Prepartum Nonesterified Fatty Acids Research Articles

Herd-level associations between the proportion of elevated prepartum nonesterified fatty acid concentrations and postpartum diseases, reproduction, or culling on dairy farms

The objectives of this herd-level prospective observational cohort study were to describe the proportion of cows with elevated prepartum nonesterified fatty acid concentrations (PropElevNEFA) in dairy herds and to assess the herd-level associations between PropElevNEFA and postpartum diseases, reproductive performance, and culling. From November 2018 to December 2020, a convenience sample of 49 herds was enrolled in this study. Blood sampling (16 to 29 cows per herd) was performed during the week before and during the 2 wk following calving to quantify the concentration of nonesterified fatty acids (NEFA) and β-hydroxybutyrate acids (BHBA), respectively. Elevated NEFA was defined as ≥280 µmol/L and hyperketonemia as BHBA ≥1.4 mmol/L. Retained placenta, metritis, purulent vaginal discharge, endometritis, and mastitis were diagnosed on-farm following standardized definitions, and success at first artificial insemination (AI) and culling events were recorded. The associations between PropElevNEFA and each individual disease, success at first AI, and culling were evaluated using Bayesian aggregated binomial regression models with weakly informative priors, from the which odds ratio (OR) and the 95% credible intervals (BCI) were obtained. A total of 981 cows were included in the statistical analyses representing 16 to 29 (median = 19) cows per herd. Cows were enrolled in the prepartum period of their first to tenth (median = third) lactation, and 41% of them had an elevated prepartum NEFA concentration. At the herd level, PropElevNEFA varied between 11% and 78% (median = 39%). The odds of metritis (OR = 1.37, 95% BCI = 1.13–1.67) increased for every 10-point increase in PropElevNEFA, whereas the odds of success at first AI decreased (OR = 0.69, 95% BCI = 0.59–0.80). The PropElevNEFA was not associated with the other tested diseases or culling. Our results suggest that the herd-level proportion of cows having elevated prepartum NEFA concentrations is associated with metritis and poor success at first AI in dairy herds.

Transition Cow Nutrition and Management Strategies of Dairy Herds in the Northeastern United States: Associations of Nutritional Strategies with Analytes, Health, Milk Yield, and Reproduction.

The objective was to identify relationships between transition cow nutritional strategies and the prevalence of elevated analytes (nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHB), and haptoglobin (Hp)), disorder incidence (DI), milk yield, and reproductive performance. Multiparous and primiparous cows from 72 farms in the northeastern US were enrolled in a herd-level cohort study. Farms were dichotomized within parity into a nutritional strategy within each period; far-off: controlled energy (CE; <16.5% starch and ≥40% forage neutral detergent fiber (FNDF)) or not CE (NCE; ≥16.5% starch or <40% FNDF or both), close-up: high FNDF (HF; ≥40% FNDF) or low FNDF (LF; <40% FNDF), and fresh: low starch (LS; <25.5% starch) or high starch (HS; ≥25.5% starch). No evidence existed that transition cow nutritional strategies were associated with milk yield outcomes (p ≥ 0.20). In general, our results support feeding multiparous cows HF close-up and HS fresh to minimize excessive BHB and DI; however, multiparous cows fed LF close-up had a higher pregnancy rate, and lower prepartum NEFA and Hp. Similarly, our results support feeding primiparous cows CE far-off, HF close-up, and HS fresh to maximize reproductive performance, and minimize BHB and DI; however, herds fed HF close-up or HS fresh had higher Hp.

Effects of prenatal dietary rumen-protected choline supplementation during late gestation on calf growth, metabolism, and vaccine response.

The objective of this study was to examine the effects of prenatal supplementation and dose of rumen-protected choline (RPC) on neonatal calf growth, metabolism, and vaccine response. Parous Holstein cows were blocked by calving month and randomly assigned within block to receive 45 g/d of RPC [20.4 g/d of choline ions (CHOL45), n = 19], 30 g/d of RPC [13.6 g/d of choline ions (CHOL30), n = 22], or no RPC (CON, n = 19) as a top-dress, starting 24 d before expected calving. Calf body weights were recorded for the first 3 wk of life. All calves were fed colostrum replacer (300 g of IgG) at birth, and apparent efficiency of IgG absorption was calculated. On d 1, 7, 14, and 21, blood samples were taken to quantify plasma reactive oxygen and nitrogen species, antioxidant potential, haptoglobin, nonesterified fatty acids (NEFA), β-hydroxybutyrate, and glucose. Calves received an intranasal vaccine at birth, and nasal secretions were collected on d 0, 7, 10, 14, and 21 to quantify bovine respiratory syncytial virus-specific IgA. Data were analyzed using linear mixed models including the fixed effects of treatment, time (when applicable), calf sex, and prepartum dam data (-24 d) along with interactions. Treatment did not affect calf body weight, β-hydroxybutyrate, or glucose concentrations. For apparent efficiency of IgG absorption, treatment interacted with the dam's prepartum body condition score. Where the dam's body condition score was ≤3.25, IgG absorption was reduced in calves born from CHOL45 dams as compared with calves from either CHOL30 or CON dams. Calves from CHOL30 dams had a lesser oxidative stress index (OSi; reactive oxygen and nitrogen species/antioxidant potential) than calves from CON dams. Haptoglobin concentrations were less in heifer calves from CHOL45 dams as compared with heifers from CON dams. The dam's prepartum NEFA concentration interacted with treatment. When dam NEFA was minimal, calves from CHOL45 and CHOL30 dams had greater or tended to have greater NEFA, respectively. Conversely, when dam NEFA was greater, calves from CHOL30 and CHOL45 dams had lesser or tended to have lesser NEFA than calves from CON dams, respectively. For vaccine response, treatment interacted with the dam's prepartum OSi. Among calves born from dams with a greater OSi, calves from CHOL45 and CHOL30 dams had lesser bovine respiratory syncytial virus-specific IgA concentrations in nasal secretions as compared with CON. Prenatal RPC supplementation during late gestation affected IgG absorption, neonatal calf metabolism, and vaccine response with some effects dependent on the dam's prepartum parameters.

