The Effect of Liquid Application Times, and Mixer Types with Different Wet Mix Times on Uniformity of Mix

Liquid addition systems are often designed to add liquid ingredients with the shortest application time in order to increase the batching capacity and efficiency of the mixing process. The quantity of liquid that is added into the mixer affects batch cycle time, particularly when there is a programmed “wet mix” time, or mixing time after liquid application has completed. Shorter application time of liquids typically produces a larger droplet size, which may lead to greater clumping tendencies in the feed and less uniformity of liquid incorporation. Two experiments were conducted to determine the effect of liquid application time and wet mix time on the uniformity of mix in different mixers. In both experiments, treatments were arranged in a 2 × 3 factorial. Experiment 1 used a double ribbon mixer with 2 liquid application times (20 vs. 30 s) and 3 wet mix times (15, 30, and 45 s). Experiment 2 used a single shaft paddle mixer with 2 liquid addition times (15 vs. 30 s) and 3 wet mix times (15, 30 and 45 s). Ten samples were collected, and coefficient of variation (% CV) determined within those samples. Each treatment had 10 separate replicates. Experiment 1 indicated that wet mix time (P \u3c 0.0001), but not application time (P = 0.653) or the interaction (P = 0.638), impacted % CV in the double ribbon mixer. As wet mix time increased, % CV decreased in a quadratic manner (P = 0.02; 37.2, 18.6, and 10.8% for 15, 30, and 45 s wet mix time, respectively). In Experiment 2, both wet mix time (P = 0.030) and application time (P = 0.001) impacted % CV, but not their interaction (P = 0.290). A longer application time led to a better uniformity of mix (P \u3c 0.05; 13.5 vs. 9.8% CV for 15 vs. 30 s liquid application time), as did a longer wet mix time (P \u3c 0.05; 17.0, 9.8, and 8.2% CV for 10, 20, and 30 s wet mix time, respectively). These results suggest that extending liquid application times may be beneficial in some mixers, and underscore the importance of a sufficient wet mix time to maximize the uniformity of liquid incorporation

Effect of Sample Preparation and Extended Mix Times with Different Salt Particle Sizes on the Uniformity of Mix of a Corn-Soybean Meal Swine Diet

The uniformity of a feed mixture is determined from the coefficient of variation (CV) of 10 samples in a single batch of feed. The feed industry standard is a CV of less than 10% using a single source tracer, such as salt, trace minerals, or iron filings. The objectives of these experiments were to determine the effects of 1) extended mix time, 2) particle size of the marker, and 3) sample preparation on the CV in a corn-soybean meal swine diet. In Experiment 1, treatments were arranged in a 3 × 7 factorial with main effects of 3 salt particle sizes (fine-350 μm, medium-464 μm, and coarse-728 μm) and 7 mix times (2, 3, 5, 15, 30, 45, and 60 min). In Experiment 2, treatments were arranged in 2 × 3 × 3 factorial with 2 sample preparations (unground vs. ground), 3 salt particle sizes (fine-350 μm, medium-464 μm, and coarse-728 μm) and 3 mix times (3, 30, and 60 min). There were 3 replicates per treatment and 10 samples per replicate. Salt concentrations were determined using a Quantab® Chloride Titrator. The result of Experiment 1 indicated no interaction between mix time and salt particle size. The extended mix time did not result in segregation (P = 0.307). Particle size of the salt significantly affected the uniformity of mix (P \u3c 0.0001; 21.2, 8.6, and 7.9% CV for the coarse, medium, and fine salt, respectively). The results of Experiment 2 indicated no interaction of sample preparation, salt particle size, and mix time. However, there was interaction between sample preparation and salt particle size (P = 0.0002). The difference in the CV% between unground and ground samples was significantly greater for the mixture with coarse salt (8.89 %) than the mixture with fine (1.35 %) and medium salt (2.59 %). The ground treatment had a significantly lower CV than the unground treatment (P \u3c 0.0001; 8.7 and 13.0 for ground and unground samples, respectively). The fine and medium salt treatments had significantly lower CV as compared to the coarse salt treatment. (P \u3c 0.0001; 7.4, 7.7, and 17.4 for fine, medium and coarse, respectively). These results indicated that feed did not segregate after mixing for up to 1 h. The greater number of particles per gram of the marker (in this case salt) increased the precision of the analysis, likely due to an increased probability that the marker was present in proportionate quantities in the sample tested. However, when coarse salt is used in the manufacturing process, the samples should be ground prior to analysis

