This study was undertaken to evaluate folate and vitamin B12 concentrations of colostrum and milk in early lactation of dairy cows fed different levels of energy during the dry period. A total of 84 ...multiparous Holstein cows were assigned to one of the following dietary treatments fed as a total mixed ration 57 d before the expected calving date: (1) high-energy one-group dry cow diet 1.35 Mcal of net energy for maintenance/kg of dry matter (DM); 56% corn silage, 12% wheat straw, and 32% concentrate mix on a daily DM basis; (2) controlled-energy one-group dry cow diet (1.14 Mcal of net energy for maintenance/kg of DM; 29% corn silage, 36% wheat straw, and 35% concentrate mix on a daily DM basis); or (3) an intermediate step-up diet (controlled-energy diet from dry off until 29 d before the expected calving date and then switching to a diet representing a 50:50 blend of the controlled- and high-energy diets from 28 d before expected calving date until parturition; 1.24 Mcal of net energy for maintenance/kg of DM). After calving, all cows were fed the same diet served as a total mixed ration (44% corn silage, 14% grass silage, and 42% concentrate mix on a daily DM basis) until 42 d in milk (DIM). Colostrum samples were taken at the first milking after parturition and milk samples were taken during the morning milking at 11 and 39±2 DIM. Colostrum from the first milking and milk yields were weighed on the day of sampling. Colostrum yield from the first milking postpartum and milk yields at 11 and 39 DIM were unaffected by treatments. Colostrum yield averaged 6.8±0.7mg at the first milking postpartum, whereas milk yields at 11 and 39 DIM were, on average, 40.3±1.5 and 48.9±1.3mg/d, respectively. Folate concentrations in colostrum and milk were not different among treatments. Folate concentration of colostrum (440.3±18.8ng/mL) was higher than folate concentration in milk at 11 (93.7±3.0ng/mL) and at 39 DIM (78.4±2.6ng/mL). Vitamin B12 concentration in colostrum was higher for controlled-energy cows (31.7±1.4ng/mL) than intermediate cows (23.5±1.4ng/mL), whereas no treatment effect was noted for vitamin B12 concentration in milk. At 11 and 39 DIM, milk concentrations of vitamin B12 averaged 3.8 and 3.2±1.4ng/mL, respectively. In summary, results suggest that dietary change during the dry period could modify vitamin B12 concentration in colostrum, but had no effect on milk concentration of folates and vitamin B12 during early lactation.
Background. We explored serum 25-hydroxyvitamin D (25OHD) levels and associated factors for insufficiency or deficiency in an adult human immunodeficiency virus (HIV) cohort and compared 25(OH)D ...levels with those in the general US population. Methods. Using baseline data from the Study to Understand the Natural History of HIV and AIDS in the Era of Effective Therapy (SUN), a prospective, observational cohort study of HIV-infected adults enrolled at 7 HIV specialty clinics in 4 US cities from March 2004 to June 2006, we estimated the prevalence of vitamin D insufficiency or deficiency (defined as 25(OH)D levels <30 ng/mL), standardized by age, race, and sex. Using multiple logistic regression, we examined risk factors for vitamin D insufficiency or deficiency. Results. Among 672 SUN participants with baseline serum 25(OH)D determinations who were not receiving vitamin D supplements, 70.3% (95% confidence interval CI, 68.1%–74.9%) were vitamin D insufficient or deficient, compared with 79.1% (95% CI, 76.7–81.3) of US adults. Factors associated with vitamin D insufficiency or deficiency included black race (adjusted odds ratio aOR, 4.51; 95% CI, 2.59–7.85), Hispanic ethnicity (aOR, 2.78; 95% CI, 1.31–5.90), higher body mass index (aOR, 1.04; 95% CI, 1.00–1.09), hypertension (aOR, 1.88; 95% CI, 1.10–3.22), lack of exercise (aOR, 3.14; 95% CI, 1.80–5.47), exposure to efavirenz (aOR, 1.98; 95% CI, 1.18–3.34), higher exposure to ultraviolet light (aOR, .78; 95% CI, .71–.86), renal insufficiency (aOR, .55; 95% CI, .36–.83), and exposure to ritonavir (aOR, .56; 95% CI, .35–0.89). Conclusions. Similar to findings in US adults generally, vitamin D insufficiency or deficiency is highly prevalent among HIV-infected adults and is associated with known risk factors. Observed associations of vitamin D levels with renal insufficiency and with use of ritonavir- and efavirenz-containing regimens are consistent with both HIV-related and therapy-mediated alterations in vitamin D metabolism. Clinicians should consider screening all patients for vitamin D insufficiency or deficiency.
