Murat Uztimür

Transition period, which encompasses the ±21 day process from calving, is an important period for dairy cattle that requires significant metabolic adaptations. One of the most important causes of diseases during this period is known to be disturbances in mineral metabolism. Even in clinically healthy dairy cows, hypophosphatemia is reported to be over 50% on the day of calving and 10-15% during the first two weeks postpartum. In the presented study, it is aimed to evaluate the changes in metabolic profile parameters in dairy cattle developing hypophosphatemia. In the study, the group of 25 dairy cows with hypophosphatemia in the fresh period formed the experimental group, while the control group consisted of 10 dairy cows determined to be healthy in general clinical examination and biochemical analyses. When examining the metabolic profile parameters, in the hypophosphatemia group, compared to the control group, calcium (p<0.037), potassium (p<0.013), albumin (p<0.002), and ALT (p<0.031) levels were found to be low, while the NEFA (p<0.001) concentration was found to be high. It has been shown that serum phosphorus concentrations may decrease at the beginning of lactation and that this condition may affect the metabolic status of the animals.

Lactate metabolism is critical for the healthy survival of animals. The imbalance of this metabolism leads to mortality. Therefore, the aim of this study was to evaluate the serum D-lactate, L-lactate, and serum methylglyoxalate concentrations in diarrheic calves infected with different infectious agents. Calves were grouped as rotavirus (n=15), coronavirus (n=15), and Cryptosporidium (n=15). The control group (n=15) calves were composed of calves determined to be healthy. While the serum methylglyoxalate and D-lactate levels of the control and diarrheic calves were determined by ELISA, the L-lactate level was determined by a blood gas analyzer. The D-lactate concentration of calves infected with rotavirus (P<0.002), coronavirus (P<0.01), and C. parvum (P<0.001) was significantly higher than that of the control group. The L-lactate concentration of the rotavirus (P<0.07) and coronavirus (P<0.006) infected calves was significantly higher than that of the control group. The White blood cell counts of the rotavirus (P<0.001), coronavirus (P<0.001), and C. parvum (P0.499). In conclusion, in this study, it was found that D-lactate and L-lactate concentrations were significantly high in diarrhea caused by different infectious agents, and as a result, these metabolites should be taken into consideration and carefully considered in the evaluation of diarrhea in calves. Future studies are needed to evaluate the effects of D-lactate and L-lactate on mortality in calves with diarrhea of different severities.

Metabolic profile analyses are widely used to determine and standardize the nutritional and disease status of animals. Metabolic profile parameters do not have the same reference ranges in every case. In this study, it is aimed to evaluate the effect of parity and lactation period on metabolic parameters in Holstein dairy cows. In the study, a total of 60 dairy cows in the transition period (the last three weeks of pregnancy and the first three weeks of lactation) were used. Dairy cows were grouped according to their parity (1 (n:20), 2 (n:20), and 3 or more (n:20)), lactation period (early period: 0-60 days (n:20), mid period: 60-120 (n:20), late period: >120 (n:20)), and 305-day average milk yield (35 L: high yield (n:20)). Significant changes were detected in the levels of non-esterified fatty acid (NEFA) and β-hydroxybutyric acid (BHBA), which indicate energy status, alanin aminotransferaz (ALT), aspartat aminotransferaz (AST), gama glutamil transferaz (GGT), and cholesterol, which indicate liver damage, and albumin levels among plasma proteins. It was concluded that considering these factors while evaluating the metabolic profile parameters in dairy cattle could be beneficial for better understanding the animals' condition and accurately interpreting the analyses.

Hypomagnesemia is a disease in ruminants characterized by biochemically low serum magnesium. Metabolic profile refers to the analysis of blood biochemical parameters used to assess and prevent metabolic and nutritional disorders in dairy farms. This study aims to evaluate the effect of magnesium on energy balance and metabolic profile parameters in fresh postpartum dairy cows. The study included 30 cows diagnosed with postpartum hypomagnesemia and 10 control group cows. Measurements of the parameters urea, creatinine, aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyl transferase (GGT), total protein, cholesterol, albumin, calcium, phosphorus, beta-hydroxybutyric acid (BHBA), and non-esterified fatty acids (NEFA) were performed on biochemical analyzer. In the hypomagnesemia group, NEFA, total protein, AST and cholesterol levels were higher compared to the control group, while glucose levels were lower. Correlation analysis revealed a negative moderate correlation between magnesium and NEFA, BHBA and AST, positive moderate correlation with glucose and urea. Significant changes were detected in NEFA and glucose parameters, which reflect energy status, and in AST and cholesterol parameters, which provide information about liver function. It was concluded that metabolic adaptation in dairy cows affected by hypomagnesemia may be weakened, and energy balance and liver function may be affected.

Studies in human medicine have demonstrated that rotavirus infection can also affect extraintestinal sites due to its systemic effects. However, in veterinary medicine, the injury caused by rotavirus diarrhea is limited to the intestines, and its effects on various systemic structures remain poorly understood. In this observational case–control study, we aimed to determine the effects of HSP-27, Caspase-3, IL-2, γ-H2AX, HMGB-1, SP-D, and GDH (or GLDH) on the pathogenesis of rotavirus infection by using biomarkers for diagnostic purposes in lung and liver injury in neonate diarrheic calves naturally infected with rotavirus, both alive and post-mortem. Fifty-two Simmental calves (1–28 days old) of both sexes, 40 infected with rotavirus and 12 healthy, were studied. Twenty-eight out of 40 survived, while the remainder underwent necropsy for histopathological and immunopathological (HSP-27, Caspase-3, IL-2, γ-H2AX) examination of the lungs and livers. Lung and liver-specific serum E-selectin, glutamate dehydrogenase, surfactant protein-D, and high mobility group box-1 were analyzed by a bovine-specific ELISA kit (Shanghai Coon Koon Biotech Co., Ltd., China). Histopathological and immunohistochemical analyses confirmed lung and liver injury in naturally infected calves. HMGB-1, SP-D, and GDH concentrations were significantly higher in naturally infected calves than in the control group (p < 0.001, p < 0.001, and p < 0.05, respectively), showing an excellent diagnostic predictive capacity for lung and liver injury. Also, IL-2, HSP-27, CASP-3, and γ-H2AX were significantly expressed in the lungs (p < 0.001, p < 0.001, p < 0.001, and p < 0.05, respectively) and liver (p < 0.001, p < 0.001, p < 0.01, and p < 0.01, respectively). All these observations led us to hypothesize that oxidative stress, apoptosis, and DNA damage may underlie the pathogenesis of this condition. Nevertheless, further studies on large populations of rotavirus-infected calves are needed to confirm the data reported in the current study.