Transition Period In Dairy Cows Research Articles

Dry period length affects rumen adaptation in dairy cattle precalving and during the first weeks after calving

Omitting or shortening the dry period may result in a fairly constant ration throughout the transition period of dairy cows, reducing the need for adaptation of cow metabolism and rumen function to a new lactation. The objective of this study was to determine the effect of dry period length on rumen adaptation and cow metabolic state during the transition period. Twelve pregnant, rumen-cannulated Holstein Friesian dairy cows at the end of their first lactation were assigned to one of 3 treatments: a conventional (60 d), short (30 d) or no dry period (0 d). At dry-off, cows received a dry cow ration until calving. Lactating cows received a lactation ration. Cows were monitored from 8 wk before calving until 8 wk after calving for milk yield and dry matter intake (DMI). Rumen biopsies were taken from 3 locations in the rumen at 60, 40 and 10 d before calving and 3, 7, 14, 28 and 56 d after calving to assess papillae dimensions. Blood was sampled weekly from 3 wk before until 8 wk after calving, and liver biopsies were taken at wk -2, wk 2 and wk 4 relative to calving. Prepartum, DMI and milk yield were greater for cows with a short or no dry period, compared with cows with a conventional dry period. Postpartum, DMI was greater for cows with a short dry period compared with cows with a conventional dry period. Plasma glucose concentration was greater for cows without a dry period, compared with the other dry period lengths postpartum. Plasma concentrations of nonesterified fatty acids and β-hydroxybutyrate, and liver triglyceride content, did not differ among dry period. Rumen papillae differed in size based on biopsy location, but there was no interaction between biopsy location and the effect of dry period length. Rumen papillae surface area for cows managed for a 30 d or 60 d dry period decreased toward calving. At 40 d prepartum, papillae surface area was greater for short and no dry period treatment compared with a conventional dry period. At 10 d prepartum, papillae surface area was greater for the no dry period treatment compared with both other treatments, and this difference was still present 3 d postpartum. Cows managed for a short dry period showed faster increase in papillae dimensions after calving compared with cows managed for a conventional dry period. From d 28 onwards, no differences in papillae surface area were observed. The faster rumen adaptation postpartum may be related to the increased DMI during the first weeks postpartum for cows managed for a short dry period. However, this did not result in improved metabolic status or milk yield. The results from the present study demonstrate that the dietary changes related to a conventional dry period length affected rumen papillae development, not only prepartum but also early postpartum. Further optimization of dry period length as well as dietary composition throughout the transition period may support cows in their adaptation to a new lactation.

Dynamic fecal microenvironment properties enable predictions and understanding of peripartum blood oxidative status and nonesterified fatty acids in dairy cows

The transition period in dairy cows is a critical stage and peripartum oxidative status, negative energy balance (NEB), and inflammation are highly prevalent. Fecal microbial metabolism is closely associated with blood oxidative status and nonesterified fatty acids (NEFA) levels. Here, we investigated dynamic changes in total oxidative status markers and NEFA in blood, fecal microbiome, and metabolome of 30 dairy cows during transition (-21, -7, +7, +21 d relative to calving). Then the Bayesian network and 9 machine-learning algorithms were applied to dismantle their relationship. Our results show that the oxidative status indicator (OSI) of -21, -7, +7 d was higher than +21 d. The plasma concentration of NEFA peaked on +7 d. For fecal microenvironment, a decline in bacterial α diversity was observed at postpartum and in bacterial interactions at +7 d. Conversely, microbial metabolites involved in carbohydrate, lipid, and energy metabolism increased on +7 d. A correlation analysis revealed that 11 and 10 microbial metabolites contributed to OSI and NEFA variations, respectively (arc strength >0.5). The support vector machine (SVM) radial model showed the highest average predictive accuracy (100% and 88.9% in the test and external data sets) for OSI using 1 metabolite and 3 microbiota. The SVM radial model also showed the highest average diagnostic accuracy (100% and 91% in the test and external data sets) for NEFA with 2 metabolites and 3 microbiota. Our results reveal a relationship between variation in the fecal microenvironment and indicators of oxidative status, NEB, and inflammation, which provide a theoretical basis for the prevention and precise regulation of peripartum oxidative status and NEB.

