Cow Sense Chronicle || Night Feeding for Daytime Calving

Written by Rachel Endecott, Beef Cattle Specialist

We’ve all experienced that middle‐of‐the‐night calving incident that sure would have been easier to manage if it had happened in the daylight. Some ranchers use an evening feeding strategy to shift more cows to calve during the day.

A case study comparing two sets of calving data with different feeding times illustrates this phenomenon well (Jaeger, et al. 2008. Professional Animal Scien st. 24:247). One group of cows was fed between 6 and 8 am (15 years of data, 1210 observations) and another group of cows was fed between 4 and 6 pm ( 5 years of data, 537 observations). Researchers divided the day into six, 4‐hour periods starting at 6 am and recorded the number of cows who calved during each 4‐hour period.

Cows who were fed in the morning had nearly equal distribution of cows calving during each period of the day. This resulted in nearly equal proportions of cows calving between 6 am and 6 pm (52%) and those calving between 6 pm and 6 am (48%).

Cows who were fed in the evening did not have an equal distribution of cows calving during each period of the day. In fact, 85% of cows calved between 6 am and 6 pm and only 15% calved between 6 pm and 6 am.

There are many factors in addition to timing of feeding that can override the timing of calving. Research in cattle and other species suggests that physical activity, daily variation in hormonal secretion, ambient temperature, or day length may play a role.

Questions for Rachel? or 406-994-3747

Cow Sense Chronicle: Wintertime Herd Bull Blues

Happy New Year! As I write, we are finally experiencing some above-zero temperatures here in Montana for the year, which are very welcome. During my travels to Extension programs this month (fondly referred to as Asphalt Cowgirl January), I’ve seen a lot of herd bulls out to winter pasture, and I’ll be very honest with you – I have concerns about the future fertility of many of the bulls I’ve driven past.

Protection from inclement weather is a critical factor in winter herd bull management because of the very real concern of frostbit of the scrotum. While mild frostbite generally has a good recovery rate, severe frostbite can leave a bull infertile. Scarring from frostbite can hinder a bull’s ability to raise and lower the testicles for proper temperature regulation. This regulation depends on coordination of three structures: the tunica dartos muscle in the walls of the scrotum, which relaxes when hot and contracts when cold; the external cremaster muscle within the spermatic cord, which lengthens or shortens to lower or raise the testicles depending on temperature; and the pampini‐ form plexus, which is a coil of veins that provide an effective counter current temperature exchange by cooling arterial blood entering the testicle and transferring its heat to the venous blood leaving the testicle. Normal sperm formation only occurs at 4‐5 degrees below body temperature, so any damage to any of these three structures could result in infertility.

Pull up that National Weather Service windchill chart and take a look at some of the effective temperatures we’ve experienced already this winter. The frostbite warning zones aren’t going to be much different for that vital part of bull anatomy than they are for human skin. You’ve invested in those herd bulls for the future of your cow herd and sustainability of your ranch. Shouldn’t you put a little insurance policy on that investment? Ensure that bulls have the ability to get out the wind and are not lying on unbedded, frozen ground. Putting testicles on ice is not conducive to fertility.

Cow Sense Chronicle is written by Rachel Endecott, Beef Cattle Specialist with Montana State University Extension

Cow Sense Chronicle: Early Weaning As a Drought Management Strategy

From Cow Sense Chronicles by Rachel Endecott, Beef Cattle Specialist

I’ve been hearing from folks experiencing drought and fires throughout the state. Other regions are in good shape, but some are ready for winter to come to the rescue! This month, I’ll give a brief overview of early weaning as one drought management tool for ranchers.

The majority of spring‐born beef calves are weaned at 6 to 7 months of age, typically in October or November. This timeframe will vary based on calving season, location, and marketing scheme. As dry conditions result in limited forage availability, producers may consider early weaning to ease some of the demand. By the time a calf is 6 to 7 months old, he or she consumes about half of the amount of forage that a mature cow consumes.

Weaning calves removes the lactation demand for nutrients. Cow requirements and intake will both decrease after weaning. A rule of thumb I use in my beef cattle management class is that for every day calves are weaned earlier than normal, 0.6 grazing days worth of forage are saved. This incorporates both the decrease in calf consumption of forage and the lower intake of a non‐lactating cow. This thumb rule was developed with a 1300‐lb cow weaning a 600‐lb calf at 7 months of age. If for‐ age is of adequate quantity and quality, we expect cow body condition to improve post‐weaning, which can pay dividends for the next breeding season. Weaning earlier gives the cow more time during mid‐gestation when her requirements are the lowest to put on weight going into winter and next year’s calving season.

