Organic fertilizers (composted manure, green manure) releases nutrients slowly and therefore should be applied as a basal fertilizer (incorporated when making mounds or ridges). During growing period, the plants form dense foliage with rapid vine growth

Body Weight Loss during Early Lactation

During this period milk yield increases more rapidly than dry matter intake (peak production). The demand for energy is therefore higher than the amount of energy consumed. Thus the cow mobilizes body reserves and losses weight (negative energy balance). The genetic potential is usually expressed during this period and the cow will be under pressure to produce a large amount of milk. However, the cow at this stage has a limited capacity to ingest the required amount of feed. Thus it is normal for the cow to mobilize body fat during early lactation. The ability of the dairy cow to mobilize body fats is contributed to by its genetic potential (i.e. cows with higher genetic potential will mobilize body fats for a longer period of time than cows with a lower genetic potential). During this period, the cow could lose as much as 0.7 kg/day.

Dry Matter Intake during Early Lactation

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. Feed intake by the dairy cow is influenced by many factors including level of production, forage quantity and quality, feed digestibility, feed processing, feeding frequency, consistency of ration ingredients etc. The following equation can be used to calculate dry matter intake DMI (% body weight) = 4.048 – 0.00387 x body weight (kg) + 0.0584 x 4% FCM (kg). to calculate 4% FCM, Use the following equation: 4% FCM = 0.4 x actual milk yield in kg/day) + 15 x milk fat in kg/day Generally, depending on the quality of the diet, a mature cow will usually consume 2-4% of her live weight (LW). Consumption of low-quality feeds may be 2-3% of LW, while green pasture may be 3-4%. The factors that influence the amount a cow will eat include her size, body condition, stage and level of production. Other factors include the quality and availability of forage, amount and type of supplements and her environment. With diets high in fibre, the rate and level of digestibility will have a large effect on intake. The faster the feed is digested, the faster it passes through the digestive tract and the more it allows for an increase in consumption. Poor-quality roughage such as straw and maize stover, on the other hand, will have a slower rate of digestion than a high-quality feed such as Lucerne. With straw, a cow weighing 500 kg l/weight would have to eat about 40 kg according to National Research Council (NRC) to meet her energy and protein requirements. This she can’t do. We can predict that she would eat only 15 kg. The cow will appear full, but she won’t be meeting her nutrient requirements. It’s a scenario seen quite often in cattle on corn stalks or other poor quality roughage.

Importance of dry matter intake

Cows have a minimum requirement for protein and energy to maintain normal body functions – known as their ‘maintenance’ requirement – which is approximately 2% of their body weight. Maximising dry matter intake provides more nutrients to rumen microbes, which in turn provides more nutrients to the cow for milk production and composition, growth, reproduction and body condition. Every day, an efficient milking cow needs a dry matter intake equivalent to at least 3% of their body weight.

Maintaining good rumination is essential in early lactation. Thus it is important to feed at least 40% of the ration dry matter as forage. About half of the forage should have a particle length of at least 2.6 cm to effectively stimulate chewing. High quality forage should be fed during this period to improve dry matter intake. Neutral detergent fiber and acid detergent fiber levels should be set at 28 and 19%, respectively to maximize intake.

Ration Change in Early lactation

Major ration changes should be avoided. 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.

Protein in Early Lactation

Protein is very critical during early lactation as the amount of body protein that can be mobilized is very limited compared with body fat. Thus in early lactation, a dietary protein content of 17-19% is recommended. About 35-30% of dietary protein should be ruminally undegraded protein while 30% should be soluble protein. 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.

Factors to consider in formulating feed for High producing Dairy Cows:

• Cows usually eat after milking. Thus fresh feed should always be available in the feed bunk immediately to encourage feed consumption. High producing cows will eat up to 12 meals per day, each averages 23 minutes.
• The best TMR dry matter is between 50-75%. Wetter or drier rations will limit intake.
• If concentrates are being fed separately from forages, they should be fed several times a day.
• Feeds should be available to cows at least 20 hours per day. • Hay should be fed before grain and / or protein supplement in the morning.
• Protein supplements should be fed with energy sources and/or feed the energy source before the protein feed
• Forage should be checked to make sure it contains enough long fiber. • If two forages are being fed, it is preferable to mix them rather than feed them separately.
• If intakes are below normal begin by checking the non-fiber carbohydrate level, forage particle size and water quality.

Feeding separately

Many dairy producers still feed forage and concentrates separately. The concentrate component is usually fed only once or twice daily. This results in non-uniform supply of nutrients and inefficiencies of nutrient utilization can occur. Providing smaller and more frequent meals of concentrates may help stabilizing the rumen environment. Several management strategies can be used: - Avoid large variation in forage quality - Feed forages frequently and push up feed frequently. This practice helps keep feed fresh and encourage cows to eat smaller meals more often. - Feed some in the morning before cows have access to concentrates. - Do not feed more than 2.5-3.5 kg of grain per feeding. Limiting the amount of grain fed at one time lowers the risk of creating acidotic conditions in the rumen due to rapid breakdown of carbohydrates in the rumen. - Watch Particle size of grain. Finely ground grains breakdown rapidly in the rumen and can lead to acidosis problems.

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

Feeding frequency affects rumen function and cow performance. If forage and concentrates are being fed separately, forages should be fed first in the morning followed by a portion of the grain mix. Feeding protein (e.g. soybean meal) and carbohydrate (e.g. corn) supplements together results in higher milk fat percentage than feeding them separately. This is because rumen microbes require both energy and protein to grow.

