Influence of body condition score on relationships between metabolic status and oxidative stress in periparturient dairy cows

Twenty-four dairy cows were monitored during the transition period. We observed changes of oxidative status and relationships between oxidative and metabolic status. Body condition score (BCS) of the 24 animals at the beginning of the trial (30.4 ± 2 d before expected calving) was between 2.0 and 3.6. The BCS was recorded and blood samples were collected weekly during the last 30 d of pregnancy and the first 30 DIM. Plasma samples were analyzed to determine indices of oxidative status: reactive oxygen metabolites (ROM); thiobarbituric acid-reactive substances (TBARS); thiol groups (SH); glutathione peroxidase (GSH-Px), and indices of energy metabolism: glucose, β-hydroxybutyrate, and nonesterified fatty acids. In erythrocytes we determined indices of oxidative status: GSH-Px, superoxide dismutase (SOD), and intracellular SH. Before calving, cows showed an increase of plasma SH, SOD, and GSH-Px, a decrease of erythrocyte GSH-Px and plasma ROM, and no changes in erythrocyte SH. After calving, cows showed a decrease of plasma and erythrocyte SH and SOD, and an increase of ROM, TBARS, and plasma GSH-Px. Cows with higher BCS at the beginning of the trial and greater loss of BCS after calving, had higher plasma ROM, TBARS, and SH, and lower SOD and erythrocyte SH in the postpartum period. Oxidative status of dairy cows was related to energy status. Cows with higher BHBA and NEFA showed higher ROM and TBARS and lower levels of antioxidants. Results of the present study demonstrated that cows can experience oxidative stress during the peripartum period, and cows with higher BCS and greater BCS losses are more sensitive to oxidative stress.     

Effects of pasture feeding during the periparturient period on postpartum anovulation in grazed dairy cows

Extended postpartum anovulatory intervals (PPAI) are a major contributor to infertility in seasonal dairy systems constrained to 365-d calving intervals. This study was conducted to evaluate the effects of pasture-based dietary energy intakes during the transitional calving period on PPAI. Sixty-eight multiparous Holstein-Friesian cows were assigned to high [11.9 kg of dry matter (DM)/d] or low (4.8 kg of DM/d) pasture intakes for 29 ± 7.7 d prepartum. After calving, cows within each prepartum diet were assigned to either a high (13.5 kg of DM/d) or low (8.6 kg of DM/d) pasture intake for 35 d in a 2 × 2 factorial arrangement. Progesterone concentrations were measured in milk samples collected twice weekly to determine PPAI, which was defined as the day on which progesterone level was elevated to ≥3 ng/mL with subsequent concentrations being consistent with an ovulatory cycle. Blood samples were collected before initiation of treatments, and at d −21, −14, −7, 0 (day of calving), 1, 2, 3, 4, 7, 14, 21, 28, and 35 in all cows. The PPAI was associated with body condition score, concentrations of plasma insulin and insulin-like growth factor-I, and growth hormone. Postpartum intake did not affect these metabolic hormones or PPAI, but yield of FCM during the first 35 d was reduced by 23% among cows on a restricted intake. No relationships were found between PPAI and milk production characteristics. These data demonstrate that when pasture is the sole dietary source during the calving transition period, PPAI may be influenced by prepartum intake levels, whereas postpartum intake influences milk yield, but not PPAI. The underlying mechanism(s) that associates the prepartum period to PPAI may involve the sensitivity of the growth hormone-insulin-like growth factor axis to dietary intake levels. Nonetheless, PPAI in grazing multiparous dairy cows appears largely unresponsive to intake levels during the calving transition period.     

Effect of rumen-protected niacin on lipid metabolism, oxidative stress, and performance of transition dairy cows

The objective of this study was to evaluate the effect of a rumen-protected niacin product (RPN; 65% nicotinic acid; NiaShure, Balchem Corp., New Hampton, NY) on lipid metabolism, oxidative stress, and performance of transition dairy cows. Thirty nonlactating multiparous Holstein cows in late gestation were paired according to expected calving date and randomly assigned to 12 g/cow per day of RPN product or to an unsupplemented control (CON) diet. Treatment diets were fed from 21 d before expected calving through 21 d after parturition. Blood samples were taken on d -21, -14, -7, 1, 7, 14, and 21 relative to calving for plasma nonesterified fatty acid (NEFA), β-hydroxybutyrate (BHBA), glucose, and superoxide dismutase (SOD) analyses. Liver samples were taken by biopsy on d 1 and 21 relative to calving for triglyceride (TG) analysis. Data were analyzed for a randomized complete block design with repeated measures. Pre- and postpartum dry matter intake, milk yield, and protein were unaffected by treatment. Milk fat percentage (5.08 vs. 4.44%) and somatic cell score (3.93 vs. 2.48) were reduced for RPN. Treatment × time interactions were observed for energy-corrected milk (ECM) and fat-corrected milk (FCM) yields; RPN reduced ECM and FCM yields by 8.5 and 8.9 kg/cow per day, respectively, in the first week of lactation. Although body weight and condition score decreased during the experimental period, no differences due to treatment were observed. However, calculated postpartum energy balance tended to be improved for RPN because of the reduction in ECM yield. Time and treatment × time effects were observed for plasma NEFA. On d 1 postpartum, NEFA reached 1,138±80 μEq/L for CON compared with 698±80 μEq/L for RPN. Cows supplemented with RPN tended to have lower plasma NEFA concentrations than CON cows on d 7 and 14 postpartum. Plasma BHBA, glucose, and SOD and liver TG concentrations were unaffected by treatment. In conclusion, supplementation with 12 g/cow per day of the RPN product provided a bioavailable source of niacin that modified lipid metabolism but did not affect milk yield over the first 3 wk of lactation or oxidative stress of transition dairy cows.     

