SNF content of Milk and Profitability
Protein on SNF content of milk
- Reduction in the level of Protein in milk may result from underfeeding with concentrates (Protein), intake of poor quality forage, failure to balance the ration for protein and minerals. Shifting rumen fermentation towards propionic acid increase milk protein and decrease fat content in milk.
- However feeding excessive dietary protein does not increase milk protein, as most of the excess protein nitrogen is excreted.
- Diet protein type also could affect milk protein levels. Use of non-protein nitrogen (NPN) compounds, like urea, as protein substitutes will reduce protein in milk by 0.1 to 0.3% if the NPN is a main provider of crude protein equivalent.
- The NPN levels in milk will be increased by excessive protein or NPN intake, heavy feeding of ensiled forages, ensiled grains, immature pasture and lack of rumen undegradable protein in the diet.
- Rations higher than recommended level of soluble protein may lower milk protein by 0.1 to 0.2 points.
- Milk protein content may be decreased by 0.1 to 0.3% in high-fat diets. This may occur due to reduced blood glucose levels.
- When the milk contains enough protein it will produce persistent Foam during (Hand) milking as the protein lower the surface tension of milk strongly.
Milk sugar on SNF content of milk
Minerals on SNF content of milk
- Minerals in milk form part of SNF. Phosphates, Citrates and Chlorides of Calcium, Magnesium, Sodium ,Potassium and traces of Iron, Iodine, Copper are the mineral components in milk.
- It is reported that the ash, calcium, phosphorus and magnesium contents of milk differs in different breeds of dairy cattle. The average ash content in milk varied from 0.74 percent for Holsteins to 0.83 percent for Jerseys. The highest calcium and phosphorus contents in milk were reported for Jerseys.
- Calcium, phosphorus, potassium, and chloride concentrations are reported to be the lowest at peak milk yield and then gradually increase as lactation progresses.
- Milk inorganic phosphorus levels were shown to be higher in first lactation cows than in multiparous cows, and milk phosphate levels are lowest during the summer.
- Mastitis increases the percentages of Sodium and Chloride in milk and decreases the percentage of potassium.
- Normal dietary regimes have little influence on the mineral composition of milk, especially the macro mineral constituents.
- Decreases in milk chloride percentage is possible when cows are fed chloride-deficient rations during early lactation. Milk potassium percentage declined along with chloride levels, reflecting altered mineral metabolism in chloride deficient cows.
- Milk Potassium level is not altered due to heat stress. However it is reported that cows offered shade had higher milk potassium percentages than cows given no shade. Percentages of sodium in milk were lowered significantly by feeding cows sodium bicarbonate and only slightly by feeding salt.
- It is reported that iodine, manganese, molybdenum, selenium, zinc, and cobalt concentrations in milk could be altered by dietary means.
- As per the Prevention of Food Adulteration Act the Cow milk and Buffalo should contain 8.5% and 9.0% SNF respectively.
When will the milk contain low SNF ?
Changes that occur in SNF are primarily due to changes in the protein and occasionally the lactose content of milk.
One of the major non-genetic factors that have been reported to affect SNF in milk is nutrition
Changes that occur in SNF are primarily due to changes in the protein and occasionally the lactose content of milk
It is reported that the major reason for decrease in SNF particularly in High yielding cows is Energy deficiency. When extra energy is fed to high producing cows, SNF increase by about 0.2 percentage units
Forage quality and quantity also affects milk SNF. Good quality hay tends to increase SNF, but poor-quality hay may reduce both intake and SNF.
Another major reason for decline in SNF in general and particularly the protein and lactose content in milk is associated with sub- clinical and clinical mastitis.
Different feeding patterns as existing in different areas influence SNF in milk
Anaemia is another reason for decline in SNF. So heavy infestation with hemoparasites particularly in cows grazed in forest areas may cause decline in SNF.
SNF content of milk decreases with increasing age of the cow.
Within any given lactation, SNF content is relatively high in the first month, drops to a low in second month and then rises as lactation progresses.
Underfeeding of cows in late pregnancy enhance reduction of SNF content resulting from low-energy intakes during the first 6 week of lactation
Feeding more protein than indicated by feeding standards (above National Research Council recommendations) appears to have no effect on protein content ( One of the constituents of SNF ) of milk.
However, feeding extra energy to high producing cows may increase the SNF by about 0.2 percentage units.
Addition of whole cottonseed or added fat to dairy cattle rations may reduce the SNF content of milk.
Forage quality and quantity may affect milk SNF. Increasing the intake of roughage such as grass and sorghum silage usually reduces SNF as high intake of roughage will naturally reduce the Energy consumption in Total Feed consumed.
Increasing energy or dry matter intake usually restores the SNF to normal. Good quality hay tends to increase SNF, but poor quality hay may reduce both intake and SNF.
Feeding of high-fiber low-energy rations reduce the SNF content
Pelleting the concentrate and hay or grinding the roughage may reduce fat percent of milk but has little to no effect on SNF content.
Buffers are sometimes used in rations to help maintain milk composition. Their effect is primarily on the fat content of milk with little to no effect on SNF content.
Disease and climatic conditions (temperature, humidity) that causes elevated body temperature of the lactating cow, affect milk yield and composition. A decline in SNF, protein, and lactose content is associated with subclinical and clinical mastitis.
Cows that conceive generally show a steeper rise in SNF content than cows that remain open through their lactation because pregnancy causes a decline in milk yield, therefore percent of SNF increases.
In general, summer SNF values are lower than fall or winter SNF values. Periods of drought, high temperatures and high humidity tend to result in lower SNF values.
Underfeeding protein will reduce both milk yield and SNF . Feeding protein over and above the National Research Council recommendations will not increase the SNF or protein content of milk.
But underfeeding total digestible nutrients (TDN) or net energy will reduce milk yield, SNF, and protein.
- SNF content of milk is highest at parturition, and reaches a minimum at the time of maximum milk yield, after which it increases to the end of lactation.
- Some research shows that underfeeding protein during the last three weeks before calving can depress milk protein and Vis-à-vis SNF.
Addition of abundant whole cottonseed or added fat to dairy cattle rations may reduce the SNF content of milk.
How to ameliorate low SNF in Milk :
- Screen the cows with low SNF for sub- clinical Mastitis
- Assess the Energy concentration of ration. Feed the ration that contain recommended concentration of energy at different level of Milk production
- Feed enough good quality and fresh forages containing cereal and legumes harvested at recommended interval
- Do not feed wilted, highly matured and spoiled forages
- Ensure only recommended level of forage intake .Do not over feed with forages as it will reduce the availability of energy
- Ensure recommended level of protein that contain proper level of Rumen Degradable and Non- degradable protein
- If Non -protein nitrogenous substances are fed ensure sufficient level of natural protein and Sulphur to facilitate microbial protein synthesis
- Do not underfeed the cows particularly during peak milk production. Ensure sufficient Dry matter intake.
- Include the mineral mixture at recommended level in the ration
- Do not graze for long hours under Sun. Tie the cows in shade.
About the Author
.png)
.png)
Comments
Post a Comment