Transition Cows Research Articles

Effect of feeding an immune modulator to multiparous Holstein cows during the dry period and early lactation on health, milk and reproductive performance

In this study we evaluated the effect of feeding an immune modulatory feed additive (OmniGen-AF®; OMN) during the dry period through early lactation on postpartum health, subsequent lactational and reproductive performance of multiparous Holstein cows. We hypothesized that feeding OMN beginning in the dry period and through 150 days in milk (DIM) would improve milk yield and reproductive performance as a result of improved immune response. To test our hypothesis, 1392 multiparous pregnant Holstein cows of a commercial dairy herd were enrolled and randomly assigned at dry-off (47.6 ± 9.4 d before calving) to OMN (n = 706) or control (CON, n = 686) treatments. Both OMN and CON (placebo) supplements were fed once per day at a rate of 56 g/d per head from dry-off through 150 DIM. Cows were milked three times a day and daily milk yield was measured once per week, starting at the second week of lactation through 140 days in milk. Postpartum health disorders were monitored daily throughout the experiment. Cows were bred following a double OvSynch protocol after a 77-d voluntary waiting period (VWP). Final pregnancy status was assessed after supplementation ended at 230 DIM. Our results indicated that cows supplemented with OMN produced more milk than CON (40.8 kg/d vs. 40.1 kg/d; P < 0.01) during the first 140 d of lactation. Once they entered lactation, cows supplemented with OMN tended (P < 0.10) to have a reduced incidence of mastitis, retained placenta, displaced abomasum (P < 0.11) and reduced number of days spent in the hospital pen relative to CON. OmniGen feeding was also associated with a 10-d reduction in days open (P < 0.05) compared to CON. However, pregnancy rate at first, second and until ∼230 DIM did not differ between treatments. In conclusion, supplementing an immunomodulatory feed additive to dry and early lactation dairy cows was associated with improved milk yield, a tendency to reduce transition cow disorders and reduced number of days open.

A meta-analysis and meta-regression of the effects of vitamin E supplementation on serum enrichment, udder health, milk yield, and reproductive performance of transition cows

Vitamin E is an essential nutrient for cows, but the effect of vitamin E supplementation is often controversially discussed in the published literature. The main goal of this meta-analysis was to evaluate the effects of vitamin E supplementation on its serum and colostrum enrichment, milk yield (MY), and somatic cell counts (SCC), as well as on various reproductive variables of transition cows, by considering a large set of variables that might influence the responses to vitamin E supplementation. After a broad search in journals and databases with keywords related to transition cows supplemented with vitamin E and appropriate filtering of the results, 36 papers including 53 trials were selected, and their data were extracted into a database. A meta-analysis was conducted on the extracted data. The analysis showed enrichment of serum vitamin E both at parturition (effect size: 2.423) and postpartum (effect size: 0.473), but no effects of vitamin E supplementation on IgG concentration in colostrum (effect size: -0.05) were found. There was a tendency for supplemented cows to produce more milk (effect size: 1.29) during the first month of lactation. Because of large heterogeneity, a meta-regression was performed but none of the presumed influencing factors was identified as a potential variable affecting MY. Milk SCC, as an indicator of udder health, was unaffected by vitamin E supplementation. Vitamin E supplementation tended to decrease the calving to first estrus period (CFP), whereby supplementing Se and taking parity into account in the analysis significantly lowered the CFP. Cows receiving additional vitamin E had, on average, 6.1% fewer cases of retained placenta, whereby Se supplementation and breed were key factors improving the effect of vitamin E to reduce retained placenta. In this regard, breeds other than Holstein responded better and these cows showed a lower incidence of retained placenta. The supplemented cows showed fewer days open (effect size: -0.31), and this improvement was affected linearly by increasing the dosage administered. Also, cows showed fewer services per conception with increasing dosage of vitamin E. In conclusion, this analysis showed that supplementing vitamin E did not affect SCC or colostrum quality but improved reproductive performance of transition cows, an effect consistent with increased levels of serum vitamin E and, for some variables, being modulated by Se supplementation.

