Western Dairy Grist - Fall 2022

Dairy Grist

WESTERN & PRAIRIE EDITION A PERIODIC NEWSLETTER PRODUCED

BY GRAND VALLEY FORTIFIERS VOLUME 2, ISSUE 3 | FALL 2022

Dear Friends, The summer of 2022 has certainly had its ups and downs. Certainly, the growing season and moisture levels have varied significantly province by province and region by region. Having visited Alberta and Saskatchewan in mid July, we learned that producers certainly are looking forward to the best crop they have had in the past three years. Of course, Manitoba has been overly wet. As predicted by some, commodity prices save soybean meal peaked back in June with decreases in corn, wheat, barley and canola prices since then, but all remain at historically high price levels. 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.

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.

compared to their lower producing herd mates. The effects of reproductive diseases retained placenta, metritis and cystic ovaries, significantly increased time to pregnancy. The only other significant factors that increased the time to achieve a pregnancy were mild effects of lactation 3+ cows, and season of calving.

On a herd basis the pregnancy rate (PR), was compared to production level. Higher producing herds were associated with better pregnancy rates than similar lower producing herds. For every 1000 kg increase in herd mature equivalent milk there was a predicted increase of 0.7% in PR. Another study evaluated the effects of transition disease on conception rate at first AI. The cows in the study had detailed health records. Twentyseven percent of the cows experienced one clinical disease event and 17% of the cows experienced two or more clinical disease events. Alarming to me is that only 56% of the cows did NOT experience any clinical disease events in the first 60 days of lactation. Having a clinical disease in the first 60 DIM dramatically decreased conception rates (see Table 1). Experiencing one clinical disease decreased first service conception rate by 8% and two or more clinical disease events decreased the first AI conception rate by 16%.

Table 1. Impact of health problems in the first 60 d postpartum on pregnancy at first postpartum AI of dairy cows1.

Prevalence

Pregnant, %

Adjusted OR (95% CI)2

Healthy

56

51.4

1.00

1 Case of disease

27

43.3

0.79 (0.69 - 0.91)

0.001

> 1 Case of disease

17

34.7

0.57 (0.48 - 0.69)

< 0.001

Health Status

In another study of reproductive performance, transition cow disease was compared to conception rate and subsequent calving. Transition cows that experienced a disease event had decreased conception at the first AI and after becoming pregnant these same cows were less likely to maintain a pregnancy (Figure 1). In this data set there was no difference in time to first AI as the herds were on a synchronization program.

Proportion of cows pregnant when experiencing transition cow disease.

Q

Can we have health, fertility, and high production together?

Producers often ask us if high producing cows are less fertile? Dairy producers have the perception that high producing cows have decreased fertility and are more susceptible to disease.

Has the fertility and health of dairy cows declined OR have our management systems become increasingly unable to meet the metabolic, nutritional, social, and housing demands of the milk production potential of the modern dairy cow? If fertility has really diminished, what is the relationship to the increase in milk production? Has disease incidence increased, or is the increase in health issues a result of better diagnostics and recording?

A recent webinar by Dr. Stephen LeBlanc discussed how high production herds have better fertility and less health challenges.

What is high production? Is it higher producing cow within a herd or is it herds that are producing well above the industry average? Looking at both definitions reveals some interesting conclusions.

Records from 13,000 plus cows, evaluated by time to pregnancy, were compared by production level, lactation number, calving season, and reproductive diseases. The higher producing cows had equal fertility, when

C

Proportion of cows with successful pregnancy %

Figure 1.

with DOUG BAZINET Dairy Management Health and Nutrition Consultant, Grand Valley Fortifiers

P

100

Subsequently calved

80 60 40

Pregnancy loss

20

Number of ClinD21 None

0 50

100

150

DIM

Single

200

250

Multiple

300

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