MF2952

Caleb E. Wurth et al., Defining Sieving Methods Used to Determine and Express Fineness of Feed Materials, Kansas State University, October 2010

Effects of mill type (hammer vs roller) and particle size uniformity on growth performance, nutrient digestibility, and stomach morphology in finishing pigs

Two experiments were conducted to determine the effects of mill type and particle size uniformity on finishing pigs. In Exp. 1, 120 pigs, with an average initial weight of 105 lb, were fed corn-soybean meal-based diets for 57 d. The corn was milled so that all diets had an average mean particle size of 800 11m (± 20), yet differed in particle size uniformity (Sgw). To obtain the most uniform treatment (1.9 Sgw), corn was milled through a roller mill. The intermediate treatment (2.3 Sgw) was obtained by milling corn through a hammermill. The least uniform treatment (2.7 Sgw) was obtained by blending coarsely and finely ground corn. Growth performance of pigs was not affected by Sgw of the diet. However, digestibilities of DM, N, and GE increased as Sgw was reduced. In Exp. 2, 128 pigs, widl an average initial weight of 150 lb, were fed diets with corn milled to 450 JLm (± 7) in a hammermill or a roller mill. The hammermilled corn had an Sgw of 1.8 and the rollermilled corn had an Sgw of 2.0. The diets were fed in meal or pelleted form. There were no interactions among mill type and diet form. Digestibilities of DM and N were greater for the hammermilled treatments, but no growth performance differences were due to mill type. Pelleting increased ADG 9% and improved efficiency of gain by 5 %. Pelleting also increased the severity of stomach lesions. In conclusion, at 800 and 450 p.m, mill type did not affect growth performance. However, nutrient digestibilities were improved by decreasing variability in particle size, a response that merits further investigation.; Swine Day, Manhattan, KS, November 19, 199

Effects of sorghum particle size on milling characteristics, growth performance, and carcass characteristics in finishing pigs

A total of 200 finishing pigs (PIC TR4 × 1050; average initial BW of 103.2 lb) were used in a 69-d growth assay to determine the effects of sorghum particle size on growth performance. Pigs were sorted by sex and ancestry and balanced by BW, with 5 pigs per pen and 10 pens per treatment. Treatments were a corn-soybean meal-based control with the corn milled to a target mean particle size of 600 μm, and sorghum diets milled to a target mean particle size of 800, 600, or 400 μm. Actual mean particle sizes were 555 μm for corn, and 724, 573, and 319 μm for sorghum, respectively. Feed and water were offered on an ad libitum basis until the pigs were slaughtered (average final BW of 271 lb) at a commercial abattoir. Reducing sorghum particle size improved (linear, P \u3c 0.01) F/G, and we observed a tendency for decreased (P \u3c 0.06) ADFI. Reducing sorghum particle size from 724 to 319 μm had no effects on HCW, backfat thickness, loin depth, or percentage fat-free lean index (FFLI), but tended to increase (P \u3c 0.06) carcass yield. Pigs fed the sorghum-based diets had no difference in growth performance or carcass characteristics compared with those fed the control diet, except carcass yield, which was numerically greater (P \u3c 0.07) for pigs fed the sorghum-based diets. When using a regression equation, we determined that sorghum must be ground to 513 μm to achieve a F/G equal to that of a corn-based diet, with corn ground to 550 μm. In conclusion, linear improvements in F/G and carcass yield were demonstrated with the reduction of sorghum particle size to 319 μm. In this experiment, sorghum should be ground 42 μm finer than corn to achieve a similar feeding value.; Swine Day, Manhattan, KS, November 17, 201

Effects of adding cracked corn to a pelleted supplement for nursery and finishing pigs