Symposium review: One-carbon metabolism and methyl donor nutrition in the dairy cow

The present review focuses on methyl donor metabolism and nutrition in the periparturient and lactating dairy cow. Methyl donors are involved in one-carbon metabolism, which includes the folate and Met cycles. These cycles work in unison to support lipid, nucleotide, and protein synthesis, as well as methylation reactions and the maintenance of redox status. A key feature of one-carbon metabolism is the multi-step conversion of tetrahydrofolate to 5-methyltetrahyrofolate. Homocysteine and 5-methyltetrahyrofolate are utilized by vitamin B12-dependent Met synthase to couple the folate and Met cycles and generate Met. Methionine may also be remethylated from choline-derived betaine under the action of betaine hydroxymethyltransferase. Regardless, Met is converted within the Met cycle to S-adenosylmethionine, which is universally utilized in methyl-group transfer reactions including the synthesis of phosphatidylcholine. Homocysteine may also enter the transsulfuration pathway to generate glutathione or taurine for scavenging of reactive oxygen metabolites. In the transition cow, a high demand exists for compounds with a labile methyl group. Limited methyl group supply may contribute to inadequate hepatic phosphatidylcholine synthesis and hepatic triglyceride export, systemic oxidative stress, and compromised milk production. To minimize the perils associated with methyl donor deficiency, the peripartum cow relies on de novo methylneogenesis from tetrahydrofolate. In addition, dietary supplementation of rumen-protected folic acid, vitamin B12, Met, choline, and betaine are potential nutritional approaches to target one-carbon pools and improve methyl donor balance in transition cows. Such strategies have merit considering research demonstrating their ability to improve milk production efficiency, milk protein synthesis, hepatic health, and immune response. This review aims to summarize the current understanding of folic acid, vitamin B12, Met, choline, and betaine utilization in the dairy cow. Methyl donor co-supplementation, fatty acid feeding strategies that may optimize methyl donor supplementation efficacy, and potential epigenetic mechanisms are also considered.

Does intrauterine cephapirin improve subsequent fertility in cows with clinical endometritis?

#### Bottom Line During a routine fertility visit, you find many cows with a white vaginal discharge 21 to 28 days after calving, and you discuss with the farmer the...

Changes in behavior and fecal cortisol metabolites when dairy cattle are regrouped in pairs versus individually after calving

Regrouping occurs when dairy cows are moved between pens, and this can negatively affect cow behavior and production. Pen changes occur frequently around calving, a time when cows are vulnerable to health problems. Regrouping cows along with a familiar conspecific after calving may make social integration easier, but little work has tested this hypothesis. The objective of this study was to compare lying behavior, feeding behavior, social behavior, and fecal cortisol metabolite concentrations (a physiological indicator of stress) between cows regrouped individually and cows regrouped with a familiar partner after calving. Holstein (n = 8) and Jersey (n = 26) cows were monitored from approximately 2 wk before until 7 d after calving. Cows were held in 1 of 2 identical maternity pens until they calved. After calving, cows were held in a transition pen for 3 d before being regrouped into the main lactation pen (regrouping of interest). On d 3 postpartum, cows were assigned to a treatment, balancing for parity and breed: regrouped into the lactation pen alone (individual; n = 17) or with a familiar partner (paired; n = 17). A familiar partner was defined as a cow that spent 3 d in the transition pen with the focal cow. Using live observation, we quantified the time cows spent feeding, standing or lying in the lying stalls, grooming, and standing in different locations in the pen during the 1 h immediately after regrouping. The frequency of competitive interactions at the feed bunk was also measured during this observation period. Lying behavior was monitored from 2 d before until 5 d after regrouping using a data logger. Fecal samples were collected for 5 d beginning on the day of regrouping to assess fecal cortisol metabolite concentrations (11,17-dioxoandrostane, 11,17-DOA). We found no effects of regrouping treatment on behaviors observed during the 1-h period immediately following regrouping. Cows that were regrouped with a partner had more lying bouts than cows moved individually (9.2 ± 0.4 bouts/d vs. 7.5 ± 0.4 bouts/d) and shorter lying bout durations (66.6 ± 3.9 vs. 78.1 ± 3.5 min/d); however, we also observed these differences during the day before regrouping, suggesting that the differences in lying behavior could not be explained by the regrouping treatment alone. Individually regrouped primiparous cows had higher 11,17-DOA concentrations than individually regrouped multiparous cows but we found no differences in 11,17-DOA between parities when cows were moved with a familiar partner. In addition, 11,17-DOA was higher in primiparous cows moved alone compared with primiparous cows moved with a partner. More research is needed to understand the mechanisms by which social familiarity affects behavior and the physiological stress response following regrouping; this may provide new insight into how to better transition cows into new environments.

