Dairy Grist
CENTRAL & ATLANTIC EDITION A PERIODIC NEWSLETTER PRODUCED BY GRAND VALLEY FORTIFIERS VOLUME 24, ISSUE 3 | FALL 2022
Dear Friends, The summer of 2022 has certainly had its ups and downs. With a decent planting season, early rains and warmth, first cut was really quite bountiful and of good quality, but with spotty, regional rains and a general dryness in Ontario, second cut did not fair near as well. As predicted by some, commodity prices save Soybean meal peaked back in June with decreases in corn, wheat, barley and canola prices since then, although prices are still at historic highs. The war in Ukraine rages on, an energy crisis for Europe is building, and numerous developed nations are setting targets for fertilizer usage reductions, and in some cases livestock reduction targets. Certainly, these are complicated and sometimes worrisome days. We believe that volatility in commodity prices will continue as traders react to geo-political, supply chain interruptions and significant weather events. Especially in these days of volatility, a wise strategy is to maximize home grown feed stuff volume and quality and minimize purchased feed costs. We trust that you will find the articles related to this helpful as you seek to harvest, process and store much of your annual feed requirements over the next couple of months. After three years of not being able to visit with you at Canada’s Outdoor Farm Show in Woodstock, we sincerely look forward to this opportunity during the days of September 13 – 15th. See you there! Sincerely, Ian Ross, President & CEO
KEY CORN SILAGE MANAGEMENT CONSIDERATIONS
by: DAVE HARWOOD Technical Services Manager, Corteva Agriscience
G
ood spring planting conditions and plenty of early season heat have helped corn plants grow well across many parts of the province. Most fields of corn were tasseled in mid-late July and thus harvest for corn silage will be underway earlier this year than traditional years. If you mark your calendars on the day your fields tassel, counting forward 40-45 days will give you a good estimate of when silage corn should be close to ½ milk line and very close to harvest ready. Following these well-known and research proven harvest management tips will help you ensure a high quality corn silage that will improve milk yield and reduce purchased feed costs for years to come.
Maturity and Moisture Recommendations vary with different storage structures (e.g. drier in vertical stave/sealed silos to prevent excess effluent). Proper maturity assures adequate fermentable sugars for silage bacteria and maximum nutritional value for livestock. Maturity has a tremendous impact on moisture to help exclude oxygen and thus reduce porosity of the silage. For “dairy quality”silage, the “ideal” harvest maturity/moisture for healthy corn silage plants is 3/4 milk line (>62% moisture).
Length of Cut It is difficult to offer generalized chop length recommendations because proper length depends on several factors including: 1) the need for physically effective fiber (peNDF) levels in the ration, 2) particle size of the other dietary ingredients, 3) the type of storage structure, and 4) silage compaction capabilities and unloading methods
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(e.g. silo unloaders, bunker facers). Other factors affecting chop length include the need to chop finer to damage corn kernels if on chopper processing is not available or if chopping longer to compensate for particle reduction from bagging or feed mixing. In general, shorter chop tends to improve compaction in the storage structure and also increases surface area of fiber (or kernels) to improve rate of digestion by rumen bacteria or intestinal enzymes. Longer chop increases the peNDF of the feed; however, excessive length can contribute to sorting by cattle in the feed bunk. It is best to work with the harvesting crew and nutritionist to decide on the proper compromise; recognizing that particle length in the final ration is what is most important. Start at the feed bunk and work backwards as to the amount of each feedstuff in the ration and how much peNDF each one of those feeds need to contribute to the entire diet. Figure 1.
CORN SILAGE How to Forecast and Determine Milk Line Progression of milk line during R5 (dent) stage
Average per Substage
% Kernel Moisture
Kernel Dry Matter Accumulation (% of Total Dry Weight)
GDU
Days
5.0
60%
45%
75
3
5.25 (1/4 milk line)
52%
65%
120
6
R Stage
5.5 (1/2 milk line)
40%
90%
175
10
5.75 (3/4 milk line) 6.0 (Physiological
37%
97%
205
14
35%
100%
360
360
575
33
Maturity)
Total (Average) © Iowa State University Extension
Ian Ross, President & CEO | David Ross, VP & CMO Mark Bowman | Jeff Keunen | Kathleen Shore, Ruminant Nutritionists
only the total plant dry weight but also the percentage of DM in the total plant. This could indicate that waiting until the plant is over 30% DM might not prevent seepage if the plant is still fully green and growing but the kernel has reached the black layer stage as sometimes happens in geographies producing very tall, healthy plants. Overall, this supports the idea that both kernel milk line and whole plant DM should drive the time to start harvesting silage. And secondly, high chop decisions to potentially improve NDFD should be based on stover DM and the amount of dead tissue (perhaps of the lowest foot of the plant in particular) and not on DM content of the entire plant. Research studies clearly show that fiber digestibility declines only minimally in healthy corn plants as they dry down from 30% dry matter to 38% dry matter (70% to 62% moisture). The combination of healthier plants in the fall, the need for starch to increase yield and digestibility and the ability to achieve higher compaction densities in bunkers/piles has allowed growers to harvest corn silage at ¾ milk line rather than 1/3 to 1/2 milk line which was common in the past. Producers who lack the ability to process (roll) kernels on the chopper may have to harvest at earlier kernel maturities and/or shorten the chop length to ensure adequate kernel processing at the cutter head.
