# Longitudinal hematological dynamics during pregnancy and lactation in Thuringian Forest dairy goats under organic farming conditions

## TL;DR

This study tracks blood cell changes in Thuringian Forest dairy goats during pregnancy and lactation under organic farming, providing new reference values for this breed.

## Contribution

First longitudinal hematological study of Thuringian Forest goats under organic conditions, offering breed-specific reference values.

## Key findings

- Red blood cell and hemoglobin levels dropped during late pregnancy and recovered during lactation.
- Platelet and white blood cell counts showed stage-specific fluctuations linked to parturition and lactation.
- Parity and milk yield influenced certain hematological parameters, but litter size did not.

## Abstract

Pregnancy and lactation place significant physiological demands on dairy goats, affecting red blood cell (RBC) indices, white blood cell (WBC) profiles, and platelet traits. Despite the diagnostic value of hematology (HA), there are no longitudinal, breed-specific reference values for Thuringian Forest goats. This study aimed to describe changes over time in differential blood counts and platelet indices in clinically healthy does kept under BIOLAND-certified organic management.

A longitudinal study was conducted over one year using 25 clinically healthy Thuringian Forest does. Monthly blood samples were collected from 3 months prepartum through 12 months postpartum, resulting in 295 samples. Hematological analyses included RBC count, hematocrit (HCT), hemoglobin (HGB), mean corpuscular volume (MCV), mean corpuscular HGB (MCH), mean corpuscular HGB concentration (MCHC), RBC distribution width (RDW), and HGB distribution width (HDW). Platelet parameters, platelet count (PLT), mean platelet volume (MPV), and platelet distribution width (PDW), and differential WBC counts (neutrophils, lymphocytes, monocytes, eosinophils, and basophils) were measured using a validated automated analyzer. Repeated-measures analysis of variance evaluated the effects of reproductive stage, parity, milk yield, milk composition, and litter size.

Significant stage-dependent hematological changes were observed. RBC, HGB, and HCT decreased during late gestation and reached their lowest levels before birth, then increased gradually during lactation. MCV and MCH remained stable. PLT increased around parturition, MPV declined before birth and rose after, and PDW decreased steadily from late gestation through lactation. Neutrophils and total WBC counts increased toward parturition, while lymphocytes and monocytes rose during lactation. Eosinophils peaked at the start of lactation, and basophils declined after birth. Parity and milk yield significantly influenced certain RBC, platelet, and leukocyte parameters, whereas litter size showed no significant effect.

Thuringian Forest goats show unique hematological changes during pregnancy and lactation, reflecting metabolic, hormonal, and immune adjustments related to reproduction and milk production. These breed-specific, stage-specific reference values improve clinical interpretation and diagnosis in dairy goat management. To our knowledge, this is the first longitudinal hematological study of this breed in organic farming conditions.