Growing and Finishing Bison: Principles and Practices

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Murray Feist
Saskatchewan Agriculture and Food

Reprinted from Smoke Signals, volumeXI, number 6, December, 2000, pages 4-9

Summary

This presentation was originally given at the International Bison Conference 2000 in Edmonton, Alberta. Murray discusses the theory of feeding bison for growth and for finishing. He also explains how to calculate break even prices for finished bison and for bison feeder calves.

Introduction

As the bison industry grows and matures in western Canada and abroad, so has the demand for the development of growing and finishing operations. While there is an effort to distinguish bison from that of beef, use of the terms "growing" and "finishing" and such production methods have been copied. However, differences in animal growth patterns, seasonal effects and end products need to be examined. As well, risk management tools for determining break even analysis and profitability need to be addressed and utilized to ensure a successful back grounding and finishing bison industry.

Growing versus Finishing

In the beef cattle industry, growing and finishing are two distinct practices. The growing phase (also known as the backgrounding or stocker phase) is used to grow calves at a controlled rate of growth to reach a target weight within a certain period of time. Backgrounding calves in a dry lot system tend to be based on dry forages (e.g. grass hay, cereal green feed, etc.) with or without grain concentrates. These diets contain lower energy levels relative to finishing rations. Average daily gains are typically lower in the backgrounding phase compared to the finishing phase. The growing/backgrounding phase is mainly used to deposit muscle on the frame of the animal while the animal is still growing. One example of back grounding in the bison industry has been to grow bull calves to weigh 700 to 750 pounds prior to entering a finishing phase.

The finishing phase utilizes high energy rations to increase muscle mass, ensure fat deposition, and in the case of grass fed animals change the color of the fat from yellow to white. Finishing bison feeder bulls can be completed in dry lots or pasture lots. Diets in a dry lot situation can utilize dry forages (hay) based or wet forages (silage) with high levels of grain concentrates. It is desirable to feed the animals to a targeted weight with targeted fat levels as soon as possible. Currently, the bison industry uses two methods in finishing bison. Grass finishing involves the feeding of bison on forages from weaning to target weight with the last 100 days feeding a high level of grain in the diet, while grain finishing involves the feeding of high levels of grains from weaning to target weight. There also are several combinations of grain and grass finishing being utilized. Given the different methods of growing bison for the meat market, finishing on high grain diets, at the present time, is desirable (in some markets) for at least the last 90 days prior to slaughter for the purpose of ensuring a white fat color at slaughter. This practice is particularly important for grass fed bison bulls as their fat will have a distinct yellow color if no grain concentrates have been fed when slaughtered.

Growth Curves

Traditional livestock such as beef cattle exhibit a live-weight growth curve called the sigmoid growth curve (Western Canada Feedlot Management School Manual, 1997). This curve indicates that body weight is consistently increasing from birth to 30 months of age, with rapid growth during puberty as juveniles, followed by slowed growth as the animal approaches mature body weight. In section 1, the young animal is rapidly growing. This rapid increase in body weight is due to the development of bone structure and the deposition of muscle, organs and nervous tissue with little body fat. In sections 2, skeletal, organ and nervous tissue growth is slowing with body weight gains attributed to the deposition of muscle mass. During section 3, the majority of the growth is due to fat deposition with some muscle mass deposition, and in section 4 nearly all increases in body weight are attributed to fat deposition only. Feed conversion is reduced as feed energy is converted into fat and is not being used to drive muscle deposition. Sections 1 to 3 are considered the growing phase, and section 4 is considered the finishing phase.

Feeding animals according to the phases of growth requires that for the first 2 sections, diets need to be high in protein, energy and minerals to support the bone, muscle, organ and nervous tissue growth. In section 3, bone, organ muscle and nervous tissue deposition nearly completed, with fat deposition becoming the main contributor to body weight gain. At this time, beef cattle feeders are providing diets high in energy necessary to drive the laying down of fat and the finishing of the animal. High protein diets are not required during section 3 as the protein will not be converted into muscle and will not contribute to increased body weight. Rather, nearly all of the excess protein will be excreted in the feces and urine, with a very small percentage of the protein converted into energy. At this time, diets high in energy are required to further fat deposition. If feeding was to continue into section 4 of the growth curve, too much fat will be deposited, resulting in down graded carcasses.

