Disorders In Dairy Cows Research Articles

The most common health disorders and welfare of dairy cows and calves

Three farms of dairy cows (A, B and C) were observed for health disorders of dairy cows and suckling calves. Farm A is farm with tied system of rearing, with 1100 cows, while farms B and C have 400 and 600 cows kept loose with outdoor pens, respectively. Data regarding welfare criteria of dairy cows (health, feeding, housing and behaviour) were collected and analysed through Protocol of Welfare Quality (2009). Health disorders of dairy cows and suckling calves were collected and statistically analysed by chi-square test (?2 test). Welfare of all of three dairy farms were assessed as acceptable, meaning that provided welfare conditions meet the minimum requirements of animals. Principle of provision of good health was rated as acceptable (?20 points) on farm A, while on farms with loose system (B and C) overall health rated as excellent (?80 points). Occurrence rate of reproductive, locomotor, skin and claws disorders and digestive and systemic disorders of dairy cows and calves up to 4 months old were very different between three farms (A, B, C) with ?2-values of 2901.71, 252.02, 204.08, 1152.31 and 184.23 respectively; ?<0.01). According presented data, it is obvious that the majority health problems were observed in tied system of rearing, on farm A, such as reproductive disorders and mastitis, as well as injuries and bad body score and lame cows. The most serious health problems of the calves were diarrhea and bronchopneumonia of different etiology.

Short communication: Circulating serotonin (5-HT) concentrations on day 1 of lactation as a potential predictor of transition-related disorders

The monoamine serotonin (5-hydroxytryptamine; 5-HT) has been described as a homeostatic regulator of lactation. Recently, our laboratory determined that 5-HT is involved in the regulation of calcium and glucose homeostasis during the transition period in rodents. More specifically, we demonstrate that 5-HT is responsible for calcium mobilization from bone and upregulation of hepatic gluconeogenic enzymes and mammary gland glucose transporters. Our objective was to investigate the correlation between circulating 5-HT concentrations and circulating ionized calcium, parathyroid hormone-related protein (PTHrP), and glucose concentrations on d 1 postpartum. We also investigated the correlation between circulating 5-HT and milk fever and ketosis incidence and severity in multiparous Holstein cows at the onset of lactation. Blood samples were collected from 42 multiparous cows on d 1 of lactation and analyzed for 5-HT, calcium, glucose, and PTHrP. Milk fever (determined subjectively for each cow on d 1 postpartum) and ketosis incidence and severity (scale 1 to 4, determined objectively for each cow during the first 10 d postpartum) were recorded for all animals. Serum 5-HT was positively correlated with serum calcium and with plasma PTHrP (r>0.37). Serum 5-HT was negatively correlated with milk fever incidence and with ketosis severity (most severe ketosis incidence recorded during the first 10 d postpartum; r<-0.33). Serum calcium and plasma glucose concentrations were negatively correlated with milk fever and ketosis severity, respectively (r<-0.39). These data indicate that 5-HT potentially plays a role in the regulation of calcium and glucose homeostasis during the transition period in cattle, which we previously demonstrated in rodents. Increased circulating concentrations of 5-HT might decrease milk fever at the onset of lactation and ketosis severity during the first 10 d postpartum in dairy cows. Understanding this physiological axis could help describe the underlying mechanisms associated with these periparturient metabolic disorders in dairy cows.

Serum paraoxonase-1 as biomarker for improved diagnosis of fatty liver in dairy cows