Effect of a mixture of supplemental dietary plant essential oils on performance of periparturient and early lactation dairy cows

Plant essential plant oils (EO) are volatile aromatic compounds with antimicrobial activity that can alter ruminal fermentation when used as dietary supplements. A feeding trial was conducted to determine the effects of dietary supplementation of periparturient and early lactation dairy cows with a specific mixture of EO. Forty multiparous Holstein cows were randomly assigned to either control (C) or EO-supplemented (1.2 g/cow per day) total mixed rations (TMR). Feeding of treatment diets commenced 3 wk before the expected calving date and continued through 15 wk in lactation. The prepartum TMR contained 70% forage [70% corn silage, 15% alfalfa silage, and 15% wheat straw; dry matter (DM) basis]. The lactation TMR contained 50% forage (60% corn silage, 33% alfalfa silage, 7% alfalfa hay; DM basis). Prepartum and lactation TMR were formulated to contain 12 and 17% CP (DM basis), respectively. There were no differences between treatments for prepartum DM intake (DMI), but DMI was 1.8 kg/d less for EO than C on average across the 15-wk lactation trial. Plasma concentrations of glucose, nonesterified fatty acids, β-hydroxybutyrate, and urea-N on samples collected −21, −14, −7, −1, 1, 8, 15, 22, and 29 d relative to calving were unaffected by treatment. There were no differences between treatments for actual or fat-corrected milk yields on average across the 15-wk lactation trial. Milk protein content was 0.15% units less for EO than C. Feed efficiency (kg of milk per kg of DMI) tended to be greater for EO than C on average and was greater during wk 8 to 14 of lactation. Prepartum and lactation body weight and condition score measurements were unaffected by treatment. There was no benefit to EO in prepartum dairy cows. Dietary supplementation with EO reduced DMI in early lactation dairy cows with no effect on milk yield.     

Heat stress abatement during the dry period influences metabolic gene expression and improves immune status in the transition period of dairy cows

Heat stress (HT) and photoperiod affect milk production and immune status of dairy cows. The objective was to evaluate the effects of HT abatement prepartum under controlled photoperiod on hepatic metabolic gene expression and cellular immune function of periparturient Holstein cows (n = 21). Cows were dried off 46 d before expected calving date and assigned to treatments by mature equivalent milk production. The treatments were 1) HT and 2) cooling (CL), both imposed during a photoperiod of 14L:10D. Rectal temperature was measured twice daily, whereas respiration rate was measured 3 times/wk at 1500 h during the entire dry period. After calving, cows were housed in a freestall barn with cooling, and milk yield was recorded daily up to 140 d in milk. Liver samples were taken at dry off, −20, 2, and 20 d relative to calving by biopsy. Under a similar schedule, neutrophil function was determined in blood of cows on HT (n = 12) and CL (n = 9). Blood samples were taken on −46, −32, −18, 0, 14, 28, and 42 d relative to calving for measurement of metabolites and were collected twice daily from −7 to 2 d relative to calving for prolactin (PRL) analysis. The HT cows had greater concentrations of PRL at 0 d relative to calving (150 vs. 93; SEM = 11 ng/mL) and had higher afternoon rectal temperatures (39.4 vs. 39.0; SEM = 0.04°C) and elevated respiration rates (78 vs. 56; SEM = 2 breaths/min) during the prepartum period compared with CL cows. Relative to HT cows, CL cows had greater hepatic expression of PRL-R, SOCS-3, and CAV-1 mRNA. Neutrophil oxidative burst was greater in CL cows relative to HT cows at 2 d (61 vs. 42; SEM = 6%) and at 20 d (62 vs. 49; SEM = 5%) relative to calving, and phagocytosis was greater in CL cows at 20 d (47 vs. 33; SEM = 4%) relative to calving compared with HT cows. Humoral response, as measured by IgG secretion against ovalbumin challenge, was greater for CL cows at −32 d (0.44 vs. 0.33; SEM = 0.05 OD) and −21 d (0.60 vs. 0.50 ± 0.04 OD) relative to calving compared with HT cows. These results suggest that HT abatement during the dry period improved innate and acquired immune status as measured by neutrophil function and immunoglobulin secretion against ovalbumin challenge, and altered hepatic gene expression related to PRL signaling in the periparturient period or subsequent lactation.     

