This blog post was adapted from the OMAFRA resource “Sheep Feeding Programs: Forage and Feed Analysis”.
It’s hay season, which means it is time to think about feed and forage quality! Forages supply about 90% of nutrients consumed by small ruminants, so quality of this forage is critical to flock or herd performance. Feed is the greatest expense on Ontario small ruminant farms, making up about 41% of production costs on sheep farms (Molenhuis, 2012) and 57% of expenses on dairy goat farms (Ontario Goat, 2016). Consequently, efficient use of feed resources is critical to the profitability of Ontario small ruminant farms.
Nutritionists use feed sample information to appropriately balance feed rations. Forage quality varies widely from year to year and field to field, so yearly forage testing of each lot is critical for the efficient use of feed resources. Feeding an excessive amount of nutrients increases the feed bill, while underfeeding will reduce flock performance. Inadequate nutrients will reduce lamb and kid growth and the body condition score of the ewe flock or doe herd. A lower body condition score is associated with reduced conception rate, litter size, birthweight of lambs and milk production. Inadequate nutrition can also result in health challenges, including pregnancy toxemia and other metabolic disorders (Williams & MacDonald, 2018).
Sampling your feed and forage is only beneficial if the sample is properly collected, otherwise results may be inaccurate. It is critical that your sample is representative of the entire hay mow, grain bin or silo. This can be difficult as hundreds of pounds of feed are characterized based on only a few handfuls. Luckily, following a few guidelines will ensure the sample is as representative as possible.
Taking a Proper Forage or Feed Sample
Roughage should be analyzed yearly, and home-grown grains should be tested at least every other year. Methods to collect a representative sample vary depending on the feed type being tested. Each method is outlined below.
1. Hay Samples
The best time to sample hay is as close to feeding as possible. Use a hay core sampler to pull from the centre of the narrow end of square bales, or the rounded side of large round bales. Hay core samplers are often available through veterinarians or feed company representatives. If you are sampling large round bales, you could use an extender on your core to ensure you are pulling hay from the centre of the bale. A good hay sample will include any leaves or stems present in the bale. Flakes of hay or samples grabbed by hand are not representative samples and analytical results will be inaccurate. Many labs will refuse to accept inappropriate samples.
To accurately sample hay, take approximately 20 cores by choosing bales at random from within a lot. One lot is equal to one cut from one field, unless the field is highly variable, or the cut is partially delayed. In this case you may have more than one lot to sample per cut and field. It is helpful to set aside bales to sample as you put away the hay so that some lots are not buried in storage. Random sampling minimizes bias and ensures that your results are more reliable.
Mix all the core samples together in a clean and dry plastic pail, and seal about two handfuls (about half a pound) in a clearly labelled plastic bag for analysis.
2. Silage and High Moisture Grain Samples
The easiest time to sample silage or high moisture grains is during harvest. Collecting samples from a horizontal silo can be very dangerous, so this method allows you to safely and conveniently collect handfuls of silage from every 3 or 4 wagonloads. These handfuls can be mixed in a plastic bag, from which you can pull a two-handful subsample to freeze in a clearly labelled bag. Do this for each day of harvest, and once your silo is filled, mix each day’s sample, and take a two-handful subsample (about half a pound). Put this in its own labelled plastic bag, and seal with as little air inside as possible. A disadvantage to this method is that the nutritional value will change with time as the feed ferments. Sampling fresh silage allows nutritionists to balance rations if the forage will be fed before it ferments, but a fermented sample will give a better indication of the nutritional value when fed the remainder of the year.
If you miss this process during harvest, there are still ways to sample your silage. Samples should be taken over a two-day period. Allow the silo unloader to run for several minutes, then grab several handfuls of freshly unloaded material and place them in a clean dry plastic bag. Mix all the subsamples at the end of the two-day period and submit a two-handful subsample for analysis.
