Isoquinoline alkaloids improve amino acid digestibility and intestinal function of pigs

Rundle, Carly Marie

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https://hdl.handle.net/2142/113843 Copy

Description

Title

Isoquinoline alkaloids improve amino acid digestibility and intestinal function of pigs

Author(s)

Rundle, Carly Marie

Issue Date

2021-11-24

Director of Research (if dissertation) or Advisor (if thesis)

Stein, Hans H

Doctoral Committee Chair(s)

Swanson, Kelly S

Committee Member(s)

• Fahey, Jr., George C
• Parsons, Carl M

Department of Study

Nutritional Sciences

Discipline

Nutritional Sciences

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• digestibility
• growth performance
• intestinal health
• isoquinoline alkaloids
• pig

Abstract

Isoquinoline alkaloids (IQ) have been used as phytogenic feed additives to improve growth performance and intestinal health of growing pigs. Therefore, 7 experiments were conducted to test the hypothesis that inclusion of IQ to corn-soybean meal diets improve growth performance and nutrient digestibility by growing and finishing pigs. The second hypothesis was that if amino acids (AA) are included in corn-soybean meal diets at concentrations that do not meet requirements, IQ may ameliorate the negative effects of formulating diets below AA requirements by increasing digestibility of nutrients and by improving intestinal health, which may result in growth performance not being different between pigs fed diets with AA below or at requirements. In experiments 1 and 2, 12 ileal T-cannulated growing and finishing barrows were fed diets that included either 0, 40, 80, or 160 mg IQ/kg feed to determine effects of IQ on apparent ileal digestibility (AID) of nutrients. Results indicated that IQ supplementation increased (P < 0.05) AA digestibility by both growing and finishing pigs, with the greatest digestibility values observed in the 40 and 80 mg/kg treatment groups. In addition, an increase (P < 0.05) in the AID of CP was observed at an IQ inclusion rate of 40 mg/kg fed to finishing pigs. Experiment 3 utilized 40 growing barrows in metabolism crates that were fed corn-soybean meal diets with either 0, 40, 80, or 160 mg IQ/kg feed to determine effects of IQ on apparent total tract digestibility (ATTD) of energy, fiber, and N and concentrations of digestible energy (DE) and metabolizable energy (ME) in the diets. Results indicated that ME tended to decrease (P < 0.10) as IQ was included in the diets. Inclusion of IQ also resulted in a decrease (quadratic, P < 0.05) in N retention by pigs, but there was no effect of IQ on the biological value of N. Due to the increase in AA digestibility observed in previous experiments, experiments 4 and 5 were designed to test the hypothesis that inclusion of IQ in diets formulated below AA requirements may result in increased growth performance, systemic health, and total tract digestibility of energy and N. Experiment 4 was conducted for 56 d and 192 growing pigs were allotted to a 2 × 2 factorial with diets formulated at requirements for indispensable AA or 10% below AA requirements and with either 0 or 90 mg IQ/kg feed. If AA were reduced in the diet, a reduction (P < 0.05) in average daily gain (ADG) and gain:feed (G:F) was observed. On d 14, gilts had greater interleukin- (IL-)1β and IL-18 than barrows if no IQ was used, but if IQ was added to the diets, IL-1β and IL-18 were reduced in plasma of gilts compared with barrows regardless of dietary AA concentration (interaction, P < 0.05). In experiment 5, 40 growing barrows were housed in metabolism crates and allotted to a 2 × 2 factorial with diets formulated at 5% below requirements for indispensable AA or 8% below AA requirements and with either 0 or 90 mg IQ/kg feed. Intake and retention of N decreased (P < 0.05) for pigs fed the diet with AA 8% below requirements compared with pigs fed the diet with AA 5% below requirements. The biological value of N was not affected by IQ inclusion or AA level. The ATTD of gross energy and DE and ME of the diet were unaffected by treatment, but ATTD of P decreased if diets contained IQ (P < 0.05). Experiment 6 was conducted to determine effects of dietary IQ and narasin, alone or in combination, when fed to finishing pigs on growth performance and carcass characteristics. Results indicated that ADG and G:F tended to decrease (P < 0.10) if IQ was added to the diet. Loin muscle area tended to be reduced (P < 0.10) if both IQ and narasin were added to the diet. Minolta L* increased (P < 0.05) with inclusion of both narasin and IQ in the diet, indicating a lighter chop compared with the chop of pigs fed the control diet or a diet in which only one of the additives was included. Because IQ increased digestibility of AA in previous experiments, experiment 7 was conducted to test the hypothesis that IQ inclusion in diets formulated below AA requirements for weanling pigs subjected to a health challenge would improve growth performance and intestinal health. Results indicated that if dietary AA were at the requirement, IQ increased lamina propria thickness, but if dietary AA were below the requirement, IQ inclusion decreased lamina propria thickness (interaction, P < 0.05), indicating greater absorptive capacity of the jejunal villi. Inclusion of IQ to diets with AA at requirements decreased IL-4 and IL-10, but if AA were below the requirement, IL- 4 and IL-10 increased if IQ was also included in the diet (interaction, P < 0.05). If dietary AA were at requirements, IQ tended to increase occludin abundance in the jejunal mucosa; however if AA were at requirements, IQ reduced occludin abundance (interaction, P < 0.10). In conclusion, IQ increase the AID of AA and CP by growing and finishing pigs. Isoquinoline alkaloid inclusion does not affect the ATTD of energy, nor does it affect the DE and ME in diets. Retention of N was reduced by IQ if diets were formulated at AA requirements, indicating that IQ influences N metabolism in addition to increasing digestibility of N-containing compounds by pigs. If AA are reduced in the diet, IQ changes cytokine expression in plasma of weanling and growing pigs, and modulates markers of intestinal function in weanling pigs, indicating that IQ reduces inflammation and improves intestinal function if included in corn-soybean meal diets. Further research is needed to elucidate the effects of IQ on systemic cytokine production and to determine the effects of IQ on function and secretion of digestive enzymes in the small intestine.

Graduation Semester

2021-12

Type of Resource

Thesis

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http://hdl.handle.net/2142/113843

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Copyright 2021 Carly Rundle

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