With bison, the growth curve does not show a continual increase in live- weight mass as it does for traditional ruminant livestock such as beef. Bison tend to grow from birth to 18 months of age. Upon reaching that age, the metabolism of the bison slows to a maintenance state where the impetus to grow is drastically reduced or eliminated. Much like other native ruminants from North America, mature bison experience a winter weight loss of up to 10 to 15% of pre-winter weight. This period of static/negative growth occurs during the majority of the wintering period. In spring, the metabolism of the bison increases nearly 2 fold, enhancing appetite and driving a growth in body weight. This growth in body weight mass continues until the animal reaches 30 months of age, upon when it enters it’s 3^rd winter. The metabolism again is reduced to a maintenance state where the bison may maintain or lose weight. At the present time, there are choices to make as to whether or not bison bull calves weaned at 6 to 7 months of age should enter a finishing feed yard immediately or start them in the feed yard as long yearlings at 15 to 18 months of age. The decision can affect how long the bulls will be fed, how old and how heavy the feeder bulls will be when marketed. Variable entry weights and mixing of bulls from different herds may depress bull calf performance in a feed yard due to stress and the necessity to renew the order of dominance between animals. Performance may not be affected if the bull calves from one source are all kept together. Feed yard feeding and finishing of bull calves from weaning to finish requires a longer period of time in the feed yard while the finishing program for long yearlings is usually shorter in duration. This means that feeding long yearlings can be cheaper if the yearling bulls were fed forages prior to the finishing period as forages based diets tend to be cheaper than grain based diets. One option that bison producers have been utilizing is feeding yearlings forages to maintain the animals during the wintering period. While this may result in slower daily gains, this practice does allow the feed yard manager to take advantage of compensatory gains in the spring and increase the marketing options available.

Creep Feeding

Creep feeding is the practice where supplemental feed is provided to calves while nursing to compensate for poor forages and/or declining pasture quality and declining milk production by the cow. The benefits of creep feeding include optimized growth of the calf when younger resulting in increased weaning weights, cheaper gains due to better feed to gain ratios, more uniform bull calves and feed bunk or self feeder recognition.

Some of the detractions to creep feeding include increased cost to the producer, possible elimination of compensatory gains in the spring, and over compensation for a poor milking cow that would make culling based on milk production more difficult. A common observation in trying to finish creep fed calves is that they don't seem to gain as much muscle mass as non-creep fed calves. Creep feeding calves may result in better calf gains prior to weaning, but upon entering the feed yard, one of two things may happen. The calf may be put onto a lower energy, forage based receiving ration, reducing gains. The object in growing and finishing bull calves is to step the energy content of the diet from low to high, not from a high to low to high energy level. This fluctuation in the energy level of the ration will affect the gain and most often reduce potential performance. Smaller framed calves that have been creep fed may actually stop depositing muscle mass earlier than the rest of the calves when place in a feed yard, resulting in feed energy being converted into fat and a higher feed to gain ratio. These animals tend not to grade as well due to excessive fat content as they become over finished. And finally, if producers are looking at selecting breeding stock from back grounded/stocker bull calves, creep fed bull calves may have problems with foot/breeding soundness and decreased breeding lifespan.

Expected Finishing Performance

Several studies have been conducted measuring the finishing performance of weaned bull calves and yearling bulls in a feed yard environment. Tables 1 is an adaptation from Anderson and Miller (2000) and show some selected seasonal data for weaned bull calves and yearling bulls.

Table 2. Break Even Purchase Price Analysis of weaned calves and yearling fed to 1,050 pounds.

	Season	Days on Feed (D)	Sale Weight (live, lb)	Gross Return	Gain (lb)	Cost of grain	BEPP/ head
Calves	Fall	240	932	$1,638	432	$540	$1,098
	Winter	360	1,004	$1,766	504	$630	$1,136
	Spring	410	1,054	$1,853	554	$692	$1,160
Yearlings	Winter	160	996	$1,699	216	$270	$1,430
	Spring	240	1,110	$1,953	360	$450	$1,503
Assumptions: Purchasing weaned calves at 500 pounds, yearlings at 750 pounds, 1.8 lb/day gain in spring, summer and fall, 0.9 lb/day gain in winter; $2.25 per head per day cost of production, 55% dressing percentage and $3.20 (Canadian dollar) per pound hot carcass weight.

This data shows that one can expect approximately 1.38 to 1.95 lb per day average gain by both weaned bull calves and yearling bulls on finishing diets in a feed yard environment. In the winter, feed intake does not change that dramatically, however expected gains and the calculated feed to gain ratio is drastically affected. When feeding bison bulls, it is important for the feed yard manager to be aware of these changes in daily gain and feed to gain as it will dramatically affect the cost of finishing those animals. It is also important to consider whether or not to finish weaned calves versus yearlings as feeding the weaned calf may result in having to feed that calf through two winters of poor feed conversion whereas feeding yearlings only results in feeding through one winter.

Feed Yard Management Tools

For existing producers or individual producers thinking of initiating a backrounding/finishing operation, the operation has to be economically viable. Two equations that analyze for the break even sale value and the break even purchasing price can be used as tools for risk analysis. These two formulae only work if costs of production and animal performance can accurately be established.

