Efficacy of feed additives to reduce the effect of naturally occurring mycotoxins fed to turkey hen poults reared to 6 weeks of age.

Corn with naturally occurring aflatoxin (AF), wheat with naturally occurring doxynivalenol (DON), and barley with naturally occurring zearalenone (ZEA) were used to make rations for feeding turkey hen poults to 6 weeks of age. Control rations with equal amounts of corn, wheat, and barley were also fed. The control rations did contain some DON while both sets of rations contained ZEA. Within each grain source, there were 4 treatments: the control ration plus 3 rations each with a different feed additive which were evaluated for the potential to lessen potential mycotoxin effects on bird performance and physiology. The additives were Biomin BioFix (2 lb/ton), Kemin Kallsil (4 lb/ton), and Nutriad UNIKE (3 lb/ton). The mycotoxin rations reduced poult body weight (2.31 vs. 2.08 ± 0.02 kg) and increased (worsened) poult feed conversion (1.47 vs. 1.51 ± 0.01) at 6 wk. Feeding the poults the mycotoxin feed also resulted in organ and physiological changes typical of feeding dietary aflatoxin although a combined effect of AF, DON, and ZEA which cannot be dismissed. The feed additives resulted in improved feed conversion to 6 wk in both grain treatment groups. The observed physiological effect of feeding the additives was to reduce relative gizzard weight for both groups and to lessen the increase in relative kidney weight for the birds fed the mycotoxin feed. In conclusion, the feed additives used in this study did alleviate the effect of dietary mycotoxins to some degree, especially with respect to feed conversion. Further studies of longer duration are warranted.

Effects of chronic exposure of diets with reduced concentrations of aflatoxin and deoxynivalenol on growth and immune status of pigs.

This study investigated the growth and immune responses of pigs fed diets containing reduced concentrations of aflatoxin (AF) and deoxynivalenol (DON) from naturally contaminated corn. Sixty gilts (13.9 ± 0.2 kg of BW) were randomly assigned to 4 treatments (5 replicate pens per treatment and 3 pigs per pen): A (a control diet without detectable AF and DON); B (a diet with 60 µg of AF/kg and 300 µg of DON/kg); C (a diet with 120 µg of AF/kg and 600 µg of DON/kg); and D (a diet with 180 µg of AF/kg and 900 µg of DON/kg). Pigs were allowed ad libitum access to feed and water for 33 d. Feed intake and BW were measured weekly and pigs were bled (8 mL) on d 33 to measure the numbers of blood cells, to conduct liver function tests, and to measure immunological variables including IgG, IgM, interferon γ, IL4, IL6, and tumor necrosis factor α. One pig representing the average BW of each pen was killed to obtain the liver, kidneys, and spleen for weight, tissue color measurement, and histological evaluation of tissue damage. When compared with A, pigs in C and D tended to have reduced ADG (0.52 vs. 0.43 and 0.41 kg/d, respectively; P = 0.058) and ADFI (1.04 vs. 0.92 and 0.88 kg/d, respectively; P = 0.061). White blood cell count of pigs in D (23.4 × 10(3) cells/µL) was greater (P < 0.05) than those in A, B, and C (18.4, 18.5, and 16.8 × 10(3) cells/µL, respectively. Serum tumor necrosis factor α concentration of pigs in D (335 pg/mL) differed (P < 0.05) from those in A and C (299 and 290 pg/mL, respectively). Pigs in B and D had greater (P < 0.05) fibrosis in liver tissues than those in A. Collectively, this study shows that diets containing both AF and DON greater than 60 and 300 µg/kg, respectively, may reduce growth and decrease feed intake, whereas diets containing 120 µg of AF/kg and 600 µg of DON/kg may result in altered immune health, systemic inflammation, and partial liver damage, causing further reduction in growth of pigs.

Alternative methods for disposal of spent laying hens: evaluation of the efficacy of grinding, mechanical deboning, and of keratinase in the rendering process.

