Response of piglets to the valine content in diet in combination with the supply of other branched-chain amino acids

Abstract

The branched-chain amino acids (BCAA) valine (Val) and isoleucine (Ile) are considered to be among the next-limiting amino acids for growth in piglets. In earlier studies, we estimated the standardized ileal digestible (SID) Val : Lys (lysine) requirement to be at least 70%, whereas the Ile : Lys requirement may be as low as 50%. Because the BCAA partially share a common route of catabolism, the supply of one BCAA may affect the availability of the other BCAA. Four experiments were conducted to determine the response of 6-week-old piglets to the Val supply in relation to the other BCAA. A deficient supply of Val or Ile typically results in a reduction in average daily feed intake (ADFI). Experiment 1 was designed to determine the effect of a limiting Val supply, independent of the effect on feed intake. In a dose-response study using restrictively fed piglets, nitrogen retention did not increase for an SID Val : Lys supply greater than 64%. In the remaining experiments, piglets were offered feed ad libitum using ADFI, average daily gain (ADG) and gain-to-feed ratio as response criteria. The interaction between the Val and leucine (Leu) was studied in Experiment 2 in a 2 3 2 factorial design (60% and 70% SID Val : Lys, and 111% and 165% SID Leu : Lys). Performance was considerably lower in piglets receiving 60% Val : Lys compared with those receiving 70% Val : Lys and was lowest in piglets receiving the diet with low Val and high Leu content. To further evaluate the interaction between Val and Leu, a dose-response study was carried out in which the response to Val supply was studied in combination with high Leu supply (165% Leu : Lys). Using a curvilinear-plateau model, the average SID Val : Lys requirement was 72%. However, low Val supply (60% SID Val : Lys) reduced performance by 13% to 38%, which was much greater than what we observed in earlier studies. Experiment 4 was carried out to test the hypothesis that the Val requirement is not affected by low Ile supply (50% SID Ile : Lys). Performance was not improved for Val : Lys supplies greater than 65%, which may indicate that Ile (and not Lys) was second-limiting in this study. In conclusion, the first response of piglets to deficient Val supply appears to be a reduction in ADFI, rather than a reduction in ADG or nitrogen retention. A large supply of Leu may not affect the Val requirement per se, but may aggravate the consequences of Val deficiency.

Requirement of standardized ileal digestible valine to lysine ratio for 8- to 14-kg pigs

“…There are not many experiments reporting the optimum SID Val : Lys ratio for the maximum growth performance of piglets. However, recent investigations indicate that the optimum SID Val : Lys ratio for piglets is ranging from 0.63 to 0.70 (Gaines et al, 2011;Gloaguen et al, 2011;Waguespack et al, 2012). The results of the present study showed that the maximum ADFI, ADG and G : .…”

“…In typical European diets, Val will often be the third to fifth limiting AA in diets for piglets (Figueroa et al, 2003;Mavromichalis et al, 1998;Nørgaard and Fernández, 2009). It has been reported that Val may be involved in appetite regulation acting as a signal of a non-dispensable AA deficiency (Gloaguen et al, 2011). According to the BCAA interaction due to the shared enzymes in their catabolic pathways, excess of specifically Leu could increase the requirements of Val and Ile (Harper et al, 1984) and it is therefore important to account for the content of the other BCAA (Ile and Leu) in the diet.…”

Response of piglets to the standardized ileal digestible isoleucine, histidine and leucine supply in cereal–soybean meal-based diets

“…Chemical analysis Chemical analyses have been described in detail by Gloaguen et al (2011). Briefly, the gross energy content was measured with an adiabatic bomb calorimeter (ISO, 1998; method 9831; IKA C2000 and IKA C5000, Staufen, Germany).…”

Performance of piglets in response to the standardized ileal digestible phenylalanine and tyrosine supply in low-protein diets

“…Chemical analysis Chemical analyses have been described in detail by Gloaguen et al (2011). Briefly, the gross energy content was measured with an adiabatic bomb calorimeter (ISO 9831, 1998; IKA C2000 and IKA C5000, Staufen, Germany).…”