Transition Period In Dairy Cows Research Articles

Aspectos clínicos, epidemiológicos, diagnóstico, tratamiento y prevención de la cetosis en vacas lecheras: Revisión

The transition period in dairy cows has undoubted importance in determining the production cycle, since the period when the animals are susceptible to a wide variety of diseases. Among such diseases, denote a ketosis, a metabolic disease that accommodates high-producing dairy cows and results from an imbalance between the amount of dangerous chemicals during the production cycle and the chemical amounts present in the diet, resulting in the mobilization of corporate reserves for maintenance and milk production, exceeding or limiting hepatic metabolism and resulting in the accumulation of ketone bodies in the body. The diagnosis provides a means of measuring non-esterified fat (AGNES) without blood, milk or urine from affected animals. Solutions based on glucose or its precursors, such as propylene glycol and glucocorticoid therapy, can be used to treat the disease. The nutritional manual for dairy cows during the transition period and the dry period is of fundamental importance to prevent the occurrence of diseases in the milk banks. This review seeks to analyze the respect of the clinical and epidemiological aspects of the disease, as well as its diagnosis, treatment and prevention, in view of the importance of the disease in dairy cattle.

Outcomes from Experimental Testing of Nonsteroidal Anti-Inflammatory Drug (NSAID) Administration during the Transition Period of Dairy Cows.

Simple SummaryThe treatment of dairy cows with nonsteroidal drugs is applied experimentally to investigate the relevance of inflammation during the periparturient period. Despite appearing healthy, dairy cows throughout the transition period and mainly after parturition can develop a pro-inflammatory status that may negatively influence milk production and cows’ health. The administration of nonsteroidal anti-inflammatory drugs (NSAIDs) has been demonstrated to have both positive or negative effects on health and milk production, depending on the type of inhibition mechanism, the dose administered and the cows’ lactation numbers. At present, the safety and efficacy of NSAIDs have not been irrefutably demonstrated; therefore, their use to improve metabolic and inflammatory status, as well as milk production and cow health after parturition, should be carefully evaluated.During the transition period, dairy cows experience great physiological stress caused by changes in metabolism and in the immune and endocrine systems. A pro-inflammatory state is another difficulty faced by even apparently healthy animals. The most significant negative consequences of inflammation in dairy cows are substantial impairment of milk production and deleterious effects on cows’ health in extreme cases. Nonetheless, a certain degree of inflammation is necessary to sustain physiological adaptations. In recent years, many studies have attempted to determine whether the use of nonsteroidal anti-inflammatory drugs (NSAID) in the transition period of dairy cows could positively affect milk production and cows’ health by controlling the inflammation status. This literature indicates that NSAIDs that act as preferential inhibitors of cyclooxygenase-1 (COX-1) activity show important side effects (e.g., increased risk of retained placenta, culling, or metritis) even if milk production is, on average, ameliorated. In contrast, preferential inhibitors of cyclooxygenase-2 (COX-2) activity have overall positive effects on cows’ health, with potential beneficial effects on milk production. Furthermore, it is important to note that with certain NSAID treatments, milk discarding is mandatory to prevent contamination with drug residues, but increased milk production can compensate for the loss of milk revenue during the withdrawal period.

Metabolic Stress in the Transition Period of Dairy Cows: Focusing on the Prepartum Period.