Pegbovigrastim treatment resulted in an economic benefit in a large randomized clinical trial in grazing dairy cows

This randomized controlled trial on 4 commercial grazing dairy farms investigated whether pegbovigrastim (PEG) treatment affected partial net return as calculated from milk revenues and costs for feed, medical treatments [clinical mastitis, uterine disease, and other diseases (i.e., any medical treatment that was not intended for clinical mastitis or uterine disease)], inseminations, and culling during a full lactation in grazing dairy cows. We also explored the effect of potential interactions of PEG treatment with parity, prepartum body condition score, and prepartum nonesterified fatty acids concentration on partial net return, milk revenues, and the costs mentioned above. Holstein cows were randomly assigned to 1 of the 2 following trial arms: a first PEG dose 9.4 ± 0.3 (mean ± standard error) days before the calving date and a second dose within 24 hours after calving (PEG: primiparous = 342; multiparous = 697) compared with untreated controls (control: primiparous = 391; multiparous = 723). The effect of PEG treatment on the outcomes of interest expressed per year was tested using general linear mixed models. Results are presented as least squares means ± standard error. Overall, PEG treatment increased the partial net return, resulting in an economic benefit per cow per year of $210 ± 100. The cost of treatment of clinical mastitis was lower for PEG treated cows compared with control cows ($9 ± 3). The largest nonsignificant difference was seen for the cost of culling; additionally, PEG treatment numerically reduced the cost of culling by $145 ± 77.

Transition cow nutrition and management strategies of dairy herds in the northeastern United States: Part II—Associations of metabolic- and inflammation-related analytes with health, milk yield, and reproduction

The objectives were as follows: (1) establish cow-level thresholds for prepartum nonesterified fatty acids (NEFA) and postpartum NEFA, β-hydroxybutyrate (BHB), and haptoglobin (Hp) concentrations associated with negative health events; (2) evaluate cow-level associations between biomarkers and 305-d mature equivalent milk at the fourth test day (ME305) and reproductive performance; and (3) identify herd-alarm levels (proportion of cows sampled above the critical threshold) for biomarkers that are associated with herd-level changes in disorder incidence (displaced abomasum and clinical ketosis), reproductive performance, and ME305. In a prospective cohort study, 1,473 cows from 72 farms were enrolled from the northeastern United States. Blood samples were collected from the same 11 to 24 cows per herd during the late-prepartum and early-postpartum periods. Whole blood was analyzed for postpartum BHB concentrations; plasma was analyzed for prepartum and postpartum NEFA and postpartum Hp concentrations. Critical thresholds for the biomarkers associated with health events for all cows were established using a receiver operating characteristic curve analysis. Poisson, linear mixed effects, and Cox proportional hazards models investigated the association of the biomarkers with health and performance. The prepartum NEFA and Hp threshold associated with culling was ≥0.17 mmol/L and 0.45 g/L, respectively. The postpartum NEFA and BHB thresholds associated with diagnosis of metritis, displaced abomasum, or clinical ketosis were ≥0.46 mmol/L and ≥0.9 mmol/L, respectively. Multiparous cows with prepartum NEFA concentration ≥0.17 mmol/L produced 479 kg less ME305. Multiparous and primiparous cows with postpartum NEFA concentration ≥0.46 mmol/L produced 280 kg less and 446 kg more ME305, respectively. Cows with BHB concentration ≥0.9 and ≥1.1 mmol/L produced 552 kg more ME305 and had a 20% decreased risk of pregnancy within 150 d in milk, respectively; however, multiparous cows with BHB concentration ≥1.5 mmol/L produced 376 kg less ME305. Cows with Hp concentration ≥0.45 g/L produced 492 kg less ME305 and had 28% decreased risk of pregnancy within 150 DIM. Cows with Hp concentration ≥0.45 g/L had 19% decreased pregnancy risk to first service (PRFS). Herds above the herd-alarm levels for prepartum NEFA had a 6.0-percentage unit increase in disorder incidence and a 6.0-percentage unit decrease in 21-d pregnancy rate (PR) for multiparous cows, a 3.9-percentage unit increase in PR and a 5.8-percentage unit increase in the probability of pregnancy for primiparous cows. Herds above the herd-alarm levels for postpartum NEFA had a 5.8- and 4.2-percentage unit increase in disorder incidence for multiparous and primiparous cows, respectively, a 789 kg decrease in ME305 for multiparous cows, and a 6.8- and 6.3-percentage unit decrease and increase in PR and PRFS for multiparous cows, respectively. Herds above the herd-alarm levels for BHB had an 8.5-percentage unit increase in disorder incidence, a 332 and 229 kg increase in ME305 for primiparous and multiparous cows, respectively, and a 3.2-, 5.2-, and 7.0-percentage unit decrease in PR, probability of pregnancy, and PRFS, respectively. Herds above the herd-alarm levels for postpartum Hp had a 5.3-percentage unit increase in disorder incidence. At the cow level and herd level, elevated biomarker concentrations were associated with an increased disorder risk and varied performance responses.

