Better Pork - June 2004Will the new three-site production units find a place in Ontario's pork industry?
Most of the traditional three-site production units or "loops" have been restructuring since the beginning of 2004. But, while bankers like the new approach, they are still keeping an open mind when it comes to independent producersby DON STONEMAN
Call them "restructured three-site" production units or call them "co-ops." There are some new ways of producing pigs out there in Ontario. Whatever their form, some observers think they look a lot like good old-fashioned farrow-to-finish operations, run on a larger scale.Bankers are keen on the new "restructured three-site" production units, where each of the players has a share in the risk as well as an opportunity to make a profit, says Mitchell-area pig farmer and real estate agent Kurt Keller.
One way to achieve shared risk and profit is to take ownership of the pigs as they go through your barn. Another way is to take a "flexible contract price that changes with the market," he suggests.
Traditional three-site production or "loops," where the pigs were owned by feed companies, entrepreneurs or investors, had been seen as less risky by lenders, who were prepared to lend money to farmers with lower equity on this basis.
The trouble with three-site production as an industry model was that every stage of production was guaranteed a profit, Keller says, and there was little, if any, money left for the entrepreneur or investor at the end of the day. He asserts that 80 per cent of those original three-site production loops have been restructured since the beginning of 2004.
Dale Snider, district manager with Farm Credit Canada (FCC) in Listowel, agrees that some different structures have taken shape in the last few months. Many producers have been forced to make changes as loops were dissolved, he says. Some co-ops have formed with several farmers coming together to form their own small loop. In addition, some farmers with sow-nurseries are now buying finishing operations so that they can feed pigs to market weight.
They aren't just waiting for another contract to come along, Snider says. The dissolution of loops has forced them to look at alternatives and one of those is farrow-to-finish, he says. "From a sheer dollars-and-cents point of view, we've known for a long time that an independent farrow-to-finish operation is more efficient than a contractual farrow-to-finish operation, from a production cost point of view."
Contract loops worked because operations with 15,000 sows could guarantee processors a consistent supply of pigs every week of a known genetic origin on a similar feeding program. "You would have some marketing power which the smaller independent guys didn't have."
The loop was able to command a higher price per kilogram of pork and hire a person just to "work the markets," he says. For independent operators, marketing was something that happened if there was spare time after the barn work and the management tasks were done.
The independent operators have now grown to a size where they can accommodate processors, Snider says. He doesn't see quality as an issue for packers any more, and he doubts that loops can command the higher price that they need for their pigs to pay for the increased costs of production associated with their business structure.
Snider says he has heard a lot of discussion about co-ops, where producers pool their resources in infrastructure and expertise but retain ownership of the pigs going through their barns. There are advantages to this approach. "There is more accountability and control when you have ownership," he notes.
As for farrow-to-finish operators: "They may not have grown in sow numbers, but they have grown in efficiency. They are better at controlling their costs. The independent guys are keeping up with the larger operations from a production point of view."
David Rose, manager with the Canadian Imperial Bank of Commerce (CIBC) in Port Perry, says established, mid-sized" farrow-to-finish operators seem to have weathered the last storm in pork markets better than some of the loops.
Why? He thinks they've adopted the same technologies as three-site producers while maintaining ownership of pigs and keeping costs lower. Pigs aren't moving through other people's hands, he says. "You have to be an excellent production manager and an excellent financial manager," he says.
So what are lenders looking for when producers knock on their door? Judging by the comments made by lenders interviewed by Better Pork, no one is prepared to shut themselves out of any aspect of the pork industry, at least not now that prices are recovering.
Vaughn Stuart, sales and market manager, agriculture and agribusiness for Ontario at the Royal Bank of Canada, says he keeps an open mind about business structures when pork producers come to his Guelph office. He is "more concerned about the viability of the business" than whether it is farrow-to-finish or part of a loop operation.