Early weaning does come with some challenges. What are you going to do with the early weaned calves? In a drought situation, you might not have forage available to wean them on pasture. Do you have harvested feedstuffs you can feed to them? Can you send them to your buyer early? Will they stay in pens built for larger calves? Are you prepared to deal with calf health issues that may arise? Do you have the resources to have them backgrounded on‐ranch or elsewhere?

There are a couple of schools of thought when it comes to early weaning. “Traditional” early weaning might be August or September instead of October or November for many spring calving herds, like what I’ve described on the previous page. Research has shown improvements in cow condition that could make a positive difference in reproductive performance next year. If, however, we are in a bad enough drought situation that we feel we need to make a positive difference in reproductive performance THIS year, calves need to be weaned before the breeding season. Cows will increase body condition and breed up well in this system. The disadvantage is that you now have a bunch of 80‐day‐old calves to manage, and that’s not for the faint‐hearted.

Don’t forget the upcoming Veterinary Feed Directive short courses around the state. We’d love to see you and visit about the implications the new rule has for livestock producers, so RSVP to the appropriate local county Extension office listed below. All meetings start at 1 pm.

VFD Short Course Schedule Summer 2016

August 3 Miles City – Fort Keogh – 406-874-3370

August 4 Billings – County Courthouse – 406-256-2828

August 9 Glasgow Cottonwood Inn – 406-228-6241

August 10 Havre – MSU NARC – 406-231-5150

August 11 Lewistown – Eagles – 406-535-3919

August 16 Sidney – Extension Office – 406-433-1206

August 24 Butte – Public Library – 406-723-0217

August 25 Missoula – Extension Office – 406-258-4200

September 12 Great Falls TBD 406-454-6980

September 21 Dillon UM-Western 406-683-3785

MSU Students Place Second in Regional Animal Science Competition

Rachel Endecott, Montana State University Extension Beef Cattle SpecialistBy Dr. Rachel Endecott, MSU Extension Beef Cattle Specialist

Happy summer! This month, I’m proud to feature this press release from MSU News Service about the MSU Academic Quadrathlon Team.

BOZEMAN – Four students from Montana State University’s Department of Animal and Range Sciences in the College of Agriculture placed second in the Western Region Academic Quadrathlon, held June 22-23 in Ruidoso, N.M.

The regional contest was held in conjunction with the 2015 Western Section American Society of Animal Science meetings, hosted by New Mexico State University. The MSU team competed with four other universities in the western region, including California State University-Chico, New Mexico State University, Oregon State University and Utah State University.

L to R, Elena Combs, Alyson Hicks-Lynch, Bailey Engle, Emily Griswold

L to R, Elena Combs, Alyson Hicks-Lynch, Bailey Engle, Emily Griswold

Elena Combs of Missoula, Bailey Engle of Big Timber, Emily Griswold of Millerstown, Pa., and Alyson Hicks-Lynch of Hood River, Ore. competed in a four-part contest that consisted of a comprehensive written exam, impromptu oral presentation, hands-on lab practicum and a double-elimination quiz bowl tournament.

“Elena, Bailey, Emily and Alyson did a spectacular job representing MSU at the contest,” said Rachel Endecott, team adviser and MSU beef cattle extension specialist. “I’m extremely proud of them and their hard work.”

All four students graduated in May from the department. Endecott said Combs has been accepted into the Washington, Idaho, Montana and Utah (WIMU) Regional Program in Veterinary Medicine and will complete her first year of veterinary school in Bozeman this fall. Engle will begin a five-year Ph.D. program in breeding and genetics at Texas A&M University. Griswold works as a veterinary technician at Sorenson Veterinary Clinic and is applying for vet school this year. Hicks-Lynch will begin a master’s degree program at Oregon State University in range management and ruminant nutrition this fall.

Beef Cattle Water Requirements Changing With Summer Heat

Dr. Rachel Endecott, MSU Extension Beef Cattle Specialist

Of the six classes of nutrients — carbohydrates, fat, protein, vitamins, minerals, and water — water is the most often overlooked, yet the most critical. Cattle performance can be affected by water intake.

Water requirements are a bit of a moving target, as feeds contain water and the metabolism of certain nutrients in the body produces water. This means that not all the water needs must be supplied as drinking water. High moisture feeds such as silages or pasture have increased water content, while harvested forages such as hay and straw contain little water. Cattle water needs are influenced by temperature, physiological stage, and weight (Table 1).

