Bioscience of ruminant intake evolution: feeding time models

Akbar Nikkhah

doi:10.4236/abb.2011.24039

Abstract

Ruminants have evolved to ruminate mostly over- night and graze during day. As such, rumen fermentation, post-rumen nutrient assimilation and peripheral metabolism have 24-h patterns. These evolutionary rhythms in eating behavior and metabolism have led to annual, seasonal, and circadian rhythms in ruminant endocrinology. Such natural patterns have encountered dramatic shifts in productivity in the last few decades. For optimum nutrient use and animal health, securing a synchrony between external cues and ruminant internal conditions is essential. Most recent discoveriess suggest alterations in post-prandial intake patterns of non-grazing lactating cows by altered feeding time. Eating rate and feed intake within the first 3 h after feeding have been increased by evening instead of morning feeding. As a result, postprandial patterns in rumen fermentation and peripheral blood levels of metabolites and hormones have been altered. These findings and insights establish a chronological nature for intake regulation in modern ruminants. Feeding time is a major external cue that affects eating extent, rate and efficiency in ruminants. Time of feeding requires special consideration and more mechanistic evaluations for animals and humans.

Highlights

Feeding timing has most recently been found to alter ruminant chronobiology [1,2,3,4]
For maximum nutrient efficiency and health, nutrient supply to reticulorumen, splanchnic and peripheral tissues should be synchronized with endogenous rhythms in ruminant endocrinology and metabolism [5]
The primary objective is to delineate an evolutionary basis of ruminant nutrition through describing the most recent chronological discoveries of feeding time effects on diurnal rhythms in intake, rumen fermentation and metabolism of high-producing ruminants

Summary

INTRODUCTION

Feeding timing has most recently been found to alter ruminant chronobiology [1,2,3,4]. For maximum nutrient efficiency and health, nutrient supply to reticulorumen, splanchnic and peripheral tissues should be synchronized with endogenous rhythms in ruminant endocrinology and metabolism [5]. Knowledge on how feeding and eating times affect diurnal and postprandial intake patterns will enable predicting diurnal patterns in rumen, post-rumen and peripheral nutrient assimilation. These will suggest optimal, suboptimal, and unfavorable times of nutrient supply. The primary objective is to delineate an evolutionary basis of ruminant nutrition through describing the most recent chronological discoveries of feeding time effects on diurnal rhythms in intake, rumen fermentation and metabolism of high-producing ruminants. A new integrative evolutionary theory will be constructed

SCIENCE OF FEED INTAKE EVOLUTION

ANTICIPATION OF FEED PROVISION

GENEARAL INTUITIONS AND DISCUSSION

Findings

IMPLICATIONS