Feeding Flaxseed and Lupins during the Transition Period in Dairy Cows: Effects on Production Performance, Fertility and Biochemical Blood Indices

Flaxseed and lupin seed were offered as an alternative dietary approach in dairy cows, through the partial substitution of soybean meal. Milk production and fertility traits were investigated. A total of 330 animals were allocated into two groups, treated (n = 176) and control (n = 154). From each group, 30 animals were selected for hematological and cytological studies. The experimental feeding period lasted for 81 days (25 days prepartum and 56 days postpartum). The control ration (group C) contained corn, barley, soybean meal, rapeseed cake, corn silage and lucerne hay; whereas, in the treatment group (group T), 50% of the soybean meal was replaced by an equal mixture of flaxseed and lupins. The two rations were formulated to be isonitrogenous and isoenergetic. Milk samples were analyzed for chemical composition, somatic cell count (SCC) content and total colony forming units (CFU). Blood samples were collected, and serum was analyzed for non-esterified fatty acids (NEFA), acute phase proteins (haptoglobin and serum amyloid) and lipid oxidation indices, namely thiobarbituric-acid-reactive substances (TBARS) and catalase activity. To assess polymorphonuclear neutrophils (PMN) numbers, endometrial samples from each cow were collected on days 21 and 42. No difference was recorded between groups in milk yield (p > 0.05). In multiparous cows, NEFA (mMol/L) concentrations were significantly lower in group T than in group C on day 14 (p > 0.009) and on day 42 (p = 0.05), while no difference was detected in the group of primiparous cows. At all time points, serum TBARS and catalase values were similar in both groups (p > 0.05). Multiparous cows in group T expressed the first postpartum estrus and conceived earlier than cows in group C (p ≤ 0.05). Between days 21 to 42 postpartum, the PMN reduction rate was higher in group T animals (p ≤ 0.05). Acute phase protein levels were in general lower in group T animals, and at specific time points differed significantly from group C (p ≤ 0.05). It was concluded that the partial replacement of soybean meal by flaxseed and lupins had no negative effect on milk yield or milk composition, and improved cow fertility; which, along with the lower cost of flaxseed and lupins mixture, may increase milk production profitability.

AdipoRon alleviates fatty acid–induced lipid accumulation and mitochondrial dysfunction in bovine hepatocytes by promoting autophagy

During the transition period in dairy cows, high circulating concentrations of nonesterified fatty acids (NEFA) increase hepatic lipid deposits and are considered a major pathological factor for liver damage. We investigated whether AdipoRon, a synthetic small-molecule agonist of adiponectin receptors 1 and 2 shown to prevent liver lipid accumulation in nonruminants, could alleviate NEFA-induced lipid accumulation and mitochondrial dysfunction. Bovine hepatocytes were isolated from 5 healthy Holstein female newborn calves (1 d of age, 30-40 kg, fasting), and independently isolated hepatocytes from at least 3 different calves were used for each subsequent experiment. The composition and concentration of NEFA used in this study were selected according to hematological criteria of dairy cows with fatty liver or ketosis. First, hepatocytes were cultured with various concentrations of NEFA (0, 0.6, 1.2, or 2.4 mM) for 12 h. In a second experiment, hepatocytes were treated with AdipoRon at different concentrations (0, 5, 25, or 50 μM for 12 h) and times (25 μM for 0, 6, 12, or 24 h) with or without NEFA (1.2 mM) treatment. In the last experiment, hepatocytes were treated with AdipoRon (25 μM), NEFA (1.2 mM), or both for 12 h after treatment with or without the autophagy inhibitor chloroquine. Hepatocytes treated with NEFA had increased protein abundance of sterol regulatory element-binding protein 1c (SREBP-1c) and mRNA abundance of acetyl-CoA carboxylase 1 (ACACA), and decreased protein abundance of peroxisome proliferator-activated receptor α (PPARA), proliferator-activated receptor gamma coactivator-1 α (PGC-1α), mitofusin 2 (MFN2), cytochrome c oxidase subunit IV (COX IV), and mRNA abundance of carnitine palmitoyltransferase 1A (CPT1A), along with lower ATP concentrations. AdipoRon treatment reversed these effects, suggesting this compound had a positive effect on lipid metabolism and mitochondrial dysfunction during the NEFA challenge. In addition, upregulated expression of microtubule-associated protein 1 light chain 3-II (LC3-II, encoded by MAP1LC3) and downregulated expression of sequestosome-1 (SQSTM1, also called p62) indicated that AdipoRon enhanced autophagic activity in hepatocytes. The fact that chloroquine impeded the beneficial effects of AdipoRon on lipid accumulation and mitochondrial dysfunction suggested a direct role for autophagy during NEFA challenge. Our results suggest that autophagy is an important cellular mechanism to prevent NEFA-induced lipid accumulation and mitochondrial dysfunction in bovine hepatocytes, which is consistent with other studies. Overall, AdipoRon may represent a promising therapeutic agent to maintain hepatic lipid homeostasis and mitochondrial function in dairy cows during the transition period.