BackgroundFatty liver is a major metabolic disorder in dairy cows and is believed to result in major economic losses in dairy farming due to decreased health status, reproductive performance and fertility. Currently, the definitive means for diagnosing fatty liver is determining the fat content of hepatic tissue by liver biopsy, which is an invasive and costly procedure, making it poorly suited to dairy farms. Therefore, the key aim of this study was to investigate the measurement of serum paraoxonase-1 (PON1), an enzyme exclusively synthesized by the liver, as a sensitive noninvasive biomarker for diagnosis of fatty liver in dairy cows.ResultsA comparative cohort study using serum specimens from Holstein–Friesian dairy cows (46 healthy and 46 fatty liver cases) was conducted. Serum PON1 (paraoxonase, lactonase and arylesterase) activity and other biochemical and hematological parameters were measured. We found that serum PON1 activity was lower (P<0.001) in cows suffering from fatty liver. The area under the receiver operating characteristic curve (AUC-ROC) of PON1 activity for diagnosis of fatty liver was 0.973–0.989 [95% confidence interval (CI) 0.941, 1.000] which was higher than the AUC-ROC of aspartate aminotransferase (AST), lecithin-cholesterol acyltransferase (LCAT), alkaline phosphatase (ALP), non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), total cholesterol, high-density lipoprotein (HDL) and low-density lipoprotein (LDL). We found that adding serum PON1 measurement to different batteries of serum diagnostic panels showed a combination of high sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (+LR), negative likelihood ratio (−LR), diagnostic odd ratio (DOR) and overall diagnostic accuracy in diagnosing fatty liver.ConclusionsThe present results indicate that addition of serum PON1 activity measurement to the biochemical profile could improve the diagnosis of fatty liver in dairy cows, which would have a considerable clinical impact and lead to greater profitability in the dairy industry.

Ultrasonography for the management of reproductive disorders in dairy cows

Ultrasonography for the management of reproductive disorders in dairy cows

Effect of 2-methyl-2-phenoxy propionic acid on serum lipid profile and ovarian activity in dairy cows

Hepatic lipidosis and ketosis are frequent metabolic disorders in dairy cows during the transition period. The 2-methyl-2-phenoxy propionic acid (MFPA) is an activator of energy metabolism. The objective of this study was to evaluate the effect of administration of MFPA 10 days prepartum to day 36&amp;nbsp;postpartum on serum lipid profile, ovarian reactivity, and milk yield. Fifty seven multiparous Holstein cows were divided into four groups. The groups 1 (n = 14) and 2 (n = 14) had body condition score (BCS) above 4; BCS of the groups 3 (n = 15) and 4 (n = 14) was between 3.25 and 3.75 at calving. The solution containing 10 mg/kg MFPA was injected intramuscularly (IM) to cows of groups 1 and 3, 10&amp;ndash;7 days prepartum and 6&amp;nbsp;h postpartum. The groups 2 and 4 received 50 ml of 0.9% NaCl as placebo in the same way. Blood samples for serum lipid profile were collected from all cows 10 days before calving without treatment, 2 days after the first administration of MFPA and postpartum at days 2, 10, and 21 after the second administration of MFPA. At days 21, 24, 27, 30, 33, and 36 postpartum, blood samples were obtained for plasma progesterone determination. Milk yield was registered daily during 60 days postpartum. Prepartum free fatty acids (FFA) were mildly increased without difference among all the groups (P &amp;gt; 0.05). b-hydroxybutyrate (BHB) was increased only at day 10 after calving in cows of group 1 treated with MFPA (P &amp;lt; 0.05) due to higher number of postpartum diseases. In cows from groups 3 and 4 (BCS normal), BHB was mildly increased, not indicating subclinical ketosis. The serum concentrations of triacylgycerols, cholesterol, albumin, activities of aspartate aminotransferase and creatine kinase were within the limits of reference values, indicating adequate liver integrity and function. Cows of normal BCS treated with MFPA presented better milk production but without significant difference among four groups (P &amp;gt; 0.05). Ovarian reactivity was present at day 21 in all groups of cows without difference (P&amp;nbsp;&amp;gt;&amp;nbsp;0.05). The administration of MFPA had no effect on serum lipid profile and ovarian activity in this study. &amp;nbsp;

Computerized identification and classification of stance phases as made by front or hind feet of walking cows based on 3-dimensional ground reaction forces