"We never make that a defining moment in a financing opportunity in the hog sector," Stuart says, qualifying that by saying that a contract "certainly makes a difference if you are looking at a finishing barn only." For a finishing barn, a debt-to-equity ratio of one to one would be ideal "if the management is strong," he says.
For pork operations in general, "we may go higher but we certainly won't go below two to one, he says. "Most commodities, if you are higher than that, can't afford bumps and no matter what sector you are in you are going to get bumps."
Dennis Crone, manager with CIBC in New Hamburg, agrees that cash flow is more important than equity. "A high equity partner that doesn't have cash flow to meet commitments isn't much good. If you getting involved with a strong partner. I don't think it's a problem." That said, "there aren't as many strong partners as there used to be."
Over the 10 years that loops have been around some lenders have strongly suggested that you be part of a loop, says Crone. "I think I've lent as much money to independent people as I have to people involved in loops. A capsule comment on a loop would be: If it's a good strong one, we are still interested in that kind of business. It depends on the cash flow and it depends on equity and management, and it really doesn't matter what the structure is."
However, FCC's Snider says, "there is still room for contracts out there. There are certain people that are great at finishing hogs, great at weaning pigs. That's what their talent is. They don't have the risk appetite to get into the marketing and into the capital of owned pigs."
For a lot of people, says real estate agent and former pork producer Claude Robin, loops facilitated entry into the pork industry. Capital requirements were generally lower than for a farrow-to-finish business and there are a number of advantages to three-site production, he says. "It was the way that it was structured that was a problem." BP
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back Small steps and giant leaps in combating ileitis
A new Iowa study has shed light on the shedding and seroconversion patterns rate of pigs infected with Lawsonia intracellularis bacteria.by S. ERNEST SANFORD
Sometimes we make giant leaps, but at other times it is the little things that make a difference. We have been battling with porcine proliferative enteropathy (PPE), colloquially known as "ileitis," for more than 50 years. It was about 25 years ago that pathologists at the University of Edinburgh in Scotland first identified the bacterium that causes ileitis in the intestinal cells of the ileum of the pig by using special stains on histology sections of the small and large intestines. It took another 20 years before the bacterium, now called Lawsonia intracellularis or LI, was actually isolated and unequivocally identified.Once we could finally grow the Lawsonia bacterium, however, we started to make some of those giant leaps I mentioned above. It immediately became possible to study the bacterium more minutely. This led to the development of new, more precise diagnostic tests. Among some of the first developed were the polymerase chain reaction (PCR) test, which afforded identification of the Lawsonia organism right in the feces of the live pig, and a serology (blood) test which showed antibodies produced by the pig after it had been infected by the bacterium. Development of these new tests then paved the way for better-targeted treatment and control programs.
Now comes one of those "little things." One missing piece of the puzzle was the ability to pinpoint more precisely how long it takes after a pig has been infected with Lawsonia before it starts to shed the organism in its feces. Furthermore, a precise knowledge was also lacking of when seroconversion (meaning the blood test turns positive) occurs relative to both the time of infection and the start of fecal shedding. This type of information could enable treatment and control programs to be targeted precisely. These would then be more effective in reducing the number of infective organisms being shed into the environment that could then infect other pigs in the same pen or barn.
Dr. Mark Hammer, a swine veterinarian in Iowa, has just completed and published a study on exactly those phenomena in nine large commercial production herds in the U.S. Midwest. He used PCR to detect the very earliest presence of Lawsonia in the pigs' feces and immunoperoxidase monolayer assay (IPMA) serology to determine when a statistically significant number of pigs in a particular group would seroconvert to Lawsonia.
What he found was that, from group to group, there was a wide range between when the first and last pigs in a group would actually start shedding Lawsonia in their feces. The earliest shedders were six weeks old, but shedding started as late as 23 weeks in other groups. Similarly, the age at which pigs would first seroconvert to LI ranged from 12 to 27 weeks of age.
