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An experiment to determine the chemical composition and protein quality of 13 fish substrates (pollock by-products, n = 5; fish protein hydrolysates, n = 5; and fish meals, n = 3) was conducted. Two of these substrates, salmon protein hydrolysate (SPH) and salmon meal with crushed bones (SMB), were used to determine their palatability as components of dog diets. Pollock by-products differed in concentrations of CP, crude fat, and total AA by 71, 79, and 71%, respectively, and GE by 4.1 kcal/g. Fish protein hydrolysates and fish meals were less variable (approximately 18, 14, and 17%, and 1.4 kcal/g, respectively). Biogenic amine concentrations were much higher in fish protein hydrolysates as compared with pollock by-products and fish meals. Pollock liver and viscera had the highest total fatty acid concentrations; however, red salmon hydrolysate and SMB had the highest total PUFA concentrations (49.63 and 48.60 mg/g, respectively). Salmon protein hydrolysate had the highest protein solubility in 0.2% KOH. Based on calculations using immobilized digestive enzyme assay values, lysine digestibility of fish meal substrates was comparable to in vivo cecectomized rooster assay values and averaged approximately 90.3%. Also, pollock milt, pollock viscera, red salmon hydrolysate, and sole hydrolysate had comparable values as assessed by immobilized digestive enzyme assay and rooster assays. A chick protein efficiency ratio (PER) assay compared SMB and SPH to a whole egg meal control and showed that SMB had high protein quality (PER = 3.5), whereas SPH had poor protein quality (PER value less than 1.5). However, using whole egg meal as the reference protein, both fish substrates were found to be good protein sources with an essential AA index of 1.0 and 0.9 for SMB and SPH, respectively. In the dog palatability experiments, a chicken-based control diet and 2 diets containing 10% of either SPH or SMB were tested. Dogs consumed more of the SPH diet compared with the control, and similar amounts of the SMB and control diets. The intake ratios for each were 0.73 and 0.52, respectively. Salmon protein hydrolysate was especially palatable to dogs. These data suggest that chemical composition and nutritional quality offish substrates differ greatly and are affected by the specific part of the fish used to prepare fish meals and fish protein hydrolysates. Key words: fish substrate, palatability, pet food, protein quality

This experiment was designed to evaluate the effects of selected soybean (SB) processing byproducts (gums, oil, soapstock, weeds/trash) when added back to soybean meal (SBM) during processing on the resulting nutrient composition, protein quality, nutrient digestibility by swine, and true metabolizable energy (TM[E.sub.n]) content and standardized AA digestibility by poultry. To measure ileal DM and nutrient digestibility, pigs were surgically fitted with a T-cannula in the distal ileum. The concentration of TMEn and the standardized AA digestibility by poultry were determined using the precision fed cecectomized rooster assay. Treatments in the swine experiment included SBM with no by-products; SBM with 1% gum; SBM with 3% gum; SBM with 0.5% soapstock; SBM with 1.5% soapstock; SBM with 2% weeds/trash; SBM with a combination of 3% gum, 1.5% soapstock, and 2% weeds/ trash; SBM with 5.4% soybean oil; and roasted SB. A 10 x 10 Latin square design was utilized. The experiment was conducted at the University of Illinois, Urbana-Champaign, and at The Ohio State University, Columbus. In the swine experiment, apparent ileal DM, OM, CP, and AA digestibilities were reduced (P < 0.05) when pigs consumed the combination by-product diet compared with the diet containing no by-products. Apparent ileal digestibilities of DM, CP, and total essential, total nonessential, and total AA were lower (P < 0.05) for any diet containing by-products compared with the diet with no by-products. Apparent ileal digestibilities of DM, OM, CP, and AA were lower (P < 0.05) for the roasted SB-compared with the SB oil-containing diet. In the rooster experiment, TM[E.sub.n] values were greater (P < 0.05) for roasted SB compared with SBM with no by-products and increased linearly as the addition of soapstock increased. Individual, total essential, total nonessential, and total AA digestibilities were lower (P < 0.05) for roosters fed roasted SB versus SBM devoid of by-products. Gums, soapstock, and weeds/ trash reduce the nutritive value of the resultant meal when they are added back during processing. Key words: amino acid, by-product, digestibility, pig, rooster, soybean meal

Evaluates the interactions between chronic heat stress (HS) and dietary nonphytate phosphorus (NPP) on mortality, egg production, feed intake, tibia ash, egg specific gravity and blood parameters in laying hens. Assessment of the effects of acute severe HS and dietary NPP level on severe heat distress in laying hens; Results indicating that there was no interaction between dietary NPP level and HS in the laying hens.