Effect of prepartum dietary-cation anion difference on performance, blood mineral and metabolite concentrations in Holstein dairy cows

Dietary cation-anion difference (DCAD) initiates a compensatory metabolic acidosis, which improves calcium (Ca) absorption and mobilization before calving and minimizes clinical and subclinical hypocalcaemia after calving. The goal of this study was to evaluate how mineral concentrations, blood metabolites, parathyroid hormone (PTH), and productive performance were affected by prepartum dietary cation-anion difference (DCAD mEq [(Na + K – Cl + S)]/kg of dry matter (DM)) in postpartum dairy cows. Forty-eight multiparous Holstein cows ranging from 2 to 5 lactations with an average body weight of 685 ± 10 kg (mean ± SD) were allocated in a randomized block design with three prepartum diets differing in DCAD (0, –100, and –180 mEq/ kg DM). All cows were fed the same postpartum diet and kept on trial for 66 days. Cows fed –180 and –100 mEq DCAD had greater prepartum non-esterified fatty acid (NEFA) concentrations than cows fed 0 mEq DCAD. Cows fed –180 mEq DCAD had greater serum Ca concentrations than cows fed –100 and 0 mEq DCAD. PTH concentrations were greater in cows fed 0 mEq DCAD than in cows fed –100 or –180 mEq DCAD. Cows fed 0 mEq DCAD had higher milk protein and solid-not-fat (SNF) levels than cows fed –100 or –180 mEq DCAD. Treatment and interaction had no effect on milk yield, 3.5% fat-corrected milk (FCM), energy-corrected milk (ECM), milk fat, total solids (TS), lactose, milk urea nitrogen (MUN), magnesium (Mg), sodium (Na), chloride (Cl), potassium (K), beta hydroxybutyric acid (BHBA), and liver or kidney functions. We concluded that adding anionic salts to dairy cows’ diets (–100 and –180 mEq DCAD) improved postpartum Ca availability and reduced clinical and subclinical hypocalcaemia while having no effect on milk yield or fat-corrected milk.

Effect of pegbovigrastim on fertility and culling in grazing dairy cows and its association with prepartum nonesterified fatty acids

This randomized controlled trial on 4 commercial grazing dairy farms investigated whether treatment with pegbovigrastim (PEG) affected fertility and culling as measured during the full lactation. We also explored the effect of potential interactions of PEG treatment with parity, prepartum body condition score, prepartum nonesterified fatty acid concentration (pre-NEFA), and early-lactation clinical disease on these outcomes. Holstein cows were randomly assigned to 1 of 2 trial arms: a first PEG dose approximately 7 d before the expected calving date and a second dose within 24 h after calving (PEG: primiparous = 342; multiparous = 697) compared with untreated controls (control: primiparous = 391; multiparous = 723). Cox's proportional hazards regression models were used to analyze rate of first insemination, rate of pregnancy [within 150 and 305 d in milk (DIM)], and hazard of culling. Additional analyses were performed on data that were stratified by parity group and pre-NEFA class (low ≤0.3; high >0.3 mM). In high pre-NEFA cows, PEG treatment increased the rate of first insemination [hazard ratio (HR) = 1.15]. Early-lactation clinical mastitis (CM) and uterine disease (UD: retained placenta, metritis, or both) were associated with a reduced rate of pregnancy within 150 DIM (HR = 0.49 and 0.78, respectively). Pegbovigrastim treatment in high pre-NEFA cows with CM and UD increased the rate of pregnancy within 150 DIM (HR = 1.75 and 1.46, respectively). In high pre-NEFA cows, PEG treatment resulted in a lower hazard of culling (HR = 0.79). No treatment effect was detected in low pre-NEFA cows. This study shows that the effect of PEG treatment on fertility and culling interacts with pre-NEFA. In high pre-NEFA cows, PEG treatment increased the rate of first insemination, counteracted the negative association of early-lactation CM and UD with the rate of pregnancy, and decreased the hazard of culling.

Responses of Outdoor Housed Dairy Cows to Shade Access during the Prepartum Period under Temperate Summer Conditions.

Simple SummaryLate pregnant dairy cows housed outdoor can be exposed to hot weather conditions for several weeks prior to calving affecting their physiology and behavior. We aimed to determine whether access to an artificial shade for outdoor-housed dairy cows during the three weeks prior to calving had a positive effect on lying, rumination, feeding, and drinking behaviors. Also, the relationship between access to shade and health status was investigated. Shaded cows increased rumination time, but the daily lying time was similar to unshaded cows. Also, shaded cows spent half of the time drinking during the warmest hours of the day and spent more time feeding during the morning feed than unshaded cows. The prepartum and postpartum body fat mobilization and presentations of clinical diseases after calving were similar between both treatments. This study presents evidence that shade is an important resource for cows during temperate summers, observing effects mainly on behavioral variables.Cows are affected by environmental factors associated with warm weather conditions; however, little is known about the effect of shade access especially during the prepartum period of dairy cows in temperate regions. This study assessed the effect of shade on the behavior (lying, rumination, feeding, and drinking), body fat mobilization, and health status of outdoor-housed dairy cows during the prepartum period under temperate summer conditions. During the 3 weeks prior to calving, 24 multiparous Holstein cows were grouped (4 cows/group) and assigned to either an open corral without shade or with access to shade until calving. We daily measured shade use, lying, rumination, feeding, and drinking behavior. Weekly, prepartum non-esterified fatty acids (NEFA) and postpartum b-hydroxybutyrate (BHB) concentrations were measured. Clinical examination was periodically performed individually until 21 postpartum days. Shade use averaged 45.6, 46.0, and 19.8% during the hottest hours of the day (11–18 h) in weeks 3, 2, and 1 prior to calving, respectively. Shaded cows had higher values for rumination time and feeding time during the morning but spent less time drinking during the warmest hours than unshaded cows. NEFA and BHB concentrations and clinical diseases were similar between both treatments. These findings suggest that under temperate summer conditions the access to an artificial shade is an important resource, observing beneficial effects mainly on behavioral variables.