Three experiments were conducted to determine the effects of supplementing cracked corn into diets of nursery and finishing pigs. In Exp. 1, 144 pigs were used in a 28-d trial. Pigs (PIC TR4 × 1050; initially 16.5 lb) were weaned and allotted with 6 pigs per pen (3 barrows and 3 gilts) and 6 pens per treatment. All pigs were fed a common diet for 7 d postweaning and the experimental diets for the next 28 d. Treatments were corn-soybean meal-based in the form of mash, pellets, and pellets with 100% of the corn either ground (618 μm) or cracked (3,444 μm) and blended into the diet after the rest of the formulation (the supplement) had been pelleted. Overall (d 0 to 28), ADG and F/G improved when pigs were fed the mash control compared to the pelleted diets (P \u3c 0.001); however, this response was caused by the poor performance of pigs fed the supplement treatments, with the pigs fed the complete pellets having improved (P \u3c 0.01) ADG and F/G compared with pigs fed the pelleted supplement blended with ground and cracked corn. Finally, pigs fed the supplement blended with cracked corn had numerically lower (P \u3c 0.11) ADG and poorer (P \u3c 0.001) F/G compared to those fed the supplement blended with ground corn. In Exp. 2, 224 nursery pigs (initially 16.3 lb) were used with 7 barrows or 7 gilts per pen and 8 pens per treatment. Treatments were corn-soybean meal-based and fed as mash, pellets, and pellets with 50% of the corn either ground (445 μm) or cracked (2,142 μm) and blended with the pelleted supplement. Pigs fed mash had improved (P \u3c 0.03) ADG and F/G compared with pigs fed the other treatments; however, this resulted from adding ground or cracked corn outside the pellets (complete pellets vs. pelleted supplement with corn, P \u3c 0.01). In Exp. 3, 252 finishing pigs (initially 88.2 lb) were used with 7 pigs per pen and 9 pens per treatment. The treatments were the same as Exp. 2. Pigs fed mash had lower (P \u3c 0.004) ADG compared with pigs fed diets with pellets. Pigs fed complete pellets had improved (P \u3c 0.03) ADG and F/G compared with pigs fed corn and the pelleted supplement. Also, pigs fed the supplement blended with cracked corn had greater (P \u3c 0.02) ADG than pigs fed the supplement blended with ground corn. Pelleting the diet led to an increase (P \u3c 0.05) in ulceration scores; however, these negative effects on ulcer scores were reduced (P \u3c 0.001) by cracking 50% of the corn and adding it postpellet.; Swine Day, Manhattan, KS, November 17, 201

Effect of Die Retention Time on Pellet Quality and Phytase Stability of a Corn-Soybean Meal Swine Diet

