Evaluation of some metabolic profile parameters in transition cows: thresholds for estimating postpartum diseases in Aydin province

This study aimed to evaluate non-esterified fatty acids (NEFA), beta hydroxybutyric acid (BHBA), magnesium (Mg2+), calcium (Ca2+) and lactate as biological tests for the detection of some metabolic diseases during transition period in selected dairy farms located in Aydın province. Cow-side analysis with body condition score evalutation were performed weekly in at least 12 dairy cattle from each farm from prepartum week 2 to postpartum week 2. According to the prepartum NEFA ≥0.4 mmol/L, postpartum BHBA ≥1.4 mmol/L and Ca2+ ≤ 2.0 mmol/L at parturition (day 0) in herd-based evaluation, it was observed that all farms were positively evaluated for negative energy balance and also at risk for subclinical hypocalcaemia. Regarding the threshold value of Mg2+ <0.61 mmol/L, subclinical hypomagnesaemia was observed at the Ist and IInd farms. It was concluded that prepartum NEFA threshold (0.68 mmol/L), obtained from the receiver operating characteristics statistical analysis could be used for observing some postpartum clinical diseases. It was suggested that it allowed planning and strategic interventions to prevent herd-based diseases in Turkey and will be a precedent for future studies and herd management.

An update on hypocalcaemia control

Clinical milk fever (hypocalcaemia) is one of the most common metabolic diseases encountered in dairy cows. Subclinical hypocalcaemia in the first days post calving is very common but not often monitored on farm. If monitoring strategies are used the timing of sampling and the parity of animals is important in interpretation of results. Several studies show subclinical hypocalcaemia predisposes cows to an increased risk of diseases such as metritis and displaced abomasum as well as reduced reproductive performance and compromised milk yields. Targeted interventions with calcium supplementation can be effective in mitigating these risks. Preventative strategies normally focus on restricting dietary potassium in the lead up to calving and ensuring adequate magnesium status. Ca binding agents can also be very effective but it is a more expensive strategy.

Effect of blood ionised calcium concentration at calving on fertility outcomes in dairy cattle

Clinical and subclinical hypocalcaemia are common in dairy cows, yet evidence in the literature assessing their impact on fertility is inconsistent. The aim of this prospective cohort study was to examine associations between blood ionised calcium concentration at calving and fertility outcomes in dairy cattle. Blood samples were taken from 137 Holstein cows from four commercial dairy herds within 24 hours of calving and analysed for blood ionised calcium using an Epocal Point of Care Analyser (Epocal, Ottawa, Canada). Data collected from routine veterinary fertility examinations and herd records were used to investigate the association of ionised calcium with the outcomes: time to first service, time to conception and endometritis. There were significant negative associations between blood ionised calcium concentration and time to first service (HR 1.33, P=0.001) and blood ionised calcium concentration and time to conception (HR 1.16, P=0.04). There was no significant association between blood ionised calcium concentration and endometritis. The results of this study imply that management policies that minimise the reduction in blood ionised calcium concentration in the periparturient dairy cow are likely to improve reproductive outcomes and should be considered as part of the multifactorial approach to optimising dairy cow fertility.

Changes of macrominerals and calcitropic hormones in serum of periparturient dairy cows subject to subclinical hypocalcaemia

The aims of the study reported in the Research Communication were to evaluate changes of macrominerals and major calcitropic hormone concentrations in 51 healthy dairy cows over the peripartum period, and to compare those cows with 51 cows subject to subclinical hypocalcaemia (SCH) on calving day. The results showed that serum calcium (Ca) and potassium (K) concentrations were lowest in the healthy periparturient dairy cows at parturition, while sodium (Na) and parathyroid hormone (PTH) concentrations were highest. Serum magnesium (Mg), chloride (Cl) and phosphorus (P) concentrations were highest 1 wk prepartum, however, the concentration of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] was highest 1 wk postpartum. The dairy cows with subclinical hypocalcaemia (SCH) had significantly lower serum levels of Ca, K, Na, Mg, Cl, 1,25(OH)2D3 and glucose and had significantly higher levels of serum P, non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHBA) than their healthy counterparts on calving day. However, the serum calcitonin and PTH concentrations were not significantly different between the two groups. These data demonstrated that the concentrations of macrominerals and major calcium regulating hormones of cows change dramatically over the peripartum period. Furthermore, SCH was associated with a risk of the development of ketosis and fatty liver.

