Buffer Feeding: Balancing cow nutritional requirments

Buffer feeding is a tool used on many dairy farms in early spring, with this being particularly evident on farms where grass availability is limited. Cows of higher genetic merit have a high nutrient requirement in the immediate period after calving, and in general, this cannot be bridged by spring grass and parlour feeding alone. Adverse weather conditions, high stocking rates and varying grass digestibility levels are all important factors that impact on the level of additional feeding required.

Transitioning cows to a predominantly grass-based diet is the main aim after calving. However, grass availability and digestibility, ground conditions and stocking rates will all dictate the level of grass available for inclusion in this regard. Early spring grass, contains both high protein and digestibility levels and has a feed value that is closely correlated to cow dry matter intake (DMI). Teagasc reports indicate, that a rise of 1% in grass digestibility will increase (DMI) by 0.3-0.4kg (DM) per cow and milk yield by 0.25 litres. Significant falls in grass (DMD) are not common in early spring, but correct management practices undertaken during this period, will condition swards for improved grazing in later rotations.

Where grass availability is limited, a well-constructed buffer feed should be used to supplement the feed deficit. As a rule of thumb, a cow will require 5.5-6.0 UFL for maintenance with an additional 0.43 UFL per kg of milk produced – solids dependent. With the cow’s (DMI) at its minimum after calving, the energy deficit in the first 3 weeks of lactation is quite large, this however, is well improved by week 6, with intakes fully restored 10-12 weeks post calving. Confining this negative energy balance (NEB) to the first 6 weeks of lactation is therefore extremely important, thus, preventing any negative effects on future milk yield potential and cow fertility.

Buffer feeding to deliver energy, protein and fibre within this time period should therefore be considered to offset this imbalance. A good buffer feed can result in positive responses to milk yield and composition while also aiding to improve cow body condition score (BCS). Maize silage, sugar beet pulp, citrus pulp, soya bean meal and straw are all high quality ingredients that can be offered. Including molasses to the list will also have many positive effects, stimulating milk protein production, increasing rumen digestion rates, preventing total mixed ration (TMR) sorting and improving palatability can all be attributed to its inclusion. However, it is important to note, that buffer feeding is there to supplement grass intake and not replace it.

 

Detailed below are sample buffer feeds and are formulated to accompany restricted grass and parlour feeding

Diet Specification Diet A Diet B
Spring grass 79% (DMD) 3.5 kg(DM) 4.0 kg(DM)
Dairy nut 14% crude protein 1.7 kg(DM)
Dairy nut 16% crude protein 1.7 kg(DM)
Buffer Feed for diet wagon
Soya Hulls 2.6 kg(DM) 1.8 kg(DM)
Sugar cane molasses 0.4 kg(DM) 0.6 kg(DM)
Maize distillers grains 1.6 kg(DM)
Maize silage 25% starch 1.5 kg(DM)
Rolled Barley 0.4 kg(DM) 0.9 kg(DM)
Barley straw 1.0 kg(DM) 0.9 kg(DM)
Energy requirements 0.88-0.95 UFL 0.88-0.95 UFL
Energy supplied 1.01 UFL 0.97 UFL
Protein requirements 15-17% CP 15-17% CP
Protein supplied 17.7 CP 15.2

Energy values are based on predicted energy requirement for a 600kg dairy cow in early lactation.