Lameness is a frequent disorder in dairy cows and in large dairy herds manual lameness detection is a time-consuming task. This study describes a method for automatic identification of stance phases in walking cows, and their classification as made by a front or a hind foot based on ground reaction force information. Features were derived from measurements made using two parallel 3-dimensional force plates. The approach presented is based on clustering of Centre of Pressure (COP) trace points over space and time, combined with logical sequencing of stance phases based on the dynamics of quadrupedal walking. The clusters were identified as full or truncated (incomplete) stance phases furthermore the stance phases were classified as originating from a front or hind foot. Data from 370 walking trials made by 9 cows on 5 experiment days were used to test the method. Four cows were moderately lame at experimental onset. On average 5.1 stance phases per cow per trial were obtained of which 3.2 were classified as full stance phases and therefore appropriate for further gait analysis (the latter not being the scope of this study). Of the 2617 identified clusters 1844 were classified as stance phases, of these 1146 (62%) were automatically identified as full stance phases and classified as made by a front or hind foot. As intended, the procedures did not favour identification of stance phases of healthy cows over lame cows. In addition, a human observer evaluated the stance phases by visual inspection, revealing a very low discrepancy (3.5%) between manual and automated approaches. Further, a sensitivity test indicated large robustness in the automatic procedures. In conclusion, the experimental setup combined with the computerized procedures described in the present study resulted in a high number of stance phases obtained per trial. It is thus a combination which has the potential to enable unsupervised gait analysis based on data collected automatically on-farm.

Liver protein expression in dairy cows with high liver triglycerides in early lactation

Fatty liver is a frequent subclinical health disorder in dairy cows that may lead to disorders related to the liver function. However, the effect of triglyceride (TG) accumulation on liver metabolic pathways is still unclear. The objective was, therefore, to characterize quantitative differences in the liver proteome between early lactation dairy cows with a low or high liver TG content. The liver proteome analysis indicated that a high liver TG content in early lactation dairy cows is associated with increased oxidation of saturated fatty acids, oxidative stress, and urea synthesis and decreased oxidation of unsaturated fatty acids. Furthermore, liver gluconeogenesis is apparently not impaired by an increased liver TG content. Based on correlations between liver proteins and plasma components, we suggest that future studies investigate the sensitivity and specificity of plasma aspartate aminotransferase, β-hydroxybutyrate, total bilirubin, total bile acids, and γ-glutamyltransferase for potential use as blood-based biomarkers for early detection of fatty liver in dairy cows. Our study is the first to study the proteome of dairy cows with naturally occurring fatty liver in early lactation.

Risk factors for displaced abomasum or ketosis in Swedish dairy herds

Risk factors associated with high or low long-term incidence of displaced abomasum (DA) or clinical ketosis were studied in 60 Swedish dairy herds, using multivariable logistic regression modelling. Forty high-incidence herds were included as cases and 20 low-incidence herds as controls. Incidence rates were calculated based on veterinary records of clinical diagnoses. During the 3-year period preceding the herd classification, herds with a high incidence had a disease incidence of DA or clinical ketosis above the 3rd quartile in a national database for disease recordings. Control herds had no cows with DA or clinical ketosis. All herds were visited during the housing period and herdsmen were interviewed about management routines, housing, feeding, milk yield, and herd health. Target groups were heifers in late gestation, dry cows, and cows in early lactation. Univariable logistic regression was used to screen for factors associated with being a high-incidence herd. A multivariable logistic regression model was built using stepwise regression. A higher maximum daily milk yield in multiparous cows and a large herd size (p=0.054 and p=0.066, respectively) tended to be associated with being a high-incidence herd. Not cleaning the heifer feeding platform daily increased the odds of having a high-incidence herd twelvefold (p<0.01). Keeping cows in only one group in the dry period increased the odds of having a high incidence herd eightfold (p=0.03). Herd size was confounded with housing system. Housing system was therefore added to the final logistic regression model. In conclusion, a large herd size, a high maximum daily milk yield, keeping dry cows in one group, and not cleaning the feeding platform daily appear to be important risk factors for a high incidence of DA or clinical ketosis in Swedish dairy herds. These results confirm the importance of housing, management and feeding in the prevention of metabolic disorders in dairy cows around parturition and in early lactation.