Plasma proteomic profiling and pathway analysis of normal and overconditioned dairy cows during the transition from late pregnancy to early lactation

This study applied a quantitative proteomics approach along with bioinformatics analyses to investigate changes in the plasma proteome of normal and overconditioned dairy cows during the transition period. Fifteen weeks before their anticipated calving date, 38 multiparous Holstein cows were selected based on their current and previous body condition scores (BCS) and allocated to either a high or a normal BCS group (19 cows each). They received different diets until dry-off to reach targeted differences in BCS and back fat thickness (BFT) until dry-off. At dry-off, normal BCS cows had a BCS <3.5 (minimum, 2.75) and BFT <1.2 cm (minimum, 0.58), and the high BCS cows had a BCS >3.75 (maximum, 4.50) and BFT >1.4 cm (maximum, 2.90). The proteomics study used a subset of 5 animals from each group. These cows were selected based on their circulating concentrations of fatty acids (FA) on d 14 postpartum and β-hydroxybutyrate (BHB) on d 21 postpartum, representing the greater or the lower extreme values within their BCS group, respectively. The high BCS subset (HE-HBCS) had 4.50 < BCS > 3.75, FA = 1.17 ± 0.46 mmol/L, and BHB = 2.15 ± 0.42 mmol/L (means ± SD), and the low BCS subset (LE-NBCS) had 3.50 < BCS > 2.75, FA = 0.51 ± 0.28 mmol/L, and BHB = 0.84 ± 0.17 mmol/L. Plasma samples from d -49, +7, and +21 relative to parturition were used for proteome profiling by applying the quantitative tandem mass tags (TMT) approach. Nondepleted plasma samples were subjected to reduction and digestion and then labeled with TMT 10plex reagents. High-resolution liquid chromatography-tandem mass spectrometry analysis of TMT-labeled peptides was carried out, and the acquired spectra were analyzed for protein identification and quantification. In total, 254 quantifiable proteins (criteria: 2 unique peptides and 5% false discovery rate) were identified in the plasma samples. From these, 24 differentially abundant proteins (14 more abundant, 10 less abundant) were observed in the LE-NBCS cows compared with the HE-HBCS cows during the transition period. Plasma α-2-macroglobulins were more abundant in HE-HBCS versus LE-NBCS cows at d +7 and +21. Gene Ontology enrichment analyses of differentially abundant proteins revealed that the acute inflammatory response, regulation of complement activation, protein activation cascade, and regulation of humoral immune response were the most enriched terms in the LE-NBCS group compared with the HE-HBCS group. In addition, we identified 24 differentially abundant proteins (16 in the LE-NBCS group, and 8 in the HE-HBCS group) during the transition period. The complement components C1q and C5 were less abundant, while C3 and C3d were more abundant in LE-NBCS compared with HE-HBCS cows. Overall, overconditioning around calving was associated with alterations in protein pathways related to acute inflammatory response and regulation of complement and coagulation cascades in transition cows.

Ultrasound and Radiographic Imaging Diagnosis of Diaphragmatic Hernia in a Transition Cow: A Case Report

A four and half-year-old recently calved cross breed Jersey cow was presented with the clinical signs of anorexia, recurrent bloat, bruxism and not voided dung for the past one week. Clinical examination revealed congested mucous membrane, sunken eyeball, and severely distended lower abdomen; clinically, bloat was evident. On Auscultation of heart at 4th intercoastal space, low-intensity heart sounds were heard. Rectal examination revealed scanty foul-smelling dung with blood tinge. In an attempt to relieve the bloat rumen stomach was intubated, which failed to relieve the gas. The clinical suspicion pointed to the possibility of foreign body syndrome. Hence radiography was done by keeping the animal in standing position; however it revealed no clear contour of heart, reticulum, and diaphragm; another attempt was made, wherein the animal was cast on right lateral recumbency and radiography was done at 90-100 kVp, 50-60 mAs and a focus film distance of 90-100 cm using an 800 mA X-ray machine. As we would not get any diagnostic confirmation findings in radiography, an ultrasonographic assessment was planned. Ultrasonography was done with (Esoate Mylab 1) 2.5. to 5 MHz curvy linear transducer. Ultrasound examination of the heart (Venkatesan et al., 2019) and reticulum (Braun et al., 1993) was done at the left side between 4th to 5th intercostal space of thoracic cavity using the window between 6th to 8th intercoastal in the abdominal cavity. Physical examination revealed a dull and depressed animal; distended left flank, moderate dehydration, elevated rectal temperature (40°C), low-intensity heart sounds with a normal heart rate was observed. Hematology was unremarkable; smear study was negative for blood parasites.

