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Chlamydia trachomatis is responsible for male infertility. The mechanism of action of C. trachomatis on male reproductive function is still controversial. The present study aims to evaluate seroprevalence and its influence on sperm quality in a male sample of 307 patients requesting serological examination for C. trachomatis, 73 of whom were examined by sperm analysis - spermocytogram and sperm culture. The patients were aged between 17 and 71 years, consulting for infertility or urology. The analysis of C. trachomatis serologies, based on the enzyme immunoassay dosage of immunoglobulin G, yielded 111 cases of positive serology, i.e. a seroprevalence of 36.2%. The age group over 60 years of age, the least represented group, had the highest frequency at 52.9%. Analysis of the 73 spermograms and spermocytograms revealed a non-significant difference in mean sperm concentration, 49.67 million sperm per milliliter, standard deviation ±45.71, in Chlamydia negative subjects versus 7.66 million sperm per milliliter, standard deviation ±10.98, in Chlamydia positive subjects. A non-significant change in total motility of 39.83%, standard deviation ±27.49, in Chlamydia-negative subjects versus 36.03%, standard deviation ±24.58, in Chlamydia-positive subjects, a 3% drop. Abnormal sperm forms, 51.86%, standard deviation ±19.60, in Chlamydia negative versus 57.17%, standard deviation ±21.41, in Chlamydia positive, an increase of 6%. The global reading of the average spermogram of Chlamydia positive individuals revealed oligospermia and asthenospermia as abnormalities. This suggests that there is a possible link between C. trachomatis infection and decreased sperm quality in Chlamydia positive patients.

An experiment was conducted to determine the effects of hen BW before molt and the percentage of BW loss during molt on the subsequent performance and profitability of hens during the second cycle of production. Results revealed that profits associated with Light hens (≤ 1,453 g, or 3.2 lb) were from 1.8¢ to 3.8¢/dozen eggs higher than those associated with Heavy hens (≥ 1,589 g, or 3.5 lb). Profits of Nonselected hens (ranging from 1,090 to 2,134 g, or 2.4 to 4.7 lb) were intermediate, ranging from 1.2¢ to 2.5¢/dozen higher than profits of Heavy hens. The increased profitability of Light hens was largely due to their improved feed conversion. Because Light hens produced predominantly Large and Extra Large eggs, the price spread between Medium and Large eggs had little impact on profits. Although not as pronounced as the effect of premolt BW, profits associated with Heavy hens that underwent a 35% reduction in BW during molt were from 0.8¢ to 1.5¢/dozen higher than those from Heavy hens with a 25% BW reduction. Reducing the BW of Light hens by 35% had no observable adverse effects in this study.

A 4×3 factorial experiment with four dietary fat levels and three protein levels was conducted to determine the influence of dietary fat on performance, egg composition, egg solids, and egg quality of Hy-line W-36 hens at different protein levels. This experiment lasted 16 weeks. Hy-line W-36 hens (n=1440) in phase 1 (21 weeks of age) were randomly divided into 12 treatments (8 replicates of 15 birds per treatment). There was no significant interaction on all parameters between protein and dietary fat. Protein had a significant effect on egg weight, egg mass, feed conversion, albumen weight, percent whole egg solids, and yolk color. Dietary fat had a linear effect on feed intake. As dietary fat increased from 0 to 3.35%, feed conversion linearly improved. A further increase of dietary fat from 3.35 to 5.04% had no additional effect on feed conversion. There was no significant difference in egg specific gravity among hens fed diets supplemented with 0%, 1.67% and 3.35% fat levels. Increasing dietary fat from 3.35 to 5.04% significantly decreased egg specific gravity. As protein increased, albumen weight significantly increased and percent whole egg solids significantly decreased. Increasing dietary fat significantly increased percent yolk, yolk/albumen ratio and percent whole egg solids, but decreased percent albumen. Based on feed conversion and egg specific gravity, the addition of 3.35% fat might be sufficient for optimal performance and egg quality of Hy-line W-36 hens during phase 1.