Endecott requirements of range livestock

Water intake increases dramatically at high temperatures; in fact, water requirements double between 50° and 95° F!  Table 2 illustrates the daily water requirements in gallons per 100 pounds of body weight for cattle at 90° F. This implies that a spring calving cow-calf pair would require 28 gallons of water for a 1400-lb cow plus an additional  7-9 gallons for a 350-450-lb calf (some of this increased calf water requirement can be met by milk intake).

Endecott water requirements cattle temperature

Providing unlimited access to clean, fresh water will ensure cattle performance is not negatively impacted; this goal becomes even more critical with increasing temperatures.

Postpartum Interval and Fertility | Rancher Education

Rachel Endecott, Montana State University Extension Beef Cattle SpecialistBy Dr. Rachel Endecott, MSU Extension Beef Cattle Specialist

After calving, cows go through a period of temporary infertility known as postpartum anestrus. Cows will not experience estrous cycles during this time. Another common term associated with this phenomenon is postpartum interval, which is the time from calving to the subsequent conception. Postpartum interval plays an important role in determining a cow’s calving interval, or the number of days from calving date in one year to calving date the next year. To maintain a 365-day calving interval, a cow must have a postpartum interval of 80-85 days. If a shorter calving interval is desired to move the cow up in the calving cycle, she must have a postpartum interval of less than 80-85 days.

Several factors can influence the length of the postpartum anestrous period, including uterine involution, short cycling, suckling effects, and nutritional status. Uterine involution is the regression of the uterus—in both structure and function—to a status that is capable of carrying another pregnancy. This entails the uterus returning to a non-pregnant size, shape, and position, shedding all fetal membranes, and the repair of uterine tissues. This process is completed in approximately 20-40 days post-calving if no complications arise.

The first ovulation postpartum often occurs without visual signs of the cow being in heat, and is often followed by abnormal function of the corpus luteum (CL). Normal CL lifespan takes up 14-18 days of the typical 21-day estrous cycle of a beef cow. The short estrous cycles experienced by cows overcoming postpartum anestrus are characterized by a CL lifespan of 10 days or less. This is thought to be due to high levels of prostaglandin production and metabolism by the uterus during uterine involution. Prostaglandin is responsible for regression and death of the CL in a normal estrous cycle, but at the elevated levels described, that regression and death of the CL is premature. If fertilization of the egg from this ovulation were to occur, maternal recognition of pregnancy would fail as CL regression would take place too soon, and the embryo would be lost.

A nursing calf can be a factor in the length of time a cow takes to return to cyclicity. One might assume that the energy demand of lactation is the major issue at play in this case, but it is actually the suckling effect and presence of a calf. Suckling triggers a complex system of brain and hormone responses that result in lack of ovulation.  Frequency of suckling has shown to have a threshold influence on postpartum fertility. Suckling sessions of two or less per day promote return to cyclicity while sessions of greater than two per day tend to cause postpartum anestrus. It has been suggested that the maternal bond between the dam and calf plays an important role in this phenomenon as well. This may be due to the cow seeing, smelling, or hearing her calf or all of the above!

Plane of nutrition is an important part of cattle management throughout the production cycle. Pre-calving nutrition is probably more important than post-calving nutrition in impacting postpartum interval length. Cows with inadequate energy reserves typically have several follicular waves before a successful ovulation. Without ovulation, no CL forms and estrous cycles are not initiated. Due to the dramatic increases in nutrient requirements during late gestation and early lactation, intervention to improve cow condition during times of the year when nutrient requirements are lowest (post-weaning, for example) will result in the most efficient use of nutrients by the cow at a lower cost.

Many different factors interact to impact the postpartum anestrous period in beef cows. This post-calving period of temporary infertility can’t be avoided, but through an understanding of the systems at play, it can be managed to ensure reproductive success during the breeding season.

Tips for Cattle Vaccination Programs | 10 Things To Know

By Rachel Endecott, MSU Extension Beef Cattle Specialist

Rachel Endecott, Montana State University Extension Beef Cattle SpecialistAs fall work starts to wind down, thoughts might turn to preparing for the next year of production and all the supplies that come with it. Vaccines are an important part of a herd health program, and this piece will cover some background and considerations about vaccines and beef cattle production. This overview is not meant to recommend vaccination programs, but will provide definitions of terminology and suggestions for effective vaccination.

Just what is a vaccine, anyway? One technical definition is a “suspension of attenuated or killed microorganisms or the antigenic proteins derived from them.” Let’s take that piece-by-piece: in this case, the suspension is a liquid that contains particles (microorganisms or proteins from them) that are mixed with the liquid but are not dissolved in it.