Effect of Anti-Mullerian Hormone, Metabolic Profile and Mineral Levels at Transition Period On The Calving – Conception Interval in Cows

The transition period in dairy cows is generally accepted as the period covering 3 weeks before calving and 3 weeks after calving. The aim of the study was to compare the profiles of β-hydroxybutyrate, calcium, magnesium, phosphorus, total cholesterol, total protein, triacylglycerol, free glycerol, serum lipid and serum protein with Anti-Mullerian Hormone (AMH) in dairy cows in the transition period, and to determine whether AMH to examine whether it can be used as a marker in the next insemination period. The cows whose blood samples were taken were followed up and it was determined that they became pregnant at the insemination and the study was terminated. According to the results obtained; It was determined that BHB and free glycerol, which are important markers of negative energy balance (NEB), have an effect on AMH concentration. However, it was determined that the concentration of magnesium and the ratio of cholesterol ester in serum total fat did not change much during the transition period. Our results suggest that AMH is a good biomarker of decreased follicular activity due to NEB in the transition period and that AMH can be used for herd weeding in reinsemination.

Is adenosine deaminase (ADA) activity in saliva and serum a more accurate disease detection tool than traditional redox balance parameters in early-lactating dairy cows?

Enzyme adenosine deaminase (ADA) is a marker of inflammation in domestic animals, but it is unclear whether it is a reliable marker of oxidative stress, especially in the transition period in dairy cows. This study aims to assess if ADA and redox status measurements in saliva provide the same utility to detect disease condition as that obtained from serum. Sixty-eight multiparous Holstein cows, between 2 and 3 weeks postpartum were selected. Five study groups were established: control (healthy), and cows with ketosis, mastitis, laminitis, and metritis. The parameters measured were ADA activity, total oxidants (TOS), antioxidants (TAC), and OSi ratio.Regarding redox status, no significant differences arise in both saliva and serum being the correlations negative and not significant. In saliva, ADA activity in healthy cows differs from those with pathological processes, having the lowest activities. In serum, ADA activity is similar in the healthy and ketosis cows, showing the lowest activities meanwhile animals with mastitis, laminitis, or metritis have significantly higher activities. In conclusion, the measurement of ADA activities and redox status in saliva does not give consistent results, being preferable to measure them in serum during the transition period.

Variations of some adipokines, pro-inflammatory cytokines, oxidative stress biomarkers, and energy characteristics during the transition period in dairy cows.

Limited information exists about the relationship of adipose tissue with inflammation, oxidative stress, and energy metabolism during the transition period in dairy cows. The objective of this study was to assess the changes and relation of some adipokines, cytokines, oxidative biomarkers, and serum biochemical parameters related to energy balance (EB) in cows during the transition period. Thirty multiparous Holstein cows were selected based on estimated parturition date, and blood samples were collected from jugular vein on one-week prepartum and one and three weeks postpartum and used to measure the parameters. The serum levels of beta-hydroxybutyric acid (BHB), non-esterified fatty acid, cholesterol, high-density lipoprotein (HDL), aspartate aminotransferase, and total antioxidant capacity increased significantly, and glucose, urea, triglyceride (TG), and low-density lipoprotein (LDL) decreased significantly after parturition. The serum values of adiponectin, resistin, leptin, and cytokines including interleukin 6 (IL-6) and tumor necrosis factor (TNF)-α were not changed significantly during the experiment. The results of the Pearson correlation revealed a significant negative correlation between BHB with glucose, albumin, cholesterol, HDL, LDL, and a positive correlation with TG and malondialdehyde. Also, there was a significant direct correlation between insulin and leptin, adiponectin, resistin, IL-6 and TNF-α in the whole experiment period. These emphasize the difficulty of dairy cows to manage the energy requirements during the transition period. It can be stated that adipokines and cytokines may have an essential role in the metabolic status in this period, and control of their production and, or secretion could be helpful in EB during the transition period.