More importantly, the interval between earliest shedding and earliest seroconversion ranged between two and eight weeks for any one group of pigs. The most common time span between shedding and seroconversion was usually two weeks. At least that two-week time span is somewhat comforting because it does coincide with what the researchers in controlled laboratory studies have been telling us for some time.
We know from previous work by other researchers that fecal shedding identified by PCR (PCR-positive fecal shedding) usually occurs about seven days and seroconversion about 14 days after experimental infection. What Dr. Hammer has reported, however, is what happens in "real-life" field situations in actual commercial herds. Not surprisingly, the "real-life" situation differs considerably from the laboratory experiments.
He was also able to show that the shedding and seroconversion patterns in continuous-flow operations were different from those in All-In/ All-Out (AIAO) units. In continuous flow operations the shedding-to-seroconversion interval was less variable (usually two weeks) -- hence more like the two-week interval reported from experimental studies -- and the seroconversion rate was usually higher in these pigs (i.e. more pigs seroconverted) than in herds following strict AIAO procedures.
These findings have several very real and immediate applications for the use and accurate interpretations of diagnostics in the control of ileitis.
In some herds, infection with LI might be starting in the nursery as early as five to six weeks of age. So even though clinical signs might not be seen until after placement in the grower-finisher barn, infection might have started earlier in some of the pigs in the group.
This is very critical for the timing of ileitis vaccine, since the vaccine has to be given to the pigs at least three to four weeks before they have been exposed to the LI organism for it to be able to protect the pigs against ileitis.
It also affects the placement of antimicrobial medication for the control of ileitis, since anti-ileitis medication has to be placed earlier earlier than usual in herds that have pigs exposed before they are moved into the finisher barn.
Overall, it enhances the value of diagnostics, once one is able to make accurate interpretations from the results of the diagnostic tests.
We can, then, conclude as follows:
- Although few diagnostic laboratories are able to culture Lawsonia intracellularis, the bacterium that causes ileitis, they are now able to identify the organism and diagnose the disease in the live pig via the PCR test which can identify Lawsonia in pigs' feces and by the use of serology (blood) tests showing antibodies in pigs' blood.
- Using various combinations of tests, Dr. Hammer shows in this study a wide range for pigs in the same group to become infected with and start shedding Lawsonia. Some pigs start shedding Lawsonia as early as six weeks of age, while others in the same group start as late as 23 weeks of age.
- In the groups he studied, seroconversion started from 12 weeks to 27 weeks of age.
- Finally, the shedding-to-seroconversion interval was more consistent (about two weeks), and more pigs seroconverted within a group, in continuous-flow operations than in AIAO units.BP
S. Ernest Sanford, DVM, Dip. Path., Diplomate ACVP, is a swine specialist with Boehringer Ingelheim Vetmedica (Canada) Ltd. in Burlington.
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back The role played by starter programs on performance in the nursery
Within every weaning group, there are some lightweight pigs. Research shows that uniformity at nursery exit can be improved if we can specifically increase the growth rate of these pigsby DENISE BEAULIEU, JOHN PATIENCE, RUURDS ZIJLSTRA and RYAN MOHR
Variability in growth and performance is a concern to pork producers due to the negative impact it has on revenues and expenditures. This experiment was designed to determine the effect of a starter program on the variability in animal weights at nursery exit.Treatments consisted of four starter programs, formulated and fed according to manufacturers' specifications from weaning (day 0) to nursery exit (day 50). Overall Average Daily Gain (ADG) was similar between programs. However, the Average Daily Feed Intake (ADFI) differed and thus, feed efficiency was affected by the program used.
Variability in pig growth, determined as the coefficient of variation, was not affected by the starter program. This was true regardless of the starting weight of the group of pigs. Therefore, although performance may be affected slightly by the use of a specific starter program, the change in performance is uniform across a group and the variability in body weight at nursery exit will not be affected.
