Disease is the top factor that causes variations in weights in a single swine herd, robbing producers of achieving maximum profit.

Kevin.Schulz, senior content specialist

May 25, 2017

10 Min Read
Disease No. 1 cause of weight variation
Even if weight variation in pigs is noticed in the weanling pen, it is too late to narrow the gap.National Hog Farmer

It seems simple enough: sick pigs don’t eat, sick pigs don’t drink. If sick pigs do not eat or drink, sick pigs don’t gain weight. If sick pigs don’t gain weight, they don’t grow, and if they don’t grow they do not make hog producers profit.

Jeff Worstell, director of market access for Boehringer Ingelheim Animal Health, says the absence of disease reduces weight variation within a swine herd, “without the influence of disease, you have removed one of the variables that can hinder a pig from reaching its full genetic potential.”

Disease is the No. 1 factor that causes variations in weights in a single swine herd, robbing producers of achieving maximum profit.

Preventing disease and advancing herd health “raises the ceiling for the pig to thrive,” he says. From growing up on his family’s Missouri hog farm, to the hog farm at the College of the Ozarks, to working with DeKalb Swine Breeders, to Cargill and now with BIAH, managing that wide weight variation that can occur in swine herds has always been on the top of Worstell’s mind.

Staggering losses
Disease impact on a swine herd can be very detrimental, and the economic losses add up quickly. Worstell says that impact is compounded if more than one virus pressures a swine herd simultaneously. Worstell points to a study done by Cara Dykhuis Haden, Iowa State University; Tom Painter of Cargill Pork and Thomas Fangman with BIAH; and Derald Holtkamp, ISU, that looks at the economic impact of multiple pathogens on finishing pigs – in particular swine influenza, porcine reproductive and respiratory syndrome, and Mycoplasma hyopenumoniae (Mhp)

Those researchers found Mhp put a $0.63 per head loss in the herd, while PRRS alone put a loss of $5.57 per head and SIV had a $3.23 loss per hog. 

Those numbers alone can be staggering over a large production model, but the loss grew to $9.69 per head when PRRS and Mhp both pressured the herd. A PRRS and SIV combination took the per-head loss to $10.41 and SIV paired with Mhp had a $10.12 per head loss. The researchers wrote. “Actual PRRS and Mhp costs were one and a half times greater when compared to the additive costs of uncomplicated PRRS and Mhp. This data confirms that in this production system Mhp in combination with other pathogens produces more than additive losses in productivity. It is clearly demonstrated that detrimental impact is greater when pathogens are combined.”

Industry wide, the cost impact of PRRS alone has been pegged at $664 million annually, according to a 2011 study funded by the Pork Checkoff and conducted by ISU. This translates into $1.8 million per day or $114.71 per sow annually. The previous economic study in 2005 calculated PRRS losses at $560 million annually. Another Pork Checkoff-funded study updating the PRRS impact figures is set to be released in 2018.

Managing weight variations in today’s swine herds is a complex issue. “Typically you’re not managing that upper end, because the pigs that are doing good you want them to continue down that road,” he says. “You try to manage that variation by focusing on the bottom end, the smaller hogs, to reduce your standard deviation.”

Catch variations ASAP
Producers need to catch weight variations in the herd as soon as possible, because Worstell says by the time it’s a noticeable variation it may already be too late. “A three-pound variation at weaning stage will only get wider as the pig grows,” he says, “ you have to get that pig off to a good start in life, get it to start healthy so that it can end strong. It’s critical to get all the basics done right from the start.”

It seems simple enough, but early pig care is vital. “What I do in the beginning affects the whole group,” he says. “It all that starts in the farrowing room. Did I get to a good birth weight, did I dry them off, did they get colostrum, did I execute on all of the basics?”

Once you have variation in a herd, it’s difficult to keep it from growing. “You end up managing to the average, if you provide the correct nutrition for the biggest hogs in the barn, you fail to meet the needs of the smallest pigs, and the variation continues to widen because the big pig gets all it needs to prosper and do well,” he says, “while the small pig becomes more and more disadvantaged. It gets harder and harder to narrow that gap.”

Conversely, if producers attempt to meet the needs of the smaller pigs in the herd, “you will end up feeding a diet that’s much more expensive than what the larger hogs require, which just results in a higher cost,” he says.

An example of variation
Worstell takes the example of lysine, one of the 10 essential amino acids, a protein that the animal needs to perform. “As the hog gets older, it has a lower lysine requirement,” he says. “Lysine comes at a cost and a high protein diet is more costly than a low-protein diet. If I feed the diet the smaller pig needs, I’m feeding a ration that could cost as much as 50% more per ton for what the smaller pig needs to grow and prosper, you’re spending money that have your herd didn’t need. Then if I feed to the bigger pig, that’s even worse because now my little pig isn’t getting the nutrition it needs.”

Catering to nutritional needs of the varying weights in a finishing barn, “if the barn is small enough, if pens are small enough, you can set up a gruel feeder for those that need a little more help,” he says, “but all that some at a cost because that means more labor, and that weight variation is already starting to nip at your efficiencies.”