Prepartum factors associated with postpartum diseases in pasture-based dairy cows

This cross-sectional observational study aimed to identify prepartum management, environmental, and animal factors associated with clinical –lameness, metritis, mastitis– and subclinical –calcium imbalance, magnesium imbalance– diseases in pasture-based dairy cows. A total of 565 cows from 25 commercial dairy farms in southern Chile were enrolled over four months. Data on prepartum management and environmental conditions were obtained through a survey and inspections of prepartum paddocks. Cows were evaluated two times. In the first evaluation, between 30 to 3 days before calving, cows were assessed for lameness, body condition score, and blood samples were collected to measure nonesterified fatty acid (NEFA), calcium (Ca), and magnesium (Mg). In the second evaluation, between 3 to 21 DIM, cows were assessed for metritis, lameness, and blood samples were collected and analyzed for total Ca and Mg concentration. Cows were considered as having Ca imbalance if Ca < 2.0 mmol/L, and Mg imbalance if Mg < 0.65 mmol/L. Postpartum clinical mastitis was diagnosed based on the foremilk's daily condition and udder assessed by the milker at each milking during the postpartum transition period. Multivariable logistic regression models, controlling for the farm as a random effect, were built to identify prepartum factors for each postpartum disease. The odds of postpartum lameness were higher for cows that were lame during the prepartum period, had elevated prepartum NEFA concentrations, had greater parity, and for cows that were kept in paddocks with no grass cover. The odds of metritis were higher in cows with lower parity, with increased prepartum NEFA, in cows that had dystocia, and farms with predominantly Holstein breed, and that did not have calving records. The odds of clinical mastitis were higher for cows lame during the prepartum period. The odds of Ca imbalance were higher in cows with a long dry period, dystocic calving, and in farms without prepartum anionic salts supplementation. The odds of Mg imbalance were higher in cows with lower prepartum Mg concentrations, higher prepartum Ca concentration, and higher parity. Our findings indicate that farmers could benefit from refining these areas to improve their cows’ health and welfare.

Effect of pegbovigrastimon clinical mastitis and uterine disease during a full lactation in grazing dairy cows.

In this randomized controlled trial on four commercial grazing dairy farms, we investigated whether pegbovigrastim (PEG) treatment affects clinical mastitis (CM) and uterine disease (i.e. retained placenta (RP), metritis and endometritis) occurrence during a full lactation. The association of prepartum body condition score and prepartum non-esterified fatty acid (NEFA) concentration with disease occurrence was also evaluated. Holstein cows were randomly assigned to one of two treatments: first PEG dose approximately 7 d before the expected calving date and a second dose within 24 h after calving (PEG) compared to untreated controls (Control). In total, 2,153 animals were included in the study: 733 primiparous cows (Control = 391, PEG = 342) and 1420 multiparous cows (Control = 723, PEG = 697). Treatment effects were evaluated with generalized linear mixed models and Cox’s proportional hazard models. Treatment with PEG reduced the occurrence of a first case of CM during the first 30 days in milk (DIM) by 24.6% and reduced the hazard of a first case and the rate of total cases of CM during the full lactation. All PEG treatment effects were independent of parity. Prepartum body condition score interacted with PEG treatment: in over-conditioned cows, PEG reduced the occurrence of a first case of CM during the first 30 DIM by 49.5%. The hazard analysis of a first case of CM during the full lactation suggested that the preventive effect of PEG disappeared with increasing DIM. Treatment with PEG did not affect the occurrence of RP or metritis. Pegbovigrastim treated cows with metritis subsequently showed a reduced occurrence of endometritis compared to control cows with metritis. Pegbovigrastim reduces the occurrence of CM particularly in cows at risk of elevated lipid mobilization, and PEG ameliorates the uterine healing process in cows that experienced metritis.

Evaluation of some metabolic profile parameters in transition cows: thresholds for estimating postpartum diseases in Aydin province

This study aimed to evaluate non-esterified fatty acids (NEFA), beta hydroxybutyric acid (BHBA), magnesium (Mg2+), calcium (Ca2+) and lactate as biological tests for the detection of some metabolic diseases during transition period in selected dairy farms located in Aydın province. Cow-side analysis with body condition score evalutation were performed weekly in at least 12 dairy cattle from each farm from prepartum week 2 to postpartum week 2. According to the prepartum NEFA ≥0.4 mmol/L, postpartum BHBA ≥1.4 mmol/L and Ca2+ ≤ 2.0 mmol/L at parturition (day 0) in herd-based evaluation, it was observed that all farms were positively evaluated for negative energy balance and also at risk for subclinical hypocalcaemia. Regarding the threshold value of Mg2+ &lt;0.61 mmol/L, subclinical hypomagnesaemia was observed at the Ist and IInd farms. It was concluded that prepartum NEFA threshold (0.68 mmol/L), obtained from the receiver operating characteristics statistical analysis could be used for observing some postpartum clinical diseases. It was suggested that it allowed planning and strategic interventions to prevent herd-based diseases in Turkey and will be a precedent for future studies and herd management.

