Technical note: optimizing sample size for broiler chicken and pig intestinal histomorphometry and prediction...

Area of Science:

• Animal Science
• Veterinary Anatomy
• Histomorphometry

Background:

• Intestinal villi exhibit natural variation, complicating reliable histomorphometry.
• Standardized methods for determining the necessary sample size for histomorphometry in broiler chickens and pigs are lacking.
• Current assessments often overlook villus perimeter and area due to measurement complexity.

Purpose of the Study:

• To establish the minimum number of villi required to minimize intra-sample variation for histomorphometric indices.
• To assess the predictability of complex metrics (villus perimeter and area) from linear measurements.
• To provide a foundation for more accurate and efficient intestinal morphology assessment in monogastric animals.

Main Methods:

• Analysis of 1,283 intestinal morphology data points from broiler chickens and 1,368 from pigs.
• Utilized SAS procedures (NLIN, CORR, REG) for broken-line analysis, correlation, and prediction equations.
• Correlated linear measurements with villus perimeter and area to develop predictive models.

Main Results:

• A minimum of 11 villi per sample for broiler chickens and 10 for pigs are recommended to minimize intra-sample variation.
• Villus height showed high correlation with villus perimeter (r=0.95 jejunum, r=0.87 ileum) and villus area (r=0.77 jejunum, r=0.63 ileum).
• Prediction equations for villus area using linear measurements (height, base width, mid width) demonstrated high accuracy (R²=0.92 jejunum, R²=0.86 ileum).

Conclusions:

• This study defines the minimum villi counts for reliable histomorphometric assessment in broiler chickens and pigs.
• Established strong relationships between linear villi measurements and more complex indices like perimeter and area.
• Developed predictive equations to facilitate efficient estimation of villus perimeter and area, reducing measurement burden.