Non-Esterified Fatty Acid Induces ER Stress-Mediated Apoptosis via ROS/MAPK Signaling Pathway in Bovine Mammary Epithelial Cells.

Elevated concentrations of non-esterified fatty acid (NEFA) induced by negative energy balance (NEB) during the transition period of dairy cows is known to be toxic for multiple bovine cell types. However, the effect of NEFA in bovine mammary epithelial cells (BMECs) remains unclear. The present study aimed to explore the role and molecular mechanism of NEFA in endoplasmic reticulum (ER) stress and the subsequent apoptosis in BMECs. The results showed that NEFA increased ER stress and activated the three unfolded protein response (UPR) signaling sub-pathways by upregulating the expression of GRP78, HSP70, XBP1, ATF6, phosphor-PERK, and phosphor-IRE1α. We also found that NEFA dose-dependently induced apoptosis in BMECs, as indicated by flow cytometry analysis and increased apoptotic gene expression. RNA-seq analysis revealed that NEFA induced apoptosis in BMECs, probably via the ATF4-CHOP axis. Mechanistically, our data showed that NEFA increased reactive oxygen species (ROS) levels, resulting in the activation of the MAPK signaling pathway. Moreover, quercetin, a well-known antioxidant, was found to alleviate ER stress-mediated apoptosis in NEFA-treated BMECs. Collectively, our results suggest that NEFA induces ER stress-mediated apoptosis, probably via the ROS/MAPK signaling pathway, as quercetin has been shown to alleviate ER stress-mediated apoptosis in NEFA-treated BMECs.

The Effect of L-Carnitine Use on Some Blood Parameters, Milk Yield, Milk Composition, and Live Weight in the Transition Period of Dairy Cows

This study aims to determine the effect of supplementing L-carnitine during the transition period on fatty liver, ketosis and milk yield of dairy cows. The control group includes ten cows fed with normal ration (n=10), while the experimental group consists of 11 cows daily supplemented with six-grams of rumen-protected L-carnitine additive orally (n=11). In the study, while there is no statistically significant difference between serum NEFA and BHBA levels between the control group and the experimental group treated with carnitine, the difference in glucose level is statistically significant (p <0.001) in terms of time. While a severe decrease in glucose levels occurs in the control group after birth, the group given carnitine remains within the normal range. The carnitine-treated group's serum BUN value is significantly lower than the control group (p <0.05). Accordingly, L-carnitine neither has a statistically significant effect on Ca, P, GGT, triglyceride values, nor milk yield, milk composition, and live weight. In conclusion, daily oral administration of 6 g L-carnitine increases the use of fatty acids in energy metabolism through the intake into tissues and decreases muscle protein catabolism.

Predicting ketosis during the transition period in Holstein Friesian cows using hematological and serum biochemical parameters on the calving date

Ketosis often occurs during the postpartum transition period in dairy cows, leading to economic and welfare problems. Previously, ketosis was reported to be associated with hematological and serum biochemical parameters. However, the association between the parameters on the calving date and ketosis during the postpartum transition period remains unclear. This study aimed to investigate this association. Blood samples were collected from the jugular vein of Holstein cows on the calving date and β-hydroxybutyrate was tested once every 3 days (8 times in 21 days). The cows were divided into three groups: non-ketosis, subclinical ketosis, and clinical ketosis. The clinical ketosis group significantly had the highest values of mean corpuscular volume, mean corpuscular hemoglobin, β-hydroxybutyrate, non-esterified fatty acids, and total bilirubin, but the lowest values of red cell distribution width, the counts of white blood cell, monocyte, and eosinophil, albumin, alanine transaminase, lactate dehydrogenase, and amylase. In contrast, the non-ketosis group showed the opposite results (p < 0.05). In conclusion, these parameters are associated with the development and severity of ketosis. Our findings suggest that these parameters on the calving date may be useful indicators to identify dairy Holstein cow susceptible to ketosis during the transition period.