Effects of encapsulated niacin on metabolism and production of periparturient dairy cows

Nicotinic acid (niacin) can suppress lipolysis, but responses to dietary niacin have been inconsistent in cattle. Our aim was to determine if 24 g/d of encapsulated niacin (EN; providing 9.6 g/d of bioavailable nicotinic acid) alters lipid metabolism and productivity of transition cows. Beginning 21 d before expected calving, primiparous (n = 9) and multiparous (n = 13) cows (body condition score of 3.63 ± 0.08) were sequentially assigned within parity to EN (12 g provided with ration twice daily) or control through 21 d postpartum. Liver biopsies were collected on d −21, −4, 1, 7, and 21 relative to parturition. Blood samples were collected on d −21, −14, −7, −4, 1, 4, 7, 14, and 21 relative to parturition. On d 7 postpartum, a caffeine clearance test was performed to assess liver function, and on d 21 to 23 postpartum, blood samples were collected every 8 h to monitor posttreatment nonesterified fatty acid (NEFA) responses. Data were analyzed using mixed models with repeated measures over time. A treatment × time × parity effect was observed on prepartum dry matter intake (DMI), which was caused by a 4 kg/d decrease in DMI of EN-treated multiparous cows compared with control multiparous cows during the final 4 d prepartum. A significant increase in plasma nicotinamide concentration occurred in EN-treated cows on d −7 and 21 relative to parturition. Prepartum glucose concentration decreased in treated animals, with no difference in plasma insulin concentration. Treatment × time × parity effects were detected for NEFA and β-hydroxybutyrate concentrations during the postpartum period. Plasma NEFA peaked at 1,467 ± 160 μM for control animals compared with 835 ± 154 μM for EN-treated animals. After treatments ended on d 21, no evidence was found for a plasma NEFA rebound in either parity group. A treatment × parity × time interaction was detected for liver triglyceride content, indicating a tendency for less liver triglyceride in EN-treated primiparous cows, but caffeine clearance rates were not affected by treatment. No treatment effects were observed for body condition score, body weight, energy balance, or milk or milk component production. A high dose of EN can decrease postpartum plasma NEFA concentration, but may also decrease prepartum DMI.     

Comparison of shortened and conventional dry period management strategies

The aim of this study was to compare 2 dry-cow management strategies and evaluate the effect of shortened dry period strategy on feed intake, metabolism, and postpartum performance of dairy cows in early lactation. Twenty-nine high-yielding dairy cows were divided into 2 groups. The control (CON) group (n = 14) was assigned to a traditional dry period of approximately 60 d (57 ± 5.9 d) and was fed a far-off dry cow ration from dry-off to −21 d relative to expected parturition. From d −21 relative to expected parturition, the cows were switched to a precalving ration containing an additional 3 kg of concentrates. The cows of the experimental group (n = 15) were assigned to a shortened dry period (SDP; 35 ± 6.3 d) and were continuously fed a late-lactation diet from d −60 d relative to expected parturition until calving. After calving, both groups were fed the same lactation diet corresponding to their lactation requirements and cows were followed for 100 d of lactation. Prepartum dry matter intake of the cows assigned to an SDP and fed a late-lactation diet was approximately 4.11 kg/cow per day greater compared with the CON group during the 60 d. However, no effect of dry period strategy on postpartum dry matter intake was detected. The cows with an SDP produced approximately 2.78 kg/d (6.9%) less milk in the first 100 d of lactation than CON cows; the difference was not statistically significant. No differences were observed in live body weight, body condition score, or back-fat thickness between the treatments. Similarly, no differences existed in concentrations of plasma metabolites. The cows of the SDP group showed lower pH and increased concentrations of lactic acid and volatile fatty acids prepartum than the CON cows. Postpartum concentrations of lactic acid, volatile fatty acids, and NH₃ and pH in rumen fluid did not differ between the treatments. Shortening of the dry period did not affect the colostrum quality or birth weights of the calves. Based on the results of this study, a traditional dry period management strategy appeared to be more favorable, considering the dry matter intake and milk production, compared with an SDP and feeding a late-lactation diet throughout the dry period.     

Supplemental Smartamine M or MetaSmart during the transition period benefits postpartal cow performance and blood neutrophil function

The onset of lactation in dairy cows is characterized by severe negative energy and protein balance. Methionine availability during this time for milk production, hepatic lipid metabolism, and immune function may be limiting. Supplementing Met to peripartal diets with adequate Lys in metabolizable protein (MP) to fine-tune the Lys:Met ratio may be beneficial. Fifty-six multiparous Holstein cows were fed the same basal diet from 50 d before expected calving to 30 d in milk. From −50 to −21 d before expected calving, all cows received the same diet [1.24 Mcal/kg of dry matter (DM), 10.3% rumen-degradable protein, and 4% rumen-undegradable protein] with no Met supplementation. From −21 d to expected calving, the cows received diets (1.54 Mcal/kg of DM, 10% rumen-degradable protein, and 5.1% rumen-undegradable protein) with no added Met (control, CON; n = 14), CON plus MetaSmart (MS; Adisseo Inc., Antony, France; n = 12), or CON plus Smartamine M (SM; Adisseo Inc.; n = 12). From calving through 30 d in milk, the cows received the same postpartum diet (1.75 Mcal/kg of DM and 17.5% CP; CON), or the CON plus MS or CON plus SM. The Met supplements were adjusted daily and top-dressed over the total mixed ration at a rate of 0.19 or 0.07% (DM) of feed for MS or SM. Liver tissue was collected on −10, 7, and 21 d, and blood samples more frequently, from −21 through 21 d. Data were analyzed using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC) with the preplanned contrasts CON versus SM + MS and SM versus MS. No differences in prepartal DM intake (DMI) or body condition score were observed. After calving, body condition score was lower (2.6 vs. 2.8), whereas DMI was greater (15.4 vs. 13.3 kg/d) for Met-supplemented cows. Postpartal diet × time interactions were observed for milk fat percentage, milk fat yield, energy-corrected milk:DMI ratio, and energy balance. These were mainly due to changes among time points across all treatments. Cows supplemented with either Met source increased milk yield, milk protein percentage, energy-corrected milk, and milk fat yield by 3.4 kg/d, 0.18% units, 3.9 kg/d, and 0.18 kg/d, respectively. Those responses were associated with greater postpartum concentration of growth hormone but not insulin-like growth factor 1. There was a diet × time effect for nonesterified fatty acid concentration due to greater values on d 7 for MS; however, liver concentration of triacylglycerol was not affected by diet or diet × time but increased postpartum. Blood neutrophil phagocytosis at 21 d was greater with Met supplementation, suggesting better immune function. Supplemental MS or SM resulted in a tendency for lower incidence of ketosis postpartum. Although supplemental MS or SM did not decrease liver triacylglycerol, it improved milk production-related traits by enhancing voluntary DMI.     

