Feed Efficiency RFI

Imagine an entire herd that takes 20% less feed to achieve the same growth.  This is regardless of the feed, hay, pasture, corn etc…

The highest scoring bull for Residual Feed Intake (RFI) at the West Virginia Wardensville Bull Test is an A.I. son of our (Pedro’s Angus) Exclusive K179.  RFI has been used for years by the poultry and hog industries to improve cost of gain efficiency. Bull Reg #17925782 is owned by Snuffer & Sons Surveyor, W. VA.  His RFI score is -8.39.

For complete details of RFI, please read the article below: 

Feed Efficiency in the West Virginia Bull Test Evaluation Program 2/17/15

By E.E.D. Felton, J.E. Warren Jr., W.R. Wagner and J.W. Yates  

 The profitability of beef production systems is a function of both minimizing inputs and maximizing outputs. Genetic improvement of the beef herd has generally targeted traits that increased outputs such as weight gain, live-weight, carcass traits and meat quality. Feed costs account for an estimated 60-70% of total beef unit operating costs and are the most significant cost item in most production systems. Furthermore, in beef production systems the weight of the animal is the single most important component in determining value. It has long been known that efficiency of energy usage is different for maintenance and growth and is different for the type of tissue deposited during growth. Thus, the ability to accurately identify and propagate cattle that are efficient in converting feed into weight gain is an important component of a successful production program. Improvements in feed efficiency selection should be attainable since feed efficiency/feed conversion ratio is considered a moderately to highly heritable trait (heritability = 0.30 to 0.46).  Even so, feed efficiency is generally not measured in beef cattle performance testing programs because the amount of feed consumed is extremely difficult and labor intensive to measure on an individual basis.  Recent technological advances are making the collection of the necessary measurements attainable.

The “GrowSafe 4000E” system was installed and used to measure individual feed intake during the 2003-2004 West Virginia Bull Test Evaluation Program. This system of hardware and software consists of feed troughs mounted on load cells. An antenna grid is incorporated in the trough, and animals are fitted with electronic ear tags that are read by the antenna grid. An animal feeding at a trough is identified at five second intervals and feed available in each trough is weighed every second with an accuracy within 50g. The animal identification and feed consumed data are sent wireless via a communication panel to a computer with software to compile individual feed intake and individual feeding events. Bulls arrived at the test station in mid-October, 2003. Following a 3-week acclimation period, bulls were weighed on d 1 and 2 (averaged for on test body weight (BW), 42, 77, and 104 and 105 (averaged for off test BW). During the acclimation period and the 105-day test, bulls were fed ad-libitum a total-mixed-ration containing 13.6% crude protein and 73.6 and 45.0 Mcals of NEm and NEg per cwt, respectively.  Of 117 bulls completing the 105 d test, 113 were Angus, 2 were Hereford and 2 were Charolais.  Means (standard deviation) for age of bulls at the end of test, initial and final BW, total and average daily weight gain, and feed consumed as percent of body weight were 370 (24) days, 811 (108) and 1268 (115) lb, 454 (49) and 4.32 (0.46) lb, and 2.6 (0.27) percent, respectively.  Raw feed efficiency measured as units of feed per unit of gain (F:G) ranged from 4.49 to 8.93 (mean of 6.50) over the entire 105 d test and was correlated (P< 0.01) with age (0.42), birth weight   (-0.32), and average daily gain (-0.60).  During the middle 35 d period when most bulls should have been on the straight line proportion of their growth curve, F:G ranged from 4.14 to 12.75 (mean of 6.08).  Since raw F:G is not independent of rate of gain and birth weight it should not be used as a single selection criterion.  This could result in concomitant selection for increased mature body size of brood cows that is generally not desired by the industry.  Residual feed intake (RFI) is calculated as the difference in expected intake versus actual intake.  When based upon the 1996 NRC beef cattle model, which included adjustments for mature size, age, and degree of finish, RFI ranged from -35.25 to -1.03 suggesting that all bulls tested were above average in efficiency compared to animals used to develop the model.   However, this method does not eliminate the relationship of feed efficiency to animal gain and mature weight.  RFI was also calculated based upon linear regression of the experimental group body weights and gains over the test period.  By this method, animals of different physiological age, breed and mature size can be accurately compared in terms of metabolic efficiency of energy use.  Animals are compared based upon the average of the contemporary group (mean of 0).  RFI calculated by this method ranged from -8.39 to +7.22.  This method allows selection for feed efficiency independent of other important production variables, particularly rate of gain and mature body size.  

Note: Bull I.D .#37  is an A.I. son of Pedro’s Angus Exclusive K179. Bull No. 37 had the best RFI results from all bulls tested with a -8.39. 

