Managing the lactating sow to maximise performance and health starts in gestation and particularly in the period just before parturition.
Sows entering lactation do not want to be over conditioned (fat) as this causes problems with the birth process and reduces intake in lactation. In most of the world and certainly in the US gestating sows are fed low and flat no bump feeding and when required to build up condition after weaning feed intake is increased in the first 30 days of gestation as this has the least adverse effect on lactation feed intake. Fat sows don’t have pigs.
Older sows do not benefit from a general increase in dietary amino acid levels in late gestation, but gilts have been reported to deposit more milk producing tissue (better mammary development) if dietary lysine and other amino acids are increased by as much as 20% in the 2-3 weeks before lactation. Whether this results in greater milk production and piglet growth remains to be proven.
The biggest change in the last 3 to 4 years has been feeding sows more frequently in the period immediately before parturition. Feeding sows more frequently in the 3-5 days before parturition reduces the duration of parturition and reduces still birth rate. It is all about energy supply around the time of parturition and a study supported by APL in Australia also showed that feeding twice daily rather than once daily for around 5-6 days before parturition also reduced subsequent culling rate and significantly increased subsequent litter size.
A simple strategy with potentially big outcomes on sow productivity and sow welfare. Similar results for the duration of parturition and still births can be achieved by top dressing the diet fed in the 2-3 days before parturition with CaCl2 (25-30 g/sow/d).
Another two changes to lactation nutrition that have occurred over the last 6-8 years are:
- Offering the sow the lactation diet adlibitum from the day of farrowing rather than going through a build up over the first week.
- Reducing the crude protein (CP) content of the lactation diet.
Feeding sow adlibitum from parturition increases overall feed intake and milk production in lactation. The sows also tend to lose less weight in lactation.
Reducing the crude protein (CP) level of the lactation diet warrants serious consideration. Lower CP diets support much better milk production especially in summer than higher CP diets (20% +). Lower CP diets also tend to improve piglet survival, and we have seen commercial lactation diets in Australia with CP levels below 17%.
The diet
There is a conundrum when designing the lactation diet because gilts and parity sows but especially gilts, have different requirements for amino acids and gilts need a higher energy diet than older sows.
In the US a major veterinary group formulates lactation diets for all their clients based on the needs of gilts (rearing 14 piglets) as the strategy does not adversely affect older sows but does cost a bit more. However, lactation feed represents only 4%-5% of total feed use in a farrow to finish system and the US group obviously think the extra cost is worthwhile.
Research by Sally Tritton many years ago also demonstrated how important dietary energy is for younger sows and this led to Australia’s largest pork producer introducing a gilt lactation diet with 15 MJ DE/kg. A recent study in the US also showed that for younger sow’s diet energy was more important than lysine in determining subsequent sow retention and number weaned. The message is to go as high as you can with the energy content of the lactation diet for younger sows.
In the US study gilts fed a diet with 14.3 MJ DE/kg and 0.85% SID Lysine exhibited marked improvements in subsequent fertility and number weaned compared to gilts fed a diet with 13.6 MJ DE/kg and 1.11% SID lysine. We would think they would do even better if fed a diet with 14.8 MJ DE/kg as at an intake of 6 kg/d this would increase daily DE intake by 3 MJ. Do not skimp on dietary energy for lactating sows.
The amount of SID lysine needed in the lactation diet will depend on the parity of the sow, feed intake and the number of piglets reared by the sow. The old rule of thumb is that lactation will be optimised if sows consume around 60 g of SID Lysine per day. However, feeding gilts a lactation diet with amino acid levels to support older sows will lead to poorer milk production and even increased pre-weaning mortality in gilt litters. A level around 0.9% SID lysine might do the trick but more would be required if gilt lactation feed intake is around 5 kg/d or less.
The balance of other amino acids relative to lysine has remained stable for many years with the possible exception of SID tryptophan which is best set at 21% of SID Lysine.
What else has changed?
Recent evidence suggests that increasing the Zn level of the lactation diet to around 250 ppm reduces preweaning mortality though improved gut health in the sow.
Recent evidence also suggests that a high proportion of sows enter the lactation facility anaemic and that this increases the duration of parturition and still birth rate. It might be wise to check the source and level of iron in the gestation and lactation diets and to buy a HemoCue which is a hand-held device to measure haemoglobin in the sow when she enters the lactation facility.
What about fibre?
Dietary fibre needs to be limited to ensure the sow receives enough energy and many who seem to know what they are doing suggest 3.5% total fibre is adequate.
Finally – offering piglets creep feed from around 10 days of age will help them eat more at and immediately after weaning and for sows weaned at 27-29 days offering piglets creep feed will markedly increase weaning weight and post weaning growth as milk production peaks at 21-22 days of lactation.
In summary
Sows need to be in good and maybe even lean condition when ready to farrow, they have to be fed a good quality mash feed at least twice daily in the period just before parturition and offered the lactation diet adlibitum from farrowing. Reduce the CP content of the lactation diet while maintaining all essential amino acids levels at “requirement” and ensure the diet contains at least 14.6 MJ DE/kg. The amount of SID lysine needed will depend on parity, litter size and sow feed intake but aim for 60 g SID lysine intake/d and check that the tryptophan to lysine ratio is 0.21 or slightly higher.
If fed and managed correctly the sow should return to oestrus rapidly after weaning and wean more and bigger piglets. Remember to offer piglets creep feed especially if weaning at 25 days or older.
Talk to your local Reid’s Poultry Specialist today about the benefits of our mash and the products we can offer to suit your requirements on 1300 REID FEED or enquire here >
Author
AuthorJohnny Barwary
PhD in Nutrition and Physiology
Monogastric Manager
In collaboration with Roger Campbell | PhD in nutrition and physiology | Science and commercial pork production | RG Campbell Advisory
