Different roughage: concentrate ratios in extruded feed, and feeding behavior of growing lambs

Abstract

Animal performance is directly related to the food quality and intake.
Analyzing feeding behavior is an important tool to evaluate diet efficiency.
This study aims to evaluate the intake of dry matter, feeding behavior and
ruminal movement amongst lambs fed with extruded feed in different
roughage (R) : concentrate (C) ratios. An experiment was carried out in the
Experimental Farm Capim Branco, Universidade Federal de Uberlandia,
from December 7, 2016 to March 22, 2017. It involved 30 3-month-old
crossbred lambs (Santa Ines x Dorper) with a mean weight of 20.67 ± 4.57
kg allocated in collective stalls equipped with feeder, water fountain, salt
shaker, and wooden slatted floor. The experiment was conducted in a
randomized complete design with 2 treatments and 15 replicates per
treatment. The treatments consisted of roughage and concentrate extruded
and mixed in the following ratio 30R:70C and 70R:30C. The dry matter
intake (DMI), 24-hour feeding behavior and 5-minute ruminal movement
were evaluated. The findings pointed to reduced DMI in relation to body
weight for 30R:70C at the end of the experiment. Reduced rumination time,
total chewing and ruminal movement were found for both ratios. However,
shorter rumination time and total chewing had been recorded for 30R:70C
at the beginning of the experiment. Extruded feed with 70R:30C increased
rumination and total chewing and, consequently, ruminal movement.