Silage growers should note the date when corn plants silk (R1) and count ahead about seven weeks to begin checking fields for kernel maturity. Modern hybrids have improved late-season plant health so to avoid effluent and also significantly increase starch deposition, it is now recommended to delay harvest of healthy plants until the kernels are closer to ¾ milk line as opposed to the older rule of thumb of ½ milk line. Most of the difference between hybrids of different relative maturities is between emergence and silking, not from silking to the 62-68% whole-plant moisture (38-32%DM) that is considered ideal for corn silage. Modern corn genetics with vastly improved late-season plant health, coupled with technologies such as foliar fungicides, allow for a plant that retains fiber digestibility much later into the growing season. Late-season plant health is also advantageous in growing seasons lagging in heat units. Fiber digestibility will be maintained longer into the fall even as harvest is delayed allowing the plant to deposit additional starch. Harvesting corn silage at the ideal stage requires coordination between the days required to plant, the days required to harvest and the maturity of the hybrids planted.
Kernel Processing
K It is common for the corn plant to dry down in the fall about 0.5-1.0 points of moisture per day, depending on drying conditions. It is also common for corn silage to deposit 0.5-1.0 points of starch per day until the kernel reaches physiological maturity at black layer. Starch deposition is what is significantly contributing to reducing the moisture in the whole-plant and the also increasing the tonnage and energy density of the silage. The continued health of the overall plant allows for continuation of photosynthesis and the deposition of sugar through the vascular system of the plant. In essence it is the “laying down of starch” in healthy plant that reduces the water content of the kernel. Thus, healthy plants are quicker at lowering their kernel moisture than those that are impaired (drought, disease, etc.). The transformation of sugar to starch is dependent on the pathway remaining not only open but steadily fed, in effect, a two way valve, at the kernel attachment to the cob. It is clear what can happen when the inputs lag (aborted kernels near the tip) or where supply (and extremity, farthest away from the source), slow the process (which can even induce premature black layer). Most people assume the kernel “air” dries from the pericarp, but prior to black layer the general consensus is that there is very little moisture movement across the pericarp. After black layer (the two-way valve now closed), kernel drydown is through the pericarp and dependent upon environmental weather and genetics. Within hybrids there appears to be varying genetic difference in levels of porosity affecting their ability to dry down quicker than comparable\ maturity hybrids. During corn maturation, the dry matter of the entire plant, being composed of stover and grain, increases for two reasons: 1. First, the stover is drying as leaves dry and stalks brown. Given that NDF digestibility decreases as plant tissue dies, NDFD also should be dependent primarily on dry matter (DM) content of the stover, not on DM content of the full plant (including the ear) because it should vary primarily. 2. Secondly, grain, being the driest portion of the plant, is still being deposited when plants are healthy. The ear is always drier than the stover, so an increase in the ear to stover ratio increases not
ernel processing of corn silage has long been popular in Europe and started to gain acceptance in North America in the late-90’s with the introduction of choppers that came from the factory with the kernel processor (on-board roller mill) as standard equipment. Pioneer has developed a simple field test for degree of kernel damage using a 32-ounce cup. Producers are encouraged to sample several loads each hour by filling the cup level with silage; spreading the sample out and quickly picking out every whole and half kernel. If that number exceeds 2-3 kernels, it is important to discuss with the chopper operator how to improve kernel processing. If left unattended, the result will be a loss in energy as unprocessed kernels escape ruminal and intestinal digestion. Validation of degree of kernel damage can be further accomplished by collecting fecal samples from 10-12 cows and submitting to a lab for fecal starch analysis. The goal is to have less than 3-5% starch in feces. Levels higher than that could indicate poor processing of corn silage (or other starch sources) resulting in inefficient use of dietary starch in addition to possibly predisposing cows to maladies such as hemorrhagic jejunum (or bowel) syndrome (HJS or HBS). There are several factors that chopper operators can check to improve processing: length of chop (longer typically more difficult to damage kernels), roller mill wear (life of 400-1000 hours depending upon mill), roller mill gap (1-3mm depending upon chop length and kernel maturity), aggressiveness of the rolls, and perhaps the most important, roller mill differential (typically 20-40%). There have also been recent innovations in roller mill design and differential speed including Shredlage® (Claas) and KernelStar Technology (John Deere).