In beef production systems the weight of the animal is the single most important component in determining value. Thus, the ability to identify and propagate cattle that are efficient in converting feed into weight gain becomes an important component of a successful production program. Because a one pound improvement in dry matter feed conversion of feeder calves reduces feed cost by as much as $50 per head, improved feed efficiency in cow-calf operations will reduce input cost and enhanced profit potential for beef producers. Furthermore, the production of offspring is the driving force behind most cow/calf operations. Thus, improving the efficiency of maintaining brood cows and of production of their offspring is of vital importance to the economic success of any cattle operation.  Appropriate means of analyzing feed efficiency must be employed to account for differences in stage of growth, maturity, and body type when growth and feed consumption are measured.

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Helping cows bond with calves

We warmed and dried a newborn in our laundry room a couple of times when the temp was -20 degrees. Then Momma had trouble bonding with her calf. After 24 hours of helping him nurse, they were OK.  This is a great article by Heather Smith Thomas for BEEF Magazine Jan 27, 2011. 

The bonding process is how a cow identifies her new calf and commits to caring for and protecting it. It’s a complex blend of hormonal-induced and learned behavior. Mature cows are more apt to quickly and successfully mother their offspring than first-time heifers. Older cows tend to be more consistent mothers and have more maternal drive than heifers, but hormones are the key factor.

“The cow is most receptive to wanting her newborn calf when she gives birth,” says Joseph Stookey of Western College of Veterinary Medicine, Saskatoon, Saskatchewan, Canada. “But, some cows become receptive up to a week before calving. Their hormone pump is already primed, and maternal hormones are reaching a level that makes them receptive to any new calf, even if it’s not theirs.”

At the other end of the spectrum are cows that lack the proper hormone profile or levels, or simply don’t want their calf. “We see this most often in heifers, or in females we assist or deliver by C-section. If it’s a rodeo getting the cow in for assistance, or she undergoes too much trauma, she may be less interested in the newborn calf,” Stookey says.

There also may be other hormones overriding the whole system due to stress and pain, or perhaps some of the drugs used during a C-section, he adds.

Oxytocin is  trigger

Changes in progesterone and estrogen levels initiate the birth process, but rising oxytocin levels released during calving trigger maternal behavior. “Oxytocin’s presence in the olfactory bulb of the brain helps explain the important role of smell and odor in the bonding process. A cow recognizes her calf by smell; she can always pick her calf out of a group,” Stookey says.

He says cervical stimulation is crucial for proper hormonal triggers, as stretching or stimulation of the cervix and birth canal causes release of oxytocin. “With a C-section there isn’t much cervical stimulation, since the fetus doesn’t come through it,” Stookey says.

Additionally, first-calf heifers produce less oxytocin than experienced cows. “Giving birth seems to prime the system and allows for release of larger quantities of oxytocin with subsequent births. Thus, heifers have two disadvantages – they’re less experienced than cows and have lower levels of oxytocin released in the brain during calving,” he explains.

While some heifers seem initially indifferent to their calves, they become more motherly within 12-24 hours as their milk comes in. If a heifer is indifferent or actively rejects her calf, assisting the calf in nursing generally helps a heifer become more receptive, as it stimulates release of oxytocin.

“If you can stimulate milk letdown a few times by assisting the calf in nursing, the hormone comes on board and improves maternal behavior,” Stookey says. “Oxytocin can switch off the heifer’s aggression, reluctance or fear and turn its interest to mothering.” 

Understand bonding

The dam reacts to sensory clues provided by the calf and birth fluids. If she’s lying down as the calf slides out, she’ll generally raise her head to get a glimpse of the calf.

“Any movement of the calf (raising or shaking its head) is a strong stimulus to the cow to get up and turn around to smell the calf and start licking it. A vigorous calf elicits a stronger response than a weak or dead calf,” Stookey says.

Stookey explains in a study of more than 200 cows and heifers that required veterinary assistance (C-section or pull), a significantly higher percentage of calves judged as weak at birth were rejected, compared to calves judged average or strong.

“The smell and taste of birth fluids is another strong attractant that drives maternal behavior and stimulates the cow to lick the calf,” Stookey says. “If the mothering process is interrupted before she licks the calf, likelihood for rejection increases. Females that had difficult deliveries and required human assistance more often reject their calves.”

If you pull a calf, it helps to smear birth fluids across the muzzle and tongue of the dam following delivery. “This seems to jumpstart the maternal response. Simply placing the newborn in front of the mother may not be sufficient stimulus to start maternal behavior, especially for some first-calf heifers.”

Pouring feed onto a newborn calf may entice some reluctant mothers to approach the calf and eventually come in contact with birth fluids as they eat the feed, he adds.