Predicting the risk of retained fetal membranes and metritis in dairy cows according to prepartum hemogram and immune and metabolic status

Uterine diseases affect a significant proportion of dairy cows, causing significant economic losses. Immune and metabolic statuses are associated with the risk of retained fetal membranes (RFM) and metritis. The hypothesis of this study was that it is possible to use such responses to predict the risk of RFM and metritis. Data from cows (Jersey = 143, Holstein = 116) previously used in four experiments were used. Cow factors [parity, BCS change from −28 to 0 d relative to calving, calf sex, calving problems (twins, stillbirth, dystocia)] were evaluated for their association with the risk of RFM and metritis. Blood samples collected in the last week of gestation were used to measure polymorphonuclear leukocyte phagocytosis, oxidative burst, and expression of CD18 and CD62L, total blood count, haptoglobin optical density, and concentrations of glucose, non-esterified fatty acids, and β-hydroxybutyrate. Cows were treated with egg ovalbumin at −21, −7, and 7 d relative to calving and blood samples were used to determine the anti-ovalbumin IgG optical density. Univariable analyses were carried out to identify variables associated with the risk of RFM and metritis. The significant (P ≤ 0.15) variables were included in multivariable models from which variables with P > 0.15 were removed in a backward stepwise fashion. Risk of RFM was reduced in the absence of calving problems [adjusted odds ratio (AOR) 95 % confidence interval (CI) = 0.13 (0.02, 0.86)], when intensity of phagocytosis [AOR (95 % CI) = 0.50 (0.25, 1.04)] and expression of CD62L [AOR (95 % CI) = 0.71 (0.46, 1.09)] by polymorphonuclear leukocyte were greater, and when prepartum non-esterified fatty acid concentration was lower [AOR (95 % CI) = 8.71 (0.49, 153.84)]. Calf sex [AOR (95 % CI) = 0.35 (0.10, 1.25)], calving problem [AOR (95 % CI) = 0.14 (0.02, 1.08)], PMNL phagocytosis intensity [AOR (95 % CI) = 0.72 (0.47, 1.11)], polymorphonuclear leukocyte intensity of expression CD18 [AOR (95 % CI) = 0.78 (0.60, 1.00)] and CD62L [AOR (95 % CI) = 0.77 (0.60, 0.98)], and haptoglobin optical density [AOR (95 % CI) = 1.16 (0.97, 1.39)] were associated with metritis. Indexes generated from the estimates of the multivariable analyses to predict the risk of RFM [area under the curve = 0.77 (95 % CI = 0.70 to 0.84)] and metritis [area under the curve = 0.76 (95 % CI = 0.70, 0.81)] demonstrated that polymorphonuclear leukocyte function, non-esterified fatty acid concentration, and haptoglobin optical density prepartum may be used as predictors of uterine diseases.

Prepartum Fat Mobilization in Dairy Cows with Equal Body Condition and Its Impact on Health, Behavior, Milk Production and Fertility during Lactation.

Simple SummaryAn excess of lipolysis and subsequent increase on non-esterified fatty acids concentrations may impair animal health, welfare, and productivity after calving. In this study, we evaluated the effect of fat mobilization in dairy cows with a recommended body condition score at the beginning of the close-up period on blood indicators of health, incidence of diseases, behavior, milk production, and fertility during postpartum. An increased fat mobilization in dairy cows with an equal body condition score modified the inflammatory and oxidative stress responses during the early postpartum without impairing their health status and fertility. Moreover, behavior and milk production were sensitive indicators that reflected the negative effects of the excess of prepartum fat mobilization through lactation.The objective of this study was to evaluate the effect of two levels of fat mobilization at the close-up period in dairy cows with an equal body condition score (BCS = 3.0) on the circulating concentrations of metabolic, inflammatory, and oxidative stress biomarkers, incidence of diseases, behavior, milk production, and fertility during the postpartum. Late-gestation multiparous Holstein cows (n = 59) with a body condition score of 3.0 (5-point scale) were enrolled at the beginning of the close-up period and then were followed during the entire lactation. Cows were retrospectively allocated into two groups: animals with prepartum non-esterified fatty acids concentration over 0.3 mmol/L were categorized as high fat mobilization (HFM) (n = 26), and below this threshold as low fat mobilization (LFM) (n = 33). Blood samples were collected 21 d before expected calving and once weekly for 3 wk postpartum in order to analyze β-hydroxybutirate, haptoglobin, fibrinogen, total proteins, and malondialdehyde. Health was observed daily for 21 d postpartum. Behavioral data was collected with an accelerometer and milk production and fertility were obtained from the farm records. An increased fat mobilization in dairy cows with equal BCS modified the inflammatory and oxidative stress responses during the early postpartum without impairing their health status and fertility. Moreover, milk production and behavior were markedly affected by excessive prepartum fat mobilization through lactation.

Associations of pre- and postpartum lying time with metabolic, inflammation, and health status of lactating dairy cows

