Saturday, September 20, 2014

Ov Synch -- do you need it or not?

Synchronization techniques (using hormones to bring animals into heat at specific times) were first in development back in the 1960s, when drug firms like GD Searle  [owner of Curtiss Breeding Service] developed “Synchro Mate B” vaginal inserts for sheep and ear implants for beef cattle.   “Lutalyse” as developed by Tuco/Upjohn  [now part of Pfizer] in injectable form, made it all easier.     Lut response was later found to be enhanced by a simultaneous use of “Gnrh” [Gonadatropic release hormone], and most OvSynch protocols today alternate Gnrh and Lutalyse shots to produce stronger heats.

No matter what you hear, however, the following is observationally true:  conception rates are much higher when breeding still occurs based upon observed heat signs.     In other words, without estrus detection, the best you typically get is 50% conception.  

I bring this up, because we hear of instances in which owners of smaller numbers of cows, especially if dependent on an external inseminator, get told by veterinary practitioners that OvSynch is “easy” – and the total detail (what has to happen when, and what results to expect) is not always covered.   This is the result of widespread use of OvSynch in Michigan dairy herds (MSU’s Dr Pursley is a leading researcher in synchronized reproduction) where it has proven to maintain reproduction at a utility level, in spite of genetic selection and feed management issues that tend to delay fertility response in many dairy cows.

Veterinarians do not always remember that the cow calf operator, like the grass-based organic dairyman, prefers a tight seasonal calving window—not calvings strung out all year long.    AI efficacy in beef has to result in calves with optimal birthdates (to fit marketing windows) and calving dates (to match peak forage production) or the profitability of weight gain can be jeopardized.

Most beef breeds are genetically selected for natural fertility response

With the possible exception of the extreme growth rate and show type bloodlines, where other factors dominate genetic selection, both the major commercial feedlot breeds and the grass-based heritage beef breeds include “fertility response” within maternal trait selection, as well as range sire behavioral trait selection.    For the grass-based cow-calf systems, where vegetative grass and sunlight are the nutrient energy sources, breed selection for high rumen feed efficiency and easy conditioning (natural marbling) has assisted in maintaining natural reproductive efficiency that was based in genetic selection.

The reason OvSynch got started in beef cattle was the demand for AI within range-managed cow herds.    Exotic genetics (for which service bulls were unavailable) could be introduced easier through AI.    But the range cow is not housed in drylots or used to being corral confined in the grazing season (when the AI needs to take place).    OvSynch presented the option of corralling the cattle, implanting or injecting them, turn them back out with the calves and the grass;  gather them up again a week or two later, run them through an AI chute, breed them, and send them back to the grass.     Thus AI became a practical option for the range cattleman, who would get 50% AI calves and 50% cleanup bull calves, enough to provide his next season genetic needs (ie, save his bulls from the AI fraction).

Ov Synch effects on genetic fertility traits

Used in the above way, OvSynch was not a substitute for natural fertility—it was a therapeutic tool to schedule existing fertility convenient to AI use.    The more fertile cows conceived to AI, and the bull calves saved from those matings helped maintain fertility in their work as cleanup bulls on cows that did not conceive via AI.      Thus the possible longer term genetic consequences were not of great concern.

Is your heat detection up to the job of doing natural heat AI?

This is the first and most important question to ask, prior to entering into the expense of OvSynch.    Given we see the highest conception rates from insemination timed from observed natural heats, and the semen many of you are using is rare and expensive, this is a valid question.

The average USA cow calf herd is only 18 cows in size.   Even in Texas, the average is only 32!    Most of you are breeding from ten to seventy cows per year (a “one man” cow calf operation) and want all the calves born in one season (the rest of you have a second calving season).     So your cows are in dry lots or in pasture paddocks of twenty acres or less that lead to your farm buildings.     

With a seasonal breeding window, you have perhaps six weeks in which daily heat detection, done three times daily if possible, can optimize your pregnancy rate.   Here is a very successful routine:  (1)  Focus heat detection around the cooler times in the day;  (2)  Use tighter grazing rotation for the AI window, so the cows are getting fresh grass (stimulant) and you have a smaller paddock to walk through to see them in heat;   (3)  Breed only those cows you see in heat for 21-24 days.      (4)  On day 25 synchronize all cows that did not show heat for natural AI;  (5)  Breed those cows who show heats from a 21-day full synchronization;   (6)   Turn in cleanup bulls based in numbers on half the synched cows plus all cows not bred on either a natural or synchronized heat.

