ANN 121: Applied Animal Nutrition-I (2+1)

PHASE 1: EARLY LACTATION - 0 TO 70 DAYS POSTPARTUM

The important features of this phase are,

• Milk production increases rapidly during this period and the peak milk production occurs at 6 to 8 weeks after calving.
• Feed intake is not adequate because the appetite of the animal during the early lactation (up to 8 weeks) is reduced by 2 to 3 kg per day. So there will be shortfall in the intake of energy and protein needed for high levels of milk production.
• The protein will also be diverted for mammogenesis, body growth in case of heifers and young animals, protein may also be diverted for synthesis of lactose (milk sugar) .The animal loses body weight since it mobilizes body tissues for sustaining milk production.
• During this period, the cow could lose as much as 0.7 kg/day.. Because of reduced dry matter or feed intake, dietary energy is the most limiting factor in milk production.

Feeding during this phase: The ration should contain :

• Feed intake is the key factor in maintaining high milk production. Cows should be encouraged to maximize their intake during early lactation. Each additional kg of dry mater consumed can support 2-2.4 kg more milk. The roughages should be of high quality with not more than 40-45 % NDF
• Protein: A protein level of 13-14 % CP can support 20 kg milk in cows and 15 kg in buffaloes. For those cows or buffaloes yielding more milk, the ideal protein content of the ration should be 19 % with 30-35 % RDP. A guideline is to feed 0.5 kg of a 34 to 50% protein concentrates for every 5 kg of milk produced above 20 kg of milk.
• A minimum level of fibre (17 to 18% Crude Fiber or 21 to 22% ADF or 28 percent NDF in the ration) is necessary because excessive levels of concentrates (over 60 percent of the total DM) fed during early lactation can cause acidosis and low milk fat percentage. To avoid any digestive problems (e.g. acidosis, depressed intake), concentrates should be added gradually at a rate of about 0.5 to 0.7 kg/day for the first two weeks. Do not feed more than 2.5-3.5 kg of concentrates per feeding.
• The roughage should not be ground or pelleted but should be chopped to a length of 2 inches or longer.
• The energy content of the ration is increased by feeding of full-fat oilseeds like cottonseed, sunflower seed and soybean . They are also rich in TDN; thus their supplementation in the diet is useful for meeting energy requirements of high yielding animals. Cottonseed is the most popular amongst farmer and it also helps in increasing milk fat.
• The energy content of the ration can also be increased by using fats or oil at 4% in the concentrate mixture or 0.5 kg / day

Challenge Feeding

• Feeding of concentrates should be started 2 weeks before calving, if no concentrate is fed during the dry period. This helps in adaptation of the rumen microbes with the grain/concentrate during the ensuing lactation period when nutrient requirement cannot be met, especially in high-yielding (more than 20 kg milk) cows without grain or concentrates.
• Generally, the animals are started with 1.5 to 2.0 kg concentrate mixture (@0.3 to 0.5 % of body weight) on the date 2 weeks before calving, followed by an increment of 0.3 to 0.5 kg daily, so that they will be receiving about 1 kg concentrate mixture per 100 kg body weight at calving. This is also called challenge or lead feeding, as it is the practice of feeding higher levels of concentrate to challenge the cow to reach her maximum milk production potential. .

Other Feeding Strategies for High Producing dairy cattle during early lactation

• Cows usually eat after milking. So fresh feed should always be available since high producing animals may eat up to 12 times in a day
• If concentrates are being fed separately from forages, they should be fed several times a day.
• Feeding frequency: Increased feeding frequency reduces daily variations in rumen pH and thus helps stabilizing the rumen environment. The proper range and consistency of ruminal pH is critical in fiber digestion.
• Feeding sequence: If forage and concentrates are being fed separately, forages should be fed first in the morning followed by a portion of the concentrates.