Attenuated means altered, usually in a way that makes something less severe—modified-live vaccines contain attenuated microorganisms. Killed vaccines contain killed microorganisms. Antigenic means that a substance causes an immune response—vaccines with this formulation contain a protein from the microorganism that is source of the immune response.

Successful vaccination depends on three critical factors: an effective vaccine, a functioning immune system, and administration of the vaccine before exposure to the disease. A vaccine may be ineffective if it is mishandled, if a booster is required but not given, or because of antigenic differences between the vaccine and field strains of the microorganism to which an animal is exposed.

An animal’s immune system may be unresponsive to vaccination because of age—a young calf’s immune system might not be fully functional at the time of vaccination, or antibodies from maternal colostrum still present in the calf inactivated the vaccine. Inadequate nutrition may also cause an animal’s immune system to be unresponsive to vaccination. Two other reasons for vaccine failure include that the animal was incubating the disease when vaccinated and that the duration of immunity after vaccination was inadequate.

Some tips for effective vaccination include:

  1. Read and follow label directions. If you are unsure, consult your veterinarian or call the vaccine company directly before using the product.
  2. Follow proper Beef Quality Assurance guidelines.
  3. Sterilize equipment between uses. Modified-live vaccines are sensitive to disinfectants, so do not use chemical disinfectants in syringes or needles for MLV use.
  4. Refrigerate and store vaccines as directed on the label. Be sure appropriate temperatures for the vaccine are maintained when they are away from the refrigerator.
  5. Keep vaccines out of sunlight, even when in the syringe.
  6. Mark syringes to avoid mixing or incorrect dosage.
  7. Mix only enough vaccine to be used in one hour or less.
  8. Choose correct needles for the job, and replace often.
  9. Keep records of vaccinations used.
  10. Good sanitation, management and nutritional practices are necessary to achieve the best results from vaccination programs.

Managing Cow Body Condition At Fall Working

By Dr. Rachel Endecott, Extension Beef Cattle Specialist, Montana State University

cattle rampIt’s finally starting to feel a bit like fall, and with that come chores like weaning, shipping, and pregnancy checking.  While those cows are in the pen for fall work, it might be worth your while to evaluate their body condition.

Body condition scores describe relative fatness of a cowherd using a 9-point system, where 1 is “emaciated” and 9 is “obese”.  The main components of body condition scoring are visible bone structure, muscling, and fat cover. A body condition score 1 cow has shoulders, ribs, backbone, hooks, and pins that are sharp to the touch and easily visible.  She would exhibit no evidence of fat or muscling.  In contrast, the bone structure of a body condition score 9 cow is not seen or easily felt and her tailhead is buried in fat. My theory is that most body condition score 9 cows have names, not numbers!  Happily, neither body condition score 1 or 9 cows are common sights in Montana beef cattle herds.

Most industry recommendations suggest that mature cows be in condition score 5 at calving and that first-calf heifers be in condition score 6 for optimal reproductive performance and colostrum production.  Characteristics of a body condition score 5 cow include that her 12th and 13th ribs are only visible if she is shrunk, and she has visible muscling and some fat on each side of her tailhead.  On the other hand, the ribs of a body condition score 6 cow are fully covered and not visible, and she has noticeable springiness over her foreribs and tailhead.

Post-weaning is a great time to improve condition of thin cows because it coincides with their lowest nutrient requirements of their production cycle.  This phenomenon can often be observed when cows graze dormant forage pastures post-weaning and gain body condition going into the winter, and shows that even in late lactation, the production of milk requires a large proportion of nutrients.  Energy requirements decrease nearly 25% when a cow transitions from late lactation to a dry cow in mid-gestation, and protein requirements decrease by nearly a third from pre-weaning to post-weaning.

Three important times of the year to take a critical look at body condition would be at weaning/preg check, the start of the third trimester, and calving. Keep in mind that as time passes between weaning and calving, the opportunity to take advantage of lower nutrient requirements of the cow slips away. Post-weaning is usually the best time to put weight on thin cows in an economical and efficient manner.

Specialists, Generalists, and Working with People

Rachel Endecott Montana Young Stockgrowers Mid Year Miles CityDr. Rachel Endecott, Belgrade, MSU Extension Beef Cattle Specialist

Sometimes, it seems that the world wants people who specialize. For example, my job title is Extension beef cattle specialist; however, “beef cattle” is a fairly general topic. In fact, I’m trained as a ruminant nutritionist, but I help folks with cattle reproductive physiology, genetics, marketing, health, and general management questions on a regular basis in addition to their nutrition questions. I’ve found that my clientele don’t care how I was trained; they just expect answers to their beef cattle questions. My ranch background and animal science training has made me pretty comfortable with the generalist role. And if you think my work makes me a Jill-of-all-trades, think about your county Extension agent. Many of you live in single-agent counties, where that one person handles all the questions that come into the office.

