Written by Trine Friis Pedersen, Consultant, SEGES Danish Pig Research Centre, Livestock Innovation [email protected]
Abstract
There is a great potential for improving piglet survival, leading to even more weaned piglets per litter. The key elements that enable sows to wean many piglets are healthy sows and piglets, the right nutrition and the right mangement throughout the lactation period. Therefore, although managing sows with high litter size is not an easy quick-fix, but implementing the right routines will increase the herd productivity.
Improving piglet survival starts before farowing, by moving healthy sows in the right condition and in the correct time before parturition. Sows should be fed 3.3 to 4.0 kg/day until farrowing begins. The feed should be distributed over three or more feedings that are equally distributed around the clock. The daily fibre content (soluble + insoluble fibres) should be 500 to 600 grams/day. Staff survilliance of sows around farrowing will improve piglet survival, as they will be able to assist the farrowing sows quickly and take care of small and surplus piglets.
During farrowing it is important to provide all piglets with colostrum and heat. Ensuring that piglets get enough colostrum can be done by split suckling, or by moving the small piglets to small nurse sows, who are still producing colostrum. Litter equalisation/standardisation should be done after eight hours. Heat may be provided by heaters in the back fat of the farrowing pen as well as in the piglet sleeping area (creep).
Introduction
Three major factors must be pressent to achieve a high piglet survival rate. Firstly, both the sow and the piglet must be healthy. Secondly, the sow needs to be on the right feeding regime, adn thirdly, the management routines before, during, and after farrowing must be well defined and performed in time.
The causes of piglet mortality varies in different parts of the world. In Denmark, most of the dead piglets die during the first four days of lactation, where crushing (47 %), starvation (18 %), and weakness (18 %) are the top three causes of mortality. From day five to weaning, the top three causes of death are blood poisoning (31 %), unthrifty piglets (13 %), and crushing (13 %).
The average Danbred sow gives birth to 19.4 total born piglets per litter, and this number will increase. Along with the higher litter size the proportion of very small piglets has increased from 1.3 % of piglets weighing 400 to 800 grams in 2002 to 10 – 14% today. Due to the successful breeding for live piglets at day five, these small piglets have a much higher survival today compared to before, but an increased focus on these challenged piglets can improve piglet survival even more.
Converting still born piglets to liveborn piglets
Approximately 60 % of the still born piglets die during the farrowing process. Thus 60 % (approximately 1.1 piglets per litter) of the still born piglets are alive when the farrowing process begins, and could potentially be born alive. Therefore, there is a great potential in optimising sows’ farrowing process, and in assisting the sow when needed to ensure more liveborn piglets.
Optimising the sows’ farrowing process begins with a healthy sow in the right condition. The recommended back fat thickness measured at the P2 site for a sow entering the farrowing unit is 16 – 19 mm. The sow should be moved to the farrowing unit 5 – 7 days before the expected date farrowing to avoid stress. In addition, sows should be provided straw or other manipulatable material which can fulfil sows’ nest building behaviour, to ensure a calm sow during farrowing.
The farrowing process can also be optimised through feeding. Optimal feeding is a combination of providing the right amount of feed with the right composition. A recent study showed that sows fed 3.3 to 4.0 kg/day (ME: 12.9 MJ/kg; 164 g CP/kg) around farrowing had the shortest farrowing duration, the lowest number of stillborn piglets, and the highest colostrum yield (Feyera et al. unpublished data). To keep blood sugar (for the farrowing process) high during farrowing sows should be fed at least three times a day with equal feeding intervals, e.g. 7.00, 15.00, and 23.00 (Feyera et al. 2018). The three meals a day should be accompanied by the right fibre content in the feed, as fibre can provide energy to the sow for a longer period than e.g. feed sources rich in starch. It is recommended to include approximately 500 to 600 grams of fibre in the sows’ daily feed ration. This is achieved by using i.e. 35 % barley and 3 % dried sugar beet pulp in the ration.
The number of still born piglets is very low on farms conducting 24-hour-a-day/around the clock surveillance of the farrowing sows. The effect on dead born piglets is mainly due to timely farrowing assistance and helping the weak piglets to colostrum. 24-hour supervision also benefits the liveborn piglets as litter equalisation can be performed continuously when the litter gets too big, to ensure that all piglets have a place at the udder. If 24-hour-a-day surveillance is not possible, a way to achieve more surveillance time is to introduce an evening check and staggered working hours. Currently, SEGES Pig Research Centre is testing the effect of video-assisted farrowing surveillance, which potentially will reduce the number of still born piglets.
