleic acids or 2) 190 g/cow daily of Ca salts of SFA + MUFA based on palmitic and oleic acids (CON). Groups were maintained in 2 pastures (6 groups of each treatment/pasture) and received daily 10.1 kg/cow (DM basis) of grass-alfalfa hay. Groups were segregated into 1 of 12 drylot pens (6 by 18 m) and individually offered treatments 3 times/wk from d 0 until calving. Cow BW and BCS were recorded, and blood samples were collected on d -7 of the experiment and also within 12 h after calving. Calf BW was also recorded within 12 h of calving. Calves were weaned on d 280 of the experiment, preconditioned for 45 d (d 280 to 325), transferred to a growing lot on d 325, and moved to a finishing lot on d 445, where they remained until slaughter. At calving, PUFA-supplemented cows had a greater ( < 0.01) proportion (as % of total plasma fatty acids) of PUFA, including linoleic, linolenic, arachidonic, docosapentaenoic, and docosahexaenoic acids. At weaning, calves from CON-supplemented cows were older ( = 0.03), although no treatment differences were detected ( = 0.82) for calf weaning BW. During both growing and finishing phases, ADG was greater ( ≤ 0.06) in calves from PUFA-supplemented cows. Upon slaughter, HCW and marbling were also greater ( ≤ 0.05) in calves from PUFA-supplemented cows. Collectively, these results indicate that supplementing eicosapentaenoic, docosahexaenoic, and linoleic acids to late-gestating beef cows stimulated programming effects on postnatal offspring growth and carcass quality. Therefore, supplementing late-gestating beef cows with Ca salts of PUFA appears to optimize offspring productivity in beef production systems.