Besides the challenges of mortality and litter disposal, the poultry industry must find economical means of disposing of laying hens that have outlived their productive lives. Because spent hens have low market value and disposing of them by composting and burial is often infeasible, finding alternative disposal methods that are environmentally secure is prudent. The feasibility of grinding or mechanically deboning spent hens with and without prior mechanical picking was evaluated for the production of various proteinaceous by-product meals. The end products were analyzed for nutrient content and found to be high in protein (35.3-91.9% CP) and, with the exception of the feathers, high in fat (24.1-58.3%), making them potentially valuable protein and energy sources. After considering physical and economic feasibility, mechanical deboning was determined to be a logical first step for the conversion of spent hens into value-added by-product meals. Because the hard tissue fraction (primarily feathers, bones, and connective tissue) generated by mechanically deboning the hens presents the greatest challenge to their utilization as feedstuffs, attention was focused on technologies that could potentially improve the nutritional value of the hard tissue for use as a ruminant protein source. Traditional hydrolysis of this hard tissue fraction improved its pepsin digestibility from 74% to 85%; however, subsequent keratinase enzyme treatment for 1h, 2h, 4h, or 20 h after steam hydrolysis failed to improve the pepsin or amino acid digestibility any further (P>0.10). Enzyme hydrolysis did, however, increase the quantities of the more soluble protein fractions (A: 45.5, 46.6, 52.8, 51.6, and 55.8% of CP; B(1): 3.2, 9.8, 6.0, 4.6, and 4.1% of CP; B(2): 11.7, 18.1, 22.8, 29.6, and 22.0% of CP for 0, 1h, 2h, 4h, and 20 h, respectively) and reduced quantities of the less soluble fractions (B(3): 30.2, 18.1, 10.8, 5.5, and 10.2% of CP; C: 9.4, 7.5, 7.6, 8.8, and 7.9% of CP for 0, 1h, 2h, 4h, and 20 h, respectively). The protein digestibility of the steam hydrolyzed hard tissue fraction from the mechanical deboning of spent hens was found to be comparable to the digestibility of feather meal, but post-hydrolysis keratinase treatment did not improve feeding value for ruminants.

Determination of nitrogen balance in goats fed a meal produced from hydrolyzed spent hen hard tissues.

To provide an economically viable and environmentally sound method for disposing of spent laying hens, we manufactured a proteinaceous meal from the hard tissue fraction of mechanically deboned laying hens (primarily feathers, bones, and connective tissue). We hydrolyzed the hard tissue and coextruded it with soybean hulls to create a novel feather and bone meal (FBM) containing 94.2% DM, 23.1% CP, 54.5% NDF, and 7.3% fat (DM basis). We evaluated the FBM in supplements for meat goats in which it provided 0, 20, 40, or 60% of the N added to the supplement compared with a negative control supplement with no added N source. The remainder of the N was contributed by soybean meal (SBM). Supplementation of N resulted in greater DMI than the negative control (P = 0.005), and DMI changed quadratically (P = 0.11) as FBM increased in the supplement. Digestibility of DM was similar in all diets, including the negative control (P > 0.10). Fiber digestibility increased linearly as dietary inclusion of FBM increased (P = 0.04 for NDF, P = 0.05 for ADF), probably as a result of the soybean hulls in the FBM. Nitrogen digestibility declined linearly from 60.5% with 0% FBM to 55.6% with 60% FBM (P = 0.07), but N retention changed by a quadratic function as FBM replaced SBM (P = 0.06). Negative control goats had less N digestibility (P < 0.001) and N retention (P = 0.008) than N-supplemented goats. Feather and bone meal had a greater proportion of ruminally undegradable B(3) protein than SBM (23.1 vs. 0.3% of CP, respectively). Ruminal VFA and pH were unaffected by replacing SBM with FBM, but supplying no source of N in the concentrate resulted in reduced total VFA in ruminal fluid (P = 0.04). Ruminal ammonia concentration increased quadratically (P = 0.07) as FBM increased, reflecting increased intake, and it was much less in unsupplemented goats (P < 0.001). Serum urea had less variation between 0 and 4 h after feeding in goats receiving 40 or 60% of added N as FBM in comparison with those receiving only SBM or 20% FBM. Feather and bone meal promoted a more stable rumen environment, possibly because of reduced rates of protein degradation within the rumen. A palatable by-product meal for ruminants can be made from spent laying hen hard tissue, one that supports N metabolism similar to that of traditional protein sources.

Evaluation of secondary protein nutrients as a substitute for soybean meal in diets for beef steers and meat goats.