Calcium and magnesium status of pregnant ewes grazing southern Australian pastures

During pregnancy, ewes graze pastures that may be marginal in calcium (Ca) and magnesium (Mg), and may also be low in sodium (Na) and high in potassium (K), with a high dietary cation–anion difference. Such pastures may increase susceptibility to hypocalcaemia and hypomagnesaemia, leading to lamb losses. Clinical hypocalcaemia and hypomagnesaemia do occur in Australian sheep; however, it is unknown whether subclinical forms of these disorders compromise ewe or lamb health and survival. The present study monitored the Ca and Mg status of ewes in late pregnancy, so as to evaluate the risk of subclinical mineral disorders in ewes grazing typical southern Australian pastures. Calcium and Mg concentrations in pasture, ewe plasma and urine were monitored in 15 flocks in southern Australia. Mineral concentrations in pasture did not indicate a widespread risk of Ca or Mg deficiency; however, urinary pH and Ca and Mg concentrations in the plasma and urine of the pregnant ewes were not entirely consistent with the expectations from pasture analysis. Urine pH was above 7 on all properties and 87.5% of properties had a mean Ca in urine below the adequate concentration of 1 µmol/mosmol. The mean plasma Ca concentration was below adequate (<90 mg/L) on only one farm but five farms had more than 20% of ewes with below adequate Ca in plasma. In addition, although average farm concentrations of plasma and urine Mg indicated adequate Mg status of the ewes (>18 mg/L), more than 20% of ewes on six farms had below adequate concentrations of plasma Mg. Only one-third of the farms had 100% of ewes measured with adequate concentrations of plasma Ca (4/15) or Mg (5/15). The mineral concentrations in pre-lambing blood and urine samples suggested that a significant number of animals grazing southern Australian pastures during winter may be at risk of subclinical hypocalcaemia and hypomagnesaemia.

Variable phenotype of pseudohypoparathyroidism in children

Background. Pseudohypoparathyroidism (PHP) is a heterogeneous group of disorders associated with tissue insensitivity to parathyroid hormone. PHP is characterized by genetic heterogeneity and variable phenotype. In addition to the hypocalcemic syndrome and resistance to parathyroid hormone, PHP is also characterized by phenotypic features and resistance to other hormones (TSH, LH, FSH, and GHRH), which are known as Albright Hereditary Osteodystrophy (AHO). Until recently, no analysis of large cohorts of patients with PHP has been performed in Russian literature. Objective — to examine a large cohort of patients with PHP and assess the clinical features of PHP. Material and methods. A group consisting of 32 patients with different variants of course of the disease who had been examined at the Endocrinology Research Center in 2014—2016 was analyzed. Results. Features of AHO phenotype in addition to hormonal resistance were identified in 16 (50%) patients; one of them had one feature (brachydactyly) and 15 patients had two and more features of AHO. Besides insensitivity to PTH, TSH resistance was found in 22 (68.75%) patients and one patient had resistance to PTH, TSH and LH/FSH. Hypothyroidism manifested before hypocalcaemia in 4 patients. Obesity was the first complaint in 8 patients; 5 of them had subclinical hypocalcaemia and the remaining 3 patients had an elevated PTH level with the normal level of calcium at the time of first examination. The most typical clinical signs of hypocalcaemia in 23 (72%) patients were seizures. Thirteen of them were misdiagnosed with epilepsy and had been followed by a neurologist for a period ranging between 2 months and 7 years before hypocalcaemia was revealed. Conclusions. Pseudohypoparathyroidism is a rare genetic disorder associated with resistance to parathyroid hormone, which can have a lot of other clinical features in addition to the symptoms of PTH resistance. Obesity or hypothyroidism can be the earliest manifestation of PHP preceding hypocalcaemia. Evaluation of serum calcium level is important for all pediatric patients with seizures to timely diagnose hypocalcaemia and avoid misdiagnosing.