The objective was to evaluate the associations of pre- and postpartum lying time (LT) with serum total calcium (Ca), nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHB), and haptoglobin concentrations, hemogram, and health status of dairy cows. A total of 1,052 Holstein cattle (401 nulliparous heifers and 651 parous cows) from 3 commercial dairy farms were fitted with electronic data loggers (IceQube, IceRobotics, Edinburgh, UK) on a hind leg 14 ± 3 d before parturition (dpp) and removed at 14 ± 3 d in milk (DIM) to assess their LT. Lying time data were summarized and reported daily (min/d or h/d). Serum concentrations of NEFA (at 14 ± 3 and 7 ± 3 dpp), total serum calcium within 48 h after calving, and BHB (at 7 ± 3 and 14 ± 3 DIM) were determined. Serum concentration of haptoglobin was determined and a hemogram was performed on a subsample of 577 cows (237 primiparous and 340 multiparous) at 7 ± 3 DIM. Cases of milk fever, retained placenta, metritis, mastitis, pneumonia, and digestive disorders within 30 DIM were recorded and cows were categorized into 1 of 4 groups: (1) nondiseased (ND, n = 613; cows without ketosis and any other health conditions); (2) cows with only ketosis (KET, n = 152); (3) sick cows experiencing ≥1 health conditions, but without ketosis (SICK, n = 198); or (4) cows with ketosis plus at least one other health condition (KET+, n = 61). Data were analyzed using mixed linear regression models or logistic regression (MIXED or GLIMMIX procedures). Lying time within 14 dpp had a significant positive quadratic association with serum NEFA concentrations at 14 ± 3 and 7 ± 3 dpp but was not significantly associated with serum Ca concentration within 48 h after calving. Lying time during the first 14 DIM after parturition had a significant linear association with the risk of ketosis within 14 DIM. For every 1-h increment in mean LT (from 8 to 15 h/d) within the first 14 DIM after calving, the risk of diagnosis with ketosis within 14 DIM increased by 3.7 percentage points. Regardless of parity, a greater proportion of KET and KET+ groups had increased serum prepartum NEFA concentration (≥400 µEq/L) and increased body condition loss from 14 dpp to 28 DIM compared with SICK and ND cows. A greater proportion of multiparous KET and KET+ cows had hypocalcemia within 48 h after calving compared with ND and SICK cows, but we did not detect a significant association between hypocalcemia and health status on primiparous cows. Multiparous KET+ cows had significantly reduced neutrophils and white blood cell count compared with ND cows, but lymphocytes did not differ. Regardless of parity, KET+ and SICK cows had significantly higher concentrations of serum haptoglobin compared with ND cows. These results suggest that LT along with energy and Ca balance are critical for transition cow health.

Metritis in dairy cows: Risk factors and reproductive performance

The objectives of this study were to assess the risk factors for metritis, its effects on milk yield and on reproductive performance, and the efficacy of ceftiofur therapy in Holstein dairy cows. Cows (n=303) from a commercial dairy herd in Argentina were studied. Cows were scored for body condition, and blood samples were collected on d −14, 7, 21, 31, 41, and 50 relative to parturition. Cows having a watery, purulent, or brown, and fetid vaginal discharge (VD) and rectal temperature ≤39.2°C were diagnosed as having clinical metritis, and those having a similar VD and rectal temperature >39.2°C were diagnosed as having puerperal metritis. Both clinical and puerperal metritis cows were randomly assigned to control (no treatment) or ceftiofur group (2.2mg/kg×3 consecutive days). Cure was declared if clear VD was observed at 21 d in milk (DIM). Blood samples were analyzed for nonesterified fatty acids, β-hydroxybutyrate, and blood urea nitrogen using commercial kits, and for insulin-like growth factor-1, insulin, and leptin by RIA. Data were analyzed with PROC MIXED, GENMOD, PHREG, and LIFETEST from SAS (SAS Institute Inc., Cary, NC). The risk for metritis increased with dystocia, retained fetal membranes, and dead calf [AOR (adjusted odds ratio)=2.58, 95% CI: 1.189–5.559], and as prepartum nonesterified fatty acids levels increased (AOR=1.001, 95% CI: 0.999–1.002). Conversely, risk decreased as prepartum insulin-like growth factor-1 increased (AOR=0.65, 95% CI: 0.349–1.219). Cows having either clinical or puerperal metritis produced less milk by 90 DIM than did healthy cows (2,236±172 vs. 2,367±77 vs. 2,647±82 kg, respectively). Cows with puerperal metritis had lower risk for pregnancy by 100 DIM (AOR=0.189, 95% CI: 0.070–0.479) and a lower hazard rate for pregnancy by 150 DIM (hazard rate: 0.753, 95% CI: 0.621–0.911), and took longer to get pregnant (129 vs. 111 vs. 109 d, for puerperal metritis, clinical metritis, and healthy cows, respectively). Ceftiofur treatment was not associated with cure rate or milk yield but was related to increased risk for pregnancy at timed artificial insemination (AOR=2.688, 95% CI: 0.687–10.832), and for lower risk of reproductive cull (AOR=0.121, 95% CI: 0.014–1.066). In conclusion, abnormal calving and negative energy balance are associated with increased risk for metritis. Metritis, especially puerperal metritis, correlates with reduced milk production and poor reproductive performance. Finally, the likelihood for having a normal VD (indicative of cure) increased 2.6% for every day of increase in postpartum time and was 2 times higher for cows with clinical metritis than for those with puerperal metritis.

Clinical endometritis in an Argentinean herd of dairy cows: Risk factors and reproductive efficiency