TABLE 1. THE EFFECT OF STARTER PROGRAM ON THE PERFORMANCE OF NURSERY PIGS. THE DATA WERE INDEXED TO A DIET WHICH WAS ARBITRARILY ASSIGNED A VALUE OF 100 TREATMENT A B C D Meana SEMa Initial weight, kg 100.00 100.00 100.00 100.00 6.26 0.018 Final weightb,kg 100.00 100.31 104.37 101.92 32.36 0.341 ADG, kg/d 100.00 100.00 103.15 102.95 0.52 0.008 ADFlb, kg/d 100.00 99.31 105.82 105..13 0.74 0.009 FCEb 100.00 100.57 97.30 99.29 0.70 0.004 Feed cost/kg gain b 100.00 104.92 109.84 101.64 0.64 0.006 Feed cost/pigb 100.00 104.74 113.89 105.39 16.34 0.193 aCalculated from untransformed data.
bSignificant effect due to treatment (P<0.05).
Two options are available to reduce the impact of variability on pork production. The first is to reduce variability and the second is to manage it. If variability is considered to be excessive, using management practices to reduce it will be a reasonable approach.The starter program has the potential to influence the relative growth of individual pigs within a group by allowing smaller or younger pigs to excel relative to their older and larger contemporaries. Variability will be reduced if the feeding regimen allows the smaller pigs to "catch-up" or meet the performance of the larger animals in their cohort. It is recognized that the subject of nursery diet impact on variability is complex; determining whether a feeding program can reduce the impact of variability was considered a first step.
A total of 560 pigs were used in this experiment. This represented all the available pigs from two consecutive weeks of weaning at PSC Elstow Research Farm. The only pigs excluded from the experiment were those deemed to be suffering from an obvious medical or physical problem. The experimental group represents a typical and complete weaning group.
Animals were blocked into one of four weight groups. The treatments consisted of four commercial programs currently in use in Western Canada and the feeding programs were fed according to the manufacturers' directions. The only restriction on the program was the medication; all diets were required to include LS20 at the recommended level.
Piglets were weighed individually when they were placed on test (day 0) and on day 4, day 7, day 13, day 20, day 34 and day 50 (nursery exit). (ED: spell out day?) The CV was computed within a pen and analyzed as a variable across pens. To ensure confidentiality of participating companies, the performance data from one company was arbitrarily assigned a value of 100, and the data from the other companies is expressed relative to this. Significance was declared at the P < 0.05 level.
TABLE 2. THE EFFECT OF GROUPING BY WEANING WEIGHT ON THE PERFORMANCE OF NURSERY PIGS. Weight Group Lightest Light Heavy Heaviest SEM Initial weight, kg 4.93 5.80 6.55 7.76 0.018 Final weight, kg 29.19 31.74 32.94 35.55 0.341 ADG, kg/d 0.479 0.519 0.521 0.545 0.008 ADFI, kg/d 0.665 0.730 0.756 0.800 0.009 FCEa 0.719 0.711 0.689 0.681 0.004 Feed cost/kg gain 0.64 0.63 0.64 0.64 0.006 Feed cost/piga 15.29 16.24 16.49 17.33 0.193 a Significant effect of weight group (P<0.05).
TABLE 3. THE EFFECT OF STARTER PROGRAM ON THE COEFFICIENT OF VARIATION (CV, %) CALCULATED FROM BODY WEIGHT a WITHING PENS. PIGS HAD BEEN BLOCKED BY WEIGHT AT WEANING. THE DATA WERE INDEXED TO DIET A WHICH WAS ARBITRARILY ASSIGNED A VALUE OF 100. TREATMENT Phase A B C D Meanb SEMb d 4 100.00 98.77 101.97 95.08 8.05 0.42 d 7 100.00 89.81 97.98 92.04 8.94 0.65 d 20 100.00 91.37 94.34 95.21 13.13 1.16 d 34 100.00 104.43 83.14 97.59 12.39 0.84 d 50 100.00 94.13 85.43 99.36 10.33 0.68 a Calculated from pen data, averaged for each treatment. The overall CV for each nursery room averaged 17.8 per cent at d 0 and 12.6 per cent at d 50.
b Calculated from untransformed data.