SUMMARY An experiment was conducted to determine the influence of dietary energy on performance, egg composition, egg solids, egg quality, and profits of Hy-Line W-36 hens fed different protein levels. The experiment was designed as a 4 × 3 factorial arrangement with 4 added dietary energy levels (0, 79, 158, and 238 kcal of ME/kg) and 3 protein levels (14.89, 16.06, and 17.38%). The basal diets of 17.38, 16.06, and 14.89% protein contained 2,751, 2,784, and 2,815 kcal of ME/kg, respectively. This study lasted 12 wk. Molted Hy-Line W-36 hens (n = 1,440) in phase 1 (70 wk of age) were randomly divided into 12 treatments (8 replicates of 15 hens per treatment). Protein had a significant effect on egg production, egg mass, feed intake, feed conversion, egg weight, percentage of egg shell components, yolk color, and yolk and albumen weight. As dietary energy increased from 0 to 238 kcal of ME/kg by addition of poultry oil, feed intake linearly decreased. Increasing dietary energy also significantly increased BW and egg yolk color. As dietary energy increased, percentage yolk solids increased at the 2 greater dietary protein levels, whereas egg-specific gravity linearly decreased at the 17.38% protein level. Increasing dietary energy and protein significantly improved feed conversion. Increasing protein intake significantly increased albumen and yolk weight but had no influence on yolk, albumen, or whole egg solids. Because feed ingredient and egg prices vary, there can be no fixed ideal dietary energy level for optimal profits during molt phase 1 (70 to 81 wk).

A 4 × 2 × 2 factorial experiment with 4 dietary energy levels (2,776, 2,820, 2,864, and 2,908 kcal/kg) and 2 strains (Bovans White and Dekalb White) with and without Tylosin was conducted to determine the influence of dietary energy and antibiotic on performance, egg solids, and egg quality. The experiment lasted 10 wk. Bovans White hens (n = 768) and Dekalb White hens (n = 768) at 55 wk of age were randomly divided into 16 treatments (8 replicates of 12 birds per treatment). Bovans hens had significantly greater egg production and significantly lower egg weight, egg-specific gravity, and shell weight than Dekalb hens. Increasing dietary energy by the addition of poultry oil had no significant effect on performance, egg solids, or eggshell quality. An ideal dietary energy level for optimal performance could not be determined. There can be no fixed ideal dietary energy level for optimal profits, due to varying feed ingredient and egg price. Although Tylosin supplementation had no effect on performance or egg solids, Tylosin significantly reduced dirty eggs, resulting in a positive effect on egg quality.

SUMMARY This experiment was a 4 × 2 × 2 factorial arrangement of 4 dietary energy levels (2,767, 2,806, 2,846, and 2,886 kcal of ME/kg), 2 molting methods (feed withdrawal and the low-salt diet), and 2 strains (Bovans White and Dekalb White). The objective of this study was to determine the effect of dietary energy and molting method on postmolt performance of 2 strains of commercial White Leghorns. Before the molt, Bovans and Dekalb hens were randomly divided into 2 groups. Feed was withdrawn from half of the hens (66 wk of age) for 9 d. A molt feed was fed from d 10 to 28. The other half of the hens was fed a low-salt diet for 28 d. After the molt, Bovans White hens (n = 720) and Dekalb White hens (n = 720) at 70 wk of age were randomly divided into 16 treatments (6 replicates of 15 birds per treatment). Bovans hens had significantly lower egg weight, percent of eggshell, egg specific gravity, and Haugh units than Dekalb hens, whereas Bovans hens had significantly higher egg production than Dekalb hens. Increasing dietary energy had no significant effect on any parameter other than yolk color. As dietary energy increased, feed conversion improved numerically from 2.13 to 2.05, resulting in a 3.8% improvement of feed conversion. With increasing dietary energy, hens adjusted feed intake, according to egg mass, to achieve the quantities of dietary energy (5.8 to 5.9 kcal) intake per gram of egg. An ideal dietary energy level for optimal postmolt performance and profits could not be determined for hens during phase 1 of the second cycle. Other than slightly reduced egg production and egg specific gravity during phase 1, feeding the low-salt diet to induce molt could be used as an alternative for the conventional feed withdrawal method.

