Changes

'''Overestimation of forage dry matter content''': The dry matter of forage must be estimated in order to calculate how much of ir should be included in the diet. The cut of for healthy rumen function is a concentrate-to-forage dry matter ration of 60:40; if this is exceeded then SARA can develop. Therefore, if the dry matter content of forage is overestimated, a relatively smaller quantity of the fodder will be included in the diet, tilting the ratio to potentially detrimental proportions.

'''Overestimation of forage dry matter content''': The dry matter of forage must be estimated in order to calculate how much of ir should be included in the diet. The cut of for healthy rumen function is a concentrate-to-forage dry matter ration of 60:40; if this is exceeded then SARA can develop. Therefore, if the dry matter content of forage is overestimated, a relatively smaller quantity of the fodder will be included in the diet, tilting the ratio to potentially detrimental proportions.

'''High proportions of starches and sugars in the diet''': Dairy farmers often include large amounts of rapidly fermentable carbohydrates in the diet in order to meet energy requirements and maintain body condition score and milk production. These carbohydrates can take the form of grain, concentrates or maize silage. However, rapid fermentation leads to over-production of volatile fatty acids, and thus subacute rumenal acidosis. This actually makes digestion less effective, so the cattle do not benefit as much as the should do from the extra sources of metabolisable energy. A vicious cycle can ensue of poorer performance and supplementary feeding of concentrates.

'''High proportions of starches and sugars in the diet''': Dairy farmers often include large amounts of rapidly fermentable carbohydrates in the diet in order to meet energy requirements to maintain body condition score and milk production. These carbohydrates can take the form of concentrates or maize silage. However, rapid fermentation leads to over-production of volatile fatty acids, and thus subacute rumenal acidosis. This actually makes digestion less effective, so the cattle do not benefit as much as they should do from the increased supply of metabolisable energy. A vicious cycle can ensue of poor performance and supplementary feeding of concentrates.

'''Slug-feeding of concentrates in the milking parlour''': If relatively large quantities of concentrates are supplied over a short period of time, rapid fermentation occurs and the rumen pH fluctuates more widely than if a less carbohydrate-rich diet is consumed more steadily. The pH also remains low for longer. ubstitution effects may also take place as the consumption of more concentrate can lower the subsequent forage intake. These factors combined can lead to the development of SARA.  

'''Slug-feeding of concentrates in the milking parlour''': If relatively large quantities of concentrates are supplied over a short period of time, rapid fermentation occurs and the rumen pH fluctuates more widely than if a less carbohydrate-rich diet is consumed more steadily. The pH also remains low for longer. Substitution effects may also take place as the consumption of more concentrate can reduce the subsequent intake of forage. These factors combined can lead to the development of SARA.  

'''Food deprivation and irregular feeding''': Food should always be available to a dairy cow, and it is recommended that slight over-feeding, with 5-10% of the ration left over at the time of the next feed, can be implemented to achieve this. If a cow goes without food for any period of time, the population of microbes in the rumen can be disrupted and the animal is likely to gorge when next presented with the ration. Both of these factors encourage subacute rumenal acidosis.

'''Food deprivation''': Food should always be available to a dairy cow, and it is recommended that slight over-feeding, with 5-10% of the ration left over at the time of the next feed, can be implemented to achieve this. If a cow goes without food for any period of time, the population of microbes in the rumen can be disrupted and the animal is likely to gorge when next presented with the ration. Both of these factors encourage subacute rumenal acidosis.

'''Inadequate dry cow diet''': the diet fed immediately before calving (the transitional cow diet) should be formulated to stimulate the development of rumen papillae and the acquisition of an appropriate colony of microflora. This should ensure that cattle can adequately ferment the post-calving diet and effectively absorb the nutrients it provides. Therefore, if the dry cow diet does not encourage these processes, volatile fatty acids can accumulate in the rumen when the lactation diet is introduced, leading to SARA. This is a particularly common problem, since dry cows are "non-milkers" and so tend to be the forgotten members of a herd.

'''Inadequate dry cow diet''': the diet fed immediately before calving (the transitional cow diet) should be formulated to stimulate the development of rumen papillae and the acquisition of an appropriate colony of microflora. This should ensure that cattle can adequately ferment the post-calving diet and effectively absorb the nutrients it provides. Therefore, if the dry cow diet does not encourage these processes, volatile fatty acids can accumulate in the rumen when the lactation diet is introduced, leading to SARA. This is a particularly common problem, since dry cows are "non-milkers" and so tend to be the forgotten members of a herd.

'''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 energy consumption should not cause problems.

'''Poor cow comfort''': The optimum daily routine of a dairy cow includes 12-14 hours lying down and 10 hours of rumination. If cow comfort is poor, the time spent performing these activities will be reduced, and less saliva will be produced to buffer the pH of the rumen.

'''Poor cow comfort''': The optimum daily routine of a dairy cow includes 12-14 hours lying down and 10 hours of rumination. If cow comfort is poor, the time spent performing these activities will be reduced, and less saliva will be produced to buffer the pH of the rumen.