Building confidence in transition cow consulting

Nutrition can greatly impact the health and productivity of the lactating dairy cow. Nutrition and management during the dry period and immediately prior to calving have a tremendous impact on the success of the cow to transition into lactation. The veterinarian may be asked to intervene on individual sick cows with transition problems (i.e. ketosis, displaced abomasum [LDA], hypocalcemia) or evaluate a herd that has a higher incidence of transition cow disease than expected. Veterinarians should develop the skills necessary to consult producers on how to diagnose whether the transition cows are having a negative impact on herd health and productivity, evaluate the cause of the increased herd-level incidence, and recommend management and nutritional changes to correct the problem. This paper will primarily focus on clinical and subclinical ketosis prevention and its sequelae.

Effects of far-off and close-up transition cow feeding on uterine health, postpartum anestrous interval, and reproductive outcomes in pasture-based dairy cows

BackgroundIn seasonal, pasture-based, dairy production systems, cows must recover from calving and become pregnant within two to 3 months. To achieve this, the uterus must involute and ovulation must occur and continue at regular intervals. As these processes are affected by the cows’ nutritional or metabolic status post-calving, the objective of this study was to evaluate the effect of cow feeding strategies on uterine health, the length of postpartum anestrous interval, and reproductive outcomes. The treatments consisted of two feeding strategies during late-lactation and early dry period (far-off period; starting 4-month pre-calving) and three close-up dry period feeding regimes (1-month pre-calving) in a 2 × 3 factorial arrangement. We randomly assigned 150 cows to one of two far-off treatments. During late lactation, the herds (n = 75 cows per herd) were either control-fed (Controlfed) or over-fed (Overfed) to achieve a low or high body condition score (4-month pre-calving; BCS; ~ 4.25 and ~ 4.75; 10-point scale) at cessation of lactation. Within each of these treatments, three feeding levels were applied during the close-up period (1-month pre-calving): ~ 65% (Feed65), ~ 90% (Feed90), or ~ 120% (Feed120) of metabolizable energy (ME) intakes relative to pre-calving requirements.ResultsUterine health improved (i.e. polymorphonucleated (PMN) cells declined) with increased feeding during the close-up period for cows in the Overfed group. The reverse was evident for the Controlfed group with the greatest PMN at the highest intakes during the close-up period. The postpartum anoestrous interval (PPAI) was shorter in cows from the Overfed group when moderately fed (Feed90) during the close-up period; in comparison, the PPAI was shorter in the Controlfed group, when those cows were overfed in the close-up period (Feed120). The cows in the Overfed treatment had greater conception and pregnancy rates if cows had moderate dry matter intakes (Feed90) during the close-up period; these reproductive variables were less under excessive feed intakes (Feed120); yet, close-up dry matter intake had little effect on conception and pregnancy rates for the Controlfed group.ConclusionsThe far-off feeding strategies increased early reproductive outcomes at 3 weeks of mating. Additionally, the interaction between far-off and close-up feeding strategies resulted in high six-week pregnancy rate with a slight restriction during the close-up period but only in the far-off Overfed group. Thus, our hypothesis is supported under these conditions.

Assessment of associations between transition diseases and reproductive performance of dairy cows using survival analysis and decision tree algorithms