Changes in metabolic and hormonal profiles during transition period in dairy cattle \u2013 the role of spexin

BackgroundThis study aimed to evaluate spexin as a novel blood marker and to describe the relationship of this peptide with selected biochemical metabolites measured during the transition period in dairy cows. Additionally, mRNA expression of the spexin gene as well as spexin receptors – galanin receptor type 2 and galanin receptor type 3, was investigated in several bovine tissues. Blood samples were collected at weekly intervals starting at 21 days before the estimated parturition day until 21 days in milk to determine concentrations of spexin, nonesterified fatty acids, β-hydroxybutyrate acid, total and active ghrelin, progesterone, glucose, insulin, IGF–I, triglycerides, cholesterol, leptin, corticosterone and 17-β-estradiol as well as the activity of aspartate transaminase, alkaline phosphatase and gamma-glutamyl transferase.ResultsSpexin concentration decreased from 21 d before parturition to calving day and next it rose during the first 14 d of lactation. The lowest concentration of spexin was recorded on the calving day and it differed from the mean level of this peptide before parturition as well as postpartum. Moreover, differences were observed between mean spexin concentrations before and after calving. Spexin levels were moderately negatively correlated with NEFA (r = − 0.39) and total ghrelin contents (r = − 0.41), weakly correlated with BHBA (r = − 0.35) while they showed a moderate positive relationship with progesterone concentrations (r = 0.42). Moreover, we detected that mRNA expression of GALR2, GALR3 and SPX is present in various bovine tissues (kidney, bowel, rumen, spinal cord, lung, skeletal muscle, liver, heart, fat and spleen).ConclusionA negative correlation between spexin concentration and NEFA, BHBA and total ghrelin contents as well as a positive relationship with levels of progesterone, metabolites and hormones, which are key players in the dairy cow transition period, may confirm an important function of this peptide in metabolism regulation. Thus measurement of spexin concentration could provide useful supplementary information for dairy cow herd health monitoring.

An Exploration of the Effects of an Early Postpartum Intravenous Infusion with Carnosic Acid on Physiological Responses of Transition Dairy Cows.

The objective of the present study was to evaluate the effects of an antioxidant and anti-inflammatory compound found in rosemary plants (Salvia rosmarinus) named carnosic acid during the transition period of dairy cows. From day 1 to 3 after calving, 16 multiparous Holstein cows received a daily intravenous infusion of either 500 mL of saline (NaCl 0.9%; Saline; n = 8) or carnosic acid at a rate of 0.3 mg/kg of BW supplied in 500 mL of saline (CA; n = 8). Blood samples were taken at –7, 2, 5, 7, 14, and 21 d relative to parturition, then analyzed for metabolites related to energy metabolism, muscle mass catabolism, liver function, inflammation, and oxidative stress. CA infusion tended to improve milk performance; however, DMI was unaffected by treatment. At 2 d relative to parturition, CA cows had lower blood concentrations of haptoglobin, paraoxonase, FRAP, and NO2– than saline cows. After treatment infusions, haptoglobin remained lower in CA cows than saline at 5 d relative to parturition. Our results demonstrate that carnosic acid promoted positive responses on inflammation and oxidative stress biomarkers and may promote beneficial effects on lactation performance in peripartal dairy cows.

Monitoring the Transition Period in Dairy Cows through 1H NMR-Based Untargeted Metabolomics

The metabolic alterations associated with the increase in milk production make the transition period critical to the health of dairy cows, usually leading to a higher incidence of disease in periparturient animals. In this manuscript, we describe the use of NMR-based untargeted metabolomics to follow how these changes impact the serum metabolome in a group of 28 transition dairy cows with no initial clinical diseases. Principal component analysis (PCA) of serum 1H NMR data from four weeks before calving to 8 weeks after parturition allowed us to clearly identify four stages during the transition period. Pairwise comparisons using orthogonal partial least square discriminant analysis (OPLS-DA) and univariate data analysis led to the identification of 18 metabolites that varied significantly through these stages. Species such as acetate, betaine, and creatine are observed early after calving, while other markers of metabolic stress, including acetone, β-hydroxybutyrate (BHB), and choline, accumulate significantly at the height of milk production. Furthermore, marked variations in the levels of lactate, allantoin, alanine, and other amino acids reveal the activation of different gluconeogenic pathways following parturition. Concomitant with a return to homeostasis, a gradual normalization of the serum metabolome occurs 8 weeks after calving. Correlations of metabolite levels with dietary and metabolic adaptations based on animal parity could also be identified. Overall, these results show that NMR-based chemometric methods are ideally suited to monitor manifestations of metabolic diseases throughout the transition period and to assess the impact of nutritional management schemes on the metabolism of dairy cows.