Mixing accuracy

A TMR or forage combination must be adequately mixed in order to provide a proper nutrient balance. When mixing small quantities of specific ingredients (e.g. minerals and vitamins), it may more appropriate to include them in a pre-mix where larger quantities can be added to the ration. Chemical analysis and estimation of the TMR ingredients must be accurate. Chemical analysis of TMR and calculated/estimated analysis of individual feed ingredients will vary, but they should be within a given range of variations. A comparison between actual and calculated dry matter of the TMR will give an indication of how ingredients are mixing. Example of formulated TMR for early lactation At this stage, the dairy cow has low appetite and feeding intake lags behind milk production, hence the cow loses weight (negative energy balance). Excessive weight loss should be avoided through formulation of appropriate rations. The roughage: concentrate ratio of the diet should be 40:60, at 19% Protein content, and fed preferably three equal proportions of 13 kg each as in Table 1 below. Table 1 An example of a total mixed ration (TMR) formulation for early lactation based a standard cow whose live weight (LW) = 500kg, milk yield (MY) = 25l/day, butterfat =3.6% at 1st calving. >

Always provide the cow with as much of good quality forage as possible e.g. young, dark green Napier. With good quality forage alone, it is possible to produce 7–10 liters of milk per day. Where protein-rich forages (legumes) are available e.g. Lucerne, Desmodium, Calliandra and Lucaena shrubs, mix with the grass at a ratio of 1-part legume to 3 parts grass. Three kg of the legume crop can replace one kg commercial dairy meal.

Maintaining Peak Milk Production The main target during this period is to maintain peak milk productions as long as possible. The cow should therefore be fed a ration that will maintain peak production as long as possible. For every 2 kg of expected milk production, large-breed cows should eat at least one kg of dry matter. For each extra kg of milk at peak production, the average cow will produce 3000 – 6000 kg more milk for the entire lactation. Thus the key strategy during mid-lactation is to maximize dry matter intake.

During this period the cow should be fed high-quality forage (minimum 40 to 45% of the ration dry matter) and the level of effective fiber should be maintained at a level similar to that of early lactation. Concentrate Feeding Concentrates should not exceed 2.3% of body weight and sources of non-forage fibers such as cereal grains, distillers’ grains and cereal bran can replace part of the starch in the ration to maintain a healthy rumen environment. Protein Feeding Protein requirements during mid-lactation are lower than in early lactation.

Therefore, rations for dairy cows in mid-lactation should contain 15-17% crude protein. During this period the cow should be bred to initiate a new pregnancy (60-70 days after calving). Example of formulated TMR for Mid lactation period This stage is critical in the determination of total lactation yield. Feed intake is optimal; with sufficient nutrient supply, the cow should be able to maintain weight gain, as well as peak milk production. The roughage proportion of the diet should be raised to 50:50, as in Table 2 below.

Table 2: An example of a TMR formulation for mid-lactation based a standard cow whose live weight (LW) =500kg, milk yield (MY) = 20 l/day, butterfat =3.6% at 1st calving

Potential problems during this period include a rapid drop, or decline, in milk production, low fat and protein test, silent heat (no observed heat), and ketosis. A cow in mid-lactation should produce about five liters of milk on roughage only and concentrate should then be given according to the milk yield. For every 1 kg of concentrate, there should be an increase of 1–1.5 liters of milk above the 5 kg from the basal feed.

During this phase, especially as lactation approaches an end, more of the increase in body weight is due to the increased size of the growing fetus. Sources of protein and energy are not very critical during this period. Cheap rations can be formulated with non-protein nitrogen and a source of readily fermentable carbohydrates such as molasses. Nutrient requirements guidelines for lactating dairy cows are shown in Table 4 and the classification of feeds based on their protein and energy content is shown in Table 5.

Example of formulated TMR for dairy cows in late lactation: 201–305 days postpartum (declining milk production)

Protein level in the ration should be maintained at 13%, comprising minimum concentrate and high quality roughage. The cow should have a body condition score (BCS) of above 2.8, preferable 3 (BCS is a measure of body fat deposits on a scale of 1–5 where 1 is very thin, and 5 is very obese).

Table 3 : An example of a TMR formulation for late lactation based a standard cow whose live weight (LW) =500kg, milk yield (MY) = 18 l/day, butterfat =3.6% at 1st calving.

During the dry period, the cow requires nutrients to maintain its body, support the unborn calf and repair milk-producing cells of the udder in preparation for the coming lactation. During this dry period phase, the cow should not gain an excessive amount of weight and the amount of concentrate given should be according to the condition of the animal and the quality of forage in the feed. In the last two weeks of pregnancy the cow’s appetite goes down (reduced feed intake due to large volume occupied by the calf), hence the amount of concentrate should be gradually increased. To satisfy these requirements, the feeding regime should be divided into two stages as follows: • Provide 3–5 kg of concentrate to adapt rumen environment to fermentable carbohydrates and stimulate normal rumen function. • Increase protein in the ration to between 14 and 15% on DM basis. The amount of concentrate provided should be increased gradually so that by the time of calving, the cow will be getting at least 4 kg per day. The increase in concentrate feeding just before calving is referred to as steaming up. This dry-cow feeding program is critical to adjusting cows, and due in-calf heifers, to the lactation ration to prevent metabolic disorders. Introduction of concentrate is necessary to begin changing the rumen from all-forage digestion to a mixed forage and concentrate environment.

Table 4. Nutrient guidelines for lactating dairy cows in Early, Mid and Late Lactation Period. 

Table 5. Classification of supplements and basal forages according to their energy and protein contents.