Effects of Dietary Chicory and Reduced Nutrient Diets on Composition and Odor of Stored Swine Manure1, The

Professional Animal Scientist, Aug 2007 by Hanni, S M, DeRouchey, J M, Tokach, M D, Goodband, R D, Et al

ABSTRACT

Two experiments were conducted to examine the impact of dietary chicory on growth performance and odor of stored swine manure. In Exp. 1, 180 nursery pigs (10.6 �2 kg BW) were used in a 21-d experiment to evaluate the effects of replacing corn with chicory (0.5 to 10.0%) on pig performance. Overall, ADG increased (linear; P

Key words: chicory, environment, manure, nutrient excretion, odor, swine

INTRODUCTION

Nutrients containing N, P, and S that are commonly found in swine diets are not completely digested by the pig, resulting in their excretion in manure. These are precursors to several compounds associated with the odor of swine manure, including ammonia, amines, S-containing compounds, VFA, indole, skatole, phenols, alcohols, and carbonyls (Curtis, L993).

Compounds associated with the odor and nutrient concentrations in swine manure can be altered through dietary or microbial manipulation. Farnsworth et al. (1995) showed that adding 3 or 6% Jerusalem artichoke to a swine diet resulted in manure that had a sweeter, less sharp, and less pungent odor, and had a lesser skatole odor than did manure from pigs eating the control diet. The tuber of the Jerusalem artichoke is rich in inulin, a fructose polymer. Like Jerusalem artichoke, chicory (Cichorium intybus) is also rich in inulin. These fructose polymers (fructooligosaccharides) cause altered VFA patterns by increasing the population of bifidobacteria in the hindgut, thereby reducing odor in feces (Hidaka et al., 1986). Rideout et al. (2004) reported that adding 5% chicory inulin extract to the diet significantly reduced skatole in manure of pigs fed a corn-soybean meal diet, but had no impact on N-related odor.

Therefore, our objectives were to determine 1) the effect of dietary chicory addition on growth performance of swine; and 2) the effects of dietary chicory addition on nutrient excretion and the odor characteristics in stored swine manure. Within the second objective, several other dietary strategies (low protein, non-S-containing trace mineral premixes, and phytase) were evaluated as models to test the effectiveness of chicory addition on nutrient excretion and odor emission.

MATERIALS AND METHODS

The Kansas State University Institutional Animal Care and Use Committee approved all protocols used in the experiments.

Experiment 1

A total of 180 weanling pigs (Line 327 � C22; Pig Improvement Co., Franklin, KY), were blocked by initial BW (10 � 6 kg) and allotted randomly to 1 of 5 dietary treatments. Each treatment had 6 replications (pens) and 6 pigs per pen.

Pigs were fed treatments for 21 d from d 20 to 41 postweaning. The treatments included a control diet with no added chicory and 4 diets with increasing percentages of chicory (0.5, 1.0, 5.0, and 10.0%). Each treatment had 6 replications (pens) with 6 pigs per pen. Analyzed values of chicory for amino acids, Ca, and P were used in diet formulation (Table 1), with NRC (1998) values used for all other ingredients. All diets were fed in meal form and formulated to be isolysinic and isocaloric (Table 2). The pigs were housed in an environmentally controlled nursery at the Kansas State University Swine Teaching and Research Center. Each pen (1.2 ? 1.5 m) had woven wire flooring and contained a stainless steel self-feeder and one nipple waterer to allow ad libitum consumption of feed and water. Pigs were weighed and feed disappearance was determined weekly to calculate ADG, ADFI, and G:F.

Experiment 2

Twelve nonlittermate barrows (Line 327 � C22; Pig Improvement Co.), initially weighing 59 � 3 kg, were used in a 4 � 4 replicated Latin square design. The Latin square consisted of 4 consecutive 10-d periods. At the beginning of period 1, pigs were weighed and assigned to a dietary treatment. Dietary treatments were changed for every 10-d period so that each pig was fed all 4 of the experimental diets.

Analyzed values of chicory for amino acids, Ca, and P were used in diet formulation (Table 1). All diets (Table 3) were formulated to provide 0.85% true digestible Lys and were fed in meal form. A conventional, 18% CP corn-soybean meal diet was formulated with no crystalline i.-Lys HCl or phytase (0.51% available P). This diet also used a trace mineral premix with the S-containing forms of trace minerals to maximize nutrient excretion and potential for odor production. A second treatment diet was formulated to reduce nutrient excretion through the use of crystalline amino acids, added phytase, and replacement of S-containing trace mineral premix with other forms. The conventional or reduced nutrient diets were fed with none or 10% added chicory, completing the 4 experimental treatments. Pigs were fed at 3% of their BW (start of each period), with feed divided equally between 2 feedings, and pigs had ad libitum access to water. Feed refusals were collected and weighed to determine actual feed intake.

The S-containing and non-S-containing trace mineral premixes used in Exp. 2 were formulated to the same trace mineral concentrations. The S-containing trace mineral premix used in the conventional diet contained zinc sulfate, ferrous sulfate, manganese sulfate, cupric sulfate, calcium iodate, and sodium selenite, whereas the non-S-containing trace mineral premix used in the diets formulated to reduce nutrient excretion and odor contained zinc oxide, ferric chloride, manganese oxide, cupric chloride, calcium iodate, and sodium selenite. Wheat middlings were used as a earner in both the S- and non-Scontaining trace mineral premixes.