Protein nutrition strategy for increasing weaning weight of calves

Christy
Jun 23, 2021
4 min read

The key indicator pursued by calf breeding is weaning weight. A 20% difference in weaning weight (85kg vs 105kg) will delay the initial mating time of the replacement heifers by one month, and the feeding cost of each replacement heifers will increase at least 600 yuan;
The impact of weaning weight on milk production in adulthood is much greater than that of birth weight. For every 100g decrease in daily weight gain before weaning, the milk production in the first 3 lactation periods will decrease at least 2,280kg, and the milk income of each adult dairy cattle will decrease by more than 9,000 yuan.

Increasing the weaning weight of calves can significantly improve the breeding benefits of dairy cattle, and ensuring the health of the intestinal tract (reducing diarrhea) is the key point to increase the weaning weight of calves.

What are the main factors that lead to unhealthy intestines of calves?

How to design feed nutrition to enhance the intestinal health of calves?

What are high-quality protein source for calf feed pellets should be?

Hope the content below can be helpful.☆☆☆☆☆

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The main factors leading to unhealthy intestines of calves

1.1 Physiological factors (internal factors)

A. The digestive tract is under development

Transition from abomasum digestion to rumen digestion: Newborn calves are similar to monogastric animals and mainly rely on the abomasum and small intestine for the digestion and absorption of nutrients. With the intake of pellet feed, the rumen begins to develop rapidly after about 5 weeks of age.
Weak intestinal barrier function: Calves absorb the functional substances in milk (IgG, mRNA, peptides, etc.), and the small intestine is “open” (small intestinal mucus layer is thinner than the cecum and colon, Michael, 2016), after 6 weeks of age The intestinal barrier function is gradually developed and perfected.

Figure 1 The thickness of the mucus layer (blue) of the calf digestive tract

B. Low activity of digestive enzyme

Low activity of protease:

Low activity of lipase + low bile secretion:

C. Weak immunity

From birth to 2 months of age, calves have experienced a process of gradual weakening of passive immunity and gradual enhancement of active immunity. 2-7 weeks of age is the period of high incidence of calf diseases.

Figure 2 Changes in immunity of calves at 0-12 weeks of age

1.2 Stress factors (external factors)

A. Management stress

Calves are weaned at 10 months of age under natural conditions, and early weaning technique is used to maximize pasture benefits in actual breeding conditions (see Table 1). The food intake of calves changes from liquid milk to solid feed. The source, form and nutrient composition of the feed cause great stress to calves, manifesting as anorexia, growth retardation, diarrhea, etc., which can lead to death in severe cases.

Table 1 Early weaning techniques for calves

B. Nutrition (diet) stress

For the early weaning technique, calves will be fed with pellets feed one week after birth. The three deficiencies of pellets feed bring great stress to the intestine of calves:

(1) Poor digestibility of feed protein (see Table 2 for the digestibility of different protein sources for calves): Commercial calf pellets feed use a large amount of non-dairy-derived protein, which can easily cause nutritional diarrhea.

Table 2 Apparent digestibility of common protein materials in calves

(2) High antigen protein content: damage the digestive tract, reduce immunity, and reduce the digestion and absorption of nutrients (see Table 3: The effect of antigen protein on calf weight gain and diarrhea)

Table 3 The influence of different antigen protein content in calf pellets feed on weight gain and diarrhea

(3) High vegetable fat content: easy to cause diarrhea and reduce growth rate (see Table 4 the effect of vegetable fat on weight gain and diarrhea)

Table 4 Effects of different vegetable fat content in calf pellets feed on weight gain and diarrhea

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Feed nutrition strategies to enhance calf intestinal health

2.1 Nutritional level

A. Crude protein: 20-27% (generally 22%, due to the low digestibility of plant protein and imbalance of amino acids, the CP level will be appropriately increased when using plant protein)

B. Fat: Control the crude fat in calf feed to about 3%

2.2 Nutritional structure

A. Protein structure: protein + peptide + amino acids (the duodenum of calves can efficiently absorb peptides, which may be the main way for calves to absorb protein--Dirienzo, 1990; Webb, 1993)

B. Fat structure: calves have poor digestibility of non-dairy fats, so the fat content in calf feeds should be controlled, especially vegetable fats (NRC, 2001)

2.3 Nutritional source

A. Protein source: nutritional value (protein * digestibility in the body * deposition rate); health value (low antigens such as glycinin and β-conglycinin, and ingredients that enhance intestinal function such as small peptides); stable ( quality, procurement, price)

B. Fat source: non-dairy-derived fat as few as possible

③

MYPro is a high-quality protein source for calf

MYPro is a high-quality protein source obtained through enzymatic hydrolysis of combined plant protein materials through an enzymatic process and it is featured with high digestibility, low anti-nutritional factors, and clear functional value, which can improve intestinal health and increase calf weaning of calves.

3.1 Risk-free, stable quality