TABLE 4. THE EFFECT OF GROUPING BY WEANING WEIGHT ON THE COEFFICIENT OF VARIATION (cv, %) CALCULATED FROM BODY WEIGHTa. Weight Group Phase Lightest Light Heavy Heaviest SEM d 4b 8.13 8.03 8.29 7.73 0.42 d 7 9.42 8.46 9.23 8.67 0.65 d 20 13.79 12.60 13.01 13.13 1.16 d 34b 12.87 13.44 10.70 12.56 0.84 d 50b 10.91 10.27 9.32 10.84 0.68 a Calculated from pen data, averaged for each weight group. The overall CV for each nursery room averaged 17.8 per cent at d 0 and 12.6 per cent at d 50.
b Significant effect due to weight group (P<0.05)
The starter program had a modest effect on performance (see Table 1). However, when examined within specific phases (data not shown), no specific program outperformed the others. A starter program did not elicit an improvement within specific weight groups. Feed cost per pig or per kilogram of gain did differ between feeding program. Feed costs were based on information provided by the collaborating feed companies and were intended to reflect the price charged to a customer for this program.As mentioned above, the objective of this experiment was to determine if differences exist among commercial starter programs in terms of their impact on variability at nursery exit. (The aim was not to determine the "best" commercial starter program, nor to examine specific nutrients which affect pig growth during the nursery phase). Although weight group had an effect on CV at nursery exit, the starter program had no effect on uniformity. Moreover, there were no interactions of the starter program by weight group, implying that within a specific weight group, no starter program consistently improved uniformity.
What are the implications? Within every weaning group, there are some very lightweight pigs. Uniformity at nursery exit will be improved if we can specifically increase the growth rate of these pigs. The effect of the starter program was not specific for any weight group, and therefore will not affect overall variability.
The authors acknowledge with gratitude the collaboration of the participating feed companies in Western Canada. Strategic program funding was provided to the Prairie Swine Centre by Saskatchewan Pork, Alberta Pork, the Manitoba Pork Council and the Saskatchewan Agricultural Development Fund. BP
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back Variation in pig performance -- can we do anything about it?
If the coefficient of variation is larger than normal, then we can look to the resources available to the pig to correct it. An alternative approach is to segregate production in some wayby J.F. PATIENCE, A.D. BEAULIEU and H.W. GONYOU
Variation is a cost to producers in reduced barn utilization and loss of revenue at market. As our barns become larger and more sophisticated, there is an increased focus on variation in pig performance. The implementation of all-in-all-out systems further directs attention to this topic, because the impact of variation on space utilization is much more obvious. In continuous flow barns, sorting at marketing tends to hide the problem.
Statistically, variation can be defined in a variety of ways. The most common terms are standard deviation (SD) and coefficient of variation (CV). The SD is a measure of dispersion. The more dispersed the weights of pigs, the larger will be the standard deviation. In a normal distribution, one above or below the mean standard deviation about the mean will include 68.27 per cent of the pigs in the total group.
The CV is calculated by dividing the standard deviation by the mean, and multiplying by 100. Table 1 describes the statistics from groups of pigs at three different ages. The CVs shown in Table 1 would be typical of a well-managed herd. Figure 1 is an example of a bell curve of pig weights at 20 weeks of age. Clearly, these data do not show a perfect bell-shaped curve, but it is very close and reflects the range from "ideal" that is seen under commercial conditions.