Changes in milk composition as a result of metabolic disorders of dairy cows

The aim of our study was the determination of blood parameters and changes in milk composition of dairy cows in relation to metabolic disorders and their evaluation. Thirty dairy cows from selected agricultural farm were divided into three groups as follow: group BL: 3-4 weeks after calving (the beginning of lactation), group ML: 3-4 months after calving (the middle of lactation), group DP: 2-3 weeks before calving (the dry period). Concentrations of selected parameters of energy profile (glucose, cholesterol, triglycerides); nitrogenous profile (urea, total proteins); hepatic profile (aspartate aminotransferase, bilirubin) in blood serum were measured. Content of fat, proteins and lactose, Non Fat Solids, urea, freezing point, Somatic Cell Count, Fat/Protein ratio in milk were evaluated. Cholesterol concentration was significantly higher in ML (5.33±1.17 mmol.l-1; p&lt;0.001) in comparison to BL (3.46±0.92 mmol.l-1; p&lt;0.001) and DP (2.70±0.71 mmol.l-1; p&lt;0.001). Concentration of triglycerides was significantly lower in ML (0.03±0.01mmol.l-1; p&lt;0.001) in comparison to BL (0.07±0.02 mmol.l-1; p&lt;0.001) and DP (0.09±0.04 mmol.l-1; p&lt;0.001). Albumin concentration in DP (36.90±2.99 g.l-1; p&lt;0.05) was significantly higher in comparison to BL (32.80±4.07 g.l-1; p&lt;0.05). AST concentration was significantly higher in ML (1.61±0.47µmol.l-1; p&lt;0.001) in comparison with DP (1.01±0.18µmol.l-1; p&lt;0.001) and BL (1.39±0.25µmol.l-1; p&lt;0.05). Acquired results of milk composition were without significant confirmation (p&gt;0.05). Fat/Protein ratio was lower than 1.1, in BL and ML, which cause rumen acidosis. The present observation confirmed that specific changes of milk composition lead to metabolic disorders.

Commensal FecalEscherichia coliDiversity in Dairy Cows at High and Low Risk for Incurring Subacute Ruminal Acidosis

Subacute ruminal acidosis (SARA) is a common digestive disorder in dairy cows characterized by prolonged periods of undesirably low rumen pH (<5.8) and is caused by the accumulation of volatile fatty acids in rumen. This disorder damages the ruminal mucosa, causes diarrhea, reduces dry matter intake (DMI), and can result in anorexia and death. In this study, nonlactating dairy cows were fed diets predisposing them to a high risk (HR; n = 6) or a low risk (LR; n = 6) for experiencing SARA. The goal was to investigate differences in antimicrobial resistance selection, proliferation, and characterization of Escherichia coli strain types among the two treatment groups. Fecal samples were used to isolate total, tetracycline-resistant (Tet(r)), and ampicillin-resistant E. coli, and selected isolates were examined. We found reduced total (1.2-fold) and Tet(r) (1.4-fold) E. coli in HR cows. Low ampicillin-resistant E. coli shedding was detected from both HR (0.22 colony forming unit/g) and LR (0.46 colony forming unit/g) cows. Overall, 39 pulsed-field gel electrophoresis (PFGE) profiles and 13 antibiotic resistance profiles (phenotypes) were identified from the total isolates examined (n = 144). The LR cows exhibited diverse genotypes (22 PFGE profiles) clustering into seven restriction endonuclease digestion pattern clusters (REPCs) within total and Tet(r) E. coli. In comparison, isolates from HR animals showed increased genotypic relatedness (16 PFGE profiles and 13 REPC with comparable phenotypes). From both HR and LR cows, no significant differences in the detection of a particular phenotype were observed (p > 0.05), and tet(A) allele was frequently detected among isolates from HR (45.2%) and tet(B) from LR (36.6%) cows. Changes in fecal E. coli genotypes should be explored further for its usefulness as an indicator for SARA since dairy cows are a reservoir of diverse E. coli strain types. Our results elucidate phenotypic and genotypic differences in fecal E. coli shed between HR and LR cows.