This study aimed to evaluate the associations between transition cow conditions and diseases TD with fertility in Holstein cows, and to compare analytic methods for doing so. Kaplan-Meier, Cox proportional hazard, and decision tree models were used to analyze the associations of TD with the pregnancy risk at 120 and 210 DIM from a 1-year cohort with 1946 calvings from one farm. The association between TD and fertility was evaluated as follows: 1 cows with TD whether complicated with another TD or not TD-all, versus healthy cows, and 2 cows with uncomplicated TD TD-single, versus cows with multiple TD TD+; complicated cases, versus healthy cows. The occurrence of twins, milk fever, retained placenta, metritis, ketosis, displaced abomasum, and clinical mastitis were recorded. Using Kaplan-Meier models, in primiparous cows the 120 DIM pregnancy risk was 62% (95% CI: 57–67 %) for healthy animals. This was not significantly different for TD-single (58%; 95% CI: 51–66 %) but was reduced for TD+ (45%; 95% CI: 33–60 %). Among healthy primiparous cows, 80% (95% CI: 75–84 %) were pregnant by 210 DIM, but pregnancy risk at that time was reduced for primiparous cows with TD-single (72%; 95% CI: 65–79 %) and TD+ (62%; 95% CI: 49–75 %). In healthy multiparous cows, the 120 DIM pregnancy risk was 53% (95% CI: 49–56 %), which was reduced for TD-single (36%; 95% CI: 31–42 %) and TD+ (30%; 95% CI: 24–38 %). The 210 DIM pregnancy risk for healthy multiparous cows was 70% (95% CI: 67–72 %), being higher than the 210 DIM pregnancy risk for multiparous cows with TD-single (47%; 95% CI: 42–53 %) or TD+ (46%; 95% CI: 38–54 %). Cows with TD-all presented similar pregnancy risk estimates as for TD + . Cox proportional hazards regressions provided similar magnitudes of effects as the Kaplan-Meier estimates. Survival analysis and decision tree models identified parity as the most influential variable affecting fertility. Both modeling techniques concurred that TD + had a greater effect than TD-single on the probability of pregnancy at 120 and 210 DIM. Decision trees for individual TD identified that displaced abomasum affected fertility at 120 DIM in primiparous while metritis was the most influential TD at 120 and 210 DIM for multiparous cows. The data were too sparse to assess multiple interactions in multivariable Cox proportional hazard models for individual TD. Machine learning helped to explore interactions between individual TD to study their hierarchical effect on fertility, identifying conditional relationships that merit further investigation.

Temporal dynamics of nutrient balance, plasma biochemical and immune traits, and liver function in transition dairy cows

The objective of this study was to analyze the dynamics of nutrient balance, physiological biomarkers and comprehensive indexes associated with metabolism and function of organs in transition cows. Fourteen transition cows were used for this research. Dietary intake was recorded daily, and samples of the diet, venous blood and milk were collected for measurements. The balance values of net energy for lactation (NEL), metabolizable protein (MP), and metabolizable glucose (MG) were calculated, and regression analysis and calculation of comprehensive indexes were performed. Accordingly, the prepartum cows presented positive balances of NEL, MP, and MG, while severe negative balances were found during the postpartum period. Dynamic changes of energy metabolism, nutrient mobilization, liver function, anti-oxidative status and immune response, as indicated by blood biomarkers and modified comprehensive indexes, were out of sync with the calculated balance values, but they were closely related to the day relative to calving. Compared with the 21 d prepartum, the plasma concentrations of non-esterified fatty acids (NEFA) and β-hydroxybutyric acid (BHBA) were significantly increased around and after calving (P<0.05), and similar variation tendency was observed for most of other parameters. The occurrence of parturition and the initiation of lactation were more responsible for the negative balances of nutrients in transition dairy cows. Although negative balances of NEL, MP and MG were not observed using the assessment model, the nutritional strategies should be applied before calving, because metabolic adaptations had been validated during the prepartum period. In addition, it was plausible to conclude that the decline of hepatic metabolism, defense function and insulin sensitivity are critical causes of metabolic dysfunction.

Modulation of immune function in the bovine uterus peripartum

There is a high risk of clinical or subclinical reproductive tract disease in the postpartum period in dairy cows. An integrated process of adaptive events should occur synchronously, including a robust but well-regulated immune response in the uterus. Failure of this process may result in reproductive tract inflammatory disease. Up to half of postpartum dairy cows are affected by metritis, purulent vaginal discharge (PVD), or subclinical endometritis. After parturition there is damage to the birth canal, the superficial layer of the endometrium is naturally wounded, and essentially all dairy cows have bacterial contamination in the uterus. Neutrophils are the most abundant type of inflammatory cell and the main line of defence against infection in the uterus. A prompt influx of neutrophils is associated with uterine health. Avoidance of clinical disease (metritis and PVD) depends in large part on how effective the immune response is at limiting the burden and effects of bacterial pathogens, while the occurrence of subclinical endometritis is more a function of avoiding excessive or persistent inflammation. Glucose supply, hypocalcemia, lipid mobilization from body fat, ketosis, and the flux of pro-inflammatory cytokines influence immune response and change rapidly and variably among individual cows. Effective but well-regulated inflammatory response will be favoured by best management practices for transition cows, but specific interventions to modulate immune response to prevent uterine disease remain developmental.