This approach guarantees that your first calves in the season are from AI selection and a natural service.  If you focus on those female calves for replacements you will be selecting for positive natural fertility response as well, but additional heifers can still draw from the synchro calves that come next, as still born within the optimal birthdate window.    Late calves by your cleanup bulls may at that point prove to be surplus to your needs, and can be marketed with your steer calves for added income.

Using what Darwin learned to evaluate OvSynch’s impact on cow fertility

The commercial dairy industry is facing higher repro costs and shorter cow herdlife that some feel can be traced back to indiscriminate use of induced reproduction technologies.

80% of the sires in dairy AI result from superovulation [induced fertility] embryo transfer, and over 50% of their parents (sire and dam) are the same.     Their progeny are then bred under continuous OvSynch protocols, in which open cows are given continuous injections and timed bred until confirmed pregnant, with many herds now averaging four AI services per pregnancy.     This has meant the annual calving interval is nearly impossible to maintain, and numbers of replacement heifers are often short of the herd needs.     Thus sexed semen (preferring females) is now selling widely in commercial dairy settings.

The per pregnancy cost of continuous OvSynch reproduction is $200 per dairy cow in many herds.    In the beef industry, this would be impractical-- $200 per calf might be our total profit margin many years.

Basically, Darwin’s least controversial research indicates that genes we do not use get lost.    “Survival of the fittest” in the natural wild environment is pretty much about being able to outrun predators while seeking out your next source of food.    “Survival of the fittest” in domesticated animal production, is more about the gene response to all the ways we interact with (“manage”) animals, and how they adapt to a more limited diet (dictated by the crops we choose to grow and the supplements we buy).      Estrus response can change if we no longer value natural fertility and preserve the traits that represent the genes supporting optimal natural fertility—whether the actual insemination is by AI or by a service bull.      

HEAT DETECTION AIDS      What options work best?

Don’t overlook the eight month old Jersey bull!!    He loves to watch for heats—he just is not quite tall enough to do anything about it.    Breed the cows he follows around each day.    You can always eat him once he gets too big to miss (Jersey beef usually ranks pretty high in blind taste tests).

Then you have the KAMAR heat mount detector—glue over the pelvis, it turns full red after mounting when the cow stands to be ridden.     For short haired animals, the Estrus Detect strip is self-adhesive and works similarly—its color is rubbed off by mounting activity.      Replace after insemination.

You can take a freemartin heifer, give her hormone shots and a chin ball marker, and she will act as a “gomer” (or you can do the gomer surgery on a bull, it just costs more)—cows in heat will have paint on their backs.     Again, you can always eat her too after the season is over.

With any heat detection aid, the trick is to have visible ID on animals, a check list (on which you write down heats observed and breedings made)—and refer to that list each time you look at the animals, so you know what you are seeing  has occurred since the last time you checked.

Friday, September 12, 2014

Here is an AI Refresher Course

(1)   Heat Detection                   (observing “estrus”)

The “best” sign is the mounting of the animal in heat.   She stands still for others to mount her.   Then our timing of insemination is easier, as you have standing heats for reference.   Breed cows standing at night the following morning, breed cows standing at morning after lunch, or if still heated up, wait to evening.     (The idea is to service at the end of standing heat—more on that later).

A beginning sign of estrus onset is the swelling of the vulva and the release of cervical mucus, which is shiny and clear.   The cow will be more active, restless, perhaps bawling a bit.   As the estrus progresses, the cow may try to mount other cows to draw attention.    Finally you see her standing to be mounted.

The stages of standing heat last several hours, so will be mixed in with feeding and other routines.    At the end of heat, cows start to refuse to be mounted (AI should occur right away, if not already).   The next day the cow will be quiet again—and within another day, you will likely see blood on the tail.

If not serviced, or if conception does not occur, you can expect her next cycle between 17 and 24 days later (21 days is the usual interval).      “False” heat signs are often seen mid cycle (ie, 9-11 days after a true heat) and are just a result of the hormonal production that stimulates the complete cycle.

(2)   Semen Handling            (protecting conception)

Your object in semen handling is to preserve unused semen by equipment and procedures that optimize the number of live sperm available in the straw after it is thawed for use.