For the producer interesting in starting a feeding operation, the break even sale value should be evaluated.
Break Even Sale Value = (Initial Value) + (Total Cost of Gain)

Sale Weight

Initial value = (purchase weight x purchase price)
Total cost of gain = (total gain x the cost of gain)

The break even sale price provides a value that shows what each animal has to sell for if there is accurate assessment of purchase weight, price, and the cost of putting weight on the animal. When purchasing individual animals or a pen of animals, the initial value plus the cost equals the break even sale price. Any number above the break even sale value can be considered a profit to the operation.

An example of how to use this equation is as follows: Suppose a producer knows that it will cost (or even custom feeds) for $2.50 per head per day, is purchasing 450 pound bison bull calves for $2.30 per pound live-weight, the calves will gain 2.0 lb. per day resulting in a cost of $1.25 per lb. and wants to put 600 pounds of gain on the calf. The equation would be:

Break Even Sale Value = (450 lb. x $2.30/lb) + (600 lb. gain x $1.25/lb gain)
1050 lb. Final Weight = $1,035 + $750
1050 = $1.70 per pound live-weight = $1,785 per head

This producer would have to return $1,785 per 1050 lb. bull to break even in that feeding operation. Any returns over that value would return a profit to the operation.

By using the Break Even Purchase Price, a manager is attempting to make decisions on what the operation can afford to pay for animals based on a determined cost to grow that animal to finish and an anticipated return from selling those animals.

Break Even Purchase Price = {Sale Value) - (Total Cost of Gain)
Purchase Weight
Sale Value = (sale weight x sale price)
Total Cost of Gain = (total gain x the cost of gain)

An example of how to use this equation is as follows: Suppose a producer knows that it will cost $2.50 per head per day to feed the bison bull, the bull will gain 2.0 lb. per day ($1.25 cost per pound of gain), how much return each 1035lb. bull will bring, and is looking at buying 450 lb. bull calves and put 600 lb. of gain on those animals. The equation would be:

Break Even Purchase Price = (1035 lb. x $1.71/1b) -(600 lb. gain x $1.25/lb. gain)
450 lb. purchase weight = $1,800 -$750
450 = $2.23 per pound live-weight = $1,050 per head

This producer would have to purchase 450 lb. for $1,050 in order to break even. Purchasing 450 pound bull calves for less than $1,050 will result in profit for the operation.

Recognizably, there are several elements that will be variable when calculating breakeven values of sale or purchase. Animal daily gain, cost per pound of gain, sale weight, sale value and purchase weight can all vary, affecting the breakeven status of the operation. Table 2 shows the change in the breakeven purchase price of weaned calves and yearlings by only varying the sale weight and days on feed (time of year) when sold. The assumptions are: purchasing weaned calves at 500 pounds, yearlings at 750 pounds, 1.8 lb/day gain in spring, summer and fall, 0.9 lb./day gain in winter, $2.25 per head per day cost of production, 55% dressing percentage and $3.20 (Canadian dollar) per pound hot carcass weight of the finished bull.

Table 2. Break Even Purchase Price Analysis of weaned calves and yearling fed to 1,050 pounds.

	Season	Days on Feed (D)	Sale Weight (live, lb)	Gross Return	Gain (lb)	Cost of grain	BEPP/ head
Calves	Fall	240	932	$1,638	432	$540	$1,098
	Winter	360	1,004	$1,766	504	$630	$1,136
	Spring	410	1,054	$1,853	554	$692	$1,160
Yearlings	Winter	160	996	$1,699	216	$270	$1,430
	Spring	240	1,110	$1,953	360	$450	$1,503
Assumptions: Purchasing weaned calves at 500 pounds, yearlings at 750 pounds, 1.8 lb/day gain in spring, summer and fall, 0.9 lb/day gain in winter; $2.25 per head per day cost of production, 55% dressing percentage and $3.20 (Canadian dollar) per pound hot carcass weight.

If a producer was then able to purchase 500 pounds bison bull calves for $1,000 per head for the purpose of finishing them to 1,050 pounds, all assumptions equal, a profit of $98 to $160 per head could be realized. If a producer was able to purchase 750 pound yearling bulls for $1,000 per head, realized profits would range from $430 to $503 per head.

Conclusions

From research studies and individual producer records, it is important to recognize that there are several production targets. Average daily gains of 1.7 to 1.9 pounds per day in the spring, summer and fall are considered average. Producers should consider culling herd animals if calves exhibit daily gains of less than 1.3 pounds per day. Feed conversions of 12 pounds of feed per 1 pound of gain are considered average, while it is not unusual for compensatory gains in the spring to reach 8 pounds of feed to 1 pound of gain. Identification and recognition of creep fed calves will affect production target values.

Production costs should be identified and used with breakeven analysis equations to identify potential profit/loss situations. Given the genetic limitation on daily gains and seasonal affects, costs of production will vary depending on how the producer manages the bull calves in the feeding operation. Pasture based feeding systems that are recognized as backgrounding operations in the beef industry may be utilized as a method of finishing bison bulls. This method of feeding quite possible may reduce the cost of production per pound of gain dramatically, greatly affecting the breakeven analysis equations.

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