The objective of this experiment was to compare the effects of 2 sources of phytase on performance of commercial Leghorns fed corn-soy diets. Seven diets were fed to Hy-line W-36 hens (n = 840; 8 replicates of 15 hens per treatment) from 21 to 33 wk of age. The treatments consisted of a control diet containing 0.38% nonphytate P (NPP) and a 2 × 3 factorial arrangement of 2 dietary NPP concentrations (0.11 and 0.26%) with 2 phytase sources [Natuphos (BASF, Mt. Olive, NJ) and Phyzyme (Danisco Animal Nutrition, Carol Stream, IL)] and without phytase. Dietary NPP had significant effects on feed intake, NPP intake, total P intake, egg production, egg weight, egg mass, egg specific gravity, and excreta P. The addition of Phyzyme or Natuphos significantly increased egg production and egg mass of hens fed the P-deficient diet (0.11% NPP) to levels that were similar to hens fed the control diet containing 0.38% NPP. Feed intake of hens fed the diets supplemented with Phyzyme or Natuphos was significantly less than that of hens fed the control diet containing 0.38% NPP. Phyzyme or Natuphos supplementation in the diets containing 0.11% NPP had significantly reduced excreta P of the control diet (approximately 58 and 54%, respectively) with no adverse effect on egg production and egg mass. There were no significant differences in feed intake, NPP intake, total P intake, egg production, egg weight, egg mass, feed conversion, egg specific gravity, mortality, BW, and excreta P between the diets supplemented with Natuphos and the diets supplemented with Phyzyme. In conclusion, Phyzyme had the same positive effects on performance of commercial Leghorns fed corn-soy diets as Natuphos.

SUMMARY Based on the assumption that the bioavailability of DL-methionine hydroxy analogue free acid (MHA-FA) is 65% on a weight basis relative to DL-methionine (DLM), the bioavailability of MHAFA was compared to DLM using molted hens. Five graded supplemental levels (0.012, 0.024, 0.036, 0.048, 0.060%) of Met from DLM (calculated as 99.7%) or MHA-FA (calculated as 65%) were added to a basal diet containing 14.97% protein and 0.27% Met. For the overall experimental period, differences between Met sources (P

SUMMARY An experiment was conducted to study copper sulfate pentahydrate (CSPH, CuSO45H2O) and tribasic copper chloride (TBCC, Cu2(OH)3Cl) as sources of supplemental Cu for layers. A total of 1,560 W-36 first cycle (Phase I) hens were randomly divided into 13 groups and fed a basal corn-soybean diet or a basal diet supplemented with 65, 130, 195, 260, 325, or 390 ppm of Cu from either CSPH or TBCC for 16 wk. The common intercept multiple linear regression over 4 Cu levels (65, 130, 195, and 260 ppm) indicated the bioavailability of TBCC relative to CSPH was 134%, and the optimal supplemental Cu level was 195 ppm for TBCC and 260 ppm for CSPH based on egg weight. There were no supplemental Cu level effects (P > 0.05) over the 4 Cu levels (65, 130, 195, and 260 ppm) based on feed intake, egg production, egg mass, feed conversion, and BW over 16 wk. Feed intake during the last 4 experimental weeks was lower (P < 0.01) for birds fed CSPH than for birds fed TBCC and basal diets, indicating that CSPH, but not TBCC, began depressing bird performance after being fed for 12 wk. Feed samples for both CSPH and TBCC at concentrations of 0, 195, and 390 ppm of Cu were taken from the diets and were stored at 40°C for up to 21 d. Samples were removed at 1-wk intervals for analysis of phytase retention. Phytase retention in diets with added TBCC was higher (P < 0.05) than in control diets or in diets with added CSPH. The results from this experiment suggest that the bioavailability of Cu in TBCC is greater than in CSPH, and TBCC is more effective than CSPH at reducing the oxidation of phytase during feed storage.