Postpartum supplementation of fermented ammoniated condensed whey improved feed efficiency and plasma metabolite profile

Postpartum dietary supplementation of gluconeogenic precursors may improve the plasma metabolite profile of dairy cows, reducing metabolic disorders and improving lactation performance. The objective of this trial was to examine the effects of supplementation with fermented ammoniated condensed whey (FACW) postpartum on lactation performance and on profile of plasma metabolites and hormones in transition dairy cows. Individually fed multiparous Holstein cows were blocked by calving date and randomly assigned to control (2.9% dry matter of diet as soybean meal; n = 20) or FACW (2.9% dry matter of diet as liquid GlucoBoost, Fermented Nutrition, Luxemburg, WI; n = 19) dietary treatments. Treatments were offered from 1 to 45 d in milk (DIM). Cows were milked twice a day. Dry matter intake and milk yield were recorded daily and averaged weekly. Individual milk samples from 2 consecutive milkings were obtained once a week for component analysis. Rumen fluid was collected (n = 3 cows/treatment) at 4 time points per day at 7 and 21 DIM. Blood samples were collected within 1 h before feeding time for metabolite analysis and hyperketonemia diagnosis. Supplementation of FACW improved feed efficiency relative to control; this effect may be partially explained by a marginally significant reduction in dry matter intake from wk 3 to 7 for FACW-supplemented cows with no detected FACW-driven changes in milk yield, milk protein yield, and milk energy output compared with control. Also, there was no evidence for differences in intake of net energy for lactation, efficiency of energy use, energy balance, or body weight or body condition score change from calving to 45 DIM between treatments. Supplementation of FACW shifted rumen measures toward greater molar proportions of propionate and butyrate, and lesser molar proportions of acetate and valerate. Cows supplemented with FACW had greater plasma glucose concentrations in the period from 3 to 7 DIM and greater plasma insulin concentrations compared with control. Plasma nonesterified fatty acid and β-hydroxybutyrate concentrations were decreased in cows supplemented with FACW compared with control cows in the period from 3 to 7 DIM. These findings indicate that FACW may have improved the plasma metabolite profile immediately postpartum in dairy cows. Additionally, supplementation of FACW resulted in improved feed efficiency as accessed by measures of milk output relative to feed intake.     

Biomarkers of inflammation,metabolism, and oxidative stress in blood,liver, and milk reveal a better immunometabolic status in peripartal cows supplemented with Smartamine M or MetaSmart

The peripartal dairy cow experiences a state of reduced liver function coupled with increased inflammation and oxidative stress. This study evaluated the effect of supplementing basal diets with rumen-protected Met in the form of MetaSmart (MS) or Smartamine M (SM) (both from Adisseo Inc., Antony, France) during the peripartal period on blood and hepatic biomarkers of liver function, inflammation, and oxidative stress. Thirty-seven multiparous Holstein cows were fed the same basal diet from −50 to −21 d relative to expected calving [1.24 Mcal/kg of dry matter (DM); no Met supplementation]. From −21 d to calving, the cows received diets (1.54 Mcal/kg of DM) with no added Met (control, CON; n = 13), CON plus MS (n = 11), or CON plus SM (n = 13). From calving through 30 d in milk (DIM), the cows received the same postpartal diet (1.75 Mcal/kg of DM; CON), or CON plus MS or CON plus SM. Liver and blood samples were harvested at various time points from −21 to 21 d relative to calving. Preplanned contrasts of CON versus SM + MS during prepartum (−21 and −10 d before calving) and postpartum (7, 14, and 21 d after calving) responses were evaluated. Cows fed MS or SM compared with CON had lower overall concentrations of plasma ceruloplasmin and serum amyloid A (SAA). Compared with CON, Met-supplemented cows had greater overall plasma oxygen radical absorbance capacity. Liver concentrations of glutathione and carnitine also were greater overall with Met supplementation. Milk choline and liver phosphatidylcholine were lower overall in cows fed Met compared with controls. Liver tissue choline concentrations did not differ. Data indicate that supplemental Met enhanced de novo glutathione and carnitine synthesis in liver and, thus, increased antioxidant and β-oxidation capacity. The greater decrease of IL-6 after calving coupled with lower ceruloplasmin and SAA in Met-supplemented cows indicated a reduction in proinflammatory signaling within liver. The lower hepatic phosphatidylcholine in Met-supplemented cows might have been associated with greater assembly or export of very low density lipoproteins. Overall, biomarker analyses in blood and tissue indicate that the beneficial effect of feeding SM and MS on postpartal cow performance is due in part to a better immunometabolic status.     