Abstract: Four digestibility trials using broilers from 12 to 21d or 7 to 21d of age were conducted to evaluate the nutrient digestibility responses of two enzyme combinations when supplemented to maize–soybean meal (SBM) based diets without (trials 1 and 3) or with (trials 2 and 4) 70 or 100g/kg maize dried distillers grain with solubles (DDGS). Apparent ileal digestible energy (AIDE), apparent ileal digestibility (AID) of amino acids (AA), total tract apparent retention (TTAR) of nitrogen (N) and N-corrected apparent metabolisable energy (AMEn) were assessed. In each trial, a control diet and the control diet supplemented with an enzyme complex containing xylanase and amylase (XA) or one containing protease, xylanase and amylase (PXA) were tested. Trials 1 and 2 had six replicate cages per treatment, with six birds per cage; and trials 3 and 4 had eight replicate cages per treatment, with five birds per cage. Data were analysed by ANOVA for each trial, as well as a combined dataset, which model included the main effects of maize-DDGS inclusion, dietary enzyme and trial site and all two-way interactions. Across trials, both XA (13.61MJ/kg) and PXA (13.70MJ/kg) increased the AIDE (P<0.05) compared to the control diets (13.29MJ/kg). XA increased (P<0.05) AMEn (12.89MJ/kg) compared to the control diets (12.61MJ/kg), and PXA further increased it (13.00MJ/kg) compared to XA. Supplementation with XA had no effect on the AID of AA, whereas PXA increased the AID of nitrogen and all AA (P<0.05) except methionine. The AA with the greatest response to PXA were cysteine (+5.4%), threonine (+4.4%), glycine (+3.6%) and valine (+3.3%). The least responsive AA to PXA inclusion were methionine (+1.0), glutamine (+2.0), lysine (+1.9%) and arginine (+2.2%). Irrespective of the AA, PXA increased AID of AA as a proportion of the ileal undigested fraction of AA in the control diets by 12–13%. Supplemental xylanase and amylase increased AIDE and AMEn and the addition of protease on top of carbohydrases further increased AID of AA and AMEn in young broilers fed maize–SBM diets without or with maize-DDGS. [Copyright &y& Elsevier]

Abstract: To determine optimal processing conditions for preparation of a SBM that will result in optimal amino acid digestibilities, six lots of high protein SBM were produced under different toasting conditions. Specifically, the bed depth in the desolventizer-toaster (DT) was varied (11.4, 12.7, 14.0, 15.2, 17.8, and 20.3cm). All soybeans were acquired from the same producer, and the preparation and extraction conditions were held constant for all lots. Protein quality indices were measured for each of the resultant SBMs. While the protein dispersability index (PDI) values suggested that all SBMs were adequately processed, the protein solubility in potassium hydroxide (KOH) data suggested that the SBMs produced at bed depths less than or equal to 14.0cm were adequately processed while those produced at bed depths greater than or equal to 15.2cm may have been overprocessed. The urease activity results, however, suggest that the SBMs produced at bed depths between 11.4 and 15.2cm were underprocessed, and those at 17.8 or 20.3cm were properly cooked. The SBMs then were fed to cecectomized roosters in order to determine true amino acid digestibilities by poultry. True digestibilities of histidine, tryptophan, cysteine, and proline increased (P<0.05) with increasing bed depth. All bed depths resulted in relatively high amino acid digestibilities. Producing SBM at a bed depth between 15.2 and 20.3cm may result in an increased digestibility of some SBM amino acids by poultry. [Copyright &y& Elsevier]