TABLE 1. MEASURED VARIATION IN BODY WEIGHT AT THREE AGES WITHIN AN UNSELECTED POPULATION AGE, DAYS 19 68 140 No. pigs 1264 700 632 Weight, kg 5.39 29.14 103.72 Mean 5.40 29.10 104.40 Mode 5.40 30.95 98.10 Minimum 2.40 23.80 74.40 Maximum 9.20 40.90 124.90 Range 6.80 17.10 50.50 Range, % of mean 121 59 48 Standard deviation, kg 1.21 3.74 8.31 Coefficient of variation, % 22.4 12.82 8.02 Body weights determined on whole groups of animals without pre-selection at weaning (19 days) nursery exit (68 days of age) and at 20 weeks of age before the first market pull. All were collected at the PSC Elstow Research Farm. The weights were collected at different times, so the three groups of pigs are not related to each other.
There are many causes of variation, but fundamentally they can be considered as being genetic or environmental. Classical genetics defines the genetic make-up of an animal as its "genotype." Other sources of variation specific to an individual pig include birth weight, weaning weight, litter of origin, gender and the parity of its dam.In an ideal world, adverse environmental effects are eliminated, so that the performance of the pig reflects its fundamental genetic make-up. In reality, it would be extremely difficult to eliminate all negative effects of the environment completely; nonetheless, a key goal of management is to minimize their influence. Environmental causes of variation include access to resources, such as food and water, exposure to pathogens and behavioural challenges, such as dominance hierarchy in dynamic and static housing circumstances.
The management practices that can be employed to reduce variation will depend on the size of the CV already existing in the barn. If CV is larger than normal (>15%), then it is likely that certain "resources" are limiting, and addressing these limitations will not only lower variation but probably also improve performance. However, when CVs are in the range of 8 to 12 per cent, people have generally been frustrated in their attempts to further reduce variability.
An alternative approach is to segregate production in some manner. One option is to segregate barrows and gilts; because barrows eat more feed than gilts, they tend to reach market weight five to seven days sooner than gilts.
Another form of segregation involves separating a group of animals into two groups. In most instances, the smallest 10 or 15 per cent of the pigs at weaning or nursery exit are split off into a separate barn, or sold altogether. Alternatively, large groups can be split into two, with the heaviest half in one group and the lighter half in the other.
An article that follows that describes an experiment designed to determine if different starter programs would have enough of an impact on performance to affect variability at nursery exit. BP
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back Electro-magnetic hog weighing system cuts costs and hog stress
by NORMAN DUNN
A new hog weighing concept introduced at the Danish winter agricultural fair Agromek this year requires no spring weighing mechanism and no load cells. With the Capamo solid-state crate, the animal simply walks between the crate walls, passing between two printed circuit copper plates coated in plastic. A weak magnetic field between the two plates is created and this is used to determine the water content of the animal.With the help of clever software, this then instantly gives a weight reading with a precision of more than 99 per cent, according to Capamo director Paul Erik Skifter and inventor Carsten Simonsen. The Danish engineers have patented the electro-magnetic weigher and are now looking for a suitable manufacturer. Weighing time required per pig is only two to three seconds.
No price has been settled yet, but inventor Simonsen says the system costs a fraction of standard modern pig weighing equipment and is so cheap that an electro-magnetic weighing crate could be built as permanent feature into every large feeding pen on a farm to offer continuous information on hog weight gain performance.
"The concept also offers a substantial reduction in labour requirements and hog stress," points out Simonsen. "We've found that the Capamo weighing crate, sited between lying area and watering and feeding points, means the hogs get used to moving through it repeatedly in a normal pen. This delivers a steady stream of weight information to the farm computer without the stress and noise of traditional weighing operations."
The electro-magnetic crate is the first commercial production from Capamo, which itself is a completely new concept in European agriculture: a private company staffed by agronomists and practical scientists for the rapid development of new ideas in the farming industry. The company aims to concentrate on electrical and mechanical solutions for usually time-consuming and repetitive jobs like hog weighing.
