Test accuracy of metabolic indicators in predicting decreased fertility in dairy cows

Abstract

Negative energy balance is a known risk factor for decreased fertility in dairy cows. This study evaluated the accuracy of plasma concentrations of nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), and insulin-like growth factor 1 (IGF-1)-factors related to negative energy balance-in predicting decreased fertility. One plasma sample per cow was collected from 480 cows in 12 herds during the period from d 4 to 21 in milk and analyzed for NEFA, BHBA, and IGF-1. For each cow, data on breed, parity, calving date, gynecological examinations, and insemination dates were obtained. Milk samples from 241 cows in 7 of the participating herds were analyzed for progesterone concentration to define the first day of luteal activity. The diagnostic sensitivity (Se) and specificity (Sp) at different cut-off concentrations of NEFA, BHBA, or IGF-1 were calculated and related to individual cow fertility status, measured as anestrus (ANEST), delayed first artificial insemination (DFAI), or delayed conception. Positive and negative predictive values (PV+; PV-) were calculated considering different levels of (within-herd) prevalence. Strata (i.e., subgroup)-specific Se and Sp and associations between test results and fertility parameters were investigated using logistic regression. The NEFA and BHBA tests for ANEST and DFAI had the highest combined Se and Sp and were thus evaluated further. Cut-off values with Sp around 80% were used in this step to provide a reasonable number of test-positive cows, representing a practical situation. This corresponded to a cut-off value for the NEFA test of 400 µEq/L (Se 0.27-0.45) and for the BHBA test of 1.8mM (Se 0.15-0.30) across all cows included in the study. The estimated Sp was generally higher than the original 80%, but the corresponding Se was further decreased when the test was used in heifers compared with older cows. The true prevalence of ANEST in the study population was 27%, which gave a PV+ of 0.36 to 0.45 and a PV- of 0.76 to 0.79. With 35% true prevalence of DFAI, PV+ was 0.29 to 0.38 and PV- was 0.64 to 0.66. Thus, overall test performance was low when metabolic indicators measured as single values in early lactation were used to predict fertility in dairy cows, but accuracy was influenced by cow-level factors such as parity. The prevalence of the target condition (in this case, decreased fertility) also influences test usefulness and should be considered when planning test systems and interpreting test results.

Nutrient requirements in Hanwoo cows with artificial insemination: effects on blood metabolites and embryo recovery rate

“…It is well known that non-esterified fatty acids (NEFA) is an indicator of cow NEB. Post parturition cows have been shown to have higher NEFA concentrations, produce less milk [ 17 ], and have lower fertility [ 18 ]. Elevated NEFA concentrations have negative effects on cow granulosa cell viability and cell growth [ 19 ], and induce apoptosis in human granulosa cells [ 20 ].…”

Association between metabolic parameters and embryo production in superovulated dairy cattle

“…High NEFA concentrations negatively affect energy metabolism and the endocrine system, resulting in lower fertility rates (Bionaz et al., 2020; Lomander et al., 2012; Moussa et al., 2015). In addition, Snider et al.…”

Microbiome and metabolome analyses of milk and feces from dairy cows with healthy, subclinical, and clinical mastitis

“…Administering propylene glycol to perinatal dairy cows represents an effective strategy to mitigate negative energy imbalances (Zhang et al, 2020). Furthermore, Lomander et al revealed that early lactation-stage supplementation with propylene glycol led to heightened milk yield without subsequent metabolic compromise (Lomander et al, 2012). Hu et al documented that cold exposure impacted the excretion levels of 4-hydroxyphenylacetate, a compound implicated in gut microbiome metabolism (Hu et al, 2021b).…”