Simple SummaryComplex pathways of metabolic adaptation occur in high-yielding dairy cows around calving. These adaptations require the redirection of nutrients to support the last stages of fetal growth and the commencement of lactation. Failure to adapt to these changes may result in the development of clinical disease in the postpartum period. Therefore, most existing literature is focused on studying the metabolic changes in the postpartum period. However, some of the risk factors associated with postpartum clinical disease can already be found in the prepartum period. This review describes adaptive changes occurring in prepartum high-yielding dairy cows, from drying off (40 to 60 days before parturition) until calving.All modern, high-yielding dairy cows experience a certain degree of reduced insulin sensitivity, negative energy balance, and systemic inflammation during the transition period. Maladaptation to these changes may result in excessive fat mobilization, dysregulation of inflammation, immunosuppression, and, ultimately, metabolic or infectious disease in the postpartum period. Up to half of the clinical diseases in the lifespan of high-yielding dairy cows occur within 3 weeks of calving. Thus, the vast majority of prospective studies on transition dairy cows are focused on the postpartum period. However, predisposition to clinical disease and key (patho)physiological events such as a spontaneous reduction in feed intake, insulin resistance, fat mobilization, and systemic inflammation already occur in the prepartum period. This review focuses on metabolic, adaptive events occurring from drying off until calving in high-yielding cows and discusses determinants that may trigger (mal)adaptation to these events in the late prepartum period.

Metabolites and hormones can predict postpartum uterine disorder during transition period of dairy cows

Metabolites and hormones can predict postpartum uterine disorder during transition period of dairy cows

Mismatch of Glucose Allocation between Different Life Functions in the Transition Period of Dairy Cows.

Simple SummaryThe reasons for the development of diseases in the transition period of dairy cows are manifold and highly farm- and cow-specific. Nevertheless, links exist between the degree of negative energy balance (NEB) and disease susceptibility, which suggest a mutual adverse relationship between immune and productive functions. Glucose is the most essential fuel and precursor for both immune cells and mammary epithelial cells (MEC). While the delivery of glucose by the intermediary metabolism is not always able to keep up with whole-body demands, trade-offs between mammary and immune cells emerge. The prioritization of mammary supply during early lactation is a physiologic principle in all mammals. In contrast, tremendous increases in milk yield and the specific demand for glucose in high-yielding dairy cows resulting from decades of selection for milk production override the evolutionary principles of nutrient partitioning. Therefore, high-producing dairy cows face an increased risk of glucose shortages in their immune cells, particularly during early lactation.Immune cell functions such as phagocytosis and synthesis of immunometabolites, as well as immune cell survival, proliferation and differentiation, largely depend on an adequate availability of glucose by immune cells. During inflammation, the glucose demands of the immune system may increase to amounts similar to those required for high milk yields. Similar metabolic pathways are involved in the adaptation to both lactation and inflammation, including changes in the somatotropic axis and glucocorticoid response, as well as adipokine and cytokine release. They affect (i) cell growth, proliferation and activation, which determines the metabolic activity and thus the glucose demand of the respective cells; (ii) the overall availability of glucose through intake, mobilization and gluconeogenesis; and (iii) glucose uptake and utilization by different tissues. Metabolic adaptation to inflammation and milk synthesis is interconnected. An increased demand of one life function has an impact on the supply and utilization of glucose by competing life functions, including glucose receptor expression, blood flow and oxidation characteristics. In cows with high genetic merits for milk production, changes in the somatotropic axis affecting carbohydrate and lipid metabolism as well as immune functions are profound. The ability to cut down milk synthesis during periods when whole-body demand exceeds the supply is limited. Excessive mobilization and allocation of glucose to the mammary gland are likely to contribute considerably to peripartal immune dysfunction.

Efficacy of Different Drenching Regimens of Gluconeogenic Precursors during Transition Period on Body Condition Score, Production, Reproductive Performance, Subclinical Ketosis and Economics of Dairy Cows

