When it comes to silage quality, the dairy industry typically looks at yield and Near-Infrared Reflectance Spectroscopy (NIR) measurements, such as those found in MILK2006. However, neither of these indicators provides an accurate measurement of milk production and dairy farm profitability, two characteristics that should not be ignored.
One of the primary shortcomings of MILK2006 is that it only uses one sample to determine hybrid value and compares that against another single hybrid. Ideally, however, hybrids should be measured over a number of environments to determine mean nutritional value. For this reason, MILK2006 may not be an accurate method to summarize hybrid performance from a statistical standpoint.
Additionally, while MILK2006 does take into account Kernel Processing Score (KPS) as a potential input value, the relationship between KPS values and in situ starch digestibility measurements is not well defined. This can result in highly variable measurements between laboratories since most silage samples are finely ground prior to analysis (the grinding may mask differences between samples).
There are other potential problems that may prevent MILK2006 from accurately evaluating silage quality. MILK2006 accounts for harvest maturity via whole plant dry matter (DM). However, this does not account for differences occurring between hybrids with varying DM content in the grain versus forage fractions of the whole-plant silage. Furthermore, the primary management condition that MILK2006 accounts for is whole plant dry matter and whether the sample was harvested with a kernel processor. It does not directly account for post-harvest fermentation characteristics versus fresh cut forage.
One final concern that should be considered: although commercial laboratories sub-sample and conduct NIRS and wet chemistry analysis in replicate, the largest source of analytical error occurs during the sampling procedure and/or collection at the farm gate. MILK2006 cannot predict sampling error.
BASF Plant Science takes a biological approach to evaluating silage quality rather than relying on NIR alone. For example, two of the testing methods BASF Plant Science utilizes are the in situ technique and the in vitro measurement. The most accurate method for determining fiber utilization is the in situ technique, which measures disappearances in the rumen. This method tells us exactly how the rumen microbial population is evaluating the nutrients within NutriDense Silage as well as the rate of fiber utilization and fiber quality. The in vitro method determines the amount of Volatile Fatty Acid (VFA) production and in turn, enables us to determine real available energy.
Using these methods, NutriDense Silage outperforms conventional silage with:
• Up to 13% additional energy as a result of favorable fiber utilization
• An increase in feed efficiency as demonstrated by an 11.4% improvement in milk production efficiency
• A reduction in feed costs up to $.26 per cow per day
Please contact your NutriDense silage sales representative for additional information on these trials.
Jerry Weigel is the manager of nutrition and tech service for BASF Plant Science. You can contact him at gerald.weigel@basf.com.
