Extremes of Dietary Protein in Pregnancy Adversely Affect Litter

Feeding either very low or excessive protein (at constant carbohydrate content) to gilts during pregnancy adversely affected the growth of the total litter and piglet birth weights, according to new research.

1 October 2010

4 minute read

C. Rehfeldt and colleagues at the Muscle Biology and Growth Department of the Leibniz Institute for Farm Animal Biology (FBN) in Dummerstorf, Germany, have published the results of their study on the effects of low and excess dietary protein levels during gestation on the growth and compositional traits of gilts and their foetuses in Journal of Animal Science.

The aim of their study was to investigate whether dietary protein intake during gestation below or above recommendations affects gilts growth and body composition, gestation outcome and colostrum composition.

German Landrace gilts were fed gestation diets (13.7MJ ME per kg) containing a low (n=18; LP, 6.5 per cent crude protein), an adequate (n=20; AP, 12.1 per cent crude protein), or a high (n=16; HP, 30 per cent crude protein) protein level corresponding to a protein:carbohydrate ratio of 1:10.4, 1:5, and 1:1.3, respectively, from mating until farrowing.

Gilts were inseminated by semen of pure German Landrace boars and induced to farrow at days post-coitum (dpc) 114 (Experiment 1). Energy and protein intake during gestation was 33.3, 34.4, and 35.8MJ ME per day (P<0.001), and 160, 328, and 768g per day, respectively, in LP, AP, and HP gilts (P<0.001).

From insemination to 109 dpc, bodyweight gain was lowest in LP (42.1kg), intermediate in HP (63.1kg) and highest in control gilts (68.3kg), whereas increase of back fat thickness was lowest in gilts fed the HP diet compared with LP and AP diets (3.8, 5.1, 5.0mm; P=0.01).

Litter size, percentage of stillborn piglets, and mummies were unaffected by the gestation diet.

Total litter weight tended to be lower in the offspring of LP and HP gilts (14.67, 13.77 versus 15.96kg; P=0.07), and the percentage of male piglets was higher in litters of HP gilts (59.4 per cent; P=0.01).

In piglets originating from LP and HP gilts, individual birth weight was lower (1.20, 1.21 versus 1.40kg; P=0.001) and birth weight / crown-rump length ratio was reduced (45.3, 46.4 versus 50.7g per cm; P=0.003).

Colostrum fat (7.8, 7.4 versus 8.1 per cent) and lactose concentrations (2.2, 2.1 versus 2.6 per cent) tended to be reduced in LP and HP gilts (P=0.10).

In another experiment (Experiment 2), 28 gilts (LP, n=10; AP, n=9; HP, n=9) were treated as in Experiment 1 but slaughtered at 64 dpc.

At 64 dpc, LP gilts were 7.0 per cent lighter than AP gilts (P=0.03), whereas HP gilts were similar to AP gilts. Body composition was markedly altered in response to LP and HP feeding with lower lean (P<0.01) and higher fat contents (P=0.02 to 0.04) in LP and lower fat content (P=0.02 to 0.04) in HP gilts.

Foetal litter weight and number, and embryonic survival at 64 dpc were not affected by the diets.

The authors concluded that the results indicate that gestation diets containing protein at 50 per cent and 250 per cent of recommendation and differing in protein:carbohydrate ratio led to marked changes in protein and fat metabolism in gilts resulting in foetal growth retardation of 15 per cent, which mainly occurred during the second half of gestation.

Reference

Rehfeldt C., Lang I.S., Görs S., Hennig U., Kalbe C., Stabenow B., Brüssow K.P., Pfuhl R., Bellmann O., Nürnberg G., Otten W. and Metges C.C. 2010. Low and excess dietary protein levels during gestation affect growth and compositional traits in gilts and impair offspring fetal growth. J Anim Sci. 2010 Oct 1. [Epub ahead of print].