Effects of bacteriophage and choline as feed additives on physiology and productivity in broilers and pigs

Abstract

Effects of Bacteriophage and Choline as Feed Additives on Physiology and Productivity in Broilers and Pigs

These experiments were performed to investigate 1) effects of bacteriophage on prevention of Salmonella enteritidis in broilers, 2) effects of bacteriophage on growth performance, fecal properties, blood profiles, and immune response in weaning pigs, and 3) effects of bacteriophage and choline supplementation on physiological responses, growth performance, microbial population, and blood profiles of lactating sows and piglets. Summarized results from each experiment are described as followings:

Experiment I. Effects of Bacteriophage on Prevention of Salmonella enteritidis in Broilers

The experiment 1 was conducted to investigate the effects of bacteriophage on prevention of Salmonella enteritidis in broilers. A total of 320 one day old male broilers (Ross 308) were allotted by randomized complete block (RCB) design in 8 replicates with 10 chicks per pen. The experimental diets were formulated for 2 phase feeding trial (phase I

0-2nd wk, phase II

3rd-5th wk), and 4 different levels (0%, 0.05%

5×108pfu/g, 0.1%

1×109pfu/g, and 0.2%

2×109pfu/g, respectively) of Salmonella enteritidis targeted bacteriophage were supplemented in the basal diet. There were no differences in body weight (BW) gain, feed intake and feed conversion ratio (FCR) during the whole experimental period (P>0.05). Relative weights of liver, spleen, abdominal fat, and tissue muscle of breast obtained from each bacteriophage treatment were similar to control and those values tended to increase when 0.2% (2×109pfu/g) bacteriophage was supplemented. In addition, a numerical difference of glutamic-oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT) and low density lipoprotein (LDL) cholesterol level were observed when 0.2% (2×109pfu) of bacteriophage were provided even though blood profiles were not affected by supplemented levels of bacteriophage (P>0.05). In the result of a 14 d feeding after Salmonella enteritidis challenge to 160 birds from 4 previous treatments, mortality and Salmonella enteritidis concentration in the cecum were decreased with increasing bacteriophage level (P<0.05). This result demonstrated that supplementation of 0.2% (2×109pfu) Salmonella enteritidis targeted bacteriophage might not cause negative effect on growth, meat production, and it reduced mortality from Salmonella enteritidis challenge. Consequently, bacteriophage could be used as an alternative feed additive to antibiotics in broiler diets.

Experiment II. Effects of Bacteriophage on Growth Performance, Fecal Properties, Blood Profiles and Immune Response in Weaning Pigs

The experiment 2 was performed to determine the effects of bacteriophage on growth performance, fecal properties, blood profiles and immune response in weaning pigs. A total of 160 pigs [(Yorkshire × Landrace) × Duroc] (BW = 6.78 ± 1.72 kg

weaned at day 24 ± 3) were allotted to 4 groups in a randomized complete block (RCB) design with 5 replication for 5 week growth trial. The experimental diets were formulated for 2 phase feeding trial (phase I

2×109pfu/g, respectively) of 16 types of pathogen targeted bacteriophage were supplemented in the basal diet. During the whole experimental period, average daily gain, average daily feed intake, and gain:feed ratio were not affected by bacteriophage levels, resulting in similar BW among all treatments (P>0.05). With increasing bacteriophage level in the diets, fecal microbial population of pathogenic Salmonella spp. (linear, P<0.01

2wk) and Escherichia coli (linear, P=0.053

5wk) were decreased. However, the concentration of Lactobacilli was increased in feces when pigs were fed 0.2% of bacteriophage, showing linear response to bacteriophage levels (linear, P<0.05, 2wk

linear, P<0.01, 5wk). The inclusion of bacteriophage in weaning pig diets resulted in decreasing the incidence of diarrhea (linear, P<0.01). In blood immune response, there was a linear decrease in IgA concentration as bacteriophage increased (linear, P<0.05). Although GOT and GPT levels were not affected by bacteriophage levels, total cholesterol (linear, P<0.01, quadratic, P<0.05, 2wk

linear, P<0.01, 5wk) and LDL cholesterol (linear, P<0.01, 2wk) levels were decreased by dietary bacteriophage. This experiment suggested that 16 types of pathogen targeted bacteriophage supplementation did not influence on growth performance. However, 0.2 % (2×109pfu/g) bacteriophage supplementation might have beneficial influences on microbial population, fecal status, immune response, and blood profiles in weaning pigs.

Experiment III. Evaluation of Bacteriophage and Choline Supplementation on Physiological Responses, Growth Performance, Microbial Population and Blood Profiles of Lactating Sows and Piglets

The experiment 3 was conducted to investigate the effects of bacteriophage and choline supplementation on physiological responses, growth performance, microbial population and blood profiles of lactating sows and piglets. A total of 50 mixed-parity (average= 4.64) crossbred sows (F1, Yorkshire × Landrace

Darby, Korea) with an initial BW of 228.71 ± 15.81 kg were used in a 3 week lactation period and sows were allotted to one of five treatments based on BW and backfat thickness with 10 replicates by 1+2×2 factorial arrangement. The experimental treatments were divided by two levels of bacteriophage (0.05%

0.5× 108 pfu/g, or 0.1%

1× 109 pfu/g) and choline chloride (0.05%

250ppm or 0.1%

500ppm) and NRC (1998) requirement is regarded as control treatment. The experimental diets were formulated based on corn-soybean meal diets, which contained 3,265 kcal of ME/kg, 16.8% crude protein, 1.08% lysine, respectively. There were no significant differences in BW, backfat thickness and feed intake of lactating sows by bacteriophage and choline supplementation. The BW changes were quadratically decreased in lactation (day 0 to 21) as dietary choline increased (P<0.05). Supplementation of bacteriophage and choline to lactating diets did not influence on mortality, litter weight and piglet weight. However, numerically higher litter weight and piglets weight gain were observed in bacteriophage and choline treatment groups compared to control. No differences were found in estimation of milk production, dry matter, and energy content of milk in lactating sows during the whole lactational period. Bacteriophage and choline supplementation in diets did not alter the population of Escherichia coli and Salmonella in feces of sows as well as piglets. However, the use of bacteriophage to lactation diets altered the concentrations of fecal Lactobacilli (P<0.001). In blood profiles, GOT, GPT, and non-esterified fatty acid (NEFA) levels of lactating sows and piglets were not affected by dietary treatment, while increasing bacteriophage levels tended to decrease GOT levels of lactating sows (linear, P=0.074). Inclusion of bacteriophage and choline did not influence on immunoglobulin concentration of sows at day 21 postpartum. This experiment suggested that choline supplementation in lactating diet showed an improvement of body reserves of lactating sows and increasing of fat contents in sow milks during lactation. But, bacteriophage had no effects on reproductive performance and physiological responses except of sows fecal Lactobacilli population. Three experiments demonstrated that positive responses were observed by bacteriophage supplementation in broilers and weaning pigs. However, sows did not show positive performance by dietary bacteriophage but body condition of sows was improved by choline supplementation.