Effects of supplemental Bacillus subtilis, injectable vitamin E plus selenium, or both on health parameters during the transition period in dairy cows in a tropical environment.

The objective of this study was to determine the effects of supplemental Bacillus subtilis (BS, 0.5 × 1011 CFU/day), injectable vitamin E and selenium (ES, 1000 mg α-tocopherol acetate and 10 mg sodium selenite), or both during the transition period on health parameters and the incidence of retained fetal membranes (RFM) of dairy cows under tropical conditions (average temperature humidity index = 77.0). Thirty-two crossbred Holstein-Friesian cows were used in a randomized design trial with a 2 × 2 factorial arrangement of treatments. Cows were randomly assigned to one of four treatments, including no supplementation (CON), single intramuscular injection of ES on day - 21 before the expected calving date (ES), daily oral supplementation of BS between day - 21 and day 21 relative to calving, or both ES and BS. Body condition score (BCS) and blood samples were collected on days - 28, - 14, 0, 14, and 28 relative to calving. Mean concentrations of corpuscular hemoglobin were higher (33.12 vs 34.03 g/dL, p = 0.06) and platelets were lower (380.97 vs 302.32 × 103/μL, p = 0.10) with ES than without ES. Cows fed supplemental BS had lower concentrations of creatinine and albumin and tended to have lower AST and β-hydroxybutyrate (BHBA) levels. However, concentrations of glucose were higher for cows fed BS than for those without BS. No differences in the incidence of RFM were observed. In summary, supplemental B. subtilis could reduce indicators of negative energy balance by increasing glucose and lowering BHBA and improve health parameters by keeping WBCs and monocytes in a healthy range during the transition period.

Sheep mastitis caused by staphylococci and streptococci and their influence on oxidative status

Article Details: Received: 2020-10-14 | Accepted: 2020-11-27 | Available online: 2021-01-31 https://doi.org/10.15414/afz.2021.24.mi-prap.53-57 Abstract The objectives of this study were to determine the relationship of oxidative product levels, using malondialdehyde (MDA) as a marker on occurrence of mastitis and its causing pathogens in two dairy flocks of ewes situated in east and north of Slovakia. The diagnosis of mastitis was performed on the basis of clinical examination of the udder, macroscopic evaluation of milk, with the evaluation of Californian mastitis test (CMT) and bacteriological analysis of individual raw milk samples. From total 537 and 444 halves ewe’s milk samples were 16.6% and 23.2% positive to CMT, respectively. The prevalence of mastitis caused by bacterial pathogenes in the monitored herds was 14.3% to 19.1%, respectively. In all monitored sheep flocks were confirmed predominantly subclinical forms (SM) of intramammary infection (IMI). The highest of etiological agents in all monitored herds had coagulase negative staphylococci and coagulase positive staphylococci especially Staphylococcus aureus . Except for staphylococci were Streptococcus uberis and Streptococcus spp. most frequently pathogens isolated from mastitic sheep. The highest MDA level was observed from clinical cases of mastitis however, increased MDA levels were detectable from subclinical cases. Bacterial isolates from mastitc halves milk samples are different in levels of MDA. In this study, we found that milk samples infected with S. aureus were higher compared to other pathogens. In conclusion, differences in both severities of IMI and mastitis pathogens were associated with differences of MDA in infected udders. Keywords: sheep, milking, mastitis, lipid peroxidation, S. aureus , coagulase negative staphylococci References Contreras, A. et al. (2007). Mastitis in small ruminants. Small Ruminant Research, 68(1-2), 145–153. https://doi.org/10.1016/j.smallrumres.2006.09.011 Fthenakis, G. C. (1995). California mastitis test and White side test in diagnosis of subclinical mastitis of dairy ewes. Small Ruminant Research , 16(3), 271–276. https://doi.org/10.1016/0921-4488(95)00638-2 Hariharan, H. et al. (2004). Bacteriology and somatic cell counts in milk samples from ewes on a Scottish farm. Canadian Journal of Veterinary Research, 68(3), 188–192. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1142138/ Malinowski, E. et al. (2008). Etiological agents of dairy cows’ mastitis in western part of Poland. Polish Journal of Veterinary Sciences, 9(3), 191-194. https://pubmed.ncbi.nlm.nih.gov/17020014/ Mork, T. et al. (2007). Clinical mastitis in ewes; bacteriology, epidemiology and clinical features. Acta Veterinaria Scandinavica , 49(1), 23. https://dx.doi.org/10.1186%2F1751-0147-49-23 Pyorala, S. and Taponen, S. (2009). Coagulase-negative staphylococci - Emerging mastitis pathogens. Veterinary Microbiology , 34(2), 3–8. https://doi.org/10.1016/j.vetmic.2008.09.015 Sharma, N. (2011). Oxidative stress and antioxidant status during transition period in dairy cows. Asian-Australian Journal of Animal Science , 24(4), 479–484. https://www.ajas.info/upload/pdf/24-58.pdf Suriyasathaporn, W. (2006). Higher somatic cell counts resulted in higher malondialdehyde concentrations in raw cow´s milk. International Dairy Journal, 16(9), 1088–1091. https://doi.org/10.1016/j.idairyj.2005.11.004 Turk, R. et al. (2017). The role of oxidative stress and inflammatory response in the pathogenesis of mastitis in dairy cows. Mljekarstvo, 67(2), 91–101. https://doi.org/10.15567/mljekarstvo.2017.0201