Your liquid nitrogen semen tank is designed to maintain semen in a full state of suspended animation. Cryogenic temperatures (-320 F in the liquid, -140 F in the vapor) are adequate to maintain that state, but any time the semen straws/canes are moving above the vapor line in the neck of the tank (or between tanks) molecular movement from warming can begin.   

Transfer of semen canes should occur within a ten second interval.   A similar eight second time limit is “the rule” on removing the straw you are ready to thaw for breeding—to protect the straws you are NOT ready to use.    (If you do not get the straw you want in eight seconds, put the cane and canister back in the bottom of the tank, let it cool down 30 seconds, then lift it up and try again.)

We find the canister in which the sire we wish to use is stored.   You can hold the canister within the neck of your tank, by light pressure on the fiberglas stem, with the same hand that holds the cane steady (with thumb and forefinger) while you remove a straw.    Then (1) drop the cane down into the canister, (2) drop the canister into the neck, (3) put the removed straw in your thaw water, (4) set the canister in its hanger, (5) plug the tank neck.     The removed straw is being thawed, it is of secondary importance to the straws returning to the safety of your semen tank—thus the logic of the order given above.

Why thaw in warm water??   Because it is likely the semen you have was collected at multiple locations and with different extenders (fluids added to protect the sperm cells through freezing and thawing).   It is known that “pocket thaw” seems to work with milk extender semen, but can damage egg yolk, citrate, and soybean oil extended semen.    But warm water thaw works equally with ALL semen straws.  

(3)   The AI technique        (rectal palpation, cervical fixation)   

The thawed straw will be wiped dry, inserted into the barrel of a warmed AI gun.   The end of the straw is cut open, a sterile sheath is drawn over it (and secured by o-ring or spiral at the shank of the gun).  A dry paper towel is wrapped over the end, to reduce temperature shock, and slipped into your vest.

You will slide an OB glove over your left arm, fitting the hand to your fingers.   You will apply OB lube to the palm of your glove, and (if a soap lube, make a suds to clean the vulva surface) wipe lubricant on the vulva lips, then enter the rectum one finger at a time to relax and dilate the anus.   Any manure she pushes back to you, should be allowed to flow out, thus keeping the rectal rings in motion (more on that later).    Once the manuring stops, with your right hand, take an unfolded towel in the flat of your hand and make a single comprehensive wipe across the vulva surface, to clean the area for entry.

Taking the AI gun in your right hand, you now enter the vulva using a slightly uphill angle (to avoid an entry into the urethra, which drains the bladder—an area very sensitive to the cow and unconnected to her reproductive system).    You will find that pushing gently down against the vulva from inside with your left hand (folded into a fist) usually will spread the vulva lips apart to make a cleaner entry.

I then relax my left arm inside the rectum, while sliding the AI gun as far into the vagina as it will go easily.    In most cases (as the vagina is a funnel and only leads to the cervix) the gun will end up at a point in front of or slightly alongside the cervix.    I then work my left hand down to find the end of the gun and explore the tissue structures it has found, to detect the size, shape and angle of the cervix.

Keep in mind the entire reproductive tract—vagina, cervix, uterus body, uterine horns, and ovaries—are mounted on a membrane that is anchored to the pelvic bones, designed to allow stretching of the weight of the calf into the body cavity as pregnancy progresses.    So the cervix and uterus can move about, and we must be careful not to “bulldoze” what we are seeking over the edge of the pelvis into the body.

The cervix can be grasped roughly half around by lifting it off the membrane, and this allows you some control of cervix movement as you seek to guide the gun into its vaginal entrance.   The cervix feels like a “chicken neck”—you may sense folds (rings) that the gun passes through to reach the uterine body.

Once you pass the gun through the cervix, you will feel the tip coming out of the cervix.   You need to hold the gun in the uterine body, by placing your index finger over the tip, so it does not slide up into one of the uterine horns.    At this point, you grasp the plunger with your right hand, push the semen into the cow, then remove the gun, and finally remove your left arm.

Once your gloved hand is out of the cow, grasp the base of the vulva between thumb and finger, and as soon as you find the clitoris (buried in the fat tissue of the vulva base), flick it repeatedly.   If done with finesse and sensitivity, the cow will arch her back—at this point, her nervous system has been sent the signal that breeding has taken place, and will then initiate the steps to trigger ovulation.