Prognostic indicators and the importance of trimming in noninfective claw disorders in cattle

A cross-sectional study was conducted in 32 smallholder dairy farms in Nairobi and its environs, in which 300 cows were examined for claw disorders. The objective was to evaluate characteristics of claw disorders in dairy cows in smallholder production units in Nairobi and its environs. After a purposive selection of the farms and a systematic sampling of the cows, hind limb claws of all the 300 cows were examined for disorders. Thorough washing and trimming of the claws were done. Claw disorders that were chronic in nature were the most destructive and incorrigible by claw trimming. Apart from chronic nature of the disorders, other prognostic indicators were the laminitic features of claw damage which mainly included invasive erosions of the horn leading to excessively thinned sole, excessively softened and crumbling horn of the sole, widespread penetrating sole haemorrhages and crookedly shaped claws. These features of chronic laminitis occurred concurrently with heel or sole erosion, white line separation, sole ulcers, horizontal hoof wall fissures and double soles. In most smallholder farms, cows with these disorders were neglected to the extent that trimming was inadequately corrective. Regular claw examination and corrective trimming should be adopted as routine procedures in dairy cow production.

Phenotypic and genetic relationships of common health disorders with milk and fat yield persistencies from producer-recorded health data and test-day yields

The objective of this study was to investigate phenotypic and genetic relationships of common health disorders in dairy cows with milk (PMY) and fat (PFY) yield persistencies. Health and production data from 398 commercial dairy herds were used. Disease traits were defined in binary form for individual lactations considering mastitis only during the first 100 d in milk (MAST1), only after 100 d in milk (MAST2), and at any stage of lactation (MAST), and reproductive disorders (REPRO), metabolic disorders (METAB), and lameness (LAME). The persistencies were defined to be uncorrelated with 305-d yields. Impact of the diseases on PMY and PFY were investigated separately in first (FL) and later (LL) lactations. Phenotypic associations of PMY and PFY with likelihood of diseases in current and subsequent lactations were examined using odds ratios from a logistic regression model. Linear-threshold sire-maternal grandsire models were used to estimate genetic correlations of displaced abomasums (DA), ketosis (KET), metritis (MET), MAST, MAST1, and MAST2 with PMY and PFY across parities. Metabolic diseases and REPRO had significantly positive relationships with PMY and PFY in both FL and LL. Significantly greater PMY and PFY were associated with MAST1 in LL. Significantly lower PMY and PFY were related to MAST2 in both FL and LL, whereas cows affected by MAST had significantly less persistent lactations. Incidence of MAST and MAST2 decreased with increasing PMY and PFY in the present and previous lactation. Heritability of disease incidences were 0.03 (DA), 0.01 (KET), 0.10 (MAST), 0.02 to 0.05 (MAST1), 0.02 (MAST2), and 0.04 to 0.10 (MET). Displaced abomasum, KET, MAST, MAST1, and MET had unfavorable genetic correlations of 0.35, 0.46, 0.17, 0.02, and 0.27 with PMY, and 0.16, 0.21, 0.07, 0.06, and 0.12 with PFY, respectively. Favorable genetic correlations were found for MAST2 with PMY (−0.24) and PFY (−0.04). Results suggest that diseases in early lactation increase persistency of milk and fat yield. Selection for greater lactation persistency must consider these antagonistic relationships.