Phytase is a phosphohydrolytic enzyme that releases phosphorus from phytate in animal feed. However, pelleting is a thermal process that can denature phytase. It is hypothesized that there are many factors that can account for phytase denaturing during the pelleting process, such as pellet mill model, die length to diameter ratio (L:D), steam quality, and residence time in conditioner and die. Therefore, the objective of this experiment was to determine the effect of pellet mill model, die thickness, and die retention time on pellet quality and phytase stability. Treatments were arranged as a completely randomized design to determine the effect of die retention time (RT). Diets were pelleted using either a 1012-2 HD California Pellet Mill (CPM) Master Model or a 3016-4 HD CPM Master Model equipped with a 3/16 × 2 in (10.6 L:D), a 3/16 × 1 1/4 in (6.6 L:D) or a 3/16 × 1 3/4 in (9.3 L:D) with 30 sec conditioning retention time at 185°F with designated production rate. These processing conditions were used to create the following RT treatments: 10.6 L:D with 4.3 sec RT, 10.6 L:D with 2.9 sec RT, 9.3 L:D with 1.7 sec RT, 9.3 L:D with 1.1 sec RT, 6.6 L:D with 2.6 sec RT, and 6.6 L:D with 1.6 sec RT. The pellet mills were run 3 separate times to provide 3 replicates for each treatment. There was an overall effect (P \u3c 0.001) of treatment on phytase stability in cooled pellets. When using the 1012 PM, phytase was more stable regardless of die retention time when diets were manufactured using the 6.6 L:D die compared to the 10.6 L:D die (P \u3c 0.05). The hot pellet temperature of 10.6 L:D die was 195–211°F, while 6.6 L:D die was 184–189°F. However, the phytase stability was similar between the feed pelleted with 1012 PM equipped with 6.6 L:D die and the 3016 PM equipped with 9.3 L:D regardless of retention time (P \u3e 0.05). The hot pellet temperature of feed pelleted with the 1012 PM equipped with 6.6 L:D die was 184–189°F, while the feed pelleted with the 3016 die equipped with 9.3 L:D die was 180–183°F. There was also a quadratic decrease in phytase stability as the die L:D increased (P \u3c 0.0001). There- fore, the pellet mill size or die retention time did not affect phytase stability when the hot pellet temperature was less than 189°F. Pellet quality increased (linear; P \u3c 0.0001 for standard pellet durability index (PDI) or quadratic; P \u3c 0.0001 for modified PDI) as die L:D increased. The die L:D had greater effects on both PDI methods than the die retention time. However, increased die retention time improved (P \u3c 0.05) pellet quality when the feed was pelleted with 6.6 L:D, but not when pelleted using the 9.3 or 10.6 L:D. In conclusion, the phytase that was produced by Trichoderma reesei strain could tolerate hot pellet temperatures up to 189°F, regardless of pellet mill model, die thickness, and die retention time. However, phytase stability was dramatically reduced when hot pellet temperatures ranged from 195–211°F. Therefore, hot pellet temperatures should be measured to monitor phytase stability. Increasing the die L:D had the greatest effect on improving pellet quality

Sensory cutaneous papillae in the sea lamprey (Petromyzonmarinus L.) : I. Neuroanatomy and physiology

Molecules present in an animal's environment can indicate the presence of predators,food, or sexual partners and consequently, induce migratory, reproductive, foraging,or escape behaviors. Three sensory systems, the olfactory, gustatory, and solitarychemosensory cell (SCC) systems detect chemical stimuli in vertebrates. While agreat deal of research has focused on the olfactory and gustatory system over theyears, it is only recently that significant attention has been devoted to the SCC sys-tem. The SCCs are microvillous cells that were first discovered on the skin of fish,and later in amphibians, reptiles, and mammals. Lampreys also possess SCCs that areparticularly numerous on cutaneous papillae. However, little is known regarding theirprecise distribution, innervation, and function. Here, we show that sea lampreys(Petromyzon marinus L.) have cutaneous papillae located around the oral disk, nostril,gill pores, and on the dorsal fins and that SCCs are particularly numerous on thesepapillae. Tract-tracing experiments demonstrated that the oral and nasal papillae areinnervated by the trigeminal nerve, the gill pore papillae are innervated by branchialnerves, and the dorsal fin papillae are innervated by spinal nerves. We also character-ized the response profile of gill pore papillae to some chemicals and showed thattrout-derived chemicals, amino acids, and a bile acid produced potent responses.Together with a companion study (Suntres et al., Journal of Comparative Neurology,this issue), our results provide new insights on the function and evolution of the SCCsystem in vertebrates