Check list:
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- Healthy sows
- 14 – 15 mm back fat at entry to farrowing house
- Move to farrowing pen 5 – 7 days before expected farrowing
- Provide straw or other material
- 3.3 – 4.0 kg/day
- Three equally distributed meals per day
- 500 – 600 grams of fibre per day
- Surveillance of all farrowing sows
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Management solutions for newborn piglets
The colostrum intake and temperature of the piglet after birth is crucial for piglet survival until weaning (Figure 1 and 2). In big litters, an effort must be made to secure colostrum intake of the smallest piglets. Small piglets are challenged by their size, as they require more energy to keep up their body temperature due to a high surface area to body weight ratio. Therefore, it is crucial to secure all piglets in the litter enough colostrum and heat during the first hours after farrowing.
Figure 1: The effect of piglets’ rectal temperature two hours after birth on mortality the first week after farrowing (Sørensen et.al. 2016)
Figure 2: The effect of colostrum intake on piglets’ mortality until weaning (Nuntapaitoon et. al. 2019)
During farrowing, weak piglets and piglets not at the udder should be assisted/moved to the udder to get colostrum. After farrowing it is important to get an overview of how many piglets have been born, including how many small piglets which need extra care. The number of functional teats can be recorded for each sow prior to farrowing, and ideally, also a score for the sows’ nursing ability based on previous litters. One way to ensure all piglets receive colostrum is to perform split suckling during the first eight hours after birth until the piglets are ready to be moved to a nurse sow. Split suckling is carried out by limiting the access to the udder for the heaviest and first-born piglets allowing the 10 – 12 smallest and last-born piglet free access to the udder. After ½ – 1 hour the heaviest piglets are allowed access again. It is recommended to move small piglets to a small nurse sow who is still producing colostrum right after birth (an early small nurse sow). This has been shown to increase small piglet survival. After nursing at the sow for eight hours, the large piglets will have ingested enough colostrum to have enough maternal antibodies and can then be moved to nurse sows. For practical instructions of how to use nurse sows, the strategies have been described by Thorup (2020).
New-born piglets are immediately cooled after birth and need to increase their body temperature during the first hours after birth. Extra heating to piglets around farrowing will support this process and can be done in several ways. One way is to install heaters at the back of the farrowing pen, providing heating behind and at both sides of the sow (figure 3). The effect of extra heat provided by two heaters was tested in an experiment with 569 piglets with a birthweight below 900 grams. The floor under the heaters was heated to 33 – 34⁰C, while the floor was 20⁰C in the control group behind the sows without heaters. The heaters increased the percentage of piglets with a rectal temperature above 37⁰C significantly from 36 – 59 %, and reduced the percentage of piglets with a rectal temperature below 35⁰C from 25 % to just 16 % (figure 4).
Figure 3: Heater warming up the area behind and at both sides of the sow
Figure 4: The effect of heating during farrowing on piglet rectal temperature after farrowing
Conclusion
Hyper prolific sows give you a high litter size. To obtain this full genetic potential by acheiving a high number of weaned piglets per sow per year, all routines around farrowing must be optimised for piglet survival. The sows should have 14 – 15 mm backfat depth at farrowing, a high feed allowance up to farrowing, fed at least three times a day around the clock (with the right diet compsition) will optimise both her farrowing performance and amount of colostrum produced. This must be supported by consistent and efficient farrowing surveillance, and assistance followed by extra care for small and surplus piglets to achieve the full potential of your DanBred sow.
Reference List
Feyera, T.; Pedersen, T.F.; Krogh, U.; Foldager, L.; Theil, P.K. (2018): Impact of sow energy status during farrowing on farrowing kinetics, frequency of stillborn piglets, and farrowing assistance. Journal of Animal Science 96:2320–2331.
Frandsen, D.P.; Bache, J.K.; Jørgensen, M. (2019): Positive effect of heat addition to the smallest new-born pigs [Positiv effekt af varmetilsætning til de mindste nyfødte grise]. Publication no. 1176. SEGES Danish Pig Research Centre.
Nuntapaitoon, M.; Muns, R.; Kappel, P.K.; Tummaruk, P. (2019): Factors influencing colostrum consumption by piglets and their relationship with survival and growth in tropical climates. Livestock science 224:31-39.
Sørensen, T.; Thorup, F.; Nielsen, M.F.N.; Hansen, C.F. (2016): Handling of cold pigs after birth [Håndtering af kolde grise efter fødsel]. Publication no. 1087. SEGES Danish Pig Research Centre.
Thorup, F. (2020): Managing high litter size from farrowing until weaning. Date accessed October 27th from https://danbred.com/managing-high-litter-size-from-farrowing-until-weaning/