What kind of tree is this? What kind of bug is this? Is this bug killing my tree? Can you help out with the community forum on the new swimming pool? Can you test my pressure cooker before canning season starts? Can you come take a look at the damage the hailstorm did to my wheat? Should I test my grain hay for nitrates? And I’ll leave all the 4-H related questions up to your imagination! I’d encourage you to sit down with your county agent(s) sometime and ask about the variety in their job; you might be surprised.

At Mid Year, I was invited to speak at the Young Stockgrower meeting about issues and trends in the beef cattle industry. I’d say that was a pretty generalist topic, so I started with changes in the use of feed-grade antibiotics and we had a good discussion about that and a few other topics. At the end, all the speakers took questions as a panel, one of which was “What advice would you give to a young person who wants to talk to their folks or grandparents about making a change on the operation?”

My answer was this: Get some soft skill leadership training before you have that conversation. Now this might raise an eyebrow or two out there in MSGA readership land, and probably did that day in Miles City, too. But here’s where I’m coming from: in school, we choose our area of interest to study with the goal specializing in that area of interest, be it animal science, ag business or whatever. I think most would agree that as you enter the workforce (and for the rest of your career), you might have to generalize some depending on the job.

Did you learn about how to effectively work with people from other generations or different personality types? I know I didn’t. And (as I was reminded at the ranch rodeo by one of my clientele), I’ve gone to a lot of school! But you know what a major part of my job is? Working with people. I bet it’s a pretty big part of your job, too. What would it be like to have some training to help you work more effectively with people?

Calculating Calving Distribution to Evaluate Reproductive Performance

Rachel Endecott, Montana State University Extension Beef Cattle SpecialistBy Dr. Rachel Endecott, MSU Extension, Beef Cattle Specialist

Calculating calving distribution is one way to evaluate the previous year’s reproductive performance for the cowherd. Calving distribution follows how cows are calving during the calving season, split into 21-day periods (the length of a cow’s estrous cycle). The starting date of the calving distribution can be determined in a couple different ways. The first is to add 283 days (average gestation length) to the breeding date or bull turnout date, and the second is to assign the starting date as the day when the third mature cow calves.

In herds where cow age can be identified along with calving date, calving distribution can be calculated for young cows separately from older cows, which may provide information about breed-up performance that might not otherwise be easily observed. Here is an example calving distribution from the Beef Improvement Federation Guidelines publication.

What is a good benchmark number for calving distribution? One example comes from the North Dakota Beef Cattle Improvement Association Cow Herd Appraisal Performance Software (CHAPS) program. The CHAPS benchmark for the first 21-day calving period is 63.4%. The benchmarks for 42 and 63 days are 88.8% and 95.6%, respectively.

table calving period evaluating calving performance

From this chart, do you see a group of cows you might be more concerned with compared to another? Perhaps the 3-year-olds? Check out a graph of this data for a more visual perspective.

Chart calving period for reproductive performance

In this format, the 3-year-old cows really jump out. All other age groups have the largest percentage of cows calving during the first 21 days, but the largest percentage of 3-year-olds calved during the second 21 days. Many beef cattle producers find that getting first-calf heifers to breed back well is a challenge. Some strategies to improve young cow reproductive performance include implementing proper heifer development and pre– and post-calving nutrition programs.

Some producers start the yearling breeding season 2-3 weeks ahead of the mature cows in an effort to give the heifers more time to recover before breeding season. On the other hand, some producers implement a shortened (say, 30-day) breeding season for yearling heifers in an effort to put selection pressure on reproduction. In this scenario, pregnancy rates will be lower than in a longer breeding season, so more potential replacement heifers may need to be kept back to ensure an appropriate replacement rate for the cowherd.

Keeping young cows separate from older cows before and after calving (if conditions allow) might also be a good young cow reproductive management strategy. Since young cows are still growing, their nutrient demands are higher than mature cows. Managing them separately allows for more targeted feeding to meet nutrient requirements. When managed together, feeding to meet mature cow requirements will result in a nutrient shortage for the young cows, while feeding to meet young cow requirements will result in overfeeding the mature cows, which could be a fairly expensive proposition.

Have you started planning for the 2014 breeding season? Or is it already well underway? An evaluation of calving distribution might give you some good insight on how last year’s management environment impacted cowherd reproductive performance.