Effects of calcium propionate by different numbers of applications in first week postpartum of dairy cows on hypocalcemia, milk production and reproductive disorders

This study was conducted to evaluate effects of calcium propionate on hypocalcemia, dry matter intake, body condition score, milk production and reproductive disorders in dairy cows. Twenty four multiparous Holstein cows were sorted by parity, body condition score (BCS) in close-up period and season of calving and assigned to one of the three treatments. The cows in treatment 1 (T1) received two drenches at calving and 24h after calving. The cows in treatment 2 (T2) received three drenches at calving, 24h after calving and 7 days after calving. The cows in treatment 3 (T3) were the control. Each drench contained 143g of calcium as calcium propionate (0.68kg). Parameters studied were serum calcium, glucose and nonesterified fatty acid (NEFA) concentrations, dry matter intake (DMI), BCS, milk production (MP), incidence of retained placenta (RP) and metritis. Milk fever developed in 5 of 8 cows, in 3 of 8 cows and in 3 of 8 cows in T1, T2 and T3, respectively, at calving. There was no cow with milk fever in T1 and T2 at 4h after second drench (about 28h after calving) but 3 of 8 cows in T3 had still milk fever at this time. The cows receiving two drenches recovered from milk fever in a shorter term as compared to the cows in T3. There were no differences among treatments for DMI, BCS, MP, RP, serum glucose and NEFA concentrations during the experimental period. There was no difference for metritis between T1 and T3 but incidence of metritis in T2 was significantly lower as compared to T3 (P<0.05). Two drenches of calcium propionate were beneficial in treating milk fever and three drenches of calcium propionate were considered to have had a preventive effect for metritis.

Changes in Feeding Behavior as Possible Indicators for the Automatic Monitoring of Health Disorders in Dairy Cows

Changes in short-term feeding behavior of dairy cows that occur with the onset of the health disorders ketosis, acute locomotory problems, and chronic lameness were investigated using data collected during previous experiments. The objective of the study was to describe and quantify those changes and to test their suitability as early indicators of disease. Feed intake, feeding time, and number of daily feeder visits were recorded with computerized feeders. Ketosis in 8 cows was characterized by rapid daily decreases in feed intake [−10.4kg of fresh matter (FM)], feeding time (−45.5min), and feeding rate (−25.3g of FM/min) during an average of 3.6 d before diagnosis by farm staff. Acute locomotion disorders in 14 cows showed smaller daily decreases in feed intake (−1.57kg of FM) and feeding time (−19.1min), and a daily increase in feeding rate (+21.6g of FM/min) during an average of 7.7 d from onset to diagnosis. The effects of chronic lameness on short-term feeding behavior were assessed by analyzing changes during the 30 d before and 30 d after all cows were checked for foot lesions and trimmed, and cows were classified as either lame (n = 81) or not lame (n = 62). During the 30 d before trimming, cows classified as lame showed significant changes in daily feeding time, number of daily visits, and feeding rate, but nonlame cows did not. In lame cows, the observed daily changes (slope) for the 30 d before and the 30 d after trimming were −0.75 and +0.32 min/d for daily feeding time, −0.35 and +0.31 for daily number of visits, and +0.77 and −0.35 g/min for feeding rate, respectively. These changes in feeding behavior were not different among cows consuming low or high forage rations. Daily feeding time was the feeding characteristic that changed most consistently in relation to the studied disorders. A simple algorithm was used to identify cows whose daily feeding time was lower than the previous 7-d rolling average minus 2.5 standard deviations. The algorithm resulted in detection of more than 80% of cows with acute disorders at least 1 d before diagnosis by farm staff. Short-term feeding behavior showed very characteristic changes with the onset of disorders, which suggests that a system that monitors short-term feeding behavior can assist in the early identification of sick cows.

Phenotypic Relationships of Common Health Disorders in Dairy Cows to Lactation Persistency Estimated from Daily Milk Weights

