Lysine Requirement Affected by Gender, Weight but Not PCV2 Vaccination

PCV2 vaccination did not increase the lysine requirement for growing and finishing barrows and gilts, according to paper presented at the Kansas Swine Day 2009 by N.W. Shelton. Differences in requirement were found between gilts and barrows as well as between growing and finishing pigs.

16 March 2010

4 minute read

A series of four experiments was conducted to determine the effect of porcine circovirus type 2 (PCV2) vaccination on the lysine requirement of growing and finishing pigs.

Experiments 1 and 2 evaluated the requirement for 85- to 140-lb gilts and barrows, respectively. Experiments 3 and 4 evaluated the requirement for 225- to 275-lb gilts and 215- to 260-lb barrows, respectively.

Data from each trial were analysed as 2 × 4 factorial designs with 2 PCV2 vaccination treatments (vaccinates and non-vaccinates) and four levels of increasing standardised ileal digestible (SID) lysine:ME ratio (2.24, 2.61, 2.99 and 3.36 g/Mcal in Experiments 1 and 2, and 1.49, 1.86, 2.23, and 2.61 g/Mcal in Experiments 3 and 4). Vaccinated pigs received two doses of commercial PCV2 vaccine (Circumvent PCV; Intervet Inc., Millsboro, Delaware).

No PCV2 vaccination × SID lysine:ME ratio interactions were observed (P>0.14) in any of the four studies.

In Experiments 1 and 2, PCV2 vaccinates had increased (P<0.04) average daily gain (ADG), average daily feed intake (ADFI), final weight and daily SID lysine intake and tended to have improved (P<0.09) F/G compared with non-vaccinates.

In Experiment 1, ADG and feed to gain ratio (F/G) improved (quadratic; P<0.03) as the SID lysine:ME ratio increased, with increases through 2.99 g/Mcal. In Experiment 2, increasing the SID lysine:ME ratio improved (linear; P<0.001) F/G and increased (linear; P<0.001) daily SID lysine intake and SID lysine intake per pound of gain. Thus, 3.36 g SID lysine/Mcal ME appears to maximise efficiency for 85- to 140-lb barrows.

In Experiment 3, PCV2 vaccinates had improved (P<0.02) F/G and increased (P<0.03) final weight, SID lysine intake per pound of gain, and backfat thickness compared with non-vaccinates. Both ADG and F/G improved (quadratic; P<0.05) as the SID lysine:ME ratio increased, with ADG improving through 1.86 g/Mcal and F/G improving through 2.23 g/Mcal, indicating the requirement may be between those levels.

In Experiment 4, both ADG and ADFI were decreased (P<0.04) in vaccinates compared with non-vaccinates. In this study, ADG, F/G, daily SID lysine intake and SID lysine intake per pound of gain increased (linear; P<0.001) and F/G improved (linear; P<0.001) through the highest level of 2.61 g lysine/Mcal, with the greatest magnitude of change when lysine was increased from 2.23 to 2.61 g/Mcal.

Because of the lack of any interactions between dietary SID lysine level and PCV2 vaccination, it appears that PCV2 vaccination did not increase the lysine requirement for growing and finishing barrows and gilts.

On the basis of these studies, which used corn-soybean meal-based diets with three per cent added fat, the requirement was 1.04 per cent SID lysine or 1.17 per cent total lysine for 85- to 135-lb gilts, 1.17 per cent SID lysine or 1.31 per cent total lysine for 85- to 140-lb barrows, 0.78 per cent SID lysine or 0.88 per cent total lysine for 225- to 275-lb gilts, and 0.91 per cent SID lysine or 1.02 per cent total lysine for 215- to 260-lb barrows.

Reference

Shelton N.W., M.D. Tokach, S.S. Dritz, R.D. Goodband, J.L. Nelssen, J.M. DeRouchey and J.L. Usry. 2009. Effects of porcine circovirus type 2 vaccine and increasing standardized ileal digestible lysine:calorie ratio on growth performance and carcass composition of growing and finishing pigs. Proceedings of the Kansas Swine Day 2009, 152-167.