Symposium review: Transition cow calcium homeostasis—Health effects of hypocalcemia and strategies for prevention

The effects of subclinical hypocalcemia have been explored in numerous observational and mechanistic studies in recent years. Besides obvious, well-known effects on muscle contractility, the role of Ca with respect to immune function and intermediary metabolism explains the contribution of subclinical hypocalcemia to the development of several diseases observed in early lactation and underlines its importance in high-performing dairy cows. The present review aims at integrating recent scientific progress, such as discoveries about the role of the mammary gland in regulating bone mobilization, into generally accepted aspects of the endocrine control of Ca homeostasis. We will discuss Ca transport mechanisms through absorption, resorption, secretion, and mobilization, as well as the physiological regulation of Ca through parathyroid hormone, 1,25-dihydroxyvitamin D, fibroblast growth factor 23, and serotonin, in addition to dietary mineral requirements. To improve hypocalcemia prevention strategies, our knowledge of the physiological mechanisms necessary to maintain normocalcemia and their endogenous regulation should be combined with data derived from herd-level studies. Using such studies, we will discuss prepartum nutritional strategies aimed at reducing the incidence of subclinical hypocalcemia, as well as options for postpartum Ca supplementation and their effects on early-lactation health and production. Especially in respect to approaches that might interfere with endogenous adaptation processes, such as supplementation with vitamin D metabolites or large doses of Ca, a thorough understanding of the underlying mechanisms that might induce unwanted hypocalcemia rebound effects will be crucial to ameliorate our future management of transition cows. Continued efforts by researchers to understand the interaction of Ca homeostasis with prevention strategies is necessary to optimize cow health and support copious milk production.

Effect of prepartum energy intake and supplementation with ruminally protected choline on innate and adaptive immunity of multiparous Holstein cows

Objectives were to evaluate the effect of prepartum energy intake and peripartal supplementation of ruminally protected choline (RPC) on select indicators of immune status in blood plasma and on lipopolysaccharide-stimulated blood cells ex vivo. At 47 ± 6 d before the expected calving date, 93 multiparous Holstein cows were assigned randomly to 1 of 4 dietary treatments in a 2 × 2 factorial arrangement. Cows were fed energy to excess [EXE; 1.63 Mcal of net energy for lactation (NEL)/kg of dietary dry matter (DM)] or to maintenance (MNE; 1.40 Mcal of NEL/kg of dietary DM) ad libitum throughout the nonlactating period. The RPC was fed at 0 or 60 g/d to supply 0 or 12.9 g/d of choline ions top-dressed for 17 ± 4.6 d prepartum through 21 d postpartum. After calving, cows were fed the same methionine-supplemented diet, apart from RPC supplementation. During the last 2 wk before calving and during the first 5 wk postpartum, blood was sampled repeatedly and analyzed for cell types, acute-phase proteins, tumor necrosis factor-α (TNFα), and neutrophil function. Samples of whole blood were collected at 3 and 14 DIM and stimulated with 1 μg/mL lipopolysaccharide (LPS) in vitro for 6 and 24 h. After 6 h of LPS exposure, peripheral blood leucocytes (PBL) were harvested, and relative transcript abundance for select cytokines were measured. Supernatant was analyzed for TNFα after 24 h of LPS exposure. The PBL from cows fed EXE diets during the whole dry period had increased transcripts for the proinflammatory cytokines CXCL8 and TNF, although the plasma concentrations of the acute-phase proteins haptoglobin and fibrinogen, and the killing activity of the blood neutrophils in the postpartum period, were not affected by feeding different energy levels prepartum. Feeding RPC to cows overfed energy prepartum modulated their inflammatory state, as evidenced by decreased IL6 in PBL and reduced mean fluorescence intensity of CD14 during the postpartum period, compared with cows not fed RPC. Feeding RPC also decreased TNFα protein production, abundances of IL1B, CXCL8, and TNF transcripts, and mean fluorescence intensity of CD80 of PBL stimulated by LPS, regardless of prepartum energy intake. In contrast, proportions of blood neutrophils undergoing phagocytosis and oxidative burst were increased at 17 d postpartum in cows supplemented with RPC. Collectively, these data indicate that transition cows supplemented with RPC experienced less inflammation, which may partially explain increased milk production in cows supplemented with RPC.

