Feeding for breeding: A checklist to evaluate your herd
Dairy farmers must be buying grazing supplements based on its energy content, not protein percentage.
The last week has brought mighty weather for the month of March, and it thankfully allowed animals to get out grazing full time and a lot of spring crops to be planted. Most farms are as much as a month ahead of last spring with regard to work and grazing progress.
The farm gate prices for cattle and milk have injected some much-needed optimism into the livestock producers. As the clocks change this weekend, we can hopefully look forward to a more normal late spring and summer ahead.
With spring calving almost complete in dairy herds, it is now important to continue with an appropriate feeding strategy. The feeding of dairy cows at grass has a huge bearing on subsequent herd fertility.
To have a successful breeding season in any herd presenting as many cows as possible for insemination is vital, meaning they must be free of infection and in a positive energy status. When all is said and done, submission rate is the main driver of having calves on the ground next spring.
What performance goals should you set for your herd?
- Maximise grass utilisation;
- Feed cows to their nutritional requirements;
- Realise cows’ genetic potential;
- Improve fertility and cow health;
- Increase milk value;
- Optimise overall herd profitability.
Energy is the most important nutrient required by milking cows and an undersupply has a negative impact on reproduction.
A slow return to cycling post-calving is magnified by significant losses of body condition during early lactation. Differences among cows in the severity of Negative Energy Balance are more closely related to how much energy they consume than with how much milk they produce.
Cows partition their feed in many directions before they contribute energy to reproduction.
The order of energy use by cows:
- Body functions;
- Grow herself (First-calvers);
- Fight disease;
- Produce milk;
- Milk quality;
- Maintain or increase body condition;
- Reproduction.
Cows producing more than 30 litres will be required to consume 18 to 20kg of Dry Matter.
Achieving more than 15kg of Dry Matter from grazed grass should be targeted, and the additional kilos of DM to complement grazing must then come from supplementation indoors. This is usually fed as concentrates in the parlour but also as a forage-based buffer feed including maize, beet, whole crop, moist feeds, straw, blends and straights.
Starch and sugar drive the rumen and microbial protein production. They also determine the level of blood Sugar produced in the Rumen. Too Little will result in Ketosis & Low yields or poor milk quality.
Grass beyond the first rotation is high in sugars and is the main driver of milk production and milk protein. Too much starch and sugars without effective fibre will induce Acidosis in the herd.
Fibre promotes Rumen Stability and encourages Dry Matter Intake. Optimum Early Lactation NDF is above 34%. Digestion of fibre also drives butter fat production.
Oils and fats are essential for energy density but too much fed to cows at grass will coat fibre and depress butter fats.
A cow’s milk protein production or percentage is an indicator of their energy status.
The protein percentage in a milk collection is an indication of the herd's energy status seven to 10 days ago, and not the previous day or two.
Protein in a cow’s diet drives intake and nutrient utilisation. Rumen Degradable Protein is used in the rumen and converted to high-quality microbial protein. Bypasses Protein skips the rumen and feeds the animal directly in the intestines. Higher yielders require more Bypass Protein.
Once cows have sufficient grass available to them, minimal protein supplementation is required. First rotation grazed grass will have 20-23% protein, while in the height of the growing season has a protein content of 22-30% depending on soil fertility, sward age and nitrogen usage.
Dairy farmers must be buying grazing supplements based on its energy content, not protein percentage.
When achieving higher yields, you MUST get mineral levels right. Request a mineral pack in your concentrates aimed at improving fertility performance.
Dry Matter Intake (DMI) for milkers in early lactation must be measured to relate it back to requirements based on animal performance; it impacts on yield, Health, Fertility, Milk Quality and Feed Costs.
Excess Body Condition Score loss (>0.5) post calving means, depressed milk yield, lower fertility, poor milk quality and an increased risk of metabolic disorders such as Ketosis and fatty liver.
Rumen Stability has a role to play in fertility as it affects DMI and energy utilisation. Low butter fats are an indication of poor fibre digestion, and this can be caused by SARA (Sub Acute Ruminal Acidosis)
Laminitis due to Acidosis results in sole ulcers & white line disease, which in turn cause poor feed intakes. Poor roadways can further exacerbate this laminitis. Optimum Rumen pH is 6 to 6.5. Encouraging cows to chew their cud with the provision of fibre will result in a more stable rumen.
- Milk Yield - Don’t just look at average yields. Monitor individual fresh calvers -especially heifers. Watch for cows/heifers with erratic yields from day to day in early lactation.
- Milk Quality - A drop in Milk protein indicates that cows are losing body condition. Drops in Butter Fat indicate poor fibre digestion.
- Milk Urea Levels, if your coop provides this information, it is very useful.
- Dung Consistency
- Cud chewing activity - (Cud Balls, etc)
- Incidence of Metabolic Disorders
- Rumen Fill
- Milkers drink a lot of water- it must be clean!
