Comparison of pasture-based feeding systems and a total mixed ration feeding system on dairy cow milk production

摘要

Diet is the one of the main determinants of milk and milk solids (MS) yield. A well-balanced total mixed ration (TMR) offers the greatest potential to maximise milk production per cow. The ability to alter the diet to suit the cows' requirements (age,stage of lactation, etc.) gives TMR diets an advantage over grass-based systems in terms of attaining maximum output per cow. Previous research has shown the potential benefits of incorporating white clover (Trifolium repens L.) into perennial ryegrass(Lolium perenne L.) swards. The objective of this experiment was to examine the effect of feeding system on dairy cow milk and MS yield. The experiment consisted of three treatments - TMR (grass silage, maize silage, concentrate), grazed grass-only receiving 250 kg nitrogen (N) ha~(-1) (GO) and grazed grass-white dover receiving 250 kg N ha~(-1) (GC) and was conducted over two full lactations. Total concentrate fed per lactation was 245 kg cow~(-1) for GO and GC, and 2,593 kg cow~(-1) for TMR. There wasno effect of grazing treatment on cumulative herbage production (13,896 kg DM ha~(-1)). The TMR treatment had the highest cumulative milk and MS yield and GO had the lowest. Incorporating white clover into the grass sward significantly increased (P < 0.05) milk production (+ 588 kg milk and + 41 kg MS cow~(-1)) compared to GO.