Finding appropriate disposal techniques for waste products is one of many challenges facing the poultry-processing industry. One waste generated in significant quantities is dissolved air floatation sludge, a product of wastewater treatment. Converting dissolved air floatation sludge into a dry feed product (meal) for incorporation into livestock feed appears to be a viable solution. This meal, called secondary protein nutrients (SPN), is high in protein (45% CP), fat (28% crude fat), and minerals. The protein consists of 85% B(2) and B(3) fractions, which are moderately to slowly degradable in the rumen, and therefore may potentially escape ruminal degradation and be available for digestion in the lower gastrointestinal tract. The goal of this research was to evaluate SPN as an alternative to traditional protein sources for ruminants by substituting it on an equivalent N basis for soybean meal in cattle and meat goat diets (0, 25, 50, 75, and 100% for cattle; 0, 20, and 40% for goats). When included in corn silage-based steer diets, increasing SPN resulted in linear and quadratic declines in both DMI and ADG (P < 0.001). Dry matter intake diminished with inclusion rates above 50%, and ADG were reduced after inclusion of SPN reached 25% of added N. Feed efficiency (the reciprocal of the efficiency of gain, which is represented by G:F) declined linearly (P < 0.001) with each incremental increase in SPN. Addition of up to 40% added N as SPN in goat diets caused no change in DMI, digestibility of DM or fiber, or N retention. Ruminal VFA concentrations showed little variation in either species. Increasing the proportion of SPN in the feed caused linear declines in ruminal NH(3) in steers (P < 0.001). Increasing SPN in goat diets, however, resulted in only a trend toward reductions of this parameter (P = 0.14). The decreases observed may have resulted from decreasing ruminal protein degradability or increasing fat caused by increasing the proportion of SPN in the feed. Urinary urea N as a percentage of urinary N showed significant declines in cattle, but not in goats, over the ranges of SPN offered. These results indicate that SPN can be included in diets for ruminants to supply up to 40% of supplemental N with little negative impact on animal performance.

Effect of level of acidification by phosphoric acid, storage temperature, and length of storage on the chemical and biological stability of ground poultry mortality carcasses.

Two experiments were conducted to evaluate the addition of feed-grade H3PO4 in comparison to lactic acid fermentation as a means of preserving ground poultry mortality carcasses. Mortality silage quality in both experiments was evaluated by measuring the rise in pH after initial acidification (deltapH) and the content of nonprotein N (NPN), volatile nitrogen (VN), NH3-N, and fecal coliform bacteria in the silage treatments. Preliminary work in Experiment 1 evaluated the preservative effects of six initial levels of acidification with H3PO4 (pH 2.0, 2.5, 3.0, 4.0, or 5.0) at two storage temperatures (21 and 45 C). Experiment 2 compared silages preserved with different levels of feed-grade 74.5% H3PO4 (4.13, 5.52, 6.90, and 8.28% wt/wt, concentrated acid basis) to silages made by lactic acid fermentation. Based on the evaluations in Experiment 1, acidification with H3PO4 to pH < or = 3.0, when incubated at 45 C, or pH < or = 2.0, when incubated at ambient temperatures, produced the most biologically favorable poultry mortality silage for subsequent use as a feed ingredient. In Experiment 2, mortality silages containing 8.28% H3PO4 (wt/wt, concentrated acid basis) contained significantly (P < 0.05) lower levels of the protein degradation by-products VN and NH3-N than silages prepared by lactic acid fermentation. Therefore, feedstuffs manufactured from mortality silages prepared using 8.28% H3PO4 would be expected to result in improved animal performance vs. feedstuffs manufactured using silages prepared by lactic acid fermentation.

The effect of ethoxyquin on the quality of ground poultry mortality carcasses preserved by lactic acid fermentation and phosphoric acid stabilization.

Fermentation and acidification have been shown to preserve the protein quality of ground poultry coproducts, but the effects of these processes on their lipid stability are unknown, especially in the presence of an antioxidant. To evaluate the effects of these treatments on lipid quality, ground poultry mortality carcasses, with and without an addition of 500 ppm ethoxyquin, were stabilized for 14 and 45 d by lactic acid fermentation or acidification with 2.76, 5.07, 7.35, or 9.65% feed-grade H3PO4. Ethoxyquin treatment significantly (P < 0.001) improved the oxidative stability of lipids from all storage treatments. However, the addition of ethoxyquin increased (P < 0.001) the levels of volatile N (VN) from 2.51 to 3.18% in products stored for 45 d and resulted in an increase (P < 0.001) in free fatty acids in all ensiled products. Ethoxyquin addition had no effect (P > 0.120) on the fatty acid profile of products stored for 14 d but significantly increased (P < 0.001) the levels of stearic (C18:0) and arachidonic acids (C20:4) in products stored for 45 d. In this experiment, the addition of ethoxyquin to preservation systems for the short-term storage of poultry mortality carcasses improved the lipid quality of the ground material without compromising the protein quality or affecting proximate analysis parameters. However, the increased oxidative stability of mortality silage materials that contain ethoxyquin may contribute to enhanced microbial or enzymatic activities that result in proteolytic or lypolytic breakdown products following longer periods of storage.