Simple SummaryAs the transition period is the most critical physiological stage of dairy cattle, propylene glycol as a gluconeogenic precursor was studied either individually or in combination with glycerol with different doses at different times. Their beneficial effects were recorded regarding productive and reproductive performances, protection against subclinical ketosis and economics.A total of 108 Holstein cows were used to evaluate the effect of drenching propylene glycol (PG) either individually or in combination with glycerol (G) on body condition score (BCS), production, reproductive performance, protection against subclinical ketosis and economic benefit of dairy cows during the transition period. The six groups (n = 18/group) were; Control group, cows received no treatment; PG300, cows were drenched 300 mL PG for 7 days pre-expected day of calving and 21 days post-calving; PG400, cows were drenched 400 mL PG for 7 days pre-and 7 days post-calving; PG500, cows were drenched 500 mL PG for 10 days pre-and 10 days post-calving; GPG150, cows were drenched a mixture of 150 mL G and 150 mL PG for 21 days pre-and 21 days post-calving; GPG250, cows were drenched a mixture of 250 mL G and 250 mL PG for 21 days pre-and 21 days post-calving. BCS at 30 days in milk (DIM) was significantly higher in all treated groups in comparison to the control one and the best values were observed in GPG250, GPG150 and PG500 groups. Lactation length (LL) was significantly (p < 0.001) shorter in GPG250, GPG150 and PG500 groups than control group. There was a significant increment in 305 milk yield (p < 0.001) and average daily milk yield (p < 0.001) in GPG250 and PG500 groups than other groups except for PG300 with the lowest values for control and PG400. Cows in all treatment groups were observed in heat and conceived earlier as well as had shorter open days and calving interval durations (p < 0.001) and low number of services per conception (p = 0.004) compared to control group with better results for PG500 and GPG250 groups. BHB level and percentage of cows suffered from subclinical ketosis at 7 DIM was significantly lower in GPG250, GPG150 and PG500 groups than control group. Cows in treatment groups had a significantly higher glucose level (p = 0.006) compared to control group. Regarding to economics, the control group showed the highest feed costs, insemination costs and total costs per animal. Additionally, control and PG400 groups had the highest cost per kilogram of milk from total and feed costs compared to other cows. PG300, PG500 and GPG250 groups recorded a greater net return and income over feed cost (IOFC). In conclusion, the continuous drenching of propylene glycol either individually or in combination with glycerol regimens for long duration (PG300, PG500, GPG150, GPG250) during the transition period of dairy cows may reduce the incidence of subclinical ketosis and consequently improve milk production, reproduction and economics compared to drenching for short duration (PG400).

Prevalence and potential risk factors of hypocalcaemia in dairy cows during transition period at Northern Egypt

Objective: To identify the most prevalent diseases of transition period in dairy cows and to highlight on risk factors supposed to play a crucial role in the prevalence of hypocalcaemia. Design: Case-control study Animals: 179 transition dairy cows belonged to five farms. Procedures: Clinical examination and serum analyses were the key to diagnose the transition disorders in the investigated cows. Cutoff points for serum analytes (Ca, Ph, Mg, PTH, glucose, K, Na and Cl) were set. A questionnaire was constructed to identify the possible risk factors associated with hypocalcaemia on both farm level and cow level. Results: Frequency test revealed the prevalence of hypocalcaemia to be (48.04%), hypophosphatemia (40.22%), hypomagnesaemia (33.52%) hypoglycemia (29.05%), hypokalemia (58.1%), clinical ketosis (5.59%) and abomasal displacement (1.12%). Moreover, prevalence of post parturient septic metritis was (26.81%), retained placenta (23.46%) and clinical mastitis was (18.99%). Generally, hypocalcaemia was significantly associated with other concurrent diseases (P ≤ 0.05). Levels of serum PTH, glucose, K and Na were significantly related to occurrence of hypocalcaemia with p values: 0.006, 0.001, 0.019 and 0.001, respectively. Impact of diet, housing criteria and periodical health monitoring by metabolic profile test were found to affect significantly on incidence of hypocalcaemia on farm level with p value ≤ 0.008 for all. On cow level, age of cows, parity, body condition score, stage of transition period, daily milk yield and previous transition period disorders were found to have a significant effect on occurrence of hypocalcaemia at p value ≤ 0.001 for each item. Conclusion and clinical relevance: Results of the current study point toward the importance of usual monitoring of transition period disorders in dairy cows, besides identifying potential risks and consequences of hypocalcaemia in an attempt to construct control measures for them, that in-turn would increase dairy herd profitability.

