Subclinical hypocalcemia, plasma biochemical parameters, lipid metabolism, postpartum disease, and fertility in postparturient dairy cows

Abstract

A study was conducted to evaluate the potential association between Ca status at calving and postpartum energy balance, liver lipid infiltration, disease occurrence, milk yield and quality parameters, and fertility in Holstein cows. One hundred cows were assigned to 1 of 2 groups based on whole-blood ionized Ca concentration ([iCa]) on the day of calving [d 0; hypocalcemic [iCa] <1.0 mmol/L (n=51); normocalcemic [iCa] ≥ 1.0 mmol/L (n=49)]. Cows were blocked based on calving date and parity. Blood samples were collected approximately 14 d from expected calving date (d -14), the day of calving (d 0), and on d 3, 7, 14, 21, and 35 postpartum for measurement of plasma nonesterified fatty acid, iCa, total Ca, glucose, and total and direct bilirubin concentrations, and plasma aspartate aminotransferase and gamma glutamyl transferase activities. Liver biopsies were obtained from a subset of cows on d 0, 7, and 35 for quantification of lipid content. Milk samples were collected on d 3, 7, 14, 21, and 35 postpartum for measurement of somatic cell count and percentages of protein, fat, and solids-not-fat. Data for peak test-day milk yield, services per conception, and days open were obtained from Dairy Herd Improvement Association herd records. Disease occurrence was determined based on herd treatment records. Hypocalcemic cows had significantly higher nonesterified fatty acids on d 0. Hypocalcemic cows also had significantly more lipid in hepatocytes on d 7 and 35 postpartum. However, no statistically significant differences were observed between groups for plasma aspartate aminotransferase and gamma glutamyl transferase activities or total and direct bilirubin concentrations. Milk protein percentage was lower in hypocalcemic cows on d 21 and 35. However other milk quality variables (somatic cell count, milk fat percentage, and solids-not-fat) and milk yield variables (peak test-day milk yield and 305-d mature-equivalent 4% fat-corrected milk yield) did not differ between groups. No differences were observed between groups in the occurrence of clinical mastitis, ketosis, displaced abomasum, dystocia, retained placenta, metritis, or fertility measures (percentage cycling at 50-60 d postpartum, services per conception, or days open). These data suggest that early lactation fatty acid metabolism differs between cows with subclinical hypocalcemia and their normocalcemic counterparts.

Hipocalcemia no deslocamento de abomaso de bovinos: estudo de 39 casos

“…No presente estudo, das 39 vacas com deslocamento de abomaso, 89,7% (36) apresentaram hipocalcemia, conforme relatado por outros autores (Zadnik 2003, El-Attar et al 2007, Mokhber et al 2013. Já foi descrito que mais de 50% das vacas destinadas à produção de leite sofrem de hipocalcemia subclínica no período pré-parto (Horst et al 2003, Reinhardt et al 2011, Chamberlin et al 2013, contudo, os animais deste estudo não tiveram as concentrações de cálcio avaliadas antes do parto ou do DA.…”

“…Vacas com níveis de cálcio abaixo de 8,8mg/dL nas primeiras duas semanas pós-parto, além de apresentarem elevado risco de desenvolverem DA, também apresentaram maior probabilidade de serem descartadas da produção nos primeiros 60 dias de lactação (Seifi et al 2011). Durante o período de transição, 51% das vacas apresentaram hipocalcemia subclínica no momento do parto, porém, não houve diferença entre vacas hipocalcêmicas e normocalcêmicas quanto a ocorrência de DA e outras doenças (Chamberlin et al 2013). A baixa concentração de cálcio plasmático pode afetar as contrações da musculatura lisa e musculatura esquelética dependentes de cálcio (Murray et al 2008) e a redução do tônus abomasal pode resultar no acúmulo de gás, os quais são pré-requisitos para a ocorrência do deslocamento de abomaso (Doll et al 2009).…”

“…Embora a hipocalcemia pareça ser a causa dos deslocamentos no presente estudo, animais com doenças infecciosas e/ou metabólicas apresentam risco significativamente maior de desenvolver DA quando comparados aos controles saudáveis (Mulligan & Doherty 2008, Martinez et al 2012) por reduzirem o consumo de matéria seca. A redução dos níveis de cálcio tem sido associada com a mobilização de lipídeos ao redor do parto (Chamberlin et al 2013) que influencia na mobilidade do trato gastrintestinal (Hansen et al 2003). Esta situação, também provoca a diminuição do consumo de matéria seca e aumento na prevalência de afecções metabólicas.…”

Correlation of Prolactin With Thyroid-Stimulating Hormone and Female Sex Hormones in Infertile Women.

“…In PCOS, too much testosterone is produced and this affects the ability of the eggs to mature within the ovaries (Wu et al, 2012). In turn, this will affect the balance of hormones in the body which affects the ovulation process thus negatively happen difficult pregnancy (Chamberlin et al, 2013).…”

“…Glucose levels were significantly (P < 0.01) higher in both secondary and primary groups than in fertile group. The high blood sugar is linked to polycystic ovarian syndrome, which in turn affects the balance of hormones in the body which affects the ovulation process thus negatively happen difficult pregnancy (Chamberlin et al, 2013). The most important hormones is insulin to keep blood sugar at a normal level.…”