By Emily Fread
Good dairy managers know that excellent quality colostrum is essential to start a calf off right. While some factors are out of our control, it is crucial to understand that some management factors can affect the colostrum's quality and quantity.
Cow-level Factors
When looking at colostrum quality, there are some cow-level traits that are out of our control. Age of the cow can affect colostrum: first lactation heifers produce less colostrum at a lower quality than older animals (Westhoff et al., 2023). This makes sense; we know that older animals produce more milk than heifers, so it follows suit that they also produce better colostrum. Maintaining an older herd can often lead to higher profitability on the dairy and higher quality colostrum could also be a benefit. The cost to raise a heifer is typically not paid off until that animal is in her third lactation, so it is favorable to keep cows in the herd longer if possible.
Body condition score at calving can also impact IgG concentration. It is common for cows to rapidly lose body condition after calving as they are ramping up their milk production. Therefore, it is important to maintain a good body condition score before calving. Aghakhani et al. (2022) showed that when cows lose body condition during the dry period, they produce colostrum with lower IgG concentration. Cows should maintain or gain body condition during the dry period to avoid this and aid in the prevention of other common transition problems.
Management Factors
Disease in the last lactation can impact colostrum production. Cows who have experienced at least two cases of mastitis late in lactation produce less colostrum (Maunsell et al., 1998). Cows freshening in with an elevated somatic cell count are also more likely to produce low-quality colostrum (Gulliksen et al., 2008). Mastitis prevention is vital; utilizing proper milking procedures in the parlor and detecting mastitis early is the best way to prevent future infections. Farms should work with their veterinarian to have a dry-off treatment protocol in place.
Vaccination protocols may also influence colostrum composition. It has been studied that cows who are vaccinated for salmonella produce colostrum with a higher concentration of IgGs (Dunn et al., 2017). Work with your veterinarian to determine the best vaccination protocol for your herd.
Photoperiod reflects the amount of light and darkness in a day and can affect the quantity of colostrum. We know cows produce more milk during long-day photoperiods, and colostrum seems to be the same. Gavin et al. (2018) did a study with 2500 Jerseys and found that they produced about three times as much colostrum in June compared to December. This can be confusing, as long days often correspond to high ambient temperatures. Dry cows kept in hot summer conditions and not provided with cooling methods such as fans and sprinklers will produce less colostrum than cooled cows (Almoosavi et al., 2021). Heat abatement must be provided to dry cows to mitigate drops in colostrum production due to high ambient temperatures.
The length of the dry period can affect colostrum. Cows with a 60-day dry period produce more colostrum than those with a 30 to 40-day dry period. IgG concentration was only affected when the dry period was removed altogether (D. Grusenmeyer et al., 2006). The length of the dry period affects more than just colostrum. A longer dry period can increase conception rate after calving and lead to a more manageable transition period.
It can be difficult when cows calve overnight to collect colostrum promptly, but it is essential. When you wait 8 hours to milk a cow for the first time after calving, IgG concentration in colostrum decreases (Westhoff et al., 2024). So, if you milk twice a day and a cow calves right after milking, it is beneficial to milk her right away instead of waiting until the next milking. After that colostrum is harvested, it should be fed to the calf as soon as possible. It should be placed into the fridge or freezer if it cannot be fed immediately. The bacterial count doubles every 20 minutes that colostrum sits out, making it unsafe to feed newborn calves with a vulnerable immune system.
Feeding cows a high-quality diet during their dry period is essential as this can impact IgG concentration in colostrum (Mann et al., 2016). Not only is feeding dry cows a high-quality diet important, but it is also essential to have enough feed in front of them. It has been shown that higher dry matter intake during the dry period leads to higher dry matter intake during the fresh period (Grummer et al., 1995). A higher dry matter intake during the fresh period leads to fewer health events such as ketosis and displaced abomasums. The feed bunk should only be empty for 1 to 2 hours daily.
What animals should you feed excellent and poor-quality colostrum to?
To learn about detecting colostrum quality, please read Colostrum Management Tools: Hydrometers and Refractometers. Even the best dairy managers have cows that produce poor-quality colostrum. It is common for many dairies to feed heifers that will be used as replacement animals with high-quality colostrum and animals who leave the herd with low-quality colostrum. It is best to feed all calves good colostrum, even those leaving the herd, as colostrum quality can impact their immune system for life. IgG concentration should be assessed for every cow's colostrum. If a cow produces high-quality colostrum and produces more than enough to feed her calf, freeze the rest to have on hand for future calves. If a dam produces low-quality colostrum, consider saving that for a second feeding and pulling high-quality colostrum out of the freezer. If a farm does not have enough good colostrum on hand, consider supplementing with colostrum replacer.
While some factors are out of your control when it comes to colostrum quality, there are plenty of factors that you can control. Dry cows are often forgotten, but they are an essential part of your herd as one day, they will be your milk cows. Dry cows should be provided with a high-quality diet and heat abatement measures. Giving cows a long enough dry period and keeping them healthy in the previous lactation will help create high-quality colostrum for the calves of your future herd.
Source : psu.edu