The impact of excellent colostrum management practices for dairy calves can’t be underestimated. Research in dairy calves has shown that that different levels of cow colostrum intake had short term effects on immunity, growth, metabolism and endocrine status of calves^1,2,3. Others have shown that good colostrum management for dairy calves also improves future lactational performance and longevity of dairy cows^4,5,6,7. Calves need sufficient amounts of good quality cow colostrum for several reasons.

Good quality bovine colostrum contains sufficient levels of immunoglobulins
Bovine colostrum contains IgG, IgA and IgM. Because IgG is the most prevalent immunoglobulin in bovine colostrum and is easy to measure, the bovine colostrum IgG concentration is often measured, rather than the total bovine colostrum immunoglobulin concentration. It is generally accepted that good quality cow colostrum has an IgG concentration ≥50 mg/ mL ¹¹. A practical method to measure colostrum quality of dairy cows is to use a colostrometer or Brix refractometer to check quality. Good quality cow colostrum should have a Brix reading of at least 22%, which correspondents roughly with 50 g/L of IgG or higher. With the IgG level in colostrum being easy to measure, it has become an important parameter to measure the quality of cow colostrum. The benefits of good quality cow colostrum go beyond feeding the neonatal calf sufficient amounts of IgG.

Calves need immunoglobulins from cow colostrum for passive immunity
Cow colostrum provides dairy calves with maternal antibodies, including IgG, but also IGA and IgM^{8,9,10,11,12,13,14}. Newborn dairy calves do no have immunological memory as they have not been exposed to pathogens. Next to this, the immune response of newborn calves is slow. Maternal antibodies from cow colostrum help protect dairy calves against pathogens during the critical early weeks of life.

During the first few hours of their lives, calves need energy from cow colostrum
Newborn dairy calves need energy from cow colostrum. At birth, body fat as a percentage of total bodyweight is less than 3%¹⁵ (see Figure 1). Part of the body fat of dairy calves is so-called brown fat, rich in mitochondria. Brown fat is crucial for survival of newborn dairy calves. Brown fat in dairy calves acts as a special heat-producing tissue by inducing non-shivering thermogenesis. Brown fat reserves are activated by cold conditions to keep neonatal calves warm. Brown fat is located around vital organs like the heart and kidneys. It is fueled by cow colostrum to kickstart this vital energy production. Depending on climate conditions, maintaining core body temperature can be challenging for a neonatal dairy calf. The energy level of cow colostrum is around 5.4 kJ ME/L, which is twice the amount of energy in milk. Calves can survive for up to 15 hours without being fed colostrum, but their fat reserves will be depleted rapidly if they do not consume colostrum during the first few hours following birth. Subsequently, their core body temperature will go down, and they will become lethargic and weak. Hypothermic dairy calves will lose their suckling reflex and stop drinking.

Bovine colostrum contains essential growth factors for dairy calves
Bovine colostrum contains several growth factors for dairy calves that are essential for gut integrity, growth and for development of the immune system. Insulin-like growth factors 1 and 2 (IGF-1 and 2) and transforming growth factors alpha and beta (TGF-α and TGF β) are the two most important growth factors for dairy calves. Bovine colostrum is the only source of these growth factors for newborn calves^9,10 (see Figure 2).

A calf should consume approximately 10-12% of its birth weight in colostrum at the first feeding. A newborn dairy calf therefore needs at least 4 litres of high-quality cow colostrum within the first 12 hours of life, with the first feeding ideally occurring within the first 1-2 hours after birth. This can be broken down into an initial 3-4 litre cow colostrum feeding as soon as possible, followed by a second 2-liter feeding six hours later, and an additional 1-2 litres at 12 hours after birth if possible. To support this schedule, a dairy cow should produce at least 6 litres of colostrum with a Brix value of 22% or greater.

In many herds, cows do not produce sufficient volumes of cow colostrum to support the recommended colostrum feeding schedule for dairy calves11,12,13,14:

• In a study11 including 1,731 Holstein lactations, 62.6% of cows produced less than 6 kg of cow colostrum at first milking. Only 27.7% of cows produced at least 6 kg of colostrum with a Brix value of 22%.
• In a University of New Hampshire study12, about 12% of cows did not produce any colostrum, and nearly 25% produced too little to fully feed their calves.
• More recent research confirmed that 73% of primiparous and 61% of multiparous dairy cows produced inadequate volumes of colostrum.

Thus, somewhere between 25% to 60% of dairy cows may produce insufficient volumes of good quality cow colostrum by recommended standards.

In-dept research has shown that feeding dairy cows Selko IntelliBond hydroxy trace minerals instead of sulphates results in an improvement of health^26,27 and performance^{28,29,30,31,32}. Feeding Selko IntelliBond will increase milk production of a dairy herd by 1-1.5 kg of ECM per day^31,32. In a study³³ carried out by Professor Santos at the University of Florida, the impact of feeding Selko IntelliBond during the close-up period of dairy cows on their colostrum production was tested.

UFL trial on cow colostrum yield, material and methods
A total of 141 Holstein cows were randomly assigned to two groups. One group of 30 heifers and 40 multiparous cows was fed sulphates, the other group of 31 heifers and 40 multiparous cows was fed full replacement Selko IntelliBond hydroxy trace minerals. The trial period started at 21 days before calving. Supplemental Zn, Cu, and Mn were incorporated at 30, 7, and 22 mg/kg of diet DM. Cow colostrum quality and cow colostrum yield at the first milking after calving was compared between the two groups.

UFL trial on cow colostrum yield, results
Replacing sulphate sources of Zn, Cu, and Mn in the dairy ration with Selko IntelliBond trace mineral sources did not affect pre-partum dry matter intake of dairy cows but tended to increase yield of cow colostrum by 1.0 kg (see Figure 3).

Differences in colostrum solids %, somatic cell score of colostrum, Brix value of cow colostrum or immunoglobulin G concentration were not observed (see Table 1). Net energy in colostrum and total amount of IgG produced were increased in both the heifers and the multiparous cows.

Fytera Lacteco is a patented PhytoComplex solution for cattle. It is a natural feed additive. Trials^33,34,35,36 have shown that feeding Fytera Lacteco to cattle during the last 30 days before calving resulted in an increase of colostrum immunoglobulin levels of cow colostrum and a significant improvement of maternal antibody transfer to calves (see Figure 4). All calves from cows fed Fytera Lacteco reached the threshold of 24 g/L that is considered to be the threshold for successful passive immunity transfer to beef calves.

Colostrum management of dairy cattle has a huge impact on dairy calves. Next to the short term effects on immunity, growth, metabolism and endocrine status of calves^1,2,3, colostrum management also has a big impact on future lactational performance and longevity of dairy cows^4,6,6,7.To enable excellent colostrum management, a dairy herd needs to produce sufficient volumes of good quality cow colostrum. To fully feed their calves, cows need to produce at least 6 litres of good quality colostrum immediately after calving. Between 25 and 60% of dairy cows produce insufficient volumes of colostrum, often in combination with poor colostrum quality11,12,13,14. A programme to improve colostrum yield can increase cow colostrum volume by 1–3 litres per cow, often without diluting IgG concentration.

Trace mineral source can have a significant impact on such a programme. Replacing the mineral package fully by Selko IntelliBond trace minerals can increase colostrum volume of the first milking by 1.0 litre without reducing colostrum IgG levels.

Trials have shown that feeding Fytera Lacteco during the last 30 days before calving can increase bovine colostrum immunoglobulin levels and further improve passive immunity transfer to calves.