An Evaluation of Paddy Rice as an Alternative Energy Source in Protein-Restricted Diets for Growing, Early-Finishing, and Late-Finishing Pigs

TL;DR

This study evaluates paddy rice as a cost-effective alternative to corn in pig diets, finding it can replace up to 30% of corn without harming growth performance.

Contribution

The study provides new evidence on the safe inclusion levels of paddy rice in low-protein diets for pigs at different growth stages.

Findings

Paddy rice can replace up to 15% of corn in growing pigs' diets without affecting growth.

Early-finishing pigs can tolerate up to 20% paddy rice without negative effects.

Late-finishing pigs can handle up to 30% paddy rice, with some improvement in performance.

Abstract

There is a need to explore alternative feed ingredients to reduce feed costs in the context of international maize price fluctuation. Rice is a staple cereal grain for human consumption. Currently, the self-sufficiency rate for rice is close to 100% in China. Due to the high yield production and poor taste quality, there is a serious backlog of early indica rice in China, especially in the southern rice-producing provinces. Thus, rice may have the potential to be used as an alternative energy source for pigs in the context of international maize price fluctuation. As a result of evaluating the effects of replacing corn with paddy rice in pig diets, using paddy rice in swine diets at up to 15% for growing pigs, 20% for early-finishing pigs, and 30% for late-finishing pigs did not cause adverse impacts on growth performance. Therefore, paddy rice can be evaluated as a valuable feed ingredient for swine diets during the growing–finishing period, if favorably priced.

Three experiments were conducted to evaluate paddy rice as an alternative energy feedstuff in low-protein diets for pigs. In Experiment 1, a total of 400 growing pigs (20.68 ± 0.29 kg initial bodyweight), were randomly allocated four dietary treatments with 0, 10, 15, and 20% paddy rice for 30 days. Feeding 10% or 15% paddy rice had no adverse impacts on average daily gain (ADG) and feed to gain ratio (F:G), while the inclusion of 20% rice in diets significantly influenced the growth performance of pigs. In Experiment 2, 364 early-finishing pigs (42.25 ± 0.47 kg) were divided into four treatments with 0, 15, 20, and 25% paddy rice for 35 days. Feeding 15% or 20% paddy rice had no negative consequences on growth performance, while pigs fed with 25% rice had the lowest ADG and the greatest F:G. In Experiment 3, 364 late-finishing pigs (79.52 ± 1.28 kg) were divided into four treatments with 0, 20, 25, and 30% paddy rice for 60 days. Paddy rice can be included at up to 30% in diets without compromising growth performance, while feeding with 25% rice significantly improved the performance for pigs compared with the corn-fed control.

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