Grass-Birdsfoot Trefoil Mixtures to Increase Pasture-Based Dairy Performance.

Abstract

With an increasing number of organic pasture-based dairies, reduced dry matter intake from grazing often becomes one of the major limiting factors in milk production and nutrient rich pastures may result in lower pregnancy rates.

It is hypothesized that grass-birdsfoot trefoil mixtures will act synergistically in pastures to provide increased herbage, energy, and low levels of condensed tannins, resulting in improved dairy heifer dry matter intake, growth, and fertility and performance on pasture settings.

In 2016, pre-puberty Jersey dairy heifers were rotationally-grazed on eight different pasture treatments. Each pasture was divided into five 0.20 acre paddocks, and heifers were rotated to a new paddock every seven days with forage sampling taking place before and after each move. Animal weights were measured every 35 days. The pasture treatments were meadow brome (MB), orchard grass (OG), perennial ryegrass (PR), and tall fescue (TF) in monoculture, and the aforementioned grasses in binary mixtures with birdsfoot trefoil (BFT). Average daily gains (ADG) were in order from highest to lowest as follows: MB+BFT, TF+BFT (1.6 lb/day) ≥ PR+BFT, OG+BFT, OG (1.5 lb/day) ≥ PR (1.3 lb/day) ≥ MB (1.2 lb/day) ≥ TF (1.0 lb/day).

Preliminary results indicate that the grass-birdsfoot trefoil mixtures have greater dry matter intake and ADG than the grass monocultures. This was especially true for tall fescue, which has the least livestock preference and nutritive energy, compared to the other grasses. This study will be repeated in 2017 to validate the results.