(4)    How conception actually occurs  

Six to twelve hours after the end of standing heat (when you bred the cow), the follicle on one ovary will rupture and release its ovum (egg).   The infindibulum membrane catches it, and sends it up the fallopian tube, where it will meet the waiting sperm cells.    Sperm rub against the enzyme shell until one is able to penetrate and complete conception.    Over the next week, during cell division, it migrates to the horn and will attach to the uterine wall.    Over the next six weeks, it transitions to full fetal attachment.    

The miracle of life—celebrated each spring with the birth of calves

Nothing beats the sight of a herd of momma cows in green paddocks, grazing grass and nursing a full crop of calves.     The cattleman knows reward for the prior season’s time and expense for breeding those cows, and can predict his likely income.

But that means we need to be picking out sires, ordering semen, restocking our supplies and preparing for heat detection, maybe estrus synchronization, and breeding.

Saturday, September 6, 2014

Seasonal Semen Tank Rentals

Our seasonal tank rental has proven an attractive option for the Beef or Goat breeder who does all AI in a seasonal window  [spring—beef;  fall—goats].     Your semen is stored here, a tank is delivered by the date you tell us AI needs to begin, the tank is picked up after your breeding window ends.  Now we need more tanks that fit our service recharge window.    So if you would like to trade up to a newer tank, your existing tank is worth more on a trade.    If you store embryos, a newer tank has advantages to you.

GRAZING CORN that can be baled – the small herd silage substitute

Masters Choice seed corn, in its continuing focus on feeding quality corn varieties, has developed a corn variety that is focused on the grazing management cattle farm--  where the higher feed tonnage per acre of which corn is capable, can be combined with a simpler grazing and baling harvesting option.

“Master Graze” is a multistalk corn that will provide a regrowth of tillers from the root base after the first cutting is grazed or harvested.     Silage baler operators indicate it is easier than baling Sorghum Sudan, as it dries a bit quicker (requires less wilt time), and its feeding value is at silage energy levels but with good grass protein levels, and is almost totally digestible.

We intend to try some at our farm this year, after a success feeding Summer Dream (BMR Sorghum Sudan) in balage form as a silage substitute through this winter season.     After the first cut, we intend to interseed some fast emerging annuals to add tonnage to the second cutting.     

These options can work well for the smaller operator, who depends on custom silage harvesting, but who is already set up (or needs an excuse to get set up) for silage baling and wrapping.     You will not have to fear running out of forage, as is often the case with a dry hay forage system in a drought year.

SORGHUM SUDAN may act as a deer repellent around corn fields

This subject came up at the recent Byron seeds/Masters Choice information meetings.   It appears that if you plant a couple drill passes around a corn field with BMR Sorghum Sudan, the deer do not find it as interesting to them as corn, and may not walk across it to reach your corn plantings.

Given the palatability of most Sorghum Sudans to cattle, this is a surprising statement.   But deer are not as adapted to the more recent forage crops as they are to field crops to which they have had generations of exposure (corn, soybeans, alfalfa).

Either way, a band of Sorghum Sudan you can harvest for cattle feed while waiting for the corn, means you do not end up knocking down bushels of corn from your headlands and check rows at harvest.

Wednesday, September 3, 2014

Fall Seeding – it is really quite simple what to do

In the last decade, forages have seen a renaissance in importance for dairy rations.    Nutritionists have gradually seen the light on the energy value in digestible fiber.    The older “state of the art” ration of pure alfalfa haylage cut early-bud (its lowest fiber point) with shelled corn as the energy source (again, starch, not fiber) and the protein targets balanced with soybean meal (which used to be a by-product feed) produced more milk than baled hay, ground ear corn, oats and corn stalks, BUT kept veterinarians busy with displaced abomasums and high blood urea levels, depressed reproduction, laminitis, etc.    Out of this “one size fits all” dairy ration grew the historically-blind concept that “grass is a weed” rather than the most basic and adaptable soil builder and ruminant feed that in earlier eras was the basis of pastoral dairying.

