Document Type

Dissertation - University Access Only

Award Date

2005

Degree Name

Doctor of Philosophy (PhD)

Department / School

Animal Science

Abstract

A series of studies was conducted with the objective of evaluating the effect of supplementing dietary nucleotides in weanling pig diets. The first study was designed to measure the concentration of nucleotides in the colostrum and milk of sows. The concentrations of5'AMP, 5'CMP, 5'GMP, and 5'IMP change during the initial week post-partum, but during the last two weeks of a 4-wk lactation period, the concentration is relatively constant. In contrast, the concentration of 5'UMP decreased from d-0 to d-28 of lactation. In colostrum, 5 'UMP represented 98% of all 5 'monophosphate nucleotides and in milk, 5 • UMP accounted for 86-90% of all nucleotides, regardless of d of lactation. In the second study, two experiments were conducted to determine the effects of adding nucleosides to starter diets for weanling pigs. In Exp. I, pigs allotted to Treatment I were fed a com casein lactose-based basal diet. Pigs allotted to Treatments 2 and 3 were fed the basal diet supplemented with nucleosides in amounts that correspond to 30% and 150% of the quantities found in sow milk on d-14 of lactation, respectively. The concentration of IgG was determined in the serum while microbial concentration was determined in fecal samples on d-0, 7, and 14 post-weaning. Exp. 2 was an in-vitro study that was conducted to determine the antimicrobial and probiotic properties of nucleosides. Broths containing microflora from pigs were prepared either without nucleosides (control) or with nucleoside supplementation. The bacterial growth in both broths was measured over a 16-h period. The results of the two experiments indicate that nucleoside supplementation during the immediate post-weaning period may positively influence the gastrointestinal microflora by decreasing enterobacteria and increasing L. acidophilus and Bifidobacterium species. In the third study, two experiments were conducted to determine the effects of adding nucleotides to starter diets for weanling pigs. In Exp. 1, pigs were allotted to two treatment groups. Pigs allotted to Treatment 1 were fed a conventional starter diet. Pigs allotted to Treatment 2 were fed Diet 1 supplemented with nucleotides in amounts that correspond to I 00% of the quantities found in sow milk (OM-basis) on d-14 of lactation. Pig performance, serum IgG concentration, intestinal morphology, intestinal microflora composition, and intestinal tissue DNA, RNA, and protein content were used to determine the effects of nucleotide supplementation on d-14 and d-28 post-weaning. Exp. 2 was an in vitro study that was conducted to determine the antimicrobial and probiotic properties of nucleotides. The results indicate that nucleotide supplementation during the immediate post-weaning period positively influence gastrointestinal morphology and microflora by increasing ilea) VH and VH:LPD, and decreasing C/. perfringens count in-vitro. In the final study, the AID and SID coefficients of AA and CP in yeast extract and SOPP by weanling pigs were measured using the difference method. The results indicate that the AID for CP and all AA with the exception of Cys and Ser are similar between yeast extract and SOPP. Likewise, no differences in SID for AA or CP were observed between yeast extract and SOPP. In addition, yeast extract and SOPP contain protein that is relatively well digested by young pigs.

Key words: Digestibility, Immunoglobulins, Microflora, Morphology, Nucleosides,Nucleotides, Pigs

Library of Congress Subject Headings

Swine -- Nutrition
Swine -- Feeding and feeds
Nucleotides

Format

application/pdf

Number of Pages

194

Publisher

South Dakota State University

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