Researchers studied how special diets fed to pregnant Jersey cows affected the health and growth of their newborn calves. They tested two different diet types with and without an added vitamin called nicotinic acid. The study found that what the mother cow ate before giving birth influenced important nutrients in her colostrum (first milk), which affected how well the calves absorbed nutrients and grew. Interestingly, adding too much of the vitamin supplement to a certain diet type actually made calves grow slightly slower and use their food less efficiently. These findings suggest that farmers need to be careful about which supplements they combine with special pre-birth diets.

The Quick Take

  • What they studied: Whether special pre-birth diets and vitamin supplements given to pregnant cows would improve their newborn calves’ health, nutrition, and growth rates.
  • Who participated: 40 adult Jersey cows (cows that had given birth before) that were fed special diets 4 weeks before giving birth. Their newborn calves were then monitored for 6 weeks after birth.
  • Key finding: Calves from mothers fed certain diet combinations received more protective nutrients in colostrum, but calves from mothers given the vitamin supplement with a specific diet type grew slightly slower and didn’t use their food as efficiently as other calves.
  • What it means for you: If you raise dairy cows, the combination of pre-birth diet and supplements matters for calf health. Adding extra vitamin supplements to certain diets may not help and could actually reduce calf growth. This suggests farmers should carefully choose which supplements to use with which diets.

The Research Details

Researchers divided 40 pregnant Jersey cows into four groups based on two factors: the type of pre-birth diet they received and whether they got a vitamin supplement. The cows were assigned to their groups 4 weeks before giving birth. After the calves were born, researchers collected the first milk (colostrum) and tested it for important nutrients. The newborn calves were then fed controlled amounts of milk and calf food for 6 weeks, and researchers measured how much they ate, how fast they grew, and various health markers in their blood.

This type of study is called a “factorial design,” which means researchers tested two things at the same time to see if they worked together or separately. The cows were also grouped by their expected birth dates to make sure the groups were as similar as possible before the study started.

The researchers carefully controlled what the calves ate and drank, measuring everything from the amount of milk they consumed to the nutrients in their blood. This level of control helps show whether differences between groups were caused by the mother’s diet or by other factors.

Understanding how a mother’s pre-birth nutrition affects her newborn’s health is important because the first milk (colostrum) contains antibodies and nutrients that protect the calf and help it grow. By testing different diet combinations, researchers can help farmers make better choices about what to feed pregnant cows. This could improve calf survival rates and growth, which matters for dairy farm success.

This study was well-designed with random assignment of cows to groups and careful measurement of many health markers. The researchers controlled the calves’ diet precisely, which reduces confusion from other factors. However, the study only included Jersey cows, so results may not apply to other cattle breeds. The sample size of 40 cows is moderate—larger studies might show clearer patterns. The study was published in a respected dairy science journal, which suggests it met high scientific standards.

What the Results Show

Calves born to mothers fed the lower diet type (-80 DCAD) received less of an important protective protein called IgG in their first milk compared to calves from mothers fed the higher diet type (-40 DCAD). This is important because IgG helps protect newborns from infections.

When mothers received the vitamin supplement (nicotinic acid), their colostrum contained more of a protective substance called lactoferrin, and their calves showed better absorption of nutrients in their intestines. This suggests the vitamin helped with nutrient absorption.

However, calves from mothers given the vitamin supplement combined with the lower diet type grew slightly slower than other calves. These calves also used their food less efficiently, meaning they needed to eat more to gain the same amount of weight. This was an unexpected negative effect that researchers did not anticipate.

Most other measurements—including how much milk calves drank, their final weight, bone growth, blood sugar levels, and overall health markers—showed no significant differences between groups.

Calves from mothers fed the vitamin supplement showed better nutrient absorption in their intestines, as measured by a special test. Interestingly, calves from mothers fed the lower diet type with the vitamin supplement had the lowest levels of ketones (a substance related to energy metabolism) in their blood, which could indicate better metabolic health. However, this benefit did not translate to better growth or feed efficiency.

This is one of the first studies to examine how these specific pre-birth diet combinations affect calf performance. Previous research showed that pre-birth cow nutrition affects colostrum quality, but this study provides new information about how vitamin supplements interact with special diets. The finding that combining the vitamin with a certain diet type reduces calf growth is surprising and suggests that more research is needed to understand why this happens.

The study only included Jersey cows, so results may not apply to other cattle breeds like Holsteins. The sample size of 40 cows is relatively small, which means some real effects might have been missed. The study only followed calves for 6 weeks, so we don’t know if the slower growth in some groups continued or caught up later. The researchers didn’t measure all possible nutrients in the colostrum, so there may be other important differences they didn’t detect. Finally, this was done on research farms with carefully controlled conditions, so results might differ on commercial farms with different management practices.

The Bottom Line

Based on this research, farmers should be cautious about adding nicotinic acid supplements to lower-level pre-birth diets for Jersey cows, as this combination appears to reduce calf growth and feed efficiency. If using nicotinic acid supplements, using a lower dose may be better than a higher dose. For cows on higher-level pre-birth diets, the vitamin supplement appears safer. However, these recommendations are based on one study with a small number of cows, so farmers should discuss these findings with their veterinarian before making changes. Confidence level: Moderate—more research is needed to confirm these findings.

Dairy farmers who raise Jersey cows and use special pre-birth nutrition programs should pay attention to these findings. Veterinarians who advise dairy farms on nutrition would find this helpful. This research is less relevant to farmers raising other cattle breeds or those not using special pre-birth diets. Consumers of dairy products may care indirectly, as better calf health can improve overall farm sustainability.

Effects on calf growth would likely appear within the first 2-4 weeks of life, as shown in this study. However, determining whether slower early growth affects long-term health and productivity would require following calves for several months or years. Farmers should monitor calf growth rates weekly to see if their diet changes are working.

Want to Apply This Research?

  • Track weekly calf weight gain (average daily gain) and feed efficiency (pounds of feed eaten per pound of weight gained) for calves born to mothers on different pre-birth diet programs. Compare these metrics between groups to see if certain diet combinations affect calf performance.
  • If using pre-birth diet programs for pregnant cows, users could adjust nicotinic acid supplementation levels based on their diet type and monitor resulting calf growth rates. They could also track colostrum quality (IgG levels if testing is available) to see if supplements are having the intended effect.
  • Establish a baseline of calf growth and feed efficiency with current feeding practices. After any changes to pre-birth diets or supplements, track these metrics weekly for at least 6 weeks to determine if changes are beneficial. Keep records by dam diet group to identify which combinations work best for your herd.

This research applies specifically to Jersey cows and may not apply to other cattle breeds. These findings are based on one study with a moderate sample size conducted under controlled research conditions. Before making changes to your cow feeding program, consult with a veterinarian or dairy nutritionist who understands your specific farm conditions. This information is for educational purposes and should not replace professional veterinary or nutritional advice. Individual cows and farms may respond differently to diet changes than shown in this research.