Variations in weights across a swine herd have other management implications, aside from making sure they are healthy and that they have a proper diet. Another consideration is controlling the environment, as pigs of varying weights require different temperatures where they are “happiest, where are they the most comfortable. … ventilation is critical, but here you are trying to adjust the temperature for a 120-pound hog and for an 80-pound hog, and they’re different. … what’s something that I can settle on, you end up settling on the ventilation requirements, rather than optimizing, and when you do that you’re giving up that precision that’s probably going to be needed to compete in the future,” he says.

A valuable lesson
A lesson learned when he worked for DeKalb Swine Breeders in 1987 has stuck with him all these years later: clean fresh feed, clean fresh water, and a warm, dry, draft-free place to live and sleep. “That has stuck with me all these years,” he says. “And then observe the pig. Let them tell you what they need.”

Not all piglets are created equal, and in one litter you can have a 2 ½-pound pig born and a 3 ½-pound pig born, “that 1 pound birthweight difference doesn’t sound like much, but that pound spread will continue to grow and that variation it just eats away at your profitability. Higher productivity leads to higher profitability,” he says.

Starting with the basics, and applying today’s knowledge and technology, and then you start heading down that path of precision agriculture “working with your veterinarian to understand the infection chain, utilizing the prevention chain to help you get the most out of your vaccination program, emphasizing early pig care to get them off to a good start and then you begin to win the battle against variation with the rest of the group,” he says.

As Worstell mentioned above, observe the pigs to allow them to tell you what they need. By the time that you can physically see the weight variation in the herd, especially in the finishing barn it’s too late to recover. “I think we forget if you want to influence variation, you may need to start with the replacement gilt. What’s her health status, how’s it compare to the rest, in, how do I introduce her to the herd, how do I not create disruption?”

Just as in newborn piglet care, Worstell says the same care extends to that of the replacement gilt, as well as with sows. “You need to make sure the sow is consuming the correct nutrition. Does she have clean feed, clean water, is she comfortable? Variation starts long before the pig is born.”

Environmental concerns
Properly managing the gilt/sow environment can also go a long way in an overall production swine herd. “I have to manage her environment where she wants 60-65 degrees and her piglet wants to be 90-95 degrees, depending on their age. And that’s where variation starts if we don’t start early, if we don’t start healthy, it seems impossible to get your hands back around variation. That three-pound gap just keeps getting bigger. If you manage to the average, the big just keep getting bigger and the smaller keep getting smaller and your variation widens.”

Hog production is a business, and any business model should be established to maximize profitability, so producers need to be focused on maximizing throughout, rather than dedicating even a small amount of energy in searching for an alternative tail-enders. Worstell says producers need to focus on management practices that will eliminate tail-enders from ever becoming an issue. “Instead of playing to win, you fall into a path of playing not to lose” if you devote too much time looking for alternative markets.

Producers can employ management techniques that can help them work with weight variations in their herd without exhausting too much energy in looking for alternative market options. Using the example of an operation that overstocks 4,800 head in the nursery phase, Worstell says rather than just emptying the pens out to move the pigs onto the next phase, it may be wise to at that point separate the large-end pigs and the small-end pigs into different pens, or even different barns. “You can then have the 2,400 largest pigs on Diet 5, and the smaller pigs can be on Diet 4, so that way you are meeting the needs of all the pigs in both groups,” he says. “You haven’t changed the variation of the 4,800, but now you have two subpopulations with tighter variation, I can manage the diet and ventilation that each of those subpopulations need. … this isn’t reducing the variation, it’s managing the variation.”

Personnel are key
The scenario that Worstell just presented illustrates the need for producers and their entire farm team to be on the same page of pig observation, and he stresses the importance of having good, properly trained personnel on the team. “I learned at Cargill, an error in execution is worse than an error in judgement, and that’s where the people aspect come in,” he says. “You can have the best management practices or SOPS, but if you don’t have the program that is well-executed, the program doesn’t matter.”

Worstell encourages producers and their team to think beyond the printed program, and to again let the pig tell you what they need. “If the program says at two weeks, the piglets need a certain temperature, but you see them piling, then you may need to adjust the ventilation to get them comfortable before a problem arises,” he says.

Not to belabor the emphasis on good personnel, Worstell stresses that producers need to make sure that all barn help is on the same page. “You (managers) need to take the time to properly train the staff,” he says. “You can’t just give them the manual and have them follow it and life will be OK. Did you take the time to educate them on the ‘whys’? Not everything is black-and-white, but if I understand the ‘why’ then I can take information, process it, and adjust.”

Worstell adds, “Weight variation is something that producers should take seriously. Don’t forget the basics, work with your local veterinarian regarding herd health, build a strong vaccine protocol, and make sure your personnel are educated and empowered. If you do those three things then you are setting your herd up for success.”

About the Author(s)


senior content specialist, National Hog Farmer

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