Potassium diformate is a special conjugate acid salt (HCOOH-HCOOK) that was approved by the European Union as a non-anti-growth additive in the diets of piglets and growing-finishing pigs in 2001 and showed significant growth promotion. However, there have been few reports of the use of potassium diformate in sows. The purpose of this study was to investigate the effects of potassium diformate on sow diet, sow performance, nutrient digestibility, sow milk composition, and microbial count in sow feces.

1 Materials and methods

Potassium Diformate (abbreviated as PDF) is a formate containing 35% formic acid and 65% potassium formate.

1.1 Selection and grouping of test animals

A total of 156 primipara and sows were selected for the trial. At the time of breeding, the average weight of the primiparous sows was 136±7.2 kg, and the average weight of the sows was 200±28 kg. The sows are divided into 4 groups according to the births of the piglets: the first group is the primiparous sow group, the second group is the sow group with 2 and 3 births; the third group is the 4 births. The sow group of 5 and 6 fetuses; the fourth group is the sow group of 7 fetuses and above. The sows in each parity group were randomly assigned to three different diet treatment groups. The average parity of the sows was 3.4. The trial begins with sow breeding and lasts for a full cycle, which includes lactation and the next breeding period.

1.2 Test diet

The trial consisted of three diets, one basal diet (control), and the other two diets added 0.8 and 1.2% potassium diformate to the basal diet.

1.3 Test pig weight and record

Sow weight and backfat thickness were measured and recorded at the time of littering, at the time of weaning, and at the time of the next breeding. The average daily feed intake of sows during pregnancy, lactation and estrus intervals is measured and recorded daily. Individual piglets were individually weighed at the time of weaning, 7 days, 14 days, 21 days and 28 days after birth.

1.4 Determination of microbial quantity

At the birth of the piglets and 10 days after birth, 8 sows were selected from the control group and the 1.2% potassium diformate addition group to take fresh fecal samples for the determination of the number of microorganisms.

2 results

2.1 Sow production performance

As can be seen from Table 1, the thickness of the backfat of the sows fed the potassium diformate group during pregnancy increased (p=0.03).

2.2 Piglet production performance

The results of piglet performance are shown in Table 2. The addition of 0.8% and 1.2% potassium diformate to the diet increased the piglet birth weight (p=0.05) and birth weight (p=0.08). The addition of potassium diformate to the diet increased the daily gain of lactating piglets (p=0.07). It is also possible to increase the body weight and litter weight of the piglets at weaning (p=0.05).

2.3 Main nutrient digestibility

The results of nutrient digestibility are shown in Table 3. The addition of 1.2% potassium diformate to the lactating sow diet increased the total intestinal apparent digestibility of crude fat (p=0.08) and crude ash (p=0.001), making the whole intestinal table of crude protein and crude fat. The digestibility was increased by 1.2% and 4.4%, respectively, and the net energy calculation was increased by 2.3% (p=0.02).

2.4 Breast milk ingredients

As can be seen from Table 4, the fat content of the milk of the sows supplemented with potassium diformate in the diet increased 12 days after birth (p=0.09).

2.5 Number of microbes in sow fresh manure

It can be seen from Table 5 that the addition of 1.2% potassium diformate to the diet has inhibitory effects on lactic acid bacteria and Escherichia coli in the sow feces at birth and 10 days after birth (p>0.05).

3 Discussion

The increase in the thickness of the backfat of pregnant sows fed 1.2% potassium diformate may be related to an increase in the apparent digestibility of total intestinal fat in the diet. Adding 1.2% potassium diformate, compared with the control group, increased the net energy content of the diet from 9.09 MJ/kg to 9.30 MJ/kg, an increase of 2.3%.

The birth weight, daily gain and weaning weight of piglets fed the diet supplemented with potassium diformate increased, which was compared with the apparent intestinal digestibility and net energy of the fat in the sow diet. The increase and the increase in nutrient availability. Nutritional intake of sows during pregnancy and lactation has an effect on the number of live piglets, the number of pigs born and dead, and the weight of piglets and weaning weight (Whittemore, 1998).

The addition of potassium diformate to sow diets increased the apparent intestinal digestibility of ash, which may be related to an increase in potassium digestion and absorption in potassium diformate in the diet. Mroz et al (2002) also reported that the addition of potassium diformate to pig diets increased the ash and potassium digestibility, indicating a higher bioavailability of potassium in potassium diformate.

The addition of 1.2% potassium diformate to the diet increased the fat content in the milk of the sow, which promoted the weight gain and weaning weight of the piglets. Compared with the control group, the addition of potassium diformate to the diet increased the total calculated output of the sow's milk by 2 to 5%.

The addition of 1.2% potassium diformate to the diet reduced the amount of lactic acid bacteria and E. coli in the fresh feces of the sow. The inhibitory effect of potassium diformate on the microbes in the gastrointestinal tract of the pig increases the utilization of energy and nutrients in the diet by the host. As a result, the whole intestinal apparent digestibility of the nutrient is improved, the growth rate of the animal is improved, and the feed is improved. Conversion rate (Øverland et al, 2000).

4 Conclusion

Adding potassium diformate to the diet can increase the backfat thickness of the sow during pregnancy, increase the net energy calculation value of the sow lactating diet and the digestibility of fat and ash, and improve the birth weight and weaning of the piglets. Heavy, inhibited the growth of E. coli and lactic acid bacteria in sow feces (p>0.05).