Metabolome profiling in skeletal muscle to characterize metabolic alterations in over-conditioned cows during the periparturient period

The transition from late gestation to early lactation is associated with extensive changes in metabolic, endocrine, and immune functions in dairy cows. Skeletal muscle plays an important role in maintaining the homeorhetic adaptation to the metabolic needs of lactation. The objective of this study was to characterize the skeletal muscle metabolome in the context of the metabolic changes that occur during the transition period in dairy cows with high (HBCS) versus normal body condition (NBCS). Fifteen weeks antepartum, 38 pregnant multiparous Holstein cows were assigned to 1 of 2 groups, which were fed differently to reach the targeted BCS and back fat thickness (BFT) until dry-off at -49 d before calving (HBCS: >3.75 and >1.4 cm; NBCS: <3.5 and <1.2 cm). During the dry period and the subsequent lactation, both groups were fed identical diets. The differences in both BCS and BFT were maintained throughout the study. The metabolome was characterized in skeletal muscle samples (semitendinosus muscle) collected on d -49, 3, 21, and 84 relative to calving using a targeted metabolomics approach (AbsoluteIDQ p180 kit; Biocrates Life Sciences AG, Innsbruck, Austria), which allowed for the quantification of up to 188 metabolites from 6 different compound classes (acylcarnitines, amino acids, biogenic amines, glycerophospholipids, sphingolipids, and hexoses). On d -49, the concentrations of citrulline and hydroxytetradecadienyl-l-carnitine in muscle were higher in HBCS cows than in NBCS cows, but those of carnosine were lower. Over-conditioning did not affect the muscle concentrations of any of the metabolites on d 3. On d 21, the concentrations of phenylethylamine and linoleylcarnitine in muscle were lower in HBCS cows than in NBCS cows, and the opposite was true for lysophosphatidylcholine acyl C20:4. On d 84, the significantly changed metabolites were mainly long-chain (>C32) acyl-alkyl phosphatidylcholine and di-acyl phosphatidylcholine, along with 3 long-chain (>C16) sphingomyelin that were all lower in HBCS cows than in NBCS cows. These data contribute to a better understanding of the metabolic adaptation in skeletal muscle of dairy cows during the transition period, although the physiological significance and underlying molecular mechanisms responsible for the regulation of citrulline, hydroxytetradecadienyl-l-carnitine, carnosine, and phenylethylamine associated with over-conditioning are still elusive and warrant further investigation. The changes observed in muscle lysophosphatidylcholine and phosphatidylcholine concentrations may point to an alteration in phosphatidylcholine metabolism, probably resulting in an increase in membrane stiffness, which may lead to abnormalities in insulin signaling in the muscle of over-conditioned cows.

Avaliação do leucograma, fibrinogênio, proteínas plasmáticas e glicose em vacas leiteiras no pré e pósparto imediato

Immunological deficiency observed during the transition period in dairy cows promotes development of puerperal diseases. Thus, the research aimed to evaluate hematological (leukogram) and biochemical (glucose, fibrinogen, and total proteins) parameters in Holstein cows (n = 44) before (day -20) and after (day +20) parturition and the possibility of identifying initial signs of reproductive illness, thereby assisting the professional in decision making. There was a difference in the number of total leukocytes, which decreased postpartum (8,888.4 cells/mm3). There was no difference in neutrophils at both time points. Females who presented high concentration of fibrinogen (5.2 g/L) and total plasmatic proteins (78.9 g/L) at postpartum presented retention of fetal appendages and later uterine disease. These results are consistent with the literature on antepartum leukocytosis and inflammation indicated by increased fibrinogen and plasmatic protein and differ in terms of neutrophil behavior. Thus, laboratory assays can be complementary tools to physical examination, aiding in the diagnosis and identification of changes even before the appearance of clinical signs in animals, which is necessary for the prevention of metabolic and infectious disorders.