Adapting silos to storage of chopped alfalfa hay appeared to solve one of the big problems of hay harvesting—the visual loss of leaf dry matter at baling and after.    Lightly wilted and windrowed alfalfa still looked like it retained its protein value in saved leaves.     We assumed that chaff that blew over the top of the wagons was all chaff and stalk.     We were usually fooling ourselves.
The mechanical storage innovation that proved you could feed hay in nearly the same quality as it was harvested, and suffer minimal loss of leaf volume, was the baleage (plastic wrapped bale) system, which proved that your return on the plastic used was 10 times its cost in saved feed.   In areas of the dairy world such as the Canadian Maritimes, where herd sizes are typically 70 to 200 cows, this matches equipment investment to available labor and gets the feed quality job done.

The lagging part of the nutrient harvesting in the cattle industry today involves dry hay.    Cows crave fiber, for rumen “scratch factor”, and crave the buffering of drier elements in an otherwise wet ration.    So the search for affordable good dry hay is still ongoing.    But those who are now adding better grasses to their alfalfa fields are finding their cows feel (and milk) better already.

What is the issue with dry hay?

The many steps involved in making dry alfalfa hay add up to a significant loss of nutrients we basically just return to the ground as surface mulch.    How much do we lose?    Here is some data that has been around awhile already:

Mowing                                2% of leaves lost             1% of dry matter lost
Mower/conditioner              3% of leaves lost              2% of dry matter lost
Discbine                               4% of leaves lost             3% of dry matter lost
Flail mower/conditioner      5% of leaves lost             4% of dry matter lost
             at 70% moisture      2% of leaves lost             2% of dry matter lost
             at 33% moisture      12% of leaves lost           7% of dry matter lost

            At 70% moisture      2% of leaves lost             1% of dry matter lost
            At 33% moisture      12% of leaves lost           6% of dry matter lost

Baling:   (stacking flat wagons by hand)
            At 20% moisture      6% of leaves lost             4% of dry matter lost
            At 12% moisture      8% of leaves lost             6% of dry matter lost
              (ejector bales thrown into basket wagons)
            At 18% moisture      8% of leaves lost             5% of dry matter lost
              (round balers, different designs)
            range of equipt        10%-21% leaves lost       6%-13% dry matter lost
              (Stack wagon picking up bales)
                                            24% leaves lost                15% dry matter lost

Total losses:                        12%-50% of leaves          7%-30% dry matter

Your equipment dealer will make a case for converting to wet wrap baling, so you can harvest all the alfalfa hay you grow.    And there is an issue, as hay values have risen to the point where this means as much as $150 per acre in feed value you grew but could not get to your cows.

There is another factor.    Is “pure alfalfa” the best dry hay “crop”, or could “mixed alfalfa grass and clover” be a better deal all the way around?    In the first place, with grass and alfalfa side by side in the field, you have the more fibrous grass to attach those flimsy alfalfa leaves and prevent some from falling to the ground.    In the second place, alfalfa’s energy values are inferior to the new, improved multi season red clovers that can add some fiber energy punch to your harvest.

SO—do you want to seed some better hay?     Here’s a simple seeding mix to get you thinking.
Kingfisher  444  or one of our other improved root structure alfalfas       15-18 pounds/ acre
Emerald Red (4 season) or Freedom Red (3 season) clovers                       2-  3 pounds/ acre
STF 43 or other endophyte free tall fescues  (improved grasses)              10-  7 pounds/ acre      

This will produce great baled hay, but would produce even better bunk silo haylage or wrapped baleage.    Clover adds fiber energy and palatability, the grass adds fiber energy and tonnage at the level of protein modern dairy rations suggest.    The alfalfa will grow in the summer heat so that you can justify the fuel and time of each cutting.    The grasses we use no longer head out ahead of the alfalfa, so you harvest optimum feed from all three species.    

The seeding rates may be higher than Grandpa used—but the blended cost of all this additional plant growth will be less than a straight alfalfa seeding at usual recommendations.    More seed means more harvestable feed value, the alfalfa+clover+grass mix means sufficient fiber levels to keep your cows healthy (fewer displacements, less laminitis, less acidosis, better reproduction).  
More importantly, returning grass to your seeding mix will add beneficial root mass to the soil, making it capable of holding more rain water and adding beneficial organic matter.

Think about it.     Fall is a great time to plant a new seeding.     We have the right seed to do it.
Of course, if you prefer, Spring is also a great time to plant a new seeding, perhaps with cover from an equally high digestible small grain like forage oats or spring triticale to harvest first.