Estimation of the ideal ratio of true ileal digestible sulfur amino acids:lysine in 8- to 26-kg nursery pigs1,2

Abstract

Four experiments were conducted to determine the ideal ratio of true ileal digestible (TID) sulfur AA to Lys (SAA:LYS) in nursery pigs at two different BW ranges using both DL-Met and 2-hydroxy-4-(methylthio)-butanoic acid (HMTBA) as Met sources. In Exp. 1, 1,549 nursery pigs (Triumph 4 x PIC Camborough 22; initial BW 8.3 +/- 0.08 kg) were allotted to one of nine dietary treatments. The basal diet (Diet 1) was a semicomplex corn-soybean meal-based diet (1.32% TID Lys) with no supplemental HMTBA or DL-Met (47.7% TID SAA:LYS). Diets 2 to 9 consisted of the basal diet supplemented with four equimolar levels of DL-Met or HMTBA (52.7, 57.7, 62.7, and 67.7% TID SAA:LYS). In Exp. 2, 330 nursery pigs (Triumph 4 x PIC Camborough 22; initial BW 11.4 +/- 0.10 kg) were allotted to one of nine dietary treatments. The basal diet (Diet 1) was a corn-soybean meal-based diet (1.15% TID Lys) with no supplemental HMTBA or DL-Met (49% TID SAA:LYS). Diets 2 to 9 consisted of the basal diet supplemented with four equimolar levels of DL-Met or HMTBA (54, 59, 64, and 69% TID SAA:LYS). In Exp. 3, 1,544 nursery pigs (Triumph 4 x PIC Camborough 22; initial BW 12.4 +/- 0.13 kg) were allotted to one of nine dietary treatments as in Exp. 2. In Exp. 4, 343 nursery pigs (Genetiporc; initial BW 12.8 +/- 0.56 kg) were allotted to one of six dietary treatments. The basal diet (Diet 1) was a corn-soybean meal-based diet (1.05% TID Lys) with no supplemental DL-Met (49% TID SAA:LYS). Diets 2 to 5 consisted of the basal diet supplemented with four levels of DL-Met (54, 59, 64, and 69% TID SAA:LYS), and Diet 6 was the basal diet supplemented with one equimolar level of HMTBA to satisfy 59% TID SAA:LYS ratio. In all experiments, increasing the TID SAA:LYS ratio resulted in quadratic improvements in ADG (P < or = 0.09) and G:F (P < or = 0.05). Three different methods were used to estimate the optimal TID SAA:LYS ratio for each experiment. The two-slope broken-line regression model, x-intercept value of the broken-line and quadratic curve, and 95% of upper asymptote across the four experiments indicated that the average optimal TID SAA:LYS ratios were 59.3, 60.1, and 57.7% for ADG and 60.6, 61.7, and 60.1% for G:F, respectively. Thus, the optimal TID SAA:LYS ratio for 8- to 26-kg pigs based on the average value of these three estimates was 59.0% for ADG and 60.8% for G:F.

Effect of source of methionine in broken rice-soybean diet on production performance, blood chemistry, and fermentation characteristics in weaned pigs

“…Therefore, Met and TSAA concentrations in the basal diet were by 10 and 8% lower, respectively, than recommendations of NRC (1998) ( Table 2). The TSAA : Lys ratio in the supplemented diets was 60% which is in accordance with the recommendation of Gaines et al (2005).…”

“…Synthetic Met is often added to diets for young pigs. In corn-soybean based diets, synthetic Met is not commonly used in the growing and finishing periods but this synthetic amino acid may be added to diets for young pigs (Gaines et al 2005;Bauchart-Thevret et al 2009). In terms of amino acids supplementation, however, the feeding value of broken rice is rela-doi: 10.17221/8077-CJAS tive to corn.…”

Practical starter pig amino acid requirements in relation to immunity, gut health and growth performance

“…Gaines et al [26,30] found a slightly higher ratio of 57 to 61% depending on the response criteria and method of assessing the breakpoint with 8 to 26 kg pigs. Yi et al [31] found a similar TSAA:lysine ratio of 58% for optimal ADG of 12 to 24 kg pigs.…”

Influence of crude protein content, ingredient complexity, feed form, and duration of feeding of the Phase I diets on productive performance and nutrient digestibility of Iberian pigs1,2

“…Kim and Easter (2001) and Gaines et al (2005) reported that the inclusion of fi sh meal in the diet improved piglet growth, and Mahan (1993) and Nessmith et al (1997) reported that the inclusion of 7.5% dried whey increased feed intake and growth rate in early weaned pigs. However, in the current trial, pigs had similar ADG and G:F from d 0 to 21 of the experiment when fed the HQ than when fed the LQ Phase I diets, confi rming the suggestion of Goodband et al (2006) and indicating that the digestive capacity of pigs after 40 to 45 d of age (approximately 11 to 12 kg BW) was large, and that there was no need of including greater amounts of high-quality ingredients in these diets.…”