Seasonal alterations in the expression of inflammatory cytokines and cortisol concentrations in periparturient Sahiwal cows

ABSTRACT Heat stress during the transition period of dairy cows disturbs the homeostasis of their physiology and ultimately their health and production. Our objective was to study the seasonal variations of plasma cortisol levels and the expression of inflammatory cytokines in the peripheral blood mononuclear cells (PBMC) of 12 periparturient Sahiwal cows. Blood samples were obtained at weekly intervals from three weeks prepartum to three weeks postpartum during the winter (Temperature–humidity index, THI = 59.7) and summer (THI = 81.5) seasons. Gene expression study of pro-inflammatory (IL-1β, IL-6, and TNF-α) and anti-inflammatory (IL-10) cytokines was done by RT-PCR and plasma cortisol by sandwich ELISA. The plasma concentration of cortisol and the relative mRNA expression of various inflammatory cytokines in PBMC were higher (p< 0.01) in the summer compared to winter season irrespective of the days of the transition period. Highest levels of cortisol and greater expression of pro-inflammatory cytokines were recorded on the day of calving in both seasons. Our study showed a higher inflammatory response, immune disturbance and greater levels of the stress hormone (cortisol) during the summer season, particularly on the day of calving.

Effect of prepartum negative dietary cation-anion difference and serum calcium concentration on blood neutrophil function in the transition period of dairy cows

Hypocalcemia and impaired immune function are recognized risk factors for clinical disease in the transition period of dairy cows. At the onset of lactation, calcium homeostasis is disrupted by redirection of calcium for colostrum production, which triggers a substantial decrease in the blood calcium concentration for 1 to 4 days. Blood calcium concentration is associated with neutrophil function, which turn is associated with the risk of retained placenta, metritis, and mastitis. Negative Dietary CationAnion Difference (DCAD) diets fed during the prepartum period increase postpartum blood calcium concentrations and reduce the risk of disease.&#x0D; Our objectives were to assess the effects of a negative dietary cation-anion difference (DCAD) on phagocytosis (P) and oxidative burst (OB) function of circulating neutrophils and to determine the associations of serum ionized (iCa) and total calcium concentrations (tCa) with P and OB. We hypothesized that multiparous cows fed a negative DCAD prepartum would have greater serum ionized (iCa) and total calcium concentrations (tCa), and thus improved P and OB.

Technical note: Assessment of neutrophil endocytosis and proteolytic degradation and its relationship with phagocytosis and oxidative burst in dairy cows

Conventional assays of polymorphonuclear cell (PMN, neutrophil) function such as oxidative burst (OB) and phagocytosis (PC) are widely used to evaluate innate immunity in the transition period of dairy cows. Oxidative burst is commonly evaluated by measuring PMN median fluorescence intensity (MFI) involving the release of reactive oxygen species after in vitro stimulation. Phagocytosis can be measured by engulfment of fluorescent beads by PMN. DQ-ovalbumin (DQ-OVA) is a molecule suitable for the assessment of intracellular proteolytic degradation, so it might be informative about an additional pathway of pathogen handling by PMN. In this study, we evaluated the use of the DQ-OVA assay for the assessment of PMN function and the relationships among OB, PC, and DQ-OVA results in PMN isolated from blood of dairy cows between 5 and 21 d post partum. Results of the DQ-OVA validation assay were assessed with mixed linear regression models. Pearson correlation tests and kappa values for agreement were used to associate the MFI between each PMN function assay (OB, PC, and DQ-OVA). For the validation assay (9 cows in 3 replicates), PMN incubated with DQ-OVA were stimulated with IFN-γ or inhibited with cytochalasin D, and fluorescence was compared with untreated PMN. Stimulated and inhibited PMN had greater (970 ± 160 units) and lesser (593 ± 55 units) MFI relative to untreated PMN (791 ± 154 units), respectively, indicating that DQ-OVA fluorescence reflected enhanced or reduced endocytic and proteolytic function. To associate the MFI outcomes among OB, PC, and DQ-OVA, 153 samples from 40 cows were analyzed. Results showed significant, although weak association between DQ-OVA and PC MFI (Pearson r = 0.16). When values of MFI were categorized according to the first ("high" PMN functionality), second and third ("moderate" PMN functionality), or fourth ("low" PMN functionality) quartiles, agreement beyond chance (κ) was moderate: κ = 0.38 for DQ-OVA and OB, κ = 0.43 for DQ-OVA and PC, and κ = 0.43 for OB and PC. The DQ-OVA assay may complement traditional PMN functional assays because it provides additional information regarding the combination of endocytosis and proteolytic degradation, but it is not a substitute for assessment of OB or PC.