SUMMARY Two studies were conducted to determine the influence of added synthetic lysine to low-protein diets. The purpose of experiment 1 was to determine the correct Met+Cys/Lys ratio in low-protein diets. The objective of experiment 2 was to determine the influence of added synthetic lysine in low-protein diets with the Met+Cys/Lys ratio maintained at 0.75. In both experiments, there were 8 replicates per treatment with 15 Hy-Line W-36 hens (37 wk old) in each replicate. Experiment 1 had 4 Met+Cys/Lys ratios (0.75, 0.80, 0.85, and 0.90), and experiment 2 was a 2 × 4 factorial arrangement of treatments with 2 protein levels (14.3 and 13.6%) and 4 added synthetic lysine levels (0.000, 0.025, 0.050, and 0.075%). The results of experiment 1 showed no difference (P > 0.05) in performance among 4 Met+Cys/Lys ratios from 0.75 to 0.90, indicating a Met+Cys/Lys ratio of 0.75 was adequate. The results of experiment 2 showed that beneficial effects (P < 0.05) of added synthetic lysine were obtained for feed consumption, egg production, egg mass and egg weight at 13.6% protein level, and for feed conversion at 14.3% protein level, indicating that the quality of low-protein diet can be improved by added lysine when the Met+Cys/Lys ratio is maintained at 0.75.

Two studies were conducted to compare bioavailability of DL-methionine hydroxy analogue-free acid (MHA-FA) relative to DL-methionine (DLM) in layers. The bioavailability was compared for egg production, egg mass, egg weight and feed conversion. In trial 1 five supplemental levels of methionine (0.02, 0.04, 0.06, 0.08 and 0.10%) from DLM or MHA-FA source were added respectively to a basal diet containing 14.97% protein, 0.27% methionine, and 0.24% cystine. Hy-Line W-36 hens (1,760) 37 weeks old were used. Egg production was not improved beyond the first 0.02% added methionine level. Thus, an accurate bioavailability value of MHA-FA relative to DLM could not be obtained, indicating that this test was not statistically sensitive enough to estimate the bioavailability of MHA-FA relative to DLM. In trial 2, 1,920 Hy- Line W-36 hens 53 weeks old were used in a 3×2×2 factorial experiment with three protein levels, two supplemental methionine levels, and two methionine sources. DLM and MHA-FA were compared at different protein and supplemental methionine levels on an equimolar basis. There were no differences (P > 0.05) between the 0.02% and 0.04% supplemental methionine level or between DLM and MHA-FA in eg g production, egg mass, or feed conversion. Because no difference in egg production, egg mass and feed conversion between 0.02% and 0.04% methionine could be detected and that difference should be greater than the difference between DLM and MHA-FA, no potential differences between DLM and MHA-FA could be detected. There was a difference (P 0.05) than that of hens fed MHA-FA, the difference was calculated to indicate that the bioavailability of MHA-FA might be 88.9% on a molar basis or 78.2% on a weight basis.

The bioavailability of liquid DL-methionine hydroxy analogue-free acid (MHA-FA) relative to dry DL-methionine (DLM) in laying hens was estimated using milo-soybean diets, which were formulated to have low methionine and cystine content to increase the sensitivity of methionine deficiency. Five graded supplemental levels of methionine (0.02, 0.04, 0.06, 0.08, and 0.10%) from DLM or MHA-FA were added to the basal diet containing 0.20% methionine on an equimolar basis. Five different models were used to determine the bioavailability of MHA-FA relative to DLM. Three of the models were exponential models