Feeding lactose to increase ruminal butyrate and the metabolic status of transition dairy cows

Twenty-four multiparous Holstein cows (775 ± 24 kg body weight; 3.4 ± 0.11 body condition score) were used in a randomized complete block design experiment to determine the impact of increased ruminal butyrate from the fermentation of lactose on metabolism and lactation. Dietary treatments were either a corn-based control diet (CON) or a diet containing lactose at 15.7% of diet dry matter (LAC). Experimental diets were fed from 21 d before expected calving through 21 d in milk (DIM). Blood was sampled at −21, −14, −7, −2, 2, 7, 14, and 21 DIM, rumen fluid at −21, −7, and 7 DIM, and liver tissue via biopsy at 7 and 14 DIM. Pre- and postpartum dry matter intake (DMI) through 28 DIM averaged 12.8 and 17.7 kg/d, respectively, and did not differ between treatments; however, cows fed LAC did not exhibit a prepartum decrease in DMI. Milk yield was unaffected by treatments and averaged 45.7 kg/d during the first 70 DIM. Plasma glucose, insulin, and non-esterified fatty acids were not affected by dietary treatments. Feeding LAC increased the ruminal proportion of butyrate both pre- (11.3 vs. 9.2 ± 0.45%) and postpartum (13.0 vs. 10.3 ± 0.67%). Likewise, circulating plasma β-hydroxybutyrate was increased both pre- (6.1 vs. 4.2 ± 0.31 mg/dL) and postpartum (14.6 vs. 8.34 ± 1.7 mg/dL) when feeding LAC compared with CON. Liver lipid content was decreased (8.6. vs. 14.7 ± 1.5% of wet weight) in cows fed LAC relative to those fed CON, whereas liver glycogen was not affected by dietary treatments. Feeding lactose to transition dairy cows increased the proportion of butyrate in the rumen and β-hydroxybutyrate in plasma and decreased liver lipid but did not affect lactation performance.     

Comparison of peripartum metabolic status and postpartum health of Holstein and Montbéliarde-sired crossbred dairy cows

Objectives of the current experiment were to evaluate plasma concentrations of metabolites and haptoglobin peripartum, uterine health and involution, and follicle growth and resumption of cyclicity of Holstein (HO) and Montbéliarde-sired crossbred cows. Cows (52 HO and 52 crossbred) were enrolled in the study 45 d before expected calving date. Cows had body weight and body condition score recorded on d −45, −14, 0, 1, 28, and 56 relative to calving. Dry matter intake was calculated for a subgroup of cows (25 HO and 38 crossbred) from 6 wk before to 6 wk after calving. Blood was sampled weekly from d −14 to 56 relative to calving for determination of glucose, nonesterified fatty acid, and β-hydroxybutyrate concentrations; from d −7 to 21 relative to calving for determination of haptoglobin concentration; and from d 14 to 56 postpartum for determination of progesterone concentration. Cows were examined at calving and on d 4, 7, 10, and 14 postpartum for diagnosis of postparturient diseases, on d 24 postpartum for diagnosis of purulent vaginal discharge, and on d 42 postpartum for diagnosis of subclinical endometritis. Uteri and ovaries were examined by ultrasonography every 3 d from d 14 to 41 postpartum. Milk yield and composition were measured monthly and yield of milk, fat, protein, and energy-corrected milk were recorded for the first 90 d postpartum. Body weight was not different between Holstein and crossbred cows, but HO cows had reduced body condition score compared with crossbred cows. Even though DMI from 6 wk before to 6 wk after calving tended to be greater for HO cows (16.8 ± 0.7 vs. 15.3 ± 0.5 kg/d), HO cows tended to have more pronounced decline in dry matter intake, expressed in percentage of body weight from d −15 to 0 relative to calving. Energy-corrected milk and nonesterified fatty acid and β-hydroxybutyrate concentrations were not different between breeds. No differences were observed in incidence of retained fetal membranes, metritis, and subclinical endometritis, but HO cows tended to be more likely to have pyrexia from d 0 to 15 postpartum (50.0 vs. 31.4%) and to have greater incidence of purulent vaginal discharge (44.2 vs. 26.5%) than crossbred cows. Holstein cows were more likely to have at least 1 uterine disorder postpartum than crossbred cows (63.5 vs. 36.7%). No differences between breeds were observed in uterine involution. Holstein cows had larger subordinate follicles (10.1 ± 0.4 vs. 8.9 ± 0.5) and a greater number of class III follicles (1.6 ± 0.1 vs. 1.2 ± 0.1) than crossbred cows. Furthermore, the first corpus luteum postpartum of HO cows was diagnosed at a slower rate compared with crossbred cows. Crossbred cows had improved uterine health compared with HO cows and this may have been a consequence of heterosis and (or) breed complementarity and less pronounced decrease in DMI during the last days of gestation.     