Thyroid hormone profiles and TSH evaluation during early pregnancy and the transition period in dairy cows

The thyroid hormone axis is one important endocrine system within a complex system of various factors and hormones necessary to establish and maintain pregnancy in cattle and in metabolic adaptations towards lactation. Pregnancy and lactation occur contemporaneously in dairy cows, and have major impacts on thyroid hormones as well as status of the hypothalamus-pituitary thyroid axis influences pregnancy and lactation. As especially the thyroid hormone axis with special focus to TSH is not well studies in the past, the aim of the study was to examine the thyroid hormone axis, especially in heifers during adaptation to the first lactation, to verify the association between lactation and thyroid hormones. Secondly, the early pregnancy period was the focus of the present investigation. To determine thyroid hormone patterns and especially thyroid-stimulating hormone (TSH) during the transition period, 12 primiparous Holstein Friesian cows and 41 pregnant and 34 non-pregnant pluriparous cows were sampled. During the transition period, thyroxin (T4) concentrations decreased after calving in primiparous cows, and the milk yield [kg] was negatively correlated with triiodothyronine (T3) and T4 concentrations. In pregnant and non-pregnant pluriparous cows, T3, T4, TSH and free T4 (fT4) decreased between the day of ovulation (day 0) and day 18. From day 18 of gestation to day 100 after AI, an increase in TSH and fT4 and a decrease in Reverse T3 (rT3) was observed in the pregnant cows. In conclusion, the results of the present study confirm that regulative processes within the thyroid hormone metabolism occur during early lactation. For the first time it could be shown in dairy cows that TSH and fT4 increased during early pregnancy whereas rT3 decreased indicating also in bovine species a TSH stimulatory effect by pregnancy.

Indicators of resilience during the transition period in dairy cows: A case study

The transition period is a demanding phase in the life of dairy cows. Metabolic and infectious disorders frequently occur in the first weeks after calving. To identify cows that are less able to cope with the transition period, physiologic or behavioral signals acquired with sensors might be useful. However, it is not yet clear which signals or combination of signals and which signal properties are most informative with respect to disease severity after calving. Sensor data on activity and behavior measurements as well as rumen and ear temperature data from 22 dairy cows were collected during a period starting 2 wk before expected parturition until 6 wk after parturition. During this period, the health status of each cow was clinically scored daily. A total deficit score (TDS) was calculated based on the clinical assessment, summarizing disease length and intensity for each cow. Different sensor data properties recorded during the period before calving as well as the period after calving were tested as a predictor for TDS using univariate analysis of covariance. To select the model with the best combination of signals and signal properties, we quantified the prediction accuracy for TDS in a multivariate model. Prediction accuracy for TDS increased when sensors were combined, using static and dynamic signal properties. Statistically, the most optimal linear combination of predictors consisted of average eating time, variance of daily ear temperature, and regularity of daily behavior patterns in the dry period. Our research indicates that a combination of static and dynamic sensor data properties could be used as indicators of cow resilience.

