One way to increase body weight and protect pigs from disease is Lactoferrin. Lactoferrin is a protein that can bind and transfer Fe3+ ions and have a bacteriostatic effect. So this research needs to be done to determine the effect of Lactoferrin in terms of body weight and the number of bacteria in pigs. The study was conducted at a pig farm in the Bangli area, Bali, Indonesia, the sample used 20 piglets given oral lactoferrin, and their anal swabs were taken. The piglets will be given Lactoferrin every day for 7 days and are weighed first, the first 10 piglets as control are not given Lactoferrin (K), the next 10 piglets are given Lactoferrin (P) at a dose of 2 ml per piglet/day then on the 7th day the anal swab was taken and the piglets were weighed again, then the number of bacteria (Total Plate Count) was calculated. The results showed that there was a weight gain of 1.24 Kg/week in piglets given Lactoferrin (P), compared to control piglets (K) which only showed a weight gain of 0.85 Kg/week, and a decrease in the number of bacteria in the treated piglets (P), which shows the number of TPC of 1.109 x 107 CFU compared to piglets that are not given Lactoferrin (K) which shows the number of TPC of 3.6183 x 108. The Lactoferrin effect on weight has no significant difference (P>0.05) but in TPC the Lactoferrin has a significant effect to reduce the TPC (P<0.05).