Paraoxonase 1 (PON1) is a negative acute phase plasma protein synthesized by the liver that has anti-oxidant activity. The aim of this study was to evaluate the association of single nucleotide ...polymorphisms (SNPs) in the PON1 promoter region with plasma PON1 activity and fertility in Holstein dairy cows. Sixty-eighty Holstein cows were used in this initial investigative study. Blood samples were collected weekly beginning 28 days prior to expected calving, twice weekly in week 1 and 2 postpartum, and then once weekly through 6 weeks postpartum for plasma PON1 activity analysis. Cows were synchronized for ovulation and timed AI at 63–70 DIM using an Ovsynch program. Pregnancy diagnosis was confirmed by rectal palpation and reproductive performance data was recorded until 210 DIM. DNA was extracted from blood of each cow and a fragment of proximal PON1 gene promoter was sequenced. Seven single nucleotide polymorphisms (SNPs) were identified in the promoter region of the PON1 gene at positions −22, −105, −176, −221, −392, −611 and −676, six of which were significantly associated with plasma PON1 activity level. The SNPs −221 and −392 were significantly associated with both plasma PON1 activity and the calving to conception interval (P < 0.05) with no significant effect on calving to first ovulation interval. In conclusion, the genotypes associated with higher plasma PON1 activity in SNP locations −221 and −392 were also associated with a reduced calving to conception interval in this study set of cows. These SNPs may provide novel genetic markers for improved fertility in future larger studies in dairy cows.
•The PON1 -221 and −392 SNPs were associated with plasma PON1 activity in dairy cows.•The PON1 -221 and −392 SNPs were associated with calving conception interval in dairy cows.•The PON1 -221 and −392 SNPs may serve as novel genetic markers for improved fertility in dairy cows.
This study investigated the effect of 2 different types of long-acting insulin on milk production, milk composition, and metabolism in lactating dairy cows. Multiparous cows (n=30) averaging 88d in ...milk were assigned to one of 3 treatments in a completely randomized design. Treatments consisted of control (C), Humulin-N (H; Eli Lilly and Company, Indianapolis, IN), and insulin glargine (L). The H and L treatments were administered twice daily at 12-h intervals via subcutaneous injection for 10d. Cows were milked twice daily, and milk composition was determined every other day. Mammary biopsies were conducted on d 11, and mammary proteins extracted from the biopsies were analyzed by Western blot for components of insulin and mammalian target of rapamycin signaling pathways. Treatment had no effect on dry matter intake or milk yield. Treatment with both forms of long-acting insulin increased milk protein content and tended to increase milk protein yield over the 10-d treatment period. Analysis of milk N fractions from samples collected on d 10 of treatment suggested that cows administered L tended to have higher yields of milk protein fractions than cows administered H. Milk fat content and yield tended to be increased for cows administered long-acting insulins. Lactose content and yields were decreased by treatment with long-acting insulins. Administration of long-acting insulins, particularly L, tended to shift milk fatty acid composition toward increased short- and medium-chain fatty acids and decreased long-chain fatty acids. Plasma concentrations of glucose and urea N were lower for cows administered long-acting insulins; interactions of treatment and sampling time were indicative of more pronounced effects of L than H on these metabolites. Concentrations of nonesterified fatty acids and insulin were increased in cows administered long-acting insulins. Decreased concentrations of urea N in both plasma and milk suggested more efficient use of N in cows administered long-acting insulins. Western blot analysis of mammary tissue collected by biopsy indicated that the ratios of phosphorylated protein kinase b (Akt) to total Akt and phosphorylated ribosomal protein S6 (rpS6) to total rpS6 were not affected by long-acting insulins. Modestly elevating insulin activity in lactating dairy cows using long-acting insulins altered milk composition and metabolism. Future research should explore mechanisms by which either insulin concentrations or insulin signaling pathways in the mammary gland can be altered to enhance milk fat and protein production.
Human immunodeficiency virus (HIV)—infected patients respond poorly to hepatitis B vaccination. Records of 194 HIVinfected patients were reviewed for factors associated with successful hepatitis B ...vaccination. Thirty-four patients (17.5%) developed a protective antibody response. In a logistic regression model, only a plasma HIV RNA level of <400 copies/mL at the time of vaccination was associated with a protective antibody response (P=.003).