Changes in rumen bacterial and archaeal communities over the transition period in primiparous Holstein dairy cows

In the present study, we hypothesized that the rumen bacterial and archaeal communities would change significantly over the transition period of dairy cows, mainly as an adaptation to the classical use of low-grain prepartum and high-grain postpartum diets. Bacterial 16S rRNA gene amplicon sequencing of rumen samples from 10 primiparous Holstein dairy cows revealed no changes over the transition period in relative abundance of genera such as Ruminococcus, Butyrivibrio, Clostridium, Coprococcus, and Pseudobutyrivibrio. However, other dominant genus-level taxa, such as Prevotella, unclassified Ruminococcaceae, and unclassified Succinivibrionaceae, showed distinct changes in relative abundance from the prepartum to the postpartum period. Overall, we observed individual fluctuation patterns over the transition period for a range of bacterial taxa that, in some cases, were correlated with observed changes in the rumen short-chain fatty acids profile. Combined results from clone library and terminal-restriction fragment length polymorphism (T-RFLP) analyses, targeting the methyl-coenzyme M reductase α-subunit (mcrA) gene, revealed a methanogenic archaeal community dominated by the Methanobacteriales and Methanomassiliicoccales orders, particularly the genera Methanobrevibacter, Methanosphaera, and Methanomassiliicoccus. As observed for the bacterial community, the T-RFLP patterns showed significant shifts in methanogenic community composition over the transition period. Together, the composition of the rumen bacterial and archaeal communities exhibited changes in response to particularly the dietary changes of dairy cows over the transition period.

Supplementation of in vitro maturation medium with serum from dairy cows at early and late lactation in the in vitro production of bovine embryos

The transition period of dairy cows is characterized by several metabolic alterations, due to the negative energy balance, which negatively affects fertility. The aim of this study was to evaluate the effect of supplementing the in vitro maturation medium with serum from dairy cows at early and late lactation in the oocyte maturation on the rates of nuclear maturation, cleavage and initial embryo development. The cumulus-oocyte complexes (COCs) were randomly divided into treatments: LL: serum from four cows at 354 ± 3.8 days in milk (DIM); and EL: serum from four cows at 10.8 ± 4.8 DIM. Subsequently, the COCs were submitted to maturation, fertilization; and in vitro culture in an incubator at 39°C with 5% CO2. For analysis of nuclear maturation; oocytes were collected after IVM, denuded and stained with Hoechst®. No difference was observed in the number of oocytes that reached metaphase II among treatments. The cleavage rate was not different between LL (59.3%; 320/540) and EL (47.0%; 243/517) treatments (P>0.05), as embryonic development between LL (15.0%; 81/540) and EL (16.6%; 86/517) (P>0.05). It was concluded that supplementation with serum from cows at different lactation periods during the bovine oocyte IVM did not influence the results of in vitro embryo production.

Managing the transition period of dairy cows to prevent major metabolic postpartum disorders

The transition period refers to the time between 3-4 weeks prior to and 4 weeks after calving. This is the period with the highest incidence of metabolic and other periparturient disorders. Many of these disorders interrelated and often coincide. Proper management and nutrition of the transition cow are critical for obtaining maximum dry matter intake, good health, increased reproductive efficiency and optimum milk production in the following lactation. The present review is comprised from two parts. In the first one, selected information is provided concerning the most important metabolic diseases of the transition period (hypocalcemia, ketosis) and, in brief, how hypocalcemia is interrelated to other diseases (mastitis, metritis, retained fetal membranes and abomasal displacement). In the second part, up-to-date nutritional methods applied in the transition period to prevent these metabolic periparturient diseases, with emphasis in hypocalcemia, are described.

Paraoxonase activity in the serum of peripartum dairy cows with different placental lactogen concentrations