Capamo director Paul Erik Skifter says development contracts for other work have already been signed with slaughterhouses, research institutes and with farmers themselves. BP
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back How to feed your boar for better reproductive performance
Excessive weight gain has led to annual culling rates for boars of 40-60 per cent. But just reducing overall nutrients consumed may not be the answer.by JANICE MURPHY
Proper nutrition of the breeding herd plays a key role in maximizing herd productivity and profit. Despite the importance of the boar to productivity, there is surprisingly little information on his nutrient requirements. The majority of the recommendations in the literature are still derived from what we know about the breeding sow. However, recent research suggests that this may not support optimum reproductive performance.For boars being raised for breeding purposes, physical soundness and future reproductive performance are as important as exceptional growth rate. Young boars are normally chosen according to a selection index that includes growth rate, lean yield, backfat depth, feed efficiency, carcass quality and breeding potential. Feeding boars to appetite may affect their physical ability to perform since the tendency to develop leg weakness may be complicated by high rates of growth.
Past reviews have reported that the annual culling rate of boars in commercial herds was 40-60 per cent, the primary reason being excessive weight gain and animals getting too large. This suggests that the nutrient requirements of the boar may not match up with those of the breeding sow.
As a result, it is important to establish the nutrient requirements and responses of the breeding boar at the various stages of development, to assess whether nutrition influences sexual development and reproductive capacity, and to make recommendations on appropriate feeding strategies to ensure good reproductive performance over the long term.
TABLE 1. ENERGY AND FEED REQUIREMENTS OF THE BREEDING BOAR. Body weight (kg) 100 150 200 250 300 350 Growth rate (g/d) 500 400 300 200 100 0 Energy (kcal ME/d) 6,700 7,400 8,100 8,600 9,100 9,500 Feed intake (kg/d)* 2.25 2.45 2.70 2.90 3.05 3.20 * Based on a diet containing 3000 kcal ME/kg
Source: Close, W.H. and Cole, D.J.A. 2004. Nutrition and management strategies to optimize performance of the modern sow and boar. Proceedings of the 2004 Manitoba Swine Seminar -- Sharing Ideas and Information for Efficient Pork Production.
Reducing overall nutrient intake is an obvious way to reduce body weight gain. However, this also results in reduced libido and semen volume. So we cannot simply reduce intake without a deeper knowledge of the nutrient requirements of the breeding boar. The practice of restricting boar feed intake during late development to maintain a lower breeding weight has risks. If the nutrient intake is below the boar's requirement, semen quality and quantity may be affected, with potential consequences for bone structure and health.This could result in poor reproductive performance and the premature culling of the boar. So the diet must be fortified to supply the required nutrients according to the boar's weight, age, body condition and collection frequency.
TABLE 2. IDEAL AMINO ACID RATIOS FOR 80-120 KG PIGS, EXPRESSED ON A TRUE ILEAL DIGESTIBLE BASIS. Amino acid Ideal ratios (%) of lysine Lysine 100 Arginine 31 Histidine 31 Isoleucine 56 Leucine 98 Methionine 27 Methionine + Cystine 60 Phenylalanine 60 Phenylalanine + Tyrosine 94 Threonine 65 Tryptophan 19 Valine 67 Source: National Research Council. 1998. Nutrient Requirements of Swine
Energy. The working boar's energy requirement can be calculated by summing up the energy required for maintenance, body weight gain, semen production and an extra component associated with mating activity. The energy requirement increases from about 6,700 kcal metabolizable energy (ME) for a 100 kg boar gaining 500 grams a day to 9,500 kcal ME/day for a 350 kg boar at maturity (see Table 1).Most of the energy expended by the breeding boar is associated with maintenance, representing between 60 and 90 per cent of the total requirement. As a result, temperature is an important variable to consider in a boar feeding strategy. All animals have a thermoneutral zone, the range of temperatures at which they are most comfortable and their body temperature remains constant. Thus it is vital that boars are kept at or above their lower critical temperature of 20C. If the temperature falls below this thermoneutral threshold, then the feed intake will need to be increased by three per cent for every 1C. The energy requirement associated with semen production and mating activity is small, representing no more than five per cent of total requirements.