It is very important to be safe if you are working with pit or bunk silos. Use a front-loader or silage defacer to bring down a pile of silage, moving the silage a safe distance away from the silo face for your safety. Mix 5-8 handfuls of feed from this pile and add a subsample of two handfuls (about half a pound) to a labelled plastic bag for analysis.
3. Dry Grain Samples
Dry grains can be sampled either by hand or with a grain probe. As always, sample randomly from areas of the bin, and mix contents in a dry pail. Grab about two handfuls and place in a clearly labelled plastic bag to be sent for analysis.
Labelling and Submitting Samples for Analysis
Clear labelling is important to ensure that feed identification is correct, and the sample gets properly analyzed. A “sample input form” must accompany each sample. Make sure to include any information you feel might be useful to the lab, as no amount of information is too much.
For hay and haylage, indicate the cutting (first, second, etc.) and the type (grass, mixed, or legume) As a general guideline to determine the type of hay sample:
- Grass = < 25% legume (alfalfa, red clover, etc.) in the sample
- Mixed = 25-75% legume in the sample
- Legume = > 75% legume in the sample
Equations, specific for the type of forage, use the Acid Detergent Fibre (ADF) analysis to predict the energy content. Most laboratories use these equations and can provide an estimated energy value, expressed as Total Digestible Nutrients (TDN) and/or Net Energy (NE), for hay, haylage and corn silage samples. Correctly labelling forage samples ensures the right energy estimating equation is used. Use of the wrong equation will under or overestimate the energy content of the forage and lead to deficiencies or excesses in the formulated ration.
You will also need to clearly label samples treated with a non-protein nitrogen (NPN) additive, such as urea or anhydrous ammonia. This is so that the lab knows in what way to dry the feed, as haylage with added NPN requires a different preservation method.
After the sample has been properly collected and labelled, it’s ready to be sent to a feed laboratory for analysis! If you are looking for a list of available laboratories this can be obtained through the OMAFRA Agricultural Information Contact Centre; 1-877-424-1300.
Conclusion
As producers, we always strive to provide the best care for our livestock. At the same time, operating in cost-efficient ways allows for your farm to yield greater net profits, which is important to sustaining a successful business. Feed sampling is a key step to ensure good nutrition for your small ruminants, while also using feed resources as efficiently as possible. Following a few simple guidelines and routinely sampling feed is an easy and cost-effective strategy to improve the production efficiency of your small ruminant flock or herd.
References and Additional Resources
Putnam, D. and Orloff, S. Recommended Principles for Proper Hay Sampling. National Forage Testing Association, 2007. Available from: http://www.foragetesting.org/exam-info
Beef Cattle Research Council. Feed Testing and Analysis for Beef Cattle Fact Sheet, 2017. Available from: http://www.beefresearch.ca/files/pdf/1%20Feed-Testing%20BCRC%20Fact%20Sheet.pdf
National Research Council. Nutrient Requirements of Sheep. 6th Revised Edition. National Academy of Science, Washington, D.C., 1985.
Molenhuis, J. Ontario Sheep Enterprise Analysis Summary 2009 and 2010, 2012. Available from: https://www.ontariosheep.org/uploads/userfiles/files/SheepbenchApr2012. pdf
Ontario Ministry of Agriculture, Food and Rural Affairs. Publication 30, Forage Production. Available from: https://www.ontario.ca/files/2022-10/omafra-guide-to-forage-production-en-2022-10-19.pdf.
Ontario Ministry of Agriculture, Food and Rural Affairs. Sheep Feeding Programs: Forage and Feed Analysis, n.d. Discontinued.
Williams, K. and Macdonald, S. Body Condition Scoring of Mature Sheep. Farm Advisory Service, 2018. Available from: http://www.fas.scot/downloads/tn702-body-condition-scoring-mature-sheep/
Ontario Goat. Cost of Production Study Results. Final Annual Report 2016, 2017. Available from: http://ontariogoat.ca/wp-content/uploads/2015/07/2016-GOAT-Annual-Report-FINAL.pdf