The action of the bovine placental lactogen (bPL) hormone on maternal metabolism is still poorly known. Some markers, such as the acute phase protein paraoxonase (PON1), are used as indicators of liver function and help to determine the metabolic condition during the transition period in dairy cows. The aim of this study was to evaluate the activity of paraoxonase (PON1) in the serum of peripartum dairy cows with different levels of bPL. Based on the plasma bPL concentration, 18 cows were divided equally into three groups: LOW ( &lt; 2,68 ng bPL mL-1), MEDIUM (2,68–2,80 ng bPL mL-1), and HIGH ( &gt; 2,80 ng bPL mL-1). The experiment was conducted between 21 days prepartum and 28 days postpartum. Serum samples were collected during the experiment for the determination of bPL concentrations and PON1 activity. The bPL concentration was significantly different between the experimental groups (P ? 0,0001) and the days of serum collection (P ? 0,0001). In the prepartum dairy cows, the PON1 levels were different between the groups (P ? 0,05) and the days of serum collection (P ? 0,05). Cows with high bPL concentration had lower serum PON1 activity (P ? 0,05), while cows with low hormone levels had higher enzyme activity (P ? 0,05). In the postpartum period, there was a significant difference between the days of serum collection (P ? 0,0001) and the interaction between groups and collections (P ? 0,01). The group with high concentrations of bPL had lower levels of PON1 (P ? 0,01), while the group with low bPL maintained higher concentrations of PON1 (P ? 0,01). It was concluded that the cows with higher concentrations of bPL in the prepartum period present a reduction in the serum activity of the PON1 enzyme during the peripartum period.

Effects of different dosages of propylene glycol in dry cows and cows in early lactation.

In this Research Paper we hypothesised that the temporary insulin resistance seen during the transition period in dairy cows may cause significant differences in the efficacy of PG at different sampling periods and that in some cases this effect will be dose dependent. Eighty four sampling sets were generated by studying 7 multiparous Holstein cows repeatedly at 4 sampling periods of 3 d length (dry cows: days 40, 39 and 38 antepartum; close up cows: days 10, 9 and 8 antepartum; fresh cows: days 3, 4 and 5 post-partum; lactating cows: days 38, 39 and 40 post-partum). On each of these days 3 h after morning feeding propylene glycol was drenched in different dosages of 100, 300 or 500 ml once per day (cross over study). The different doses were applied in an alternating order (Latin square). Blood samples were taken before, every 30 min up to 4 h, after 6 and 12 h after PG application. Following parameters have been measured: insulin, non-esterified fatty acids (NEFA), betahydroxybutyrate (BHB), bilirubin, cholesterol, potassium, aspartate aminotransferase (AST) and glutamate dehydrogenase (GLDH). Revised Quantitative Insulin Sensitivity Check Index (RQUICKI) was calculated. It was found that glucose, insulin, NEFA, BHB, bilirubin and potassium concentrations were influenced differently by the three defined dosages of propylene glycol at four different sampling periods. Whereas RQUICKI, cholesterol, AST and GLDH did not differ between the sampling periods and treatments. The major results of the study are that the effect of PG is dose-dependent and that the effect of PG is depending on the time of application according to calving. It can be concluded that in fresh cows higher dosages are necessary to provoke similar effects in comparison to dry, close up and lactating cows. Although the study did not compare to topdressing of PG from the results it is reasonable to believe that bolus application of a specific PG volume is necessary to provoke the effect.

Association between prepartum dry matter intake, net energy balance, and postpartum diseases in dairy cows

The transition period in dairy cows is characterized by a drop in dry matter intake, leading to lipid mobilization in the form of nonesterified fatty acids [NEFA) and an increase in ketone bodies such as beta-hydroxybutyrate. Concentrations of NEFA &gt; 0.3 mEq/L during 14 to 2 days prepartum can predict diseases like displaced abomasum, clinical ketosis, metritis, and retained placenta (RP). These diseases reduce milk yield, impair reproductive performance, and increase culling, hence incurring economic losses. The association between DMI prepartum and disease incidence postpartum has not been extensively studied. The primary objectives of this study were to determine the association between prepartum dry matter intake (DMI), DMI as percentage of body weight (DMI%BW), and net energy balance (NEB) (-21 days) and postpartum diseases or disorders; calving problems (dystocia, twins, stillbirth), RP, metritis, mastitis, metabolic problems (hypocalcemia, ketosis), digestive problems (indigestion, displaced abomasum), lameness, and disease (Dz) (no disease, 1 disease, &gt;2 diseases). A secondary objective was to use DMI, DMI%BW and NEB prepartum to predict Dz postpartum.