Cows have to calve in order to produce milk. Lactation cycle is defined as the period between one calving and the next.The lactation cycle is generally split into four phases, namely - early, mid, late (each lasting approximately 120 days), and dry period (which normally last as long as 65 days). In an ideal world, cows calve every 12 months.
Getting cows off to a good start and successful navigation through the early lactation phase is crucial to the health and performance of the cow. This will have very significant impact on the reproductive performance and cow profitability. First, let us define peak milk. From DHIA, peak milk is defined as the highest level of milk a cow produces within the first 90 days of lactation or days in milk (DIM). In a normal lactation curve, milk increases to the peak level, which on average is around 56 DIM, then it gradually decreases till the end of the lactation phase. The rate of decrease is known as persistency. Historically, peak milk has been used as a benchmark to determine the success of dry period and early lactation nutrition and management. This is because there is a correlation between peak milk production and how well the cow responded to feeding management during dry period, calving and early lactation phase.
As a general rule of thumb, each pound of additional peak milk forecasts 200 to 250 pounds more milk during the entire lactation cycle. It is therefore vital to understand how nutrition and management during the transition period affects the cow's performance. Figure 1 shows the interactions of nutrition and metabolic and other health disorders in early lactation that impact peak milk.
Here's 10 suggestions to improve early lactation performance and increase peak milk yield.
1. Ensure that cows are off to a good start by having a successful dry period. Research over the past decade showed the importance of dry period nutrition and management on postpartum health and performance. In order to improve the dairy cattle performance, it is important to evaluate the dry cow program. The dry period is a time necessary for the cow to rest and rebuild. Here are a few tips from MFA during the dry period:
a) Cows should be aiming for a minimum body condition score (BCS) of 3.0 at dry-off and that should be maintained throughout the entire dry period.
b) Cows should not be milked 45-60 days prior to calving.
c) Dry cows should be segregated from the milking herd.
d) Dry cow treat every quarter on every cow for mastitis prevention.
2. Reduce the risk of subclinical milk fever during the first week of lactation. Dairy cows with subclinical fever, also known as subclinical hypocalcemia do not show clinical symptoms but have low blood concentration of calcium usually within 24 hours after calving. Usually, the only way to know whether the cow is experiencing subclinical milk fever is to analyse blood for the concentration of calcium within 1 - 2 days after calving. Low blood calcium (< 8.0 mg/dL) is correlated with ketosis, elevated somatic cell count, delayed uterine involution, metritis, depressed feed intake, and reduced milk yield.
3. Optimising the feed intake immediately after calving. It is important to provide the dairy cow 10 - 15 gallons of warm water with drinkable drench, access to fresh TMR, 5 - 10 lb of alfalfa or grass hay and to maintain the cleanliness and freshness at the feed bunk.
4. Optimising cow comfort. Ensure that the stocking density is around 80-85% of capacity in the fresh cow group. Providing each cow 36 inches of feedbunk space as well as one free stall per cow or 100 square feet of resting space. It is also important to prevent any isolation situations where the cows are separated from normal herd activities. Finally, use shade, fans and sprinklers to reduce heat stress.
5. Preventing ruminal acidosis. Ruminal acidosis is increasingly recognised as a significant disorder in ruminants. Acidosis is a pathological condition associated with the accumulation of acid or depletion of alkaline reserves in blood and body tissues, and characterised by increased hydrogen ion concentrations (Blood and Studdert 1988). Ruminal acidosis refers to a series of conditions that reflect a decrease in pH in the rumen of cattle. The primary cause of acidosis is feeding a high level of rapidly digestible carbohydrate, for example, barley or other cereals. The key to preventing ruminal acidosis is to reduce the amount of readily fermentable carbohydrate consumed at each meal. This would require good diet formulation (for example, a proper balance of fibre and non-fibre carbohydrates) as well as excellent feed bunk management.
6. Identifying cows with a history of metabolic or health problems. This is important as cows with a history of health problems are likely to be repeat offenders. Extra attention is needed in order to prevent the cows from falling sick again. A good example would be moving the cows carrying twins or first calf heifers into the dry group as early as possible as research shows a correlation with a 7 - 10 day earlier calving date.
7. Evaluate body condition score (BCS). A cow's BCS provides a reasonably accurate picture of its energy reserve. BCS targets can be used at key stages of lactation in order to optimise dairy production. New industry suggest a target BCS of 3.0 at calving vs the previous recommendation which was 3.5. The main reason for this is to avoid cows that are in the "4+" category. A lower BCS at calving allows some room of margin (0.5 - 1.0 units of BCS) to avoid any overweight cows that have a higher risk for ketosis, fatty liver, and are more often difficult to breed back.
8. Position the feed additives. The fresh cow group has the greatest potential to offer a high return on investment (ROI) for feed additives. Research shows that this applies to the following additives: ionophores (increased glucose availability), choline (improves liver health and function), protected amino acids (meet amino acid requirements without over-feeding protein), supplemental protected fat (increases energy intake), and yeast culture (stabilises rumen fermentation).
9. Avoiding anti-nutritional factors. Examples of this would include feeds containing mold, wild yeast, and poorly fermented feeds. In generally, mold counts more than 100,000 colonies/gram are likely to decrease feed intake and affect diet digestibility.
10. Feed the right amount of antioxidants. Antioxidants (vitamin E and selenium) are able to help reduce the impact of oxidative stress (for example, excessive fat mobilisation, poor air quality, disease as well as injury). Reducing oxidative stress will decrease the efficiency of immune system function.