Effects of dietary butyrate supplementation and oral nonsteroidal anti-inflammatory drug administration on serum inflammatory markers and productivity of dairy cows during the calving transition

Dairy cattle experience inflammation during the calving transition period, and butyrate and nonsteroidal anti-inflammatory drugs (NSAID) are expected to reduce the inflammation. Our objective was to evaluate the effects of dietary butyrate supplementation and oral NSAID administration on feed intake, serum inflammatory markers, plasma metabolites, and milk production of dairy cows during the calving transition period. Eighty-three Holstein cows were used in the experiment with a 2 × 2 factorial arrangement of treatments. The cows were blocked by parity and calving date, and randomly assigned to a dietary butyrate or control supplement, and NSAID or a placebo oral administration. Experimental diets were iso-energetic containing calcium butyrate at 1.42% of diet dry matter (DM) or the control supplement (1.04% commercial fat supplement and 0.38% calcium carbonate of diet DM). The close-up diets contained 13.3% starch and 42.4% neutral detergent fiber on a DM basis, and were fed from 28 d before expected calving date until calving. The postpartum diets contained 22.1% starch and 34.1% neutral detergent fiber on a DM basis and were fed from calving to 24 d after calving. Oral NSAID (1 mg of meloxicam/kg of body weight) or placebo (food dye) was administered 12 to 24 h after calving. Dietary butyrate supplementation and oral NSAID administration did not affect milk yield or postpartum serum concentrations of amyloid A and haptoglobin. However, butyrate-fed cows increased plasma fatty acid concentration on d ?4 relative to calving (501 vs. 340 μEq/L) and tended to increase serum haptoglobin concentration (0.23 vs. 0.10 mg/mL). There was a supplement by drug interaction effect on plasma glucose concentration on d 4; in cows administered the placebo drug, butyrate supplementation decreased plasma glucose concentration compared with control-fed cows (62.8 vs. 70.1 mg/dL). Butyrate-fed cows tended to have lower milk crude protein yield compared with cows fed the control diet (1.21 vs. 1.27 kg/d). Dietary butyrate supplementation and oral NSAID administration did not have overall positive effects on production performance of dairy cows during the calving transition period.     

Short communication: Relationship between body condition score and plasma adipokines in early-lactating Holstein dairy cows

We hypothesized that plasma adipokine concentrations of early-lactation dairy cows are related to body condition score (BCS) at calving and to markers of metabolic status of the cow. As part of a larger study with 117 multiparous Holstein dairy cows, which had high BCS (BCS >4.0) or normal BCS (3.25–3.5) at calving, 22 cows were randomly selected (n = 11 per group) to be enrolled in this study. Cows were divided into 2 groups based on their BCS at calving: (1) normal BCS with BCS of 3.35 ± 0.13 (mean ± SD) and (2) high BCS cows with BCS of 4.14 ± 0.17. The 22 selected animals did not have a clinically diagnosed health problem after calving. Blood samples were taken right after calving (d 1) and before morning feeding on d 8, 15, and 21 postpartum concurrently with body condition scoring for all cows. Blood samples were analyzed for plasma adiponectin, leptin, tumor necrosis factor-α, and IL-6. The mean BCS remained highest in high-BCS cows during the first 21 d in milk. Leptin concentrations decreased progressively for all cows after calving. However, differences in BCS at calving were not related to leptin concentrations. Adiponectin, IL-6, and tumor necrosis factor-α concentrations were neither influenced by days in milk nor BCS after calving. Leptin and the leptin-to-adiponectin ratio did not show any correlation at any time point during the first 21 d in milk with plasma concentrations of nonesterified fatty acids or β-hydroxybutyrate, which are considered as markers of metabolic status. Only for IL-6 at d 8 did we find a strong correlation with metabolic status indicators. In conclusion, plasma adipokine concentrations during the first 3 wk postpartum were not related to BCS in lactating Holstein cows that were clinically healthy at calving.     

Effect of protein level and methionine supplementation on dairy cows during the transition period

Cows experience a significant negative protein balance during the first 30 d of lactation. Given the functional effects of AA on health, especially in challenging periods such as calving, higher levels of protein and specific AA in the diet may act to improve health and feed intake. The response of dairy cows to 3 protein supplementation strategies during the transition period and through the first 45 d in milk was evaluated. The final data set had 39 Holstein cows blocked based on parity (primiparous vs. multiparous) and expected calving and randomly assigned within each block to one of 3 dietary treatments: low protein (LP), high protein (HP), or high protein plus rumen-protected methionine (HPM). Treatments were offered from d ?18 ± 5 to 45 d relative to parturition. Pre- and postpartum diets were formulated for high metabolizable protein (MP) supply from soybean meal, and HP and HPM provided higher MP balance than LP. Preplanned contrasts were LP versus HP+HPM and HP versus HPM. Significance was declared at P ≤ 0.05 and trends at 0.05 < P ≤ 0.10. Cows fed HP and HPM had greater fry matter intake (DMI) prepartum than LP (+2 kg/d), and there was a trend for greater DMI with HPM than with HP (+1.6 kg/d). Body weight and condition score before and after calving did not differ among treatments. High protein (HP and HPM) tended to increase milk yield during the first 45 d of lactation (+1.75 kg/d), increased milk lactose content and urea-N in milk and plasma, tended to increase blood BHB 14 d postpartum, and tended to reduce milk/DMI compared with LP. Blood concentrations of calcium at calving and of glucose, and nonesterified fatty acids pre- and postpartum did not differ. High protein induced lower concentration of plasma IL-1 at calving and lowered blood lymphocytes 21 d postpartum, suggestive of a reduced inflammatory status compared with LP. The concentrations of IL-10, tumor necrosis factor alpha, and other hemogram variables did not differ among treatments. Addition of rumen-protected methionine to the HP diet did not alter milk yield but increased fat and total solids concentrations. The rumen-protected methionine had no effect on blood metabolites and immunity markers, with the exception of increased pre-partum insulin concentrations. The data indicate that dairy cows around calving respond positively to an increase in the supply of MP and to rumen-protected methionine supplementation of the HP diet by increasing intake and improving immune status.     

