Sow productivity has increased substantially during the past few decades and this has put a special focus on management and feeding. Essential parameters to consider are sow health, viability of the newborn piglets and a sow’s milk yield, which is correlated with the feed intake of the lactating sow.

Sow feed acidifier

In a recent experiment in Spain, adding dry semi-coated acidifier in sow feed was investigated with respect to production parameters in two Spanish herds with 750 (Herd A) and 350 (Herd B) cross-bred (LY) sows, respectively. The sows were randomly allocated to the control or FA groups at service, with the restriction that first litter sows were equally divided on the groups.

The FA group of sows were fed the same pregnancy and lactation diets as the control sows were, except for the addition of the 0.5% BOLIFOR FA2300S acidifier.

The sows’ back fat was ultrasonically measured at farrowing and weaning. Rectal temperature was measured the day after farrowing and all piglets were individually weighed at birth and at weaning.

The feed intake of the sows was measured on groups of sows in Herd A and individually in Herd B. Health records of the piglets were collected during the suckling period. In Herd A, weaning took place at 21 days and in Herd B at 28 days. Statistical analysis was performed with the Statistical Analysis System, version 9.2 (SAS Institute Inc., Cary, NC, USA). The statistical model included effects of herd and treatment.   

Feed research results

The production facilities and other conditions differed between the herds and so did the production performance. Sows in both herds responded more or less on the dietary addition of FA (see Table 1 ).
The sows were randomly selected and fed the same feed allowances during pregnancy within the herd. Still, the FA group had more fat on the body, compared with control sows, indicating improved feed efficiency for these sows. During the lactation period the FA sows consumed more feed in both herds. In Herd B, keeping records on individual basis, the difference, proved to be statistically significant.
Lactation failure is a common disease, resulting in medical treatments of the sows, increased piglet mortality and deprived weight gain of the litters. Diseased sows have high rectal temperature and 39.5 degrees C is often used as an indicative limit for sickness.
In Herd A, 13 sows in the control group exceeded 39.5 degrees C the day after farrowing, compared with four sows in the FA group and the average temperature differed significantly between groups in this herd. Herd B had no sows with rectal temperature passing 39.5 degrees C. Sub-clinical disease may, however, affect the weight gain of litters, even when sow rectal temperature not exceeds 39.5˚C.
The litter size at birth was not affected, but there was a tendency for more piglets per litter in the FA group at weaning in both herds. The FA treatment did not affect birth weight in either herd, but the weaning weight and the weight gain of the piglets were significantly improved in Herd B. Improved litter size in the FA treatment for both herds combined with higher weight gains of the FA piglets in Herd B gave over all significantly heavier litters at weaning.

The within-litter standard deviation for piglet´s weight, as a measure of variation in weight, did not differ between control and FA treatment at birth, but differed highly significantly in Herd B at weaning. 


The health status and cause of death was closely monitored in Herd A. The numbers of piglets dead due to weakness, runt syndrome and diarrhea were in majority in the control group as shown in Figure 1 .

In the control group, 71 percent of piglets once medicated for diarrhea were repeatedly treated, compared with none of the piglets in the FA group needing medication for a second time.

Value for pig producers

The results from this sow feeding experiment demonstrate the potential of using the acidifier to decrease the risk of lactation failure and increase sow feed intake and milk yield. Additionally, acidifier increased energy use which also have been demonstrated for conventional mixtures of organic acids. In an earlier study in Thailand, the product was compared with a medicated control diet and still similar results were found.

In practical pig production, lactation failure (PDS, MMA, agalactia, hypoagalactia) is a costly disease. The clinical sickness is identified and treated medically to a high cost, but the question is if the subclinical form of the disease is not as costly.

It has been experimentally proven that there is a significant correlation between the first day post-partum rectal temperature in clinically healthy sows never exceeding 39.5 degrees C at farrowing and piglet mortality and homogeneity of the litter in the first week of life.   

This trial indicated that including acidifier in asow´s feed helps to improve feed efficiency and body condition. It also enhanced sow feed intake during lactation and led to heavier piglets at weaning, as well as less diarrhea during the suckling period and less variation in weight at weaning.


Notes: The effects of Bolifor® FA2300S on sow health and productivity – A field study in two Spanish herds; L Göransson1, C Andersson2, M Collell Suriňach3, G Ausin Ortega41PhD, Consultant in pig nutrition, Kågeröd, Sweden, 2Regional sales manager, Yara, Helsingborg, Sweden, 3 Pig veterinarian consultant, Barcelona, Spain, 4 Pig veterinarian consultant, Burgos, Spain.