Comparison of laparotomic omentopexy vs. laparoscopic abomasopexy treatments of left displaced abomasum in dairy cows under field conditions: biochemical analysis

The objective of this retrospective study was to compare the effects of the two methods (laparoscopic or laparotomic) of LDA (left displaced abomasum) correction under field conditions by means of survival rate and biochemical profile evaluation. Holstein cows from one farm with LDA over a 20-month period were included in the study. Cows underwent laparoscopic abomasopexy (Janowitz’s method, LS) or a laparotomic right flank omentopexy (Dirksen’s method, LT). Blood samples for biochemical analysis were taken just prior to surgery (D1) and on days 10 (D10) and 30 (D30) following surgery. Blood profiles of healthy cows identified from the farm’s routine transition cow monitoring program were used as control (C). Aiming to minimize disruptive effects of quite a long period of data collection, the cows’ biochemical profile was evaluated in three orthogonal comparisons: LS cows vs. control group, LT cows vs. control group, and LS cows vs. LT cows. The rate of animal survival was similar for both methods (loss of about 11% until 30 days after treatment). Most of the blood parameters from LS and LT groups were comparable in all three sampling terms indicating continual organism recovery. At D10 the difference of higher cholesterol concentration and lower haptoglobin concentration were favourable for the LS group (P &lt; 0.05). Total protein, calcium, magnesium and albumin showed more positive dynamics in the LS group too. This proves previous laboratory and clinical indices of expediency of LDA laparoscopy treatment under field conditions.

Accuracy of direct vs calculated ionized calcium in treatment planning for transition cow medical care: A review of 104 dairy cows

Accuracy of direct vs calculated ionized calcium in treatment planning for transition cow medical care: A review of 104 dairy cows

Responses to rumen-protected choline in transition cows do not depend on prepartum body condition

It is often suggested that the benefits of supplemental rumen-protected choline (RPC) might be greater in cows predisposed to fatty liver, such as those that are overconditioned; however, limited data support this suggestion. Therefore, the hypothesis of this study was that responses to supplementing RPC to transition dairy cows is not dependent on the degree of fatness prepartum. Objectives were to evaluate the effects of supplementing RPC to transition dairy cows according to body condition score (BCS) prepartum on production and metabolic responses. Data from 2 randomized block experiments that evaluated the effects of RPC supplementation during the transition period were combined. Within each experiment, cows were assigned randomly to receive 0 (CTRL) or 12.9 g/d choline ion in an RPC form (CHOL) daily top-dressed onto the diet from 21 d prepartum to 21 d postpartum. Body condition was evaluated twice prepartum before enrollment and the mean value was used as an explanatory variable for statistical analyses. Data were collected for the last 21 d of gestation and the first 105 d postpartum. The BCS (mean ± standard deviation) prepartum were 3.51 ± 0.29 and 3.51 ± 0.32 for CTRL and CHOL, respectively, and ranged from 2.69 to 4.25. A total of 215 cows were enrolled in the respective experiments and contributed data for the incidence of diseases, whereas 192 cows contributed data for analyses of production responses, plasma metabolites, and liver composition. Irrespective of BCS, supplementing transition diets with CHOL increased yields of milk by 1.8 kg/d, fat by 0.08 kg/d, lactose by 0.08 kg/d, true protein by 0.04 kg/d, energy-corrected milk (ECM) by 1.9 kg/d, and fat-corrected milk by 2.1 kg/d. The improvements in productive performance were not followed by increased dry matter intake or measures of lipomobilization. Therefore, CHOL cows were more efficient in converting dry matter intake into ECM. Feeding CHOL increased concentration of hepatic triacylglycerol (CTRL = 3.23 vs. CHOL = 3.87% wet basis) in the first 21 d postpartum. Overconditioned cows were more prone to having exacerbated lipomobilization and increased prevalence and incidence of fatty liver, but no interactions between treatment and BCS were observed for body weight, BCS, or concentrations of metabolites in plasma or hepatic triacylglycerol. Treatment did not affect incidence of clinical diseases. Opposite to common suggestions, cows with increased hepatic triacylglycerol content also had increased yields of milk and ECM in the first 105 d postpartum. Collectively, these findings indicate that the effects of RPC supplementation during the transition period are independent of the degree of fatness of dairy cows prepartum. The findings also suggest that the effects on productive performance are not necessarily mediated by improvements in markers of metabolic health or reductions in hepatic triacylglycerol.

