Larry Rueff, swine veterinarian from Greensburg, IN, believes real-world sow feeding problems do not require complicated answers.
For starters, Rueff believes it is common for sows' energy needs to go unmet. This problem became exacerbated when sows were moved inside from outside lots. “We were lead to believe that we could reduce the amount of feed that we offered those sows. It is true, a lot of the feed that used to get trampled in the mud is now on the floor of the confinement barn,” he acknowledges. And, switching to much leaner, more productive breeding stock compounded the problem,
“The mind-set became — these sows don't need a whole lot of feed. Wrong!” he admonishes. “We really need to rethink how much feed we offer these sows. Management must understand the significance of the relationship between weaning weights, weaning average, reproductive efficiency and feed intake. We have to look more closely at how much feed these sows are really getting. Most people think they are giving them more feed than they are.”
Rueff has a relatively easy calculation that will give producers a “ballpark” estimate of sow feed intake — even those with not-so-good records.
Start with the number of litters farrowed in a specific timeframe (i.e. month, quarter, farrowing group). Next, it's usually pretty simple to get average weaning age of the pigs. And, usually, it's not too much trouble to figure out how much lactation feed was delivered/consumed during that specific timeframe.
Calculate Feed Intake
Now, to find the total lactation days for that time period, Rueff multiplies the average weaning age times the number of litters farrowed. Narrowing it down a little further, estimate how many days a sow spends in the crate before she farrows. Four days is fairly common. In that case, multiply the number of litters times four days to get the total “pre-lactation” days; multiply that figure times the estimated feed consumed before farrowing (i.e. 5 lb./day × 4 days). This total must be subtracted from the total lactation feed delivered for the time period. That figure, representing the “true” lactation feed consumed, is then divided by total lactation days.
“Bingo, you have just calculated the average daily feed consumption of that group of sows,” says Rueff. The accompanying box reviews the easy, five-step calculation.
“The range I see when I do this calculation on farms is from 9 lb. to 16 lb./day. Thirteen to 14 lb. would be pretty good,” he says.
The figure allows producers to do two things: identify feed consumption problems and formulate diet nutrients better, based on pounds of feed consumed per sow.
“I know this — when you find a farm that's below 12 lb., you don't have very good weaning weights and you don't have sows that breed back very well,” he attests.
This figure is more valuable than most of the information people spend time writing down on individual sow cards he believes. “I think that crude measure can be a really good teaching tool to help producers understand what is the normal amount of feed going through their farm vs. what they think it ought to be.”
Just having the information obviously doesn't solve the problem. If daily feed intake falls short, he suggests feeding sows three times a day, beginning the fourth or fifth day after farrowing.
Rueff reflected on a feed intake problem he was called in to help solve in North Carolina. While conducting a walk-through of the farrowing rooms at 10:30 a.m., he picked up the feed scoop and started feeding sows. “Everybody got up,” he relates. “The problem wasn't that the sows wouldn't eat; the problem was, nobody was giving them enough feed.”
“My simple rule of thumb is — if a feeder is empty, put 8 lb. of feed in there. If it's got less than 2 lb. of feed in there, give her 4 lb. If there's more than 2 lb. in the feeder, don't give her any. There's no reason to make it complicated.”
“I know sows don't eat very well when you wean them, but they will eat something, so feed them for 3 to 4 days,” he says. “Regardless what you may think or have heard, it does not help them come into heat.”
He continues, “If you want to fix a problem of skinny sows from poor lactation feed intake or from being restricted in gestation, you have to over-compensate for five months.
“If the herd has been fed 5 lb./day in gestation and the sows are too skinny, feeding 6 lb./day will not fix the problem. You'll come back six months later and the sows will still be too thin. In the real world, you have to really over-compensate, but when you get to the body condition you want, you've got to be ready to back off,” he warns.
Water is Critical
Rueff remembers a nutrition course taken at Purdue University that described water as “the forgotten nutrient.”
“It still is,” he argues. Routine flow rates for sows should be 1,500 ml./minute for sows.
“You probably can get by with less than that in the farrowing house, but you may be impacting feed intake,” he says.
“Sows don't have all day to drink. You might say: ‘what's time to a sow?’ Well, it's important enough that she won't stand there and drink all day long,” he says to make the point.
Rueff confesses to a “funny little habit” of tapping nipple waterers while doing walk-throughs. He came by the habit the hard way. “About 18 years ago, I was embarrassed on a farm when the only problem was the water flow rate was so bad that the sows wouldn't even drink in the farrowing house. A local building contractor found the solution to the problem after I spent hundreds of dollars in diagnostics trying to figure out what was wrong with the sows and why they weren't weaning very good litters.
“I never forgot the lesson — water is important. Make sure the flow rate is there,” he insists, adding these tips:
Measure flow rate at various locations in the barn at different times of the day.
If you've expanded on a site with an existing well without checking the impact on flow rate — check it.
If your veterinarian or consultant has checked flow rate and reported it's inadequate, fix it. Too often, action is not taken.
Calculating Daily Lactation Feed Intake
- (Average weaning age) × (Number of litters farrowed) = Total lactation days
- (Number pre-lactating days) × (Number of litters farrowed) = Total number pre-lactating days
- (Pre-lactating days) × (Pounds feed/day) = Pounds pre-lactation feed
- (Pounds lactation feed delivered) - (Pounds pre-lactation feed) = Lactation feed post-farrowing
- (Lactation feed post-farrowing) ÷ (Total lactation days) = Total lactation feed consumed/day