Changes

'''Post-calving nutrition''': The "transitional period" for a dairy cow is defined as the period four weeks pre-calving, to four weeks-post calving. Often, farmers will provide a transition diet before calving, but introduce the lactating cow diet immediately afterwards. In the first four weeks after calving, the rumen cannot properly handle diets that are dense in energy: the ration fed in this period ideally should contain 10% more energy than the transition diet fed before calving. the rationale to this is that dry matter intake will be increased, and will then remain at high levels throughout lactation. Animals do not achieve their peak milk yield in the first few weeks post-calving, and so optimising dry matter intake rather than maximising the energy consumed should not cause problems.

'''Post-calving nutrition''': The "transitional period" for a dairy cow is defined as the period four weeks pre-calving, to four weeks-post calving. Often, farmers will provide a transition diet before calving, but introduce the lactating cow diet immediately afterwards. In the first four weeks after calving, the rumen cannot properly handle diets that are dense in energy: the ration fed in this period ideally should contain 10% more energy than the transition diet fed before calving. the rationale to this is that dry matter intake will be increased, and will then remain at high levels throughout lactation. Animals do not achieve their peak milk yield in the first few weeks post-calving, and so optimising dry matter intake rather than maximising the energy consumed should not cause problems.

'''Sorting of long fibre''':

'''Sorting of long fibre''': When the fibre in a total mixed ration is longer than 10cm, cows tend to sift through the diet and consume smaller, more palatable particles and the pieces of forage too small to sort out. This alters the concentrate-to-forage dry matter ratio which is actually eaten by the cow (even if it is correct in the diet presented to the animals), which increases the risk of developing subacute rumenal acidosis. There is the additional problem in this situation that animals lower down the hierarchy, such as heifers, will eat the remainder of the sorted diet and thus not receive tbe energy they require. Both groups of animals are then likely to be in negative energy balance, but for different reasons.

If the fibre in a TMR is longer than 10 cm, cows are likely

to sort the food and only consume small particles and

short fibres, leaving the long fibre alone (Lammers and

others 1996). Cows which sort food in this manner will

be at risk of developing SARA. If feed barrier space is

restricted, dominant cows may sort the food and thus

develop SARA. Subordinate animals, such as heifers and

lame animals, will then consume the sorted diet and

so obtain a diet of lower energy but greater fibre content

than is intended. The net result is that both groups are

at risk of negative energy balance, although for different

reasons. Ensuring that fibre length in a TMR is adequate

oper-atoi- a1njid appr-oprialtc safectV guLardl-CIs illust be eni1ployed.

'''Slug feeding of concentrates in the milking parlour''':

'''Slug feeding of concentrates in the milking parlour''':