Mathematical approaches to detect low concentrations in progesterone profiles

Abstract

There is a general need for higher objectivity and accuracy in describing the physiological fertility performance of dairy cows. To develop the alternative meaningful starting points for the selection of genetically superior dairy cows, this study focused on the detection of low progesterone concentrations, which are indicative of estrus events. Three mathematical approaches were used: one based on the exponentially weighted moving average control chart, and two threshold methods, which were developed in-house. Data were collected from one data set that included 97 insemination data of first-lactating Holstein dairy cows, and a second set that included 160 inseminations of primiparous and multiparous Holstein dairy cows. On the basis of these 2 data sets, and using a threshold of 1.2 ng progesterone/ml skimmed milk, the sensitivity of the 3 models was high and ranged between 100% and 93.13%, with an error rate between 4% and 22.17%. The specificity varied between 97.92% and 99.93%. The average concentration levels of true-positive-detected progesterone measures were low and ranged between 0.18 and 0.28 ng progesterone/ml skimmed milk (first data set) and 0.21 to 0.26 ng progesterone/ml skimmed milk (second data set). False-positive-detected low progesterone concentrations during estrus events were closely related to progesterone values around the 1.2 ng progesterone/ml skimmed milk threshold and the detecting rules of the control chart. Thus, we suggest that a threshold of 0.8 ng progesterone/ml skimmed milk is indicative for luteal activity in defatted foremilk. By means of the three methods used, the detection of low progesterone concentrations was possible and it can be assumed that this is a good starting point for further studies (such as interval calculation) in this area.

Effect of genetic merit for energy balance on luteal activity and subsequent reproductive performance in primiparous Holstein-Friesian cows

“…First luteal activity was determined by the first postpartum progesterone value above the threshold value of 0.8 ng of progesterone/ mL of skim milk, preceded by low progesterone. The threshold (0.8 ng/mL) for identifying the presence of luteal activity was chosen based on a preliminary study (von Leesen et al, 2013).…”

A novel system for on-farm fertility monitoring based on milk progesterone

“…For milk P4 to be useful as an indicator for fertility events, the raw P4 measurements should be converted into specific information, or even better, actions to be taken by the herdsmen on farm. In this context, it is shown that both the variability of the measurements and the variability between estrous cycles should be taken into account (Friggens and Chagunda, 2005;Friggens et al, 2008;von Leesen et al, 2013). In general, this means that the monitoring algorithm should meet following requirements: (1) it should be robust against outliers and different levels of measurement errors, which might be dependent on the measurement and calibration technique (Adriaens et al, 2017); (2) it should be able to discriminate between luteal and follicular concentrations to indicate actions such as insemination, embryonic loss, and possible cyst in an individualized way; and (3) it should be automated and implementable on farm.…”

A novel system for online fertility monitoring based on milk progesterone

“…Nevertheless, for milk P4 to be useful as an indicator for fertility events, the raw P4 measurements should be converted into specific information, or even better, ‘actions’ for the farmer. In this context, it is shown that both the variability of the measurements and the variability between estrous cycles should be taken into account (Friggens and Chagunda, 2005; Friggens et al, 2008; von Leesen et al, 2013). In general, this means that the monitoring algorithm should meet following requirements: (1) it should be robust against outliers and different levels of measurement errors; (2) it should be able to discriminate between luteal and follicular concentrations to indicate actions such as ‘inseminate’, ‘embryonic loss’, ‘cyst possible’ in an individualized way and (3) it should be automated and implementable on-line.…”