α-1-Acid glycoprotein (AGP) is an acute-phase protein that may suppress dry matter intake (DMI), potentially by acting on the leptin receptor in the hypothalamus. Our objectives were to characterize ...plasma AGP concentration and associations with DMI during the transition period, and to determine the utility of AGP to identify or predict cows with low DMI. Plasma samples (n = 2,086) from 434 Holstein cows in 6 studies were analyzed on d −21, −13 ± 2, −3, 1, 3, 7 ± 1, 14 ± 1, and 21 ± 1 relative to parturition. A commercially available ELISA kit specific for bovine AGP was validated, and 2 internal controls were analyzed on each plate with interplate variation of 15.0 and 17.3%, respectively. Bivariate analysis was used to assess the relationship between AGP and DMI. For significant associations, treatment(study) was added to the model, and quadratic associations were included in the model if significant. Plasma AGP concentration (±SEM) increased from 213 ± 37.3 μg/mL on d −3 to 445 ± 60.0 μg/mL on d 14. On d 3, AGP was associated negatively with DMI in a quadratic manner for wk 1 and wk 2 and linearly for wk 3. Day 7 AGP was associated negatively with DMI in a quadratic manner for wk 2 and linearly for wk 3. Similarly, d 14 AGP was negatively associated with DMI for wk 3 and wk 4. As d 3 AGP concentration increased over the interquartile range, a calculated 1.4 (8.5%), 0.5 (2.7%), and 0.4 (1.9%) kg/d reduction in predicted DMI was detected during wk 1, 2, and 3, respectively. Using bivariate analysis, d 3 AGP explained 10% of the variation in DMI during wk 1. We explored the clinical utility of d 3 AGP to diagnose low DMI, defined as wk 1 DMI >1 standard deviation below the mean. Receiver operating characteristic analysis identified a threshold of 480.9 μg/mL, providing 76% specificity and 48% sensitivity (area under the curve = 0.60). Limited associations occurred between AGP and blood biomarkers; however, AGP was associated with plasma haptoglobin concentration postpartum and incidence of displaced abomasum, retained placenta, and metritis. These results demonstrate a negative association between plasma AGP concentration and DMI in early-postpartum dairy cows, although its diagnostic performance was marginal. Further investigation into whether AGP directly suppresses DMI in dairy cattle is warranted.
Multiparous Holstein cows (n=108) were used to determine the associations of cytological endometritis (CE) with plasma nonesterified fatty acids (NEFA) and β-hydroxybutyrate (BHBA) as markers of ...energy metabolism, calculated energy balance (EB), and plasma haptoglobin (Hp) as a marker of inflammation during the periparturient period and early lactation. Evaluation of endometrial cytology by low-volume uterine lavage was conducted on 1d between 40 and 60d postcalving. The incidence of CE among cows sampled was 40%. The area under the curve (AUC) was calculated for both NEFA and BHBA using data collected from 3wk before to 3wk after parturition. Data for NEFA and BHBA AUC were stratified into prepartum (wk −3 to parturition) and postpartum (parturition to wk +3) for statistical analysis. Prepartum AUC for neither NEFA nor BHBA was associated with subsequent CE; however, cows that subsequently developed CE tended to have higher postpartum AUC for NEFA and had higher postpartum AUC for BHBA. Consistent with the results for plasma NEFA and BHBA, calculated EB during the prepartum period was not different in cows that did or did not develop CE; however, cows with CE had lower EB during the 6-wk postpartum period compared with cows without CE. Analysis of EB by week (wk −3 to −1 before calving and wk +1 to +6 postcalving) indicated that EB in cows with CE was lower at wk +1, +2, and +3 and tended to be lower at wk +6 than cows without CE. Plasma Hp concentrations were analyzed from wk +1 to +8 of lactation; concentrations of Hp were not different during either wk +1 or the entire postpartum period between cows that did or did not develop CE. These results suggest that lower energy status during the first 3wk postpartum, but not necessarily systemic inflammation, is associated with subsequent development of CE.