If cows are closely confined in groups, they don’t get a chance to isolate themselves to calve. Jack Whittier, Colorado State University Extension beef specialist, says that allowing cows and heifers plenty of room can help prevent problems. Some cows may try to claim another’s newborn. If older cows intimidate a heifer, she may not mother her calf.

“First-calf heifers are more likely to isolate themselves from the herd. Researchers who have studied this behavior suspect that heifers leave the herd to move away from more dominant individuals that might disturb the bonding process,” Stookey says.

“There are always a few individuals, particularly heifers, that initially lack a strong mothering instinct,” Whittier explains. “Allowing them to calve out in the field by themselves is best. If they don’t bond quickly, moving them into a pen with their calf can sometimes work – so they can continue the bonding process without interruption by herdmates. Getting from point A to point B can be a challenge, however, and may confuse a heifer more and make it worse than if you’d left her alone,” he says.

If it’s cold or windy and the calf’s survival is at risk, you may have no choice but to bring the pair in for shelter. “In a blizzard, the need for protection overrides everything else,” Whittier says. If weather necessitates shelter, it’s best to quietly move each calving female to a private place to calve – such as her own barn stall. Moving her and her calf afterward can be more disruptive, especially for a heifer.

Older cows are more likely to follow you and the calf, especially if you put the calf in a sled or some other conveyance low to the ground so the cow can follow and keep sniffing her calf. But heifers may become confused, especially if they haven’t had time to lick and bond with the calf. She may run back to the birth site to seek her calf, rather than follow you or allow herself to be herded to the barn.

“You can’t just take the calf in the house to warm, then put it in the barn and move the heifer to the barn and expect her to mother it. She’s more apt to accept the calf if you take it back to the birth site. If you grabbed the calf before she filled in that template of recognition/bonding, she may not recognize the calf in the barn as hers. She’ll try to get back to the spot where she gave birth to find her calf,” Stookey says.

Make sure the cow has a chance to smell the calf. “If you move a calf from the birth site, make certain the cow follows. And, don’t totally dry a newborn because birth fluids are a strong stimulus in eliciting maternal behavior,” he says.

Tricks to get cows to claim calves

There are a number of tricks to get a cow to claim a calf, such as ranchers grafting an orphan calf onto a cow, says Jack Whittier, Colorado State University Extension beef specialist. Some of those methods can help with a bonding problem. Proximity is number one – keeping them close to one another – as sometimes hormonal triggers are slow to kick in.

There’s a complex hormone system involved in causing birth and initiating lactation. Like any biological system, it can get a little out of sequence; so just giving the heifer a little time may work things out, Whittier explains.

“I prefer to wait and see, rather than immediately jump in and try to change something. There are occasions when you need to do that, of course, but I caution producers not to be too anxious. Let the mother and calf figure it out,” he says.

Whittier says producers with many years of experience in calving heifers often develop a “sixth sense” in assessing a situation. “There’s no substitute for experience. Inexperienced people would do well to work with someone like that, and be observant and teachable.” he says.

If a cow is aggressive and kicking or hitting the calf with her head, some type of restraint may be needed to prevent injury to the calf or to help the calf find the udder. Often, it just takes one nursing to change her mind, but some females are still determined to attack the calf. House the calf in a small pen next to the cow’s, or in a paneled-off corner of the barn stall, and let the calf out for nursing only while you can supervise.

Another trick is to feed the cow her hay at nursing time. If she’s interested in eating, she’ll focus less on attacking her calf or moving away. Stand guard while the calf nurses and then return it to its safe corner. You may need to hobble the cow so she can’t kick, until she becomes more accepting.

If the cow won’t stand still, leave a halter on her, dragging the rope. Then you can easily get hold of the rope, and tie her while she eats her hay, enabling the calf to catch up with her and nurse. After dragging the rope and stepping on it, she quickly learns to respect this restraint.

It may take up to two weeks to change her mind about motherhood, but she’ll eventually accept the calf. Once she starts showing interest, mooing at the calf or licking it as it nurses, you can leave them together. Leave her hobbled until you’re sure she won’t try to kick him.

Another trick with an aggressive heifer is to lightly tranquilize her during the first day. This may mellow her attitude to allow the calf to nurse, which will help stimulate the hormones of motherhood. Ask your vet about proper use of tranquilizers.

Sometimes, the problem is physical. A heifer with a painful udder may kick at her calf just because it hurts. Injured teats or frostbitten teats may be too sore to allow suckling.

“Patience, good husbandry, astute observation and being in tune with cattle are most helpful. Look for ways to overcome problems,” Whittier says.

Excerpts from Jan 27, 2011 by  Heather Smith Thomas for BEEF Magazine.