Protein and amino acids. Amino acid requirements vary, depending upon the body weight of the boar and its rate of growth. To match the feed intakes indicated in Table 1, the literature suggests a requirement of approximately eight grams of lysine per kilo of feed, with the same amino acid balance used for the growing pig between 90 and 120 kg body weight (Table 2).
This is in contrast to the recommendations in the Nutrient Requirements of Swine (NRC, 1998) where the suggested lysine requirement is only six grams per kilo and the other amino acid requirements are based on gestating sows. The bottom line is that protein and amino acid intake of the boar cannot be limited or reproductive performance will suffer.
TABLE 3. MINERAL AND VITAMIN REQUIREMENTS OF SEXUALLY ACTIVE BOARS (AMOUNT/KG FEED). Minerals NRC1 Suggested2 Vitamins NRC1 Suggested2 Calcium (g) 7.5 7.5 Vitamin A (IU) 4,000 6,000 Phosphorus (g) 6.0 6.0 Vitamin D3 (IU) 200 500 Chlorine (g) 1.2 1.5 Vitamin E (IU) 44 50 Sodium (g) 1.5 1.3 Vitamin K (mg) 0.5 1 Potassium (g) 2.0 2.5 Thiamin (B1) (mg) 1.0 1.5 Magnesium (mg) 400 400 Riboflavin (B2) (mg) 3.75 4 Iron (mg) 80 80 Niacin (mg) 10 15 Zinc (mg) 50 100 Pantothenic Acid (mg) 12 15 Manganese (mg) 20 20 Pyridoxine (B6) (mg) 1.0 2 Copper (mg) 5.0 5.0 Canocobalamin (B12) (mg) 0.015 0.02 Cobalt (mg) - 0.1 Biotin (mg) 0.2 0.3 Iodine (mg) 0.14 0.5 Choline (mg) 1.25 1.5 Selenium (mg) 0.15 0.3 Folacin (mg) 1.3 1.3 Chromium (ppb) - 200 Vitamin C (mg) - 300 1 National Research Council. 1998. Nutrient Requirements of Swine.
2 Close, W.H. and Cole, D.J.A. 2001. Don't ignore the boar! Minerals and vitamins for breeding boars. Feed Mix, Volume 9 (1)Ten years ago, researchers in Nebraska examined the effects of protein alone or a combination of energy and protein intakes on semen characteristics. At similar levels of energy intake (6,100 kcal ME/day), lowering the lysine intake of the boars from 18.1 to 7.7 grams per day reduced the volume of the ejaculate and overall sperm output. However, similar effects were not evident when the energy intake was reduced from 7,700 to 6,100 kcal ME/day, as long as lysine intake was maintained at 18.1 grams per day. This research demonstrated that the energy intake, but not protein intake, of adult breeding boars could be reduced to restrict weight gain to 150 grams a day while maintaining libido, semen production and sperm output.
Minerals and vitamins. There is very little information available on the mineral and vitamin requirements for boars, but it has been suggested that these should be the same as those used for the lactating sow. Based on our current level of knowledge (Table 3), special consideration should be given to calcium, phosphorus and biotin, since these are important components in bone mineralization and can have an impact on the structural soundness of the legs. In addition, zinc plays a role in spermatogenesis, while selenium and vitamin E serve as antioxidants in boar sperm and influence testicular and or spermatozoa development and subsequent sperm motility.
The mineral source may also be an important consideration. Recent research has shown that the addition of organic selenium and vitamin E significantly improved sperm concentration and the total number of sperm, while significantly reducing the proportion of defects compared with inorganic selenium and vitamin E in the diet of young boars. BP
Janice Murphy is Swine Nutritionist with the Ontario Ministry of Agriculture and Food in Fergus. E-mail janice.murphy@omaf.gov.on.ca
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