The objectives of this study were to assess the clinical and metabolic risk factors for clinical endometritis, the likelihood for having a normal vaginal discharge during postpartum, and the effects of endometritis on milk yield, reproductive efficiency, and metabolic status in Holstein cows. The study was conducted in a commercial dairy herd (Cordoba, Argentina) where 303 Holstein cows were enrolled. Cows were body condition scored (1 to 5) and tail bled on −14, 7, 21, 31, 41, and 50d relative to parturition. Cows having a vaginal discharge with presence of pus between 21 and 41d postpartum (dpp) were diagnosed as having clinical endometritis. Plasma blood samples were analyzed for nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), and blood urea nitrogen using commercial kits and insulin-like growth factor 1, insulin, and leptin by RIA. Data were analyzed with PROC MIXED, PROC GENMOD, and PROC PHREG of SAS (SAS Institute Inc., Cary, NC). Abnormal calving and puerperal metritis increased the risk for endometritis [adjusted odds ratio (AOR)=2.21 for both]. High prepartum NEFA and high postpartum BHBA increased the risk for endometritis (AOR=1.003 and 1.001, respectively), whereas high prepartum blood urea nitrogen reduced it (AOR=0.853). Cut-offs of 456.6μM NEFA and 402.5μM BHBA had sensitivities of 0.69 and 0.58, and specificities of 0.88 and 0.86, respectively. The likelihood for having normal vaginal discharge increased with time (∼1% × dpp) and with normal calving. Cows with endometritis had higher milk yield than normal herdmates (27.8±0.9 vs. 25.7±0.4kg/d), lower risk for pregnancy by 100dpp (AOR=0.10), higher nonpregnancy risk by 200dpp (AOR=2.87), and higher risk for culling than normal cows (AOR=2.28). Cows with endometritis had a lower hazard rate (0.44) for pregnancy and had approximately 70d longer calving-to-conception intervals. Finally, endometritis had no effect on metabolic hormones. In conclusion, the risk for clinical endometritis increases with abnormal calving and puerperal metritis, as prepartum NEFA and postpartum BHBA concentrations increase. Prepartum NEFA and postpartum BHBA could be useful for the prediction of endometritis. Last, clinical endometritis has detrimental effects on reproductive efficiency, as affected cows take longer to get pregnant and are at higher risk for culling.

Associations of prepartum plasma cortisol, haptoglobin, fecal cortisol metabolites, and nonesterified fatty acids with postpartum health status in Holstein dairy cows

The association between negative energy balance and health has led to the testing of blood analytes such as nonesterified fatty acids (NEFA) to identify opportunities for improving the management of transition dairy cows. The objective of this study was to evaluate whether prepartum analytes associated with stress (cortisol) or inflammation (haptoglobin) could also identify dairy cattle at increased risk for health complications after calving. Prepartum blood and fecal samples were collected once weekly from 412 Holstein dairy cows on 2 commercial dairy farms (at wk −3, −2, and −1 relative to calving) and analyzed for concentrations of NEFA, haptoglobin (Hp), and cortisol in plasma and cortisol metabolites in feces. Retained placenta (RP), displaced abomasum (DA), subclinical ketosis (SCK), high Hp concentration (HiHp), and death were recorded up to 30 d in milk (DIM), and animals were subsequently categorized into 3 health categories: (1) no disorder of interest (NDI); (2) one disorder (RP, DA, SCK, or HiHp); or (3) more than one disorder (RP, DA, SCK, HiHp) or death. With the exception of prepartum NEFA, no associations were detected between prepartum concentrations of our analytes of interest and the occurrence of one disorder (RP, DA, SCK, or HiHP) by 30 DIM. Haptoglobin concentration tended to be greater during wk −2 and −1 in cows that developed more than one disorder or that died by 30 DIM; however, when calving assistance was included as a covariate in the analysis prepartum, Hp was no longer a significant risk factor for this postpartum health outcome. Primiparous cows with plasma cortisol concentrations >22.2nmol/L during wk −2 had reduced odds [odds ratio (OR) 0.41; 95% confidence interval (CI) 0.17–0.98] of developing more than one disorder or death by 30 DIM, whereas multiparous cows with plasma cortisol >34.1nmol/L during wk −2 tended to have greater odds (OR 2.53; 95% CI 0.87–7.37) of developing more than one disorder or death by 30 DIM. Individual variation in daily cortisol secretion patterns and stress responses to the restraint and handling associated with sample collection make prepartum plasma cortisol data and its relationship to postpartum health difficult to interpret. Among multiparous cows, for every 500-unit (ng/g of fecal dry matter) increase in fecal cortisol metabolite concentration during wk −2, cows had increased odds (OR 1.41; 95% CI 1.12–1.79) of developing more than one disorder or dying after calving. For multiparous cows, every 0.15mmol/L increase in plasma NEFA concentration during any of the 3 wk before calving was associated with an approximately 2-fold increase in the odds of developing more than one disorder or dying by 30 DIM. Fecal cortisol metabolite concentration during the prepartum period did not predict which cows would go on to develop more than one disorder or die within 30 DIM as accurately as prepartum NEFA concentration; therefore, this analyte is not a suitable substitute for NEFA for assessing opportunities to improve herd health.

Prepartum dietary energy intake affects metabolism and health during the periparturient period in primiparous and multiparous Holstein cows

An experiment was conducted to determine the effect of prepartum plane of energy intake on metabolic profiles related to lipid metabolism and health in blood and liver. Primiparous (n=24) and multiparous (n=23) Holsteins were randomly assigned by expected date of parturition to 1 of 3 prepartum energy intakes. A high energy diet [1.62 Mcal of net energy for lactation (NEL)/kg; 15% crude protein] was fed for either ad libitum intake or restricted intake to supply 150% (OVR) or 80% (RES) of energy requirements for dry cows in late gestation. To limit energy intake to 100% of National Research Council requirements at ad libitum intake, chopped wheat straw was included as 31.8% of dry matter for a control diet (CON; 1.21 Mcal of NEL/kg of dry matter; 14.2% crude protein). Regardless of parity group, OVR cows had greater concentrations of glucose, insulin, and leptin in blood prepartum compared with either CON or RES cows; however, dietary effects did not carry over to the postpartum period. Prepartum nonesterified fatty acids (NEFA) were lower in OVR cows compared with either CON or RES cows. Postpartum, however, OVR cows had evidence of greater mobilization of triacylglycerol (TAG) from adipose tissue as NEFA were higher than in CON or RES cows, especially within the first 10 d postpartum. Prepartum β-hydroxybutyrate (BHBA) was not affected by diet before parturition; however, within the first 10 d postpartum, OVR cows had greater BHBA than CON or RES cows. Prepartum diet did not affect liver composition prepartum; however, OVR cows had greater total lipid and TAG concentrations and lower glycogen postpartum than CON or RES cows. Frequency of ketosis and displaced abomasum was greater for OVR cows compared with CON or RES cows postpartum. Controlling or restricting prepartum energy intake yielded metabolic results that were strikingly similar both prepartum and postpartum, independent of parity group. The use of a bulky diet controlled prepartum energy intake in multiparous and primiparous cows, improved metabolic status postpartum, and reduced the incidence of health problems. When metabolic profiles are considered collectively, cows overfed energy prepartum exhibited an “overnutrition syndrome” with characteristics of clinical symptoms displayed by diabetic or obese nonruminant subjects. This syndrome likely contributed to metabolic dysfunction postpartum.