Dairy Grist THE MEMORY OF A HOT SUMMER LIVES ON IN THE COW’S HOOF
Figure 2. Ruminal response to heat stress (adapted from Mishra et al, 1970).
by: KATHLEEN SHORE Ruminant Nutritionist, Grand Valley Fortifiers, Nutrition Direct
W
arm summer days and nights that are not much cooler means cows standing and perching in stalls longer than they would when temperatures are more comfortable. That time spent standing puts a great deal of pressure on the hoof, but by the time we truly see the impact in the barn the warm summer air is often a distant memory, and we are troubleshooting on farm concerns without considering that the real culprit is in fact that beautiful weather 2-3 months ago (see Figure 1).
Score
Description
Back
Assessment
1
Normal
Flat
Stands and walks normally with a level back. Makes long, confident strides.
Other conditions in the barn will also increase the incidence of lameness. A study done by Chapinal et al, 2013 found clinical lameness increased with sawdust bedding and decreased with herd size, deep bedding, and access to pasture. Access to pasture led to a 50% variation in clinical lameness compared to cows without access to pasture irrespective of deep bedding also being available to the herd. While pasture availability may not be practical for all barns it is something to consider when cows are in the dry cow period during the warmer months to give their hooves a chance to heal/recover before the next lactation. The same study went on to show that in barns where severe lameness occurred, the incidence increased with the number of manure contaminated stalls and the use of sawdust bedding. Other factors that helped reduce the incidence was a having a neck rail further from the curb (lower perching tendency), greater water drinking space per cow and frequency of foot baths per week. However, if the barn is overcrowded then improving drinking space and stall size no longer had as much of an impact. Footbathing has become a big part of managing hoof health but doing it correctly will make the time and money much more well spent. Ultimately the goal of footbathing is to prevent infectious claw lesions that lead to depressed cow movements and thus production. For footbaths to be truly effective it is important to understand the lesion on the cow. M1 lesions are early, subclinical and small measuring <0.75” and they are susceptible to improvement with footbaths. M2 are more painful, acute lesions >0.75” and they require treatment. Establishing how often footbathing should be done on your farm can be estimated based on how clean cow’s legs are. There is a strong relationship between leg hygiene and infectious claw disease so a nice visual cue to stay on top of things. A score of 3 (moderately dirty with distinct plaques of manure on the foot, progressing up the limb) and a score of 4 (very dirty with lots of caked-on manure on the foot and higher up on the lower limb (see Figure 3).
2
Mildly lame
Flat or arched
Stands with flat back, but arches when walks. Gait is slightly abnormal.
Figure 3. Leg hygiene score (Olsen, Zinpro)
Arched
Stands and walks with an arched back and short strides with one or more legs. Slight sinking in dew-claws in limb opposite the affected limb may be evident.
Proportion of Cows Hygiene 3&4
Footbath frequency
<25%
As required
Arched
Arched back standing and walking. Favoring one or more limbs but can still bear some weight on them. Sinking of the dew-claws is evident in limb opposite to the affected limb.
25-50%
2 days/week
51-75%
5 days/week
Arched
Pronounced arching of back. Reluctant to move, with almost complete weight transfer off the affected limb.
>75%
7 days/week
Figure 1. Incidence of lameness peaks at the end of summer – highest temperatures were in July. (Adapted from NB Cook, 2004)
The flare up of hoof health can be identified by walking through the barn and scoring cows for locomotion. Often the cows we see every day as they make their way to the bunk are not the ones with concerns. Cows that are struggling with sore feet will be the cow whose budget to eat/drink/socialize (7 hrs), milk (3 hrs) and lay down (12 hrs) will be off and her production will suffer. Routine hoof trimming with a hoof trimmer that provides good feedback is a key element to supporting consistent hoof health. However, between those visits regular locomotion scoring on at least 10% of the herd can tell you when there is a higher-than-normal incidence of trouble, which means scoring the herd routinely (see Table 1). Table 1. Locomotion Scorning Guide (adapted from Sprecher et al, 1997).
3
4
5
Moderately lame
Lame
Severely lame
When heat stressed, cows will also eat less feed (though often eat more per meal – slug feeding) and are more prone to sorting the TMR thus eating less forage. These eating behaviors and feed digestion realities increase the risk of acidosis with reduced butterfat and milk yield as well as impacting lameness and reproduction if not managed well (see Figure 2).
Staging a footbath requires following some well researched recommendations as outlined by the University of Wisconsin. Current recommendations are as follows: 1. Side walls sloped outwardly 70o angle to ensure cattle get feet in the bath (treated) with every step or high walls (3 ft) with optimally one wall able to come down should a cow fall.