The objective of this study was to investigate the phenotypic relationship between common health disorders in dairy cows and lactation persistency, uncorrelated with 305-d yield. The relationships with peak yield and days in milk (DIM) at peak were also studied. Daily milk weights and treatment incidence records of 991 Holstein lactations from experimental dairy herds at Virginia Tech and Pennsylvania State University were used. Persistency was calculated as a function of daily yield deviations from standard lactation curves, developed separately for first (FL) and later lactations (LL), and deviations of DIM around reference dates: 128 for FL and 125 for LL. Days in milk at peak and peak yield were computed for each lactation by using Wood's function. The disease traits studied were mastitis (MAST) only during the first 100 d (MAST1), only after 100 DIM (MAST2), both before and after 100 DIM (MAST12), and at any stage of lactation (MAST1/2), as well as metritis, displaced abomasums, lameness, and metabolic diseases. Each disease was defined as a binary trait, distinguishing between lactations with at least one incidence (1) and lactations with no incidences (0). The relationships of diseases to persistency, DIM at peak, and peak yield were investigated separately for FL and LL for all disease traits except MAST12, which was investigated across parities. The relationships of persistency to probability of the diseases in the same lactation and in the next lactation were examined using odds ratios from a logistic regression model. Metritis and displaced abomasums in FL and LL were associated with significantly higher persistencies. Metabolic diseases and MAST1 in LL were significantly related to higher persistencies. The relationships of MAST2 in both FL and LL, and MAST12 across parities were significant but negative. Cows affected by MAST tended to have less persistent lactations. Most of the diseases had a significant impact on DIM at peak in LL. In LL, metritis, metabolic diseases, and displaced abomasums tended to significantly delay DIM at peak. Mastitis only after 100 DIM was associated with significantly earlier DIM at peak in LL. Increasing persistency was associated with low MAST2 and MAST1/2 in primiparous cows. None of the diseases studied was significantly related to persistency of the previous lactation.

Effect of Glucogenic vs. Lipogenic Diets on Energy Balance, Blood Metabolites, and Reproduction in Primiparous and Multiparous Dairy Cows in Early Lactation

Increasing the availability of glucogenic nutrients relative to lipogenic nutrients has been hypothesized to decrease the production of milk fat, to improve the energy balance (EB), and to decrease the incidence and severity of metabolic and reproductive disorders in dairy cows in early lactation. Therefore, our objective was to evaluate the effects of a glucogenic, lipogenic, or mixed diet on EB, plasma metabolites and metabolic hormones, liver triacylglycerides (TAG), and reproductive variables in high-producing dairy cows in early lactation. Cows (n=114) were randomly assigned to 1 of 3 diets and were fed either a mainly lipogenic diet, a mainly glucogenic diet, or a mixture of both diets (50:50 dry matter basis) from wk 3 before the expected calving date until 9 wk postpartum. Diets were isocaloric (net energy basis) and equal in intestinal digestible protein. Dry matter intake, net energy intake, milk yield, and milk protein percentage did not differ among diets. Milk lactose percentage was less for cows fed the lipogenic diet. Milk fat percentage was less for multiparous cows fed the glucogenic diet compared with cows fed the mixed or lipogenic diet (3.69 vs. 4.02 vs. 4.22±0.07%, respectively). The calculated EB was less negative for multiparous cows fed the glucogenic diet compared with cows fed the mixed or lipogenic diet [−33 vs. −125 vs. −89±21 kJ/(kg0.75 · d), respectively]. Postpartum, the glucogenic diet decreased plasma nonesterified fatty acids, β-hydroxybutyrate, and liver TAG concentrations and increased insulin concentration in multiparous cows. The glucogenic diet tended to decrease the number of days until first milk progesterone rise in multiparous cows compared with the mixed or lipogenic diet (20.4 vs. 24.4 vs. 26.4±2.1 d, respectively). Diet had no effect on any of the above-mentioned variables in primiparous cows, except that milk lactose percentage was greater for primiparous cows fed the glucogenic diet. We concluded that the glucogenic diet was effective in improving the calculated EB and decreasing plasma β-hydroxybutyrate and liver TAG concentrations, suggesting a reduced risk of metabolic disorders in multiparous dairy cows fed a glucogenic diet.