Association between the proportion of sampled transition cows with increased nonesterified fatty acids and β-hydroxybutyrate and disease incidence, pregnancy rate, and milk production at the herd level

In this study the herd alarm level was defined as the proportion of sampled transition cows per herd with increased prepartum nonesterified fatty acid (NEFA), postpartum β-hydroxybutyrate (BHBA), or NEFA concentrations that were associated with herd-level incidence of displaced abomasum (DA) or clinical ketosis (CK), pregnancy rate (PR), and milk production. The objectives were to 1) identify the herd alarm level for excessive negative energy balance and 2) describe the herd-level prevalence of this proportion. This was a prospective cohort study of 60 free-stall herds fed total mixed rations in the northeast United States. Two cohorts of approximately 15 animals were assessed for prepartum NEFA and postpartum BHBA and NEFA. The herd alarm level (i.e., the proportion of sampled animals above a certain metabolite threshold) was as follows: 15% had prepartum NEFA of 0.27 mEq/L; 15 and 20% had BHBA of 10 and 12 mg/dL, respectively; and 15% had postpartum NEFA of 0.60 and 0.70 mEq/L. The different herd alarm levels correspond to differences between the metabolites and respective herd-level effect. The herd-level effects for herds above the herd alarm level for prepartum NEFA were 3.6% increase in DA and CK incidence, 1.2% decrease in PR, and 282kg decrease in average mature equivalent 305-d (ME 305) milk. For BHBA, the herd-level effects were a 1.8% increase in DA and CK, 0.8% decrease in PR, and 534 and 358kg decrease in projected ME 305 milk yield for heifers and cows, respectively. For postpartum NEFA, the herd-level effects were 1.7% increase in DA and CK, 0.9% decrease in PR, and 288 and 593kg decrease in projected ME 305 milk yield for heifers and cows, respectively. The prevalence of herds in which more than 15% of animals sampled had prepartum NEFA concentration ≥0.30 mEq/L was 75%, BHBA ≥12 mg/dL was 40%, and postpartum NEFA ≥0.70 mEq/L was 65%. This study showed that there were detrimental herd-level effects if a large enough proportion of cows had increased metabolite concentrations, and further demonstrated that a high prevalence of herds have opportunity for improvement.

Associations of elevated nonesterified fatty acids and β-hydroxybutyrate concentrations with early lactation reproductive performance and milk production in transition dairy cattle in the northeastern United States

The objectives were to evaluate the effects of elevated pre- and postpartum nonesterified fatty acids (NEFA) and β-hydroxybutyrate (BHBA) concentrations during the transition period on reproductive performance and milk production in dairy cattle. In a prospective cohort study of 91 freestall, total mixed ration-fed herds in the northeastern United States, blood samples were collected from approximately 15 prepartum and 15 different postpartum transition animals in each herd. All samples were stratified based on pre- or postpartum status at the time of sample collection, and 2,259 and 2,290 animals were used to evaluate reproductive and milk production performance, respectively. Reproductive performance was assessed by time to conception within 70 d post-voluntary waiting period (VWP) and milk production was assessed using mature-equivalent 305-d (ME305) milk yield estimated at 120 d in milk. While controlling for body condition score (BCS), calving season, median ME305 milk production, and parity, NEFA and BHBA concentrations were evaluated with time to event analysis to investigate reproductive performance. These same predictor variables were used to determine the effects of elevated NEFA and BHBA concentrations on ME305 milk yield with herd as a random effect. Heifers and cows were grouped in the final analyses if the results between groups were similar. In all animals sampled prepartum, the risk of pregnancy within 70 d post-VWP was reduced by 19% when NEFA concentrations were ≥0.27mEq/L. In all animals sampled postpartum, those with NEFA concentrations ≥0.72mEq/L had a 16% decrease in risk of pregnancy and those with BHBA concentrations ≥10mg/dL had a 13% decrease in risk. In cows and heifers, ME305 milk yield was decreased by 683kg when prepartum NEFA concentrations were ≥0.33mEq/L. In heifers sampled postpartum, ME305 milk yield was increased by 488kg when NEFA concentrations were ≥0.57mEq/L and increased by 403kg when BHBA concentrations were ≥9mg/dL. In cows sampled postpartum, ME305 milk yield was decreased by 647kg when NEFA concentrations were ≥0.72mEq/L and decreased by 393kg when BHBA concentrations were ≥10mg/dL. With the exception of milk production in heifers, this study indicates that increased concentrations of serum NEFA and BHBA had a detrimental effect on reproductive performance and milk production.