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2. Length – 10 to 12 ft to allow 2 full immersions in the bath a. 6 ft bath likely to get 2 full immersions 53% of the time. b. 8 ft bath likely to get 2 full immersions 84% of the time. c. 10 ft bath likely to get 2 full immersions 96% of the time. 3. Step in height should be 10 inches – a study showed that this height (compared to 5 in) allowed more chemical to stay in the footbath. 4. Footbath should be at least 24 inches wide. Solutions recommended for footbaths are Formalin (2-3% dilution) which is effective long term since bacteria do not tend to develop resistance but should be used with protective gear to avoid harm to people and is not very effective in cool weather (<7C or 45F). Copper sulphate (3-5%) is a nice antibacterial/hardening agent that is mostly soluble though its dilution in water is improved when acidified. The pH of the solution should not be below 3.0 (normal pH of bovine skin is 3.6). A solution of Zinc sulfate (10-20%) can also be used with similar benefits to copper sulfate but it is much less soluble so again acidification will help. Lastly, soap and water should always be a part of the regime to simply improve that leg hygiene. For other effective footbath products visit our farmersdepot.ca website and search “hoof bath”. Changing the footbath is recommended when aerobic bacteria load reaches above 100,000 cfu/mL which is tough to measure looking at the bath so the estimation is 100 cow passes. Footbath errors are the biggest impediment to their ineffectiveness. Managing the regime to avoid poor design, too weak or too strong chemical solution, and areas of urine/manure accumulation after the footbath. Keeping a good management schedule throughout the year will help alleviate chronic problems in the herd and come the summer months when there is more pressure put on their feet it becomes a very important part to avoiding Fall Hoof Health problems.
longer harvest window. This extra harvest window can be valuable in wet years when getting on the land proves difficult. Triticale is best followed by a slightly shorter day corn than rye, or beans in the rotation. Triticale should outyield rye by 25-30%. In a typical year, rye will be ready to harvest around the middle of May. It is important to keep close watch on maturity as the harvest window is only a couple days long. For Milk Cows Fall cereals make excellent milk cow feed when harvested in the flag leaf or boot stages. They bring in protein and sugars into the ration, but also have excellent digestibility. This allows for higher forage rations which are desirable from a feed cost perspective. The excellent fiber digestibility also helps with summer feeding programs to maintain dry matter intakes during periods of heat stress. For Heifers If the optimal harvest window is missed, fall cereals quickly lose digestibility, protein, and overall quality. Once headed out, protein quickly drops below 15%. Its important to ensile with adequate moisture as heifers will sort away from the heads, especially if dealing with unprocessed balage. For Dry Cows Another option for fall cereals is to include in dry cow rations as a replacement for straw. Straw is an increasingly expensive feed ingredient. Triticale and rye will bring in more protein than straw in a Goldilocks ration and will also bring in extra moisture to the TMR. Overall, this helps to decrease protein costs in dry cow rations and increases feed bunk stability with less need to add water. However, we still need to manage potassium levels in order to mitigate risk for milk fever.
Visit with us at…
with BRIAN NELSON Dairy Specialist, Grand Valley Fortifiers
SEPT. 13-15, 2022
Q
What should I plant after corn silage this fall? For a few years now we have seen producers experiment with fall cereal crops after corn silage. With land and commodity prices driving interest in double cropping, and lots of success stories around the province, fall rye and triticale are gaining in popularity. Fall cereals can fit into any dairy feed program, but plant maturity at harvest will decide if it is suitable for milk cows. Nutritionally, rye and triticale are very similar. In the Cumberland Valley lab database with over 250 samples of each, triticale silage samples average 14.9% CP, 66.5% 30hrNDFd, 1.43 NEL; while Rye samples averaged 15.2% CP, 66.5% 30hr NDFd, 1.41 NEL. In Central Ontario, I consistently see triticale and rye samples harvested in the boot stage at 15-16% CP. With optimal nitrogen management and harvest at the flag leaf stage, protein tests in the 16-20% range can be achieved. Although rye and triticale are similar nutritionally, there are some key differences to consider. Rye is earlier maturing than triticale. This may be important in the spring if you are trying to get longer day corn planted following rye harvest as rye will be ready to cut 7-10 days before triticale. Triticale on the other hand is a little later to mature but has the benefit of a
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Thought for the Day
Freely Give “Freely you have received, freely give.” | Matthew 10:8b
When we begin to struggle in giving what we have to others, we have forgotten where we received our possessions. Every good thing we have ever received has come from God (James 1:17). All that we have acquired has been dependent upon His grace (1 Cor. 4:7). If you struggle to give freely to others, you have become more attached to the gift than to the Giver. The account of the rich young ruler shows the tragedy of becoming too attached to worldly treasures (Luke 8:18 – 24). Take time to reflect on all that you have been blessed with. - Adapted from Experiencing God Day by Day, Henry T. Blackaby & Richard Blackaby