Relationship between reproductive efficiency and blood calcium level during transition period in dairy cows

Metabolic disorders cause severe losses to dairy farmers, with adverse effects on milk yield and dairy cattle's reproductive efficiency. Hypocalcemia is the most common metabolic defects affecting dairy cows during transition periods and affecting reproductive efficiency. This research aimed to study the relationship between the most common metabolic disorder (hypocalcemia) and the reproductive efficiency in dairy cows. Fifty-three dairy cows were grouped based on blood calcium level into normal and subclinical hypocalcemic cows. Body condition scours and reproductive disorders were recorded. Moreover, reproductive efficiency was reported until 280 days in milk. Results reported a significant increase and positive correlation between reproductive disorder (dystocia, stillbirth, retained placenta, metritis, and vaginitis) in animals suffering from subclinical hypocalcemia. These results conclude that subclinical hypocalcemia impairs reproductive efficiency in dairy cows and subsequently it lowers the benefit from dairy farming.

Insulin resistance indexes of grazing cows and mineral or vitamin supplementation under tropical conditions.

Background:During the transition period in dairy cows, metabolic changes occur, many of which are related to energy metabolism, which causes metabolic diseases or productive alterations. Aim:The objective of the present work was to evaluate two mineral and vitamin supplementations related to metabolic regulation mechanisms associated with insulin during the transition period and the first phase of lactation in grazing cows under tropical conditions through metabolic indicators and insulin resistance indexes. Methods:Twenty-one animals were distributed in three groups: control (CTR), iodine supplementation (SUPP-1), and mixed mineral and vitamin supplementation (SUPP-2). The experimental period was from day 30 prepartum to day 45 postpartum. Evaluation of the body condition score and the blood samples’ collection by coccygeal venipuncture was carried out for serum analysis of metabolites, such as beta-hydroxybutyrate (BHB), glucose, and non-esterified fatty acids (NEFA), and hormones, such as insulin, thyroxine, triiodothyronine, and cortisol. Variables related to energy and hormone metabolism were analyzed. Four proposed indexes were calculated to identify insulin resistance: Homeostasis Model Assessment (HOMA), Quantitative Insulin Sensitivity Check Index (QUICKI), Revised Quantitative Insulin Sensitivity Check Index, and QUICKI–BHB. Through linear regression, the effect of metabolites and hormones on the indexes of insulin resistance studied was estimated. Results:The groups with supplementation did not show significant changes in the mobilization of body reserves, NEFA, or triiodothyronine for interaction between treatments and periods. HOMA and QUICKI indexes used to estimate insulin resistance showed an inverse correlation (−0.97; p<0.001), and a greater capacity of linear adjustment to estimate the evaluated metabolites. Conclusion:The indexes’ values of insulin sensitivity in the present work constitute a starting point in tropical dairy cows to characterize insulin resistance and metabolic alterations. Vitamins and mineral supplementation did not show a positive effect on the metabolism of dairy cows during the transition period and the first phase of lactation in the study.

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.