Feeding sows ad lib during lactation results in higher feed intake, boosting piglet weaning weights and improving reproductive performance in the subsequent parity, says Dr. Malachy Young, a nutritionist with Gowans Feed Consulting.
“Advances in litter size and changes in the sow’s genetics have created new challenges in feeding lactating sows, which generally have lower voluntary intake and are leaner with greater body size at maturity,” he says. “Though most producers agree that maximal intake throughout lactation is the correct goal, considerable debate exists on the best method to achieve that goal.”
Traditionally, feed has been given according to a scale, which gradually increases as lactation progresses. But Young points out this leads to considerable variation in feed intake, especially in the first week after farrowing.
“This pattern of feeding may reduce sow feed intake in the first week of lactation by 15 per cent or more compared with a more aggressive system of feeding,” he notes. “Restricting feed intake throughout or during any week of lactation will result in a higher risk of sows being culled for anoestrus than sows having a rapid increase in lactation feed intake.”
In addition, sows which have an earlier peak in feed intakes have higher overall lactation feed intake, he adds. This extra feed intake achieved with a more aggressive feeding strategy will increase milk yield, piglet growth rate and reduce weight loss in lactation.
Young’s own research (Table 1) showed that more than four per cent of all sows ate less than four kg and 17.5 per cent ate less than five kg over a 19.5-day lactation.
“There is evidence to show that although short-term undernutrition may not affect milk yield, it can cause acute and chronic changes in the reproductive hormone system, even without noticeable changes in body composition, and these negative effects can reduce ovulation rate and embryo survival,” Young says. “Also, such undernutrition in any week of lactation can reduce subsequent litter size.”
Data from a large survey investigating the effects of lactation feed intake on various reproductive parameters showed that for each additional kilogram increase in feed intake in lactation, an additional 0.11 pigs were born at the subsequent farrowing.
The most important aspect of all feeding methods is to provide the sow with access to feed at all times, Young stresses. “Restrict feeding in early lactation is commonly adopted because of the belief that overfeeding sows in early lactation may cause udder problems, piglet scours or sow constipation and may lead to sows going off feed in mid-to late lactation,” he explains. “However, there are many farms feeding lactating sows ad libitum soon after farrowing with no detrimental effects on sow performance.”
There are a number of commercially available ad lib feeding systems that can easily be fitted to farrowing crates and some producers have made their own.
“Typically with an ad lib feeding system sows are gradually increased on to feed during the first four days of lactation and on day five the mechanized system is turned on and they are given ad lib access to feed through to weaning,” Young notes. “However,” he continues, “it is important to remember that a mechanized system of feeding during lactation does not omit the need for sows to be individually checked, got up, the feed drop checked to ensure feed is freely accessible and water nipples checked for water flow rate each day.”
Ad lib feeding in practice
At Sinke Farms Ltd., an 850- sow farrow-to-finish operation near Picture Butte in southern Alberta, the Intak ad lib feeder is being used. Sows nose a ball mechanism at the base of the Intak feed hopper to release feed and the flow rate can be adjusted by the stockperson (Figure 1).
The amount in the feeder can be adjusted to restrict feed intake if required. “Prior to farrowing and on the day of farrowing, sows are given 2.0 kg/day, then on day two the feed level is increased to 2.75 kg/day, followed by 3.6 kg/day on day three,” explains Marieke Klok, who works in the barn.
On the fourth day the adjustment is opened up all the way, which allows the sow to eat up to 11.5 kg per day. A water nipple above the feed trough allows the sows to wet the feed.
“The main benefit of the system is that sows have access to clean, fresh food all the time,” says Klok. “Not only is feed intake increased, but there is less wastage,” she says. “Sows are weaned in better condition and fewer sows are culled due to poor body condition.”
In addition less time is spent feeding sows and the problem of staff under-or overfeeding is eliminated. While the feeder does require regular attention to make sure it is working correctly, overall the benefits far outweigh any disadvantages, Klok says.
Dr. Malachy Young and Marieke Klok will be presenting a paper on this topic at the Red Deer Swine Technology Workshop on Nov. 3 at the Capri Centre. For further information or to register, contact Bernie Peet at (403) 782-3776 or (403) 392-3104.
Young et al, unpublished
Feed intake group ADFI, KG% of sowsLactation length, daysWeaning to strus interval, daysNumber weanedRemoved, %effect of lactation feed intake on performanceSubsequent total born<4 4-5 5-6 6-7 7+ 3.35a 4.55b 5.52c 6.47d 7.47c184.108.40.2065.5 21.419.2a 19.5a 19.7ab 19.6a 20.0b5.19.545.510.85.39.821.4220.127.116.1118.104.22.168.719.722.214.171.1249.6
“There is evidence to show that although short-term undernutrition may not affect milk yield, it can cause acute and chronic changes in the reproductive hormone system…”
DR. MALACHY YOUNG
NUTRITIONIST, GOWANS FEED CONSULTING