The effects of standardized ileal digestible His to Lys ratio on growth performance, intestinal health, and mobilization of histidine-containing proteins in pigs at 7 to 11 kg body weight

Abstract

The objectives were to evaluate the effects of standardized ileal digestible (SID) His:Lys ratio above the current NRC requirement on growth performance, intestinal health, and mobilization of His-containing proteins, including hemoglobin, carnosine, and trypsinogen, in nursery pigs from 7 to 11 kg body weight (BW). Forty pigs (26 d of age; initial BW of 7.1 ± 0.5 kg) were allotted to 5 dietary treatments based on a randomized block design with sex and initial BW as blocks. Dietary treatments were supplemented with varying SID His to Lys levels of 26, 32, 38, 43, and 49% and fed to pigs for 14 d (SID Lys = 1.22%). Feed intake and BW were recorded at d 0, 7, and 14 to measure growth performance. Blood samples were collected on d 12. Pigs were euthanized on d 14 to collect pancreas, longissimus dorsi muscles, mid-jejunum, and jejunal mucosa. Data were analyzed using the Proc Mixed of SAS. Growth performance was not affected, whereas varying SID His to Lys ratio affected hemoglobin (P < 0.05, max: 12 g/dL at 36%), immunoglobulin A (IgA, P < 0.05, min: 1.25 μg/mg at 35%) in jejunal mucosa, villus height (P = 0.065, max: 536 μm at 40%) in jejunum, trypsinogen (P = 0.083, max: 242 pg/mg at 41%) in pancreas, and carnosine (P = 0.051, max: 4.7 ng/mg at 38%) in muscles. Varying SID His to Lys ratios linearly increased (P < 0.05, from 1.95 to 2.80 nmol/mg) protein carbonyl in muscles and decreased (P < 0.05, from 29.1 to 26.9%) enterocyte proliferation. In conclusion, SID His to Lys ratio between 35 and 41% in diets fed to nursery pigs at 7 to 11 kg enhanced intestinal health and maximized concentrations of His-containing proteins, indicating that His-containing proteins are effective response criteria when determining His requirement.

Efficacy of a bacterial 6-phytase supplemented beyond traditional dose levels on jejunal mucosa-associated microbiota, ileal nutrient digestibility, bone parameters, and intestinal health, and growth performance of nursery pigs

“…The BW and feed intake were recorded at the end of each week to calculate the average BW, ADG, ADFI, and G:F as indicators of growth performance. The fecal score was also recorded daily using a 1 to 5 scale: (1) very firm stool, (2) normal firm stool, (3) moderately loose stool, (4) loose, watery stool, and (5) very watery stool, as previously described ( Cheng et al, 2021 ; 2022 ). In phase 3, TiO 2 (0.4%) was added to the diets as an indigestible external marker to further determine the apparent ileal digestibility (AID) of nutrients.…”

Impacts of Maternal Nutrition on Sow Performance and Potential Positive Effects on Piglet Performance

“…Considering exceptionally high leucine in typical corn soybean meal-based sow diets and ideal balance among branch chain amino acids [56,57], investigation of optimal Ile:Lys ratios and Ile:Val:Leu in sow diets would refine the current feeding program of sows. Considering the functional role of histidine with antioxidative property and behavioral influences through carnosine and histamine [58][59][60] and increased leanness and milk production [2,6] as well as behavioral concerns due to gestation housing [61,62] of modern sows, investigation of the optimal His:Lys ratios in sow diets would refine the current feeding program as well. Thus, careful reexamination of the amino acid requirements for sows could reveal optimal levels that differ from current recommendations.…”