Beyond Antibiotics: How Natural Feed Additives & Outdoor Access Can Boost Pig Health

Mira Elwood in Health & Wellness August 2025 • 5 min read.

"Discover the potential of mannan oligosaccharides (Bio-Mos) and outdoor housing to improve pig growth and well-being, offering a promising alternative to traditional antibiotic use in livestock farming."

In an era where concerns about antibiotic resistance are escalating, the livestock industry is under increasing pressure to find alternative strategies for promoting animal health and growth. Traditional reliance on antibiotics as growth promoters is being questioned, leading researchers and farmers to explore innovative solutions that prioritize both animal welfare and sustainable practices. This article delves into a compelling study that investigates the potential of mannan oligosaccharides (Bio-Mos) and outdoor access housing systems to enhance pig health, growth, and overall carcass composition.

The study, conducted by researchers at The Ohio State University, examines the effectiveness of Bio-Mos, a prebiotic, in comparison to subtherapeutic antibiotic treatments and conventional housing systems. The core objective is to identify viable alternatives to antibiotics that not only maintain but also improve pig performance and health. This research is particularly relevant as legislative bans on antibiotic use in livestock gain traction globally, pushing the industry towards more sustainable and health-conscious farming methods.

This comprehensive analysis not only sheds light on the immediate benefits of these alternative approaches but also addresses broader implications for the future of swine farming. By understanding the interplay between natural feed additives, housing conditions, and pig physiology, we can pave the way for more responsible and effective strategies in livestock management.

Unpacking the Science: Bio-Mos and Outdoor Housing

Healthy pig in a green field, symbolizing natural approaches to livestock farming.

The research design was structured as a 3 × 2 factorial experiment, involving 360 pigs from a Landrace breeding female population. The pigs were divided into groups receiving one of three dietary treatments: a control diet, a diet supplemented with Bio-Mos, or a diet including a subtherapeutic antibiotic (tetracycline). The Bio-Mos was administered at varying inclusion rates across different growth phases, ensuring a targeted approach to nutritional support.

In addition to dietary variations, the study also assessed the impact of different housing systems. Pigs were housed in either a conventional indoor facility or an outdoor access system. The conventional indoor (IN) facility provided 1.0 m²/pig of solid concrete space and 0.3 m²/pig of slatted floor, accommodating 12 pigs per pen. The outdoor access (OUT) system offered 1.1 m²/pig of indoor, bedded concrete space and 1.9 m²/pig of outdoor solid concrete, with only 6 pigs per pen. This design acknowledges the potential confounding of space with the number of pigs per pen, allowing for a comprehensive analysis of environmental factors.

Bio-Mos (BM): A prebiotic that supports gut health.
Antibiotic (AB): Tetracycline, included at 0.0055% in all dietary phases.
Control (CON): A standard diet without additives.
Indoor (IN): Conventional, indoor facility with limited space per pig.
Outdoor Access (OUT): More space per pig with bedded concrete and outdoor area.

Throughout the study, researchers meticulously measured several key indicators, including average daily gain (ADG), average daily feed intake (ADFI), feed conversion ratio (G:F), ultrasonic carcass composition, blood hematocrit levels, and the occurrence of observed illnesses. These measurements provided a detailed view of how each treatment affected pig health and performance. The data collected were then subjected to rigorous statistical analysis to determine the significance of each variable.

Moving Forward: Towards Sustainable Swine Farming

The insights gained from this study offer a promising outlook for the future of swine farming. By integrating natural feed additives like Bio-Mos and optimizing housing conditions to include outdoor access, the industry can move towards more sustainable and responsible practices. These changes can not only reduce our reliance on antibiotics but also promote better animal welfare and improve overall production efficiency. As consumer awareness and regulatory pressures continue to grow, adopting these innovative approaches will be crucial for ensuring the long-term viability and ethical integrity of the swine farming industry.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.2527/jas.2013-6582, Alternate LINK

Title: Effect Of Mannan Oligosaccharides (Bio-Mos) And Outdoor Access Housing On Pig Growth, Feed Efficiency And Carcass Composition

Subject: Genetics

Journal: Journal of Animal Science

Publisher: Oxford University Press (OUP)

Authors: B. A. Wenner, H. N. Zerby, D. D. Boler, W. A. Gebreyes, S. J. Moeller

Published: 2013-08-13

Everything You Need To Know

What is Bio-Mos and what role does it play in the context of the study?

Bio-Mos is a prebiotic that supports gut health in pigs, it was compared to subtherapeutic tetracycline antibiotics and a standard diet in a study. This helps to see the effectiveness of this additive compared to the use of antibiotics. The use of tetracycline is an example of traditional antibiotic use. The study wanted to find alternatives to antibiotics to improve pig performance, health, and overall carcass composition. The study found the Bio-Mos could be used instead of antibiotics.

What treatments and systems were compared in the study?

The research compares the use of Bio-Mos, a prebiotic, against traditional antibiotic treatments, specifically tetracycline, and also examines conventional indoor housing versus outdoor access systems. It includes a control diet without additives. Indoor housing provides limited space per pig while outdoor access provides more indoor and outdoor space per pig. Researchers meticulously measured average daily gain, average daily feed intake, feed conversion ratio, ultrasonic carcass composition, blood hematocrit levels, and the occurrence of observed illnesses. These measurements show how each treatment affected pig health and performance.

What is the difference between indoor and outdoor access housing and why is it important?

Outdoor access systems offer pigs more space with bedded concrete indoors and access to an outdoor area. The indoor system provides less space per pig. The OUT system provides more space, which can reduce stress and improve the overall welfare of the pigs. This is important for promoting pig health and growth. The inclusion of outdoor access systems is a key element of the study as it focuses on the environmental impact on pig well-being.

What is the significance of tetracycline in the study?

Tetracycline is a subtherapeutic antibiotic used in the study. The research is particularly relevant because legislative bans on antibiotic use in livestock are gaining traction globally. The study's goal is to identify alternatives to antibiotics that not only maintain but also improve pig performance and health. The research is addressing concerns about antibiotic resistance in livestock, promoting both animal welfare and sustainable practices.

What are the broader implications of the study's findings for the swine industry?

The study investigated how Bio-Mos and outdoor access could improve pig health and growth, which is important for the swine industry. The study used a 3 x 2 factorial experiment involving 360 pigs. The experimental design allowed researchers to assess the impacts of Bio-Mos and outdoor housing. The key indicators include average daily gain, feed intake, feed conversion ratio, and carcass composition. By integrating these natural feed additives and optimizing housing conditions, the industry can move towards more sustainable and responsible practices to improve overall production efficiency.