24 Digestibility of energy and concentrations of digestible and metabolizable energy in diets containing pistachio blanks fed to growing pigs

Abstract

Pistachio blanks are a mixture of pistachio byproducts that consists of hardshell, tree branches, unsized seeds, and unripe seeds. They can be used as a high-fiber ingredient in diets for pigs, but there is no information about the nutritional value when fed to pigs. Therefore, an experiment was conducted to test the null hypothesis that apparent total tract digestibility (ATTD) of gross energy (GE), digestible energy (DE), and metabolizable energy (ME) in pistachio blanks are not different from those in wheat middlings fed to growing pigs. Twenty-four growing pigs (initial body weight = 23.01 kg ± 0.90 kg) were individually housed in metabolism crates. A basal diet contained corn and soybean meal as the sole sources of energy. Two additional diets were prepared to include corn and soybean meal and 30% pistachio blanks or 30% wheat middlings. Pigs were allotted to one of the three diets and there were eight replicate pigs per diet. Feces and urine samples were quantitatively collected for 4 days. The ATTD of GE and concentrations of DE and ME in pistachio blanks and wheat middlings were calculated by difference. Data were analyzed using Proc MIXED of SAS. The statistical model included diet or ingredient as fixed variable and replicate as random variable. Results from the experiment indicated that the ATTD of dry matter (DM) and GE was less (P < 0.05) in the diet containing wheat middlings than in the basal diet and the diet containing pistachio blanks (Table 1). Concentrations of DE and ME were less (P < 0.05) in the wheat middlings diet compared with the basal and pistachio blanks diets. There were no differences in the ATTD of DM and GE and concentrations of DE and ME between the basal and pistachio blanks diets. The ATTD of GE, ME to GE, and concentrations of DE and ME were greater (P < 0.05) and ME to DE tended to be greater (P < 0.10) in pistachio blanks than in wheat middlings fed to growing pigs. In conclusion, concentrations of DE and ME in pistachio blanks were 3,553 and 3,385 kcal/kg, respectively, which were greater than those in wheat middlings fed to growing pigs. Because pigs fed the pistachio blanks diet did not have any problems with feed intake and this ingredient contains relatively high energy, pistachio blanks can be used in diets for growing pigs.