Influence of different phosphorus levels and phytase supplementation in gestation diets on sow performance
Lyberg, K., Andersson, H.K., Simonsson, A., Linberg, J.E. (2007) Journal of Animal Physiology and Animal Nutrition, 91: 304-311
13-Dec-2007 (18 years 5 months 25 days ago)Accumulation of phosphorus (P) in the environment due to pig production is a major
concern. By feeding the animals with correct and close levels of P to the requirements
of the animals, output of P to the environment may be reduced. Available information
on the P requirements for sow is limited, although they contribute to a great
extent to the P originating from pig production. The aim of the study was to evaluate
the influence of P level in the gestation diet on sow performance over two parities.
A total of 104 sows (1 to 6 parities) were evaluated over two reproductive cycles.
During the gestation sows received one of four experimental diets: low P diet
(LP-, 3.7 g P/kg feed), low P diet with phytase (LP+, containing 765 FTU/kg feed),
medium P diet (4.5 g P/kg feed) and high P diet (6.0 g P/kg feed), the last representing
the Swedish feeding recommendations for pregnant sows. The source of P in medium
and high P diets was monocalcium phosphate. Gestation diets presented a relatively
high phytase activity. During the lactations sows were fed the same diet. It was
evaluated the farrowing performance of the sows, sow and piglet performance during
lactation, and the mineral concentration in sows milk, and on blood serum of sows
and piglets.
Low dietary levels of P, without or with phytase (LP- and LP+) presented a higher
number of total born piglets at farrowing, being the mortality at birth the highest
in LP- diet. Therefore no modifications in the number of live-born piglets were
found between diets. No differences were found between experimental diets in terms
of sow and piglet performance during the lactation. Mineral levels were only modified
in milk samples, being the P level in milk higher in the medium P diet.
From the results it may be concluded that reducing by 25% the Swedish recommendations
on P may not affect the performance of the sows. However, it must be taken into
account that the experiment was done only over two parities and therefore long-period
effects of a lowered P supply should be further studied. Moreover, it should be
kept in mind that during the lactation sows received diets with a high supply
of P, and that the experimental diets had a relatively high phytase activity.