Effects of dietary lysine restriction and number of dietary phases in the growing-finishing period on growth performance of pigs

The study reported in this thesis was carried out to evaluate the effects of dietary lysine restriction in the growing period and the number of dietary phases used in the growing-finishing period on growth performance of growing-finishing pigs (32.7 ± 9.43 kg to 115.5 ± 8.18 kg BW). A randomized complete block design was used (blocking factors were gender and day of start of study) with a 3 × 2 factorial arrangement of treatments: 1) Dietary Lysine Level {Control [NRC (2012) recommended Standard Ileal Digestible (SID) lysine level]; Moderate Restriction [0.15% lower SID lysine level than Control]; Severe Restriction [0.30% lower SID lysine level than Control]} and 2) Number of Dietary Phases in the growing-finishing period (4 Phases vs. 2 Phases). The Dietary Lysine Level treatment was applied from 32 to 64 kg BW. All diets were formulated to meet or exceed requirements proposed by NRC (2012) for each phase, with the exception of lysine levels which were according to treatment. The study was carried out in a commercial growing-finishing facility involving a total of 4,420 pigs that were housed in single-sex groups of 34 pigs (22 replicates) at a floor space of 0.63 m2/ pig. Pigs had ad libitum access to feed and water throughout the study. Pigs in each pen were weighed as a group at the start and end of the study, and every two weeks during the study; all additions of feed to the feeders were recorded. Pen was the experimental unit and data were analyzed using R version 3.6.2. The model accounted for the fixed effects of the two treatments, and the interaction, and the random effect of block. There were no Dietary Lysine Level by Number of Dietary Phases treatment interactions (P > 0.05). During the restriction period, pigs on the Severe Restriction treatment had lower (P < 0.05) ADG and G:F than pigs on the Control treatment, with the ADG and G:F of pigs on the Moderate Restriction treatment being intermediate to and different (P < 0.05) from the other two treatments. Pigs on the Severe Restriction treatment had lower (P < 0.05) ADFI than pigs on the other two treatments during the restriction period. During the recovery period, pigs on the Control treatment grew slower (P < 0.05) than those on the other treatments, which did not have different (P > 0.05) ADG. Pigs on the Severe Restriction treatment had lower (P < 0.05) ADFI during the recovery period than the other two treatments, which were not different (P > 0.05). In addition, G:F ratio during the recovery period was greater (P < 0.05) for the Severe Restriction treatment than the Control treatment, with the Moderate Restriction treatment being intermediate to and different (P < 0.05) from the other two treatments. For the overall study period, the two Dietary Lysine Level treatments had lower (P < 0.05) ADFI and ADG than the Control but no difference (P > 0.05) in G:F ratio compared to the Control. During the growing period, pigs on the 4 Phases compared to the 2 Phases treatment had higher (P < 0.05) ADFI and ADG but did not have different (P > 0.05) G:F ratios. There was no effect (P > 0.05) of Number of Dietary Phases on growth performance during the finishing and overall periods. The results of this study indicate that restricting dietary lysine level during the growing period reduced growth rate during the period of restriction but increased growth rates during the finishing period after the dietary lysine restriction was removed. However, compensation in live weight gain was incomplete with pigs subjected to dietary lysine restriction having lower growth rates during the overall growing-finishing period. In addition, these results indicate that reducing the number of dietary phases reduced ADG and ADFI during the growing period, but had no effect on growth performance during the finishing and overall growing-finishing periods.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Animal Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2022

Author dc:creator

• Knight, Jadelyn Gayle

Contributors dc:contributor

• Ellis, Mike

• Lysine Restriction
• Lysine
• Pigs

Statement dc:rights

• Copyright 2021 Jadelyn Knight

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/113091

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/113091