The effect of ex vivo lipopolysaccharide stimulation and nutrient availability on transition cow innate immune cell AKT/mTOR pathway responsiveness

Postpartum dairy cows experience a heightened inflammatory state coinciding with the time of greatest nutrient deficit. Nutrient availability is sensed on the cellular level by nutrient sensing kinases, such as the PI3K/AKT/mTOR (mTOR) pathway, a key orchestrator of immune cell activation and inflammatory balance. Our objective was to determine the responsiveness of this pathway to inflammatory stimulation with and without nutrient supplementation ex vivo. Blood samples were collected from Holstein cows (n = 14) at -42, -14, 7, 21, and 42 d relative to calving. Control samples and samples pretreated with a mixture of amino acids, glucose, and insulin (AAM) were stimulated with 100 ng/mL E. coli lipopolysaccharide (LPS; LPS, AAMLPS) or left unstimulated (control, AAM). After 1 h, ratios of mean fluorescence intensity for phosphorylated to total protein of AKT and mTORC1 substrates S6RP and 4EBP1 were analyzed in polymorphonuclear cells (PMN), and monocytes by flow cytometry. A separate aliquot was stimulated with LPS for 2 h and relative mRNA abundance of IL10, IL12A, IL12B, and TNFA in whole blood leukocytes from 10 cows was measured by reverse-transcription quantitative PCR. Repeated measures ANOVA was performed with fixed effects of time, treatment, and their interaction. Cells had different ratios of pathway proteins with PMN having the highest phosphorylation of AKT, S6RP, and 4EBP1. Stimulation with LPS consistently activated mTOR signaling in PMN regardless of nutrient supplementation except for postpartum 4EBP1, which increased in response to nutrients alone. In monocytes, AKT baseline phosphorylation was lower and activation could not be induced by either treatment, whereas activation of 4EBP1 responded to nutrient supplementation. Treatment with LPS increased phosphorylation of S6RP in both innate immune cell types. Nutrient supplementation increased baseline IL10 expression and decreased baseline as well as LPS-induced IL12B and TNFA expression. We conclude that the mTOR pathway in bovine innate immune cells can be differentially activated in response to inflammatory stimulation and nutrient supplementation in monocytes versus PMN. Effects of nutrient supplementation on cytokine mRNA abundance are likely specific to immune cell type.

Identifying barriers to successful dairy cow transition management

Many dairy cows become ill in the weeks after calving, a period when cows also experience numerous environmental and physiological changes. Most research on this transition period has focused on biological factors including nutrition, immunology, and physiology, but little work has examined sociological factors affecting how farmers care for their cows. The aim of the current study was to describe barriers preventing the adoption of more successful management practices. We used individual and group interviews, paired with photo elicitation, to understand the perspectives of farmers (n = 11) and veterinarians (n = 8) living and working in the lower Fraser Valley of British Columbia, Canada. Participants viewed transition period management as difficult. The lack of a single definition of the transition period emerged as one barrier to improvement; providing a clear and consistent definition for the transition period may be an important first step to improved practices on dairy farms. Participants also identified other barriers hindering improvement, including variation in both farmer attitude toward transition cow management and veterinarian involvement, stocking density of cows, and nutrition management. Barriers to improved practices varied by farm, suggesting that a tailored approach is required to make meaningful change.

Peripheral concentrations of metabolic and inflammatory indicators during transition period and their relationship with postpartum clinical endometritis in dairy cattle

The aim of this study was to investigate the peripheral concentration of metabolic and inflammatory indicators during transition period and their relationship in cows that developed clinical endometritis (CE) and remained nonendometritis during later postpartum period. A total of 70 cows were selected and blood was collected from 21 days before calving to 21 days after calving. After adjusting the sampling date based on the actual calving date (–21±2, –7±1, 0, 7±1, 14±1 and 21±2 days) and health status, a minimum of 8 samples each from the CE and nonendometritis cows were used at each time point of transition period for the estimation of acute phase proteins (APPs) (haptoglobin, Hp; serum amyloid A, SAA; and alpha-1 acid glycoprotein, AGP), pro-inflammatory cytokines (IL-1􀁅, TNF-􀁄, IL-6 and IL-8) and energy indicators (NEFA, BHBA, Leptin and IGF-I) using bovine specific ELISA kits. APPs (Hp, SAA and AGP), cytokines (IL-1􀁅, TNF-􀁄, IL-6) and energy indicators (NEFA, BHBA, Leptin) levels significantly increased, while IL-8 and IGF-I levels significantly decreased in transition cows that eventually developed to CE compared to the cows which remained non-endometritis during 22–47 days postpartum. It is concluded that cows that diagnosed as CE during postpartum period were experienced negative energy balance and compromised their immune status during transition period.