The digestion and utilization of amino acids of heat-treated fish meal by growing/finishing pigs

Abstract

A batch offish meal was (a) untreated, (b) heated to 130°C and (c) heated to 160°C under controlled conditions.In trial 1, these materials were incorporated into a diet based on barley meal (278·7 g/kg), wheat starch (412·5 g/kg), maize meal (245·3 g/kg) and tallow (33·5 g/kg) at a rate of inclusion of 100 g/kg. Diets contained a vitamin/mineral pre-mix together with the inert marker titanium dioxide and were given to four pigs fitted with simple T-piece Heal cannulas over four time periods each of which lasted for 6 days and which allowed the determination of faecal and Heal apparent digestibilities of nitrogen and amino acids. The results indicated that over-heating fish meal results in a reduction in both Heal and faecal apparent digestibility although, as there was no effect of treatment on the quantity of nitrogen absorbed from the large intestine, the two measurements were directly related. Heal and faecal apparent digestibilities for individual amino acids were not the same as data for nitrogen and, accordingly, the latter cannot be used to predict the two former.In trial 2, the three fish meal samples were included in diets formulated on the basis of total, faecal and Heal apparent digestible amino acids. The nine diets were given to pigs over the live-weight range 27·5 to 52·5 kg. Giving diets formulated on the basis of both faecal and Heal apparent digestible amino acids resulted in improved performance compared with giving diets based on total amino acids when the diets containing fish meal heated to 160°C, but performance achieved with diets containing untreated fish meal was still higher.Heal apparent digestible amino acids from heat-treated fish meal are not completely available to the pig, and it is suggested that care needs to be taken in equating digestibility with subsequent availability. There appears to be no advantage of using Heal rather than faecal, apparent digestible amino acid values in texms of accuracy of diet formulation.

The effect of formic acid and buffering capacity on the ileal digestibilities of amino acids and bacterial populations and metabolites in the small intestine of weanling pigs fed semipurified fish meal diets

“…The apparent ileal digestibilities of AA in this study (Table 2) are in the range of values for growing pigs fed diets containing fish meal as the sole source of protein (Knabe et al 1989;Wiseman et al 1991). This suggests that the protein in fish meal is easily digested by weanling pigs.…”

“…Improvements in protein digestibility can be achieved if fish meal is heated at 70oC under vacuum instead of just being heated at 100oC (Danielsen et al 1991). Excessive heat treatment (160oC) reduces (P < 0.05) the apparent ileal digestibilities of AA in fish meal (Wiseman et al 1991). The fish meals used by Jgrgensen et al (1984) may have originated from a different fish species or contained more bone than the fish meal used in this study.…”

“…No diarrhea was Knabe et al (1989) and Wiseman et al (1991). The concentration of calcium and phosphorus in the HCaP diets was approximately twice that in the NCaP diets.…”

Fish flour of Loricaria sp. Processed by Refractance Windows for Food Security

“…La humedad fue de 6.89 ± 0.41, y está acorde con los parámetros internacionales, la humedad ideal de la harina al final del proceso, no debe sobrepasar el 10% de agua, ni debe bajar del 6%; si es inferior, significa que se ha recalentado, y su calidad nutritiva y proteica se ha alterado. Por el contrario, si está demasiado húmeda, no se puede vender y además puede desarrollar hongos y otras bacterias (Aguilera et al, 1974;Terrazas et al, 2005;Wiseman et al, 1991). La calidad del producto obtenido fue excelente, ya que el contenido de amoniaco libre (TVN) fue 14.38 ± 0.72 mg/100 g, valor inferior al máximo permisible (120 mg/100 g) en una harina estándar (Aguilera et al, 1974;Giannini, 2003;Terrazas et al, 2005).…”

Development of a novel bioassay for determining the available lysine contents of foods and feedstuffs

“…However, the failing of these assays is that they do not take into account the possibility that the digestion and absorption of unmodified lysine in a food protein may be less than 100 %. This is an important consideration since the amino acid (including reactive lysine) digestibility of processed foods or feedstuffs is often far from complete 29,32,48,64,89 . Moughan et al 46 using a heated glucose -casein mixture clearly demonstrated that considerable amounts of dietary reactive lysine were not absorbed from the small intestine of the growing pig ( Table 1).…”