Four multiparous lactating cows (175 to 220 d in milk DIM) were used in a 4 x 4 Latin square design to assess the effects of four doses (0.0, 0.5, 1.0, and 1.5 microgram/kg of body weight) of ...lipopolysaccharide (LPS; Escherichia coli 0111:B4) on performance and plasma metabolite and hormone concentrations. In addition, effects of immune activation on in vitro hepatic metabolic capacity were evaluated in 12 multiparous lactating cows (150 to 220 DIM) infused with 0 (n = 6), 1.0 (n = 4) or 2.0 (n = 2) microgram of LPS/kg. Milk production and DMI decreased linearly with LPS dose for 24 h after LPS infusion. Overall mean plasma tumor necrosis factor-alpha, insulin, glucagon, and cortisol concentrations increased linearly with LPS dose, and plasma beta-hydroxybutyrate decreased linearly by dose after LPS infusion. Infusion of LPS decreased the insulin:glucagon molar ratio, but did not affect plasma concentrations of growth hormone, insulin-like growth factor-1, leptin, or L-(+)-lactate. Plasma concentrations of glucose tended to increase initially and subsequently decrease, and there was a quadratic tendency for increased plasma nonesterified fatty acid concentrations after LPS administration. In vitro hepatic capacity for conversion of 1-14CL-(+)-lactate and 1-14Cpalmitate, but not 1-14Cpropionate or 1-14CL-alanine, to CO2 increased after LPS administration. Hepatic capacity to convert 1-14Cpropionate to glucose tended to increase, but neither esterification nor the conversion of palmitate to acid soluble products was altered by LPS. The LPS infusion resulted in significant changes of endocrine mediators responsible for regulation of energy metabolism of lactating cows and tended to alter subsequent in vitro hepatic metabolic capacity.
Reduction of milk fat secretion by the use of conjugated linoleic acid (CLA) supplements may alleviate energy demands during early lactation. The objective of the present study was to evaluate ...lactational performance, net energy balance, and reproductive response of dairy cows supplemented with 2 doses of CLA from 2 wk before predicted calving until 9 wk postpartum. Holstein cows (n = 48) were divided into 3 treatment groups: 1) control, 2) low dose CLA treatment (CLA-1), and 3) high dose CLA treatment (CLA-2). Supplements for all treatments provided 230 g/d of fat; the control group received Ca salts of palm fatty acid distillate and the CLA groups received a mixture of Ca salts of CLA isomers and Ca salts of palm fatty acid distillate (31.6 and 63.2 g/d of CLA isomers for CLA-1 and CLA-2, respectively). Supplementation with CLA resulted in an 11 and 21% decrease in milk fat yield for CLA-1 and CLA-2, respectively. Milk production and secretion of other milk components did not differ among treatments. Milk energy output was significantly reduced with CLA-2, but net energy balance, body weight, and body condition scores were unaffected. Treatment had no effect on hepatic triglyceride concentration or plasma glucose and insulin, but nonesterified fatty acids tended to be lower for CLA-1. There were no consistent dose-related effects on reproduction variables, and no adverse effects were observed during the treatment or posttreatment period. Supplemental CLA was effective in reducing milk fat content, but it did not have a significant effect on milk yield or net energy balance.
Multiparous Holstein cows (n=95) were used to evaluate changes in hepatic propionate and palmitate metabolism and liver composition over time during the transition period, along with the ...relationships of these variables with cumulative increases in nonesterified fatty acids and β-hydroxybutyrate during the periparturient period. Data from 3 previous experiments were used to address the study objectives, accounting for a total of 95 multiparous Holstein cows. Liver slices from biopsies on d −21, 1, and 21 relative to parturition were used to determine conversion of 1-14Cpalmitate to CO2 and esterified products (EP) and the conversion of 1-14Cpropionate to CO2 and glucose. Hepatic glycogen content was highest on d −21 and was 26.9 and 36.5% of prepartum values on d 1 and 21, respectively. Liver triglyceride content was lowest at d −21 and was 271 and 446% of prepartum values on d 1 and 21, respectively. We detected no difference in the capacity for the liver to oxidize 1-14Cpalmitate to CO2 between d −21 and d 1; however, on d 21, oxidation was 84% of prepartum values. The capacity of the liver to convert 1-14Cpalmitate to EP was 148 and 139% of prepartum values on d 1 and 21, respectively. The capacity of liver to convert 1-14Cpropionate to CO2 was 127 and 83% of prepartum values on d 1 and 21, and the capacity of liver to convert 1-14Cpropionate to glucose was 126 and 85% of prepartum values on d 1 and 21, respectively. Correlation relationships suggest that overall, cows with elevated prepartum liver triglyceride content had elevated triglycerides throughout the transition period along with increased 1-14Cpalmitate oxidation and conversion to EP and a decreased propensity to convert 1-14Cpropionate to glucose. Cows with increased 1-14Cpropionate oxidation had increased conversion of 1-14Cpropionate to glucose throughout the transition period. Overall, conditions that lead to impairments in fatty acid metabolism during the transition period appear to be associated with impaired postpartum hepatic propionate metabolism.
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