# Association between body condition score and abdominal fat assessed by ultrasound in Jersey cows

## TL;DR

This study finds that body condition scores in cows only weakly predict abdominal fat levels, suggesting health risks may exist even in cows with average scores.

## Contribution

The study introduces ultrasound-based regression models to assess abdominal fat in Jersey cows and its association with body condition scores.

## Key findings

- BCS has low-to-moderate correlation with abdominal fat depots, with higher correlation for omental and total abdominal fat.
- Cows with higher BCS scores had significantly more fat in abdominal regions, indicating potential metabolic risks.
- Variability within BCS scores suggests fat accumulation patterns differ from subcutaneous fat.

## Abstract

Body condition score (BCS) is a subjective tool and the deposition of subcutaneous fat differs from the deposition of abdominal fat.

The aim of this study was to evaluate by multivariate regression models and ultrasonography the amount of fat accumulated in different areas of the abdominal cavity in Jersey non‐pregnant non‐lactating cows and its association with their BCS.

From a commercial farm, 21 non‐pregnant non‐lactating Jersey cows were selected at random. Cows were placed in a headlock line, and BCS was evaluated (scale 1–5 with a 0.25 unit increment) by the same assessor. Ultrasonographic evaluation was performed using a Sonosite machine in duplicate, considering key anatomical points of the body to predict total abdominal fat (AT), retroperitoneal fat (RT), omental fat (OT) and mesenteric fat (MT). A regression analysis for each abdominal fat depot and the BCS was run using SAS.

Models from the lowest to the largest r
2 are reported. The r
2 for the models were MT r
2 = 0.023; RT r
2 = 0.1047; OT r
2 = 0.323 and AT r
2 = 0.369. Correlation between BCS and abdominal fat depots was positive, lower for mesenteric and retroperitoneal fat, but higher for omental and total abdominal fat. Cows were divided on the basis of the median of BCS distribution to high (≥3.5) and low (≤3.25). Those with high BCS had significantly larger amounts of fat in different anatomical areas of abdominal cavity than cows with low BCS.

BCS has a low‐to‐moderate association with abdominal fat depots, but a high variability exists within each BCS punctuation, which supports the notion that fat accumulation patterns and metabolic turnover between abdominal and subcutaneous fat differ from each other.

Abdominal fat deposits (retroperitoneal, omental and mesenteric) in non‐lactating non‐pregnant Jersey cows were estimated by regression mixed models using ultrasonography assessment of external anatomical areas (subcutaneous fat), and retroperitoneal layers were moderately associated with body condition score. These findings suggest that cows with fair body condition scores (3.25–3.5) still can have large amounts of abdominal fat deposits, implying that they can be at higher risk of developing metabolic diseases such as fatty liver, ketosis and displacement of the abomasum.