Nutwean
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Executive summary - download here
Final report - download here
Interim factsheet - download here
Research partners: Scottish Agricultural College (SAC), Universities of Leeds, Newcastle and
Nottingham, and MLC
Industrial partners: ABNA, Frank Wright, Primary Diets, Provimi
Sponsors: Defra (LINK) HGCA and BPEX
Project duration: 2003-2007
Nutwean’s objective was to develop sustainable systems for the management of weaner pigs through nutrition, in the absence of reliance on antimicrobial growth promoters, whilst maximising use of
home-grown cereals and oilseeds. This aim was achieved by modifying pre- and post-weaning pig
nutrition in ways which exploit the potential of dietary components to enhance gut health and improve
food intake. Different nutritional treatments were tested under different management systems, where
weaning age and/or lactation environment (outdoor versus indoor) varied. Work was carried out in a
large number of controlled studies, including large-scale commercial trials.
The main results are
summarised below:
Strategies for creep feed provision
• Providing sodium butyrate in feed enhanced gut development and improved feed conversion.
• Inclusion of sodium butyrate or inulin in creep feed did not deliver added benefits in post
weaning performance or microbial indicators of gut health beyond that provided by high quality,
commercial-specification creep.
Source and processing conditions of raw materials on their in vitro characteristics and nutritional value
• Soft wheat differs in hydration characteristics between batches, which shows the importance of
characterising hydration and physicochemical properties of cereals in trials. As starch needs to
hydrate for effective hydrolysis, difference in hydration patterns can affect digestibility.
• Endogenous alpha-amylase activity may influence both in vitro rheological and in vivo digestibility
data. In vitro data may be used to predict in vivo small intestinal starch digestibility.
• Wheat processing (especially extrusion) may increase its nutritional value for weaned piglets.
• Soft wheat may be associated with higher nutritional value, which can increase the confidence in
using wheat of particular backgrounds in piglet diets.
The role of ‘functional fibre’ on enteric health
• To minimise the risk of post weaning diarrhoea whilst maximising performance, diets containing
sources of predominantly soluble NSP, which do not lead to increased digesta viscosity, such as
inulin, might be recommended. This will be particularly beneficial in diets containing high levels
of crude protein and on farms with increased disease risk, although under commercial
conditions with a low infection pressure, such benefits may be minimal.
The role of protein nutrition on enteric health
• Diets lower in crude protein content may be beneficially fed to newly weaned pigs to maintain
gut health and decrease the risk of post weaning diarrhoea, especially in younger pigs and under
increased disease challenge.
• Under commercial conditions, the small penalty on performance in pigs fed lower protein diets
in the immediate post-weaning period does not seem to affect long-term performance, carcase
weights and quality at slaughter.
Acid buffering characteristics of the post-weaning diet
• In this study formic acid or phytase did not affect gut health or performance, although phytase
may be a viable alternative to adding inorganic phosphorus.
Utilisation of rapeseed as a home-grown protein source
• Micronised whole rapeseed has the potential (at low inclusion levels) to be a cost effective
home-grown protein and energy source in diets for weaned piglets, since inclusion levels greater
than previously accepted can be used without adversely affecting feed conversion ratio or feed
cost per kilogram gain. However, studies on how to overcome the detrimental effect on intake
need to be further developed.
Consequences of lactation environment and weaning age on health and performance
• Compared to indoors, outdoor reared piglets performed better post-weaning, although
pre-weaning mortality rate was somewhat higher.
• Delaying weaning until 6 weeks of age disadvantaged indoor reared piglet performance, but may
not be disadvantageous to outdoor reared piglets, depending upon the subsequent feeding
regime. Regardless of rearing environment all pigs responded positively to both zinc oxide and
antimicrobial growth promoters.
• Outdoor rearing improves gut development post-weaning, possibly due to the opportunities to
forage and consume substrates prior to weaning.
Translating experimental finding into commercial applications
• Under commercial conditions, high quality diets (cooked cereals and animal protein sources) led
to improved health and performance immediately post-weaning compared to low quality diets
(raw cereals and plant protein sources). There was however no long-term effect of
post-weaning diet on pig health and performance.
• Under commercial conditions, wheat extrusion improves weight gain and feed intake in the
immediate post-weaning period but these benefits were not apparent any more some four
weeks post-weaning. Extrusion did not improve pig performance under low levels of amylase,
but resulted in increased weight gain and intake at high levels of amylase. These benefits were
still apparent by day 26 post weaning.
Expected benefits
The expected benefits from Nutwean’s outcomes include:
• Decreased occurrence of post-weaning diarrhoea leading to improved pig health and welfare
• Increased profits as a result of improved post-weaning performance
• Improved feed efficiency resulting in a decrease in nitrogen output and reduced environmental
impact
• Potential increase in market for UK cereals and oilseeds and decrease in protein imports
• Reduced environmental burden of minerals and chemical residues
• Reduced dependency on antimicrobial agents