Effects of dry period length on milk production and health of dairy cattle

Holstein cows (n = 781) in a commercial dairy herd were used in a randomized design to evaluate 2 dry period (DP) management strategies on milk production, milk components, milk quality, colostrum quality, and incidence of metabolic disorders. Cows were randomly assigned to a traditional 55 d (T) or shortened 34 d (S) DP. Cows assigned to T were fed a low-energy diet until 34 d before expected calving at which time all cows were fed a moderate-energy transition diet until calving. Postpartum, cows assigned to T produced more milk and tended to produce more solids-corrected milk than cows on S. Treatment differences in milk and solids-corrected milk yield were accounted for by cows in their second lactation. Milk fat percentage did not differ between treatments, but milk protein percentage was greater for cows assigned to S. Colostrum quality measured as IgG concentration did not differ between management strategies. Somatic cell score and cases of mastitis were not affected by management strategy. There was a tendency for prepartum nonesterified fatty acid (NEFA) to be lower for cows assigned to T compared with S. However, postpartum, cows assigned to S had significantly lower NEFA concentrations than those assigned to T. The incidences of ketosis, retained placenta, displaced abomasum, and metritis did not differ between treatments. Postpartum energy balance, as indicated by plasma NEFA, may have been improved for cows assigned to S; there was no detectable effect on animal health.     

Changes in plasma electrolytes,minerals, and hepatic markers of health across the transition period in dairy cows divergent in genetic merit for fertility traits and postpartum anovulatory intervals

Peripartum metabolism and subsequent reproductive performance of dairy cows are linked, with maladaptation over the transition period associated with poor reproductive success. A herd of seasonal calving, grazing dairy cows was established that differed in their genetic merit for fertility traits. The heifers were produced by a customized mating program to achieve a 10-percentage point divergence in the New Zealand fertility breeding value (FertBV) as follows: +5 FertBV (POS) versus ?5% FertBV (NEG), while also limiting divergence in other breeding values, including body weight, body condition score, and milk production. In this study, we aimed to characterize differences in metabolic, mineral, and metabolic stress marker profiles during their first postpartum transition period as primiparous heifers and to examine if animals with longer postpartum anestrous intervals (PPAI; more than 66 d compared with less than 35 d) had greater metabolic dysfunction. Blood was sampled at ?21, ?14, ?7, 0, 4, 7, 10, 14, 17, 21, 28, and 35 d relative to calving in 455 primiparous cows and plasma analyzed. The NEG cows had lower concentrations of both plasma nonesterified fatty acids and β-hydroxybutyrate at d 7 compared with POS cows. Detailed temporal profiling of various metabolic, mineral, and metabolic stress markers was undertaken in a subset of cows (n = 70). Cows were selected retrospectively to create 4 groups in a 2 × 2 factorial design with either a POS or NEG FertBV and either a short (19–35 d) or long (66–131 d) PPAI. The NEG cows tended, on average, to have lower nonesterified fatty acids and β-hydroxybutyrate concentrations compared with POS cows across the transition period. Mean body weight and body condition score was greatest in NEG cows when compared with the POS cows and an interaction with day demonstrated this only occurred precalving. They also had indications of improved liver health precalving, with higher albumin-to-globulin ratios and lower bilirubin concentrations. Concentrations of aspartate aminotransferase were lower, and the Na-to-Cl ratio was greater in cows with a long versus a short PPAI at d 28 and d 35 after calving, potentially because of cows with a short PPAI (19–35 d) returning to estrous during this time. Magnesium concentrations were lower in NEG cows with a short PPAI from d 21 onwards, indicating NEG cows may metabolically respond to estrous differently than POS cows. The NEG-long PPAI cows had greater gamma-glutamyl transferase concentrations from calving until d 28 and lower bilirubin concentrations throughout the transition period. Together, the results demonstrate significant effects of FertBV on peripartum metabolic status. However, most of the markers tested returned to reference intervals within 4 d after calving or remained within those intervals for the whole transition period, indicating relatively minor biological effects of FertBV on transition period adaptation. The profound differences in reproductive performance among the groups was not explained by underlying differences in metabolic responses during the transition period.     

