Ingestive behaviour in heifers fed diets with increasing levels of babassu cake

Abstract

ABSTRACT The aim of this study was to assess the effect of increasing levels of babassu cake on the ingestive behaviour of dairy heifers in confinement. Twenty-four heifers with an average initial weight of 190.8 ± 40.8 kg were fed diets containing babassu cake (0, 100, 200, 300 mg kg-1 (dry matter basis) as a substitute for sugar cane, in a completely randomised design with four treatments and six replications. Observations were made every five minutes for 24 hours, assessing rumination, feeding, idle time, sleeping and other activities, in addition to the frequency with which the heifers searched for water, urinated and defecated. The time spent on feeding and rumination decreased by 0.1138% and 0.3106%, respectively, for every 10 g kg-1 substitute, while idle time increased by 0.3368% for every 10 g kg-1 substitute. The time spent sleeping and on other activities was not affected. Longer feeding times were seen whenever feed was offered, with more rumination activity at night. There was no effect on the specific activities (urination, defecation or drinking); however, urination and drinking were affected by the period, and was more frequent during the day. There was a linear increase in intake, and in feed and rumination efficiency for dry matter and neutral detergent fibre, with a reduction in total chewing time. Substituting babassu cake for sugar cane affects both the ingestive behaviour of dairy heifers and the rumination process as it does not stimulate chewing.