Feed processing parameters and their effects on nursery pig growth performance

A total of 180 nursery pigs (PIC 327 × 1050; initially 27.8 lb) were used in an 18-d study to determine the effects of conditioning parameters and feed form on pig performance. All diets were the same corn, dried distillers grains with solubles (DDGS), and soybean meal-based formulation with different processing parameters used to create the experimental treatments. Treatments included: (1) negative control mash diet, (2) positive control pelleted diet conditioned at 60 rpm, (3) pelleted diet conditioned at 30 rpm and reground, (4) pelleted diet conditioned at 60 rpm and reground, and (5) pelleted diet conditioned at 90 rpm and reground. The different rpm values among treatments represent the time in the conditioner during processing. The lower the rpm value, the longer time feed was in the conditioner. Pigs were weaned and fed a common acclimation diet for 21 d prior to the start of the experiment. Average daily gain and F/G did not differ (P > 0.12) between treatments overall, but ADFI decreased (P = 0.03) for pigs fed the pelleted, positive control diet compared with all other diets. Although no overall treatment effects were significant for ADG or F/G, the experiment was designed more specifically to evaluate treatment differences using preplanned comparisons. When considering preplanned contrasts, we observed that pigs fed mash diets tended to have greater (P = 0.10) ADG than those fed pelleted and reground diets, suggesting that processing may have had a negative influence on feed utilization, a hypothesis that is further supported because pigs fed mash diets tended to have greater (P = 0.06) ADG compared with those fed diets that were heat-processed, regardless of regrinding. Considering these results, it was not surprising that pigs fed mash diets had greater (P = 0.05) ADG and ADFI (P = 0.01) than those fed pelleted diets. When directly comparing diets conditioned at 60 rpm, fed either as whole pellets or reground to mash consistency, pigs fed pelleted diets had improved (P = 0.01) F/G due to lower ADFI (P = 0.004) but similar ADG (P = 0.60). This unexpected negative impact of pelleting on ADG may be due to a negative influence of heat treatment on palatability. The expected improvement in F/G from pelleting (6.8%) was observed but lost when diets were reground to near original mash particle size. This result may indicate that diet form (high-quality pellets vs. mash) affects F/G more than degree of starch gelatinization or other intrinsic factors associated with conditioning ingredients

Effects of the Pelleting Process on Diet Formulations with Varying Levels of Crystalline Amino Acids and Reducing Sugars on Nursery Pig Growth Performance

Pelleting swine feed and the use of crystalline amino acids and by-product ingredients can potentially create ideal conditions that further facilitate the Maillard browning reaction. The Maillard reaction combines an amino group of a free amino acid and a carbonyl group of a reducing sugar (RS), making the amino acid less available. The objective of this study was to determine the effects of pelleting swine diets containing free amino acids and reducing sugars at high temperatures on nursery pig growth performance. A total of 360 pigs (initially 25.0 lb; Line 200 × 400; DNA, Columbus, NE) were used in a study evaluating the effect of crystalline AA, reducing sugars, and feed form on growth performance of nursery pigs. Treatments were arranged in a 2 × 2 × 2 factorial with main effects of crystalline AA concentration (low vs. high), reducing sugars (RS; low vs. high), and diet form (mash vs. pellet). Diets were formulated with low or high crystalline AA and low or high reducing sugars provided by co-product ingredients, DDGS and bakery meal. Diets were pelleted to a conditioning temperature of 187.5°F. When pigs weighed approximately 25 lb, they were weighed, and pens were randomly assigned treatments. There were 9 replications per treatment and 5 pigs per pen. There were no 3-way or 2-way interactions. For the main effect of form, there was no evidence of difference in ADG, and ADFI increased (P = 0.001) in pigs fed mash diets compared to pellets. Feed efficiency and caloric efficiency improved (P = 0.001) in pigs fed pelleted diets compared to mash diets. For the main effect of crystalline AA, there was no evidence of difference in ADG or F/G; however, pigs fed high crystalline AA had increased (P = 0.024) ADFI compared to those fed low crystalline AA diets. For the main effect of RS inclusion, pigs fed low RS diets had increased (P \u3c 0.041) ADG and ADFI compared to pigs fed high RS inclusion diets. There was an improvement (P = 0.019) in F/G and caloric efficiency for pigs fed high RS inclusion diets compared to those fed low RS diets. There was no evidence of difference in IOFC for form, crystalline AA, or RS. In conclusion, there was no evidence of interactions between diet types, indicating that increasing amounts of crystalline AA and RS did not increase the Maillard reaction or reduce growth performance when pelleting diets by using the reported conditions. Pigs fed pelleted diets had similar ADG and an 8% improvement in F/G compared to those fed mash diets. Pigs fed the high RS diets had reduced feed intake, which resulted in reduced gain and improved feed and caloric efficiency. Additionally, pigs fed high AA diets had increased feed intake