Effect of prepartum anionic supplementation on periparturient feed intake, health, and milk production

Our objectives were to determine if dietary cation-anion difference (DCAD) and source of anions influence periparturient feed intake and milk production of dairy cattle during the transition period. Diets differed in DCAD (cationic or anionic) and anionic supplement. The 4 diets used prepartum were (1) control [DCAD +20 mEq/100 g of dry matter (DM)], (2) Bio-Chlor (DCAD −12 mEq/100 g of DM; Church & Dwight Co. Inc., Princeton, NJ), (3) Fermenten (DCAD −10 mEq/100 g of DM; Church & Dwight Co. Inc.), and (4) salts (DCAD −10 mEq/100 g of DM). Urine pH was lower for cows that consumed an anionic diet prepartum compared with control. Prepartum diet had no effect on prepartum dry matter intake (DMI) of multiparous or primiparous cows. Postpartum DMI and milk yield for multiparous cows fed anionic diets prepartum were greater compared with those fed the control diet. Postpartum DMI and milk yield of primiparous cows were similar for prepartum diets. Feeding prepartum anionic diets did not affect plasma Ca at or near calving. However, cows fed anionic diets began their decline in plasma Ca later than control cows. Postpartum β-hydroxybutyrate and nonesterified fatty acids were lower for primiparous cows fed prepartum anionic diets compared with those fed the control diet. Prepartum and postpartum plasma glucose concentrations were not affected by prepartum diet for all cows. Liver triglyceride differed for parity by day. Parities were similar at 21 d prepartum, but at 0 d and 21 d postpartum, levels were greater for multiparous cows. Results indicate that decreasing the DCAD of the diet during the prepartum period can increase postpartum DMI and milk production of multiparous cows without negatively affecting performance of primiparous cows.     

Investigation of the effect of pegbovigrastim on some periparturient immune disorders and performance in Mexican dairy herds

This study analyzed the efficacy of pegbovigrastim (Imrestor, Elanco Animal Health, Greenfield, IN) on some health and production parameters in lactating dairy cows. Primiparous and multiparous Holsteins from 17 Mexican dairy herds (n = 10,238) were included in this study, which was conducted in 2015. Treated cows (n = 5,025) received Imrestor approximately 7 d before expected calving and again within 24 h after calving; control cows (n = 5,213) did not receive a placebo. Clinical mastitis (MAS; 0 to 30 DIM), retained placenta (RP), and clinical metritis (MET; 0 to 21 DIM) occurrences were recorded, as well as the number of medication days, medical treatments needed, and the number of days that milk was discarded due to medication administered for disease. Milk yield was measured from calving until 120 d in milk. Imrestor reduced the incidence of MAS by 25%, and the odds ratio of having mastitis in the first 30 d in milk was 35% greater for control cows than for Imrestor cows. Imrestor treatment reduced the number of medical treatments required for MAS by 6%, and less milk was discarded due to medication for MAS as a result of the Imrestor treatment. The incidence of RP was reduced by 4.15% with Imrestor and the odds of cows having RP were 4.6% greater for control than Imrestor treatments, but they did not differ. The MET incidence was increased by 17.1% with Imrestor. The use of Imrestor around parturition increased by 5.8% the odds of inseminating cows during the first 100 d after calving. Imrestor-treated multiparous cows with MAS produced 2.1 kg/d more milk than control cows with MAS during the first 30 d of their lactation. Imrestor-treated multiparous cows with MET produced 2.3 kg/d more milk than MET control cows during the first 120 d of their lactation. We conclude that Imrestor can help the dairy cow cope with immune periparturient disorders and can increase the milk yield of dairy cows due to a healthier transition, despite a reported increase in the incidence of MET.     

Effect of heat stress during the dry period on mammary gland development

Heat stress during the dry period negatively affects hepatic metabolism and cellular immune function during the transition period, and milk production in the subsequent lactation. However, the cellular mechanisms involved in the depressed mammary gland function remain unknown. The objective of the present study was to determine the effect of heat stress during the dry period on various indices of mammary gland development of multiparous cows. Cows were dried off approximately 46 d before expected calving and randomly assigned to 2 treatments, heat stress (HT, n = 15) or cooling (CL, n = 14), based on mature equivalent milk production. Cows in the CL treatment were provided with sprinklers and fans that came on when ambient temperatures reached 21.1°C, whereas HT cows were housed in the same barn without fans and sprinklers. After parturition, all cows were housed in a freestall barn with cooling. Rectal temperatures were measured twice daily (0730 and 1430 h) and respiration rates recorded at 1500 h on a Monday-Wednesday-Friday schedule from dry off to calving. Milk yield and composition were recorded daily up to 280 d in milk. Daily dry matter intake was measured from dry off to 42 d relative to calving. Mammary biopsies were collected at dry off, −20, 2, and 20 d relative to calving from a subset of cows (HT, n = 7; CL, n = 7). Labeling with Ki67 antigen and terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling were used to evaluate mammary cell proliferation and apoptosis, respectively. The average temperature-humidity index during the dry period was 76.6 and not different between treatments. Heat-stressed cows had higher rectal temperatures in the morning (38.8 vs. 38.6°C) and afternoon (39.4 vs. 39.0°C), greater respiration rates (78.4 vs. 45.6 breath/min), and decreased dry matter intake (8.9 vs. 10.6 kg/d) when dry compared with CL cows. Relative to HT cows, CL cows had greater milk production (28.9 vs. 33.9 kg/d), lower milk protein concentration (3.01 vs. 2.87%), and tended to have lower somatic cell score (3.35 vs. 2.94) through 280 d in milk. Heat stress during the dry period decreased mammary cell proliferation rate (1.0 vs. 3.3%) at −20 d relative to calving compared with CL cows. Mammary cell apoptosis was not affected by prepartum heat stress. We conclude that heat stress during the dry period compromises mammary gland development before parturition, which decreases milk yield in the next lactation.