Effects of dietary energy source on energy balance, metabolites and reproduction variables in dairy cows in early lactation

This paper summarizes three recent studies by the same authors with the objective to study the effect of dietary energy source on the energy balance (EB) and risk for metabolic and reproductive disorders in dairy cows in early lactation. The first study, a literature survey, illustrated that feeding extra glucogenic nutrients relative to lipogenic nutrients, decreased milk fat and seems to decrease plasma non-esterified fatty acid (NEFA) and β-hydroxybutyrate (BHBA) concentration. However studies are scarce and mostly confound the effect of energy source with level of energy intake, compromising eventual effects on EB and fertility. Therefore, in the second study, 16 dairy cows were either fed a glucogenic or a lipogenic diet (isocaloric) and EB was determined in climate-controlled respiration chambers from week 2 until 9 of lactation. Glucogenic diet decreased milk fat yield and milk energy and tended to decrease body fat mobilization compared with lipogenic diet. The objective of the third study was to study the effect of dietary energy source on EB, metabolites and reproduction variables. Dairy cows ( n = 111) were fed glucogenic, lipogenic or mixed diet from week 3 until week 9 relative to calving. Multiparous cows fed glucogenic diet had lower milk fat yield, higher calculated EB, and lower plasma NEFA, BHBA and liver triacylglyceride concentration and tended to have fewer days to first postpartum ovulation. In conclusion, increasing the glucogenic nutrient availability improved the EB and had potential to reduce the risk for metabolic disorders and to improve reproductive performance in dairy cows.

Follicular cysts in dairy cows

ABSTRACTFollicular cysts are the most critical reproductive disorder in dairy cows and disturb the normal ovarian cycle, resulting in a prolonged interval from calving to conception. Therefore, this condition causes significant economic losses to the dairy industry. Two direct causal factors for cysts are suggested in this review; ovulation disorder and the delay of regression. Ovulation disorder has been accepted to be a main etiology of cystic follicle. This seems to be caused by the deficiency of positive feedback of estrogen to the hypothalamus, leading to the lack of luteinizing hormone surge. On the other hand, if a large anovulatory follicle is regressed immediately after the failure of ovulation, its follicle does not continue to grow, resulting in no cystic follicle being formed. Therefore, it is proposed that another cause of a cystic follicle is the delay (or absence) of the degeneration system of the follicle. This review will introduce these two causes separately, referring to recent advances in understanding the follicular cyst in dairy cows.

Selenium and vitamin E: Reproductive disorders in dairy cows

Selenium and vitamin E deficiency leads to reproductive disorders in dairy cows: placental retention, ovarian cysts, metritis, reduced percentage of conception, abortions, birthing of poorly vital calves. Placental retention is a post partal disorder of multifactorial etiology which has harmful effects on reproduction and the feasibility of milk production. The administration of selenium and vitamin E reduces the incidence of placental retention, which suggests that oxidative stress is responsible for the occurrence of this disorder. The occurrence of ovarian cysts has as its consequence a disorder in the oestral cycle. Vitamin E prevents oxidative damage of lipid membranes by preventing the forming of destructive hydroperoxides, acting in synergy with selenium. These nutrients protect cell membranes and lipid organelles, inhibit and destroy endogenous peroxides, and in that way protect the integrity of the membranes and reduce oxidative stress.

Risk factors influencing lameness and claw disorders in dairy cows

Claw health of dairy cows was investigated in an observational study in different housing systems in Switzerland. Twenty-five professional hoof trimmers examined lameness and claw disorders in 4621 cows on 290 farms during routine hoof trimming. 82 farms had tie-stall barns without exercise (T1) and 166 had tie-stall barns with exercise (T2), another 42 farms kept their animals in loose housing systems with exercise (L2). The prevalence was 10.0% for lameness (LN), 15.7% for sole disorders (SD), 6.1% for white line disorders (WD), 13.6% for heel erosions (HE), and 5.3% for disorders of skin and interdigital space (ID). LN and SD showed the highest prevalence (13.2%; 16.4%) and the highest odds ratio (OR=1.89; 1.33) in T1. WD was more often detected in L2, accounting for 9.4% (OR=1.0). HE was identified most in T2 (17.1%, OR=4.72) and T1 (13.2%, OR=4.45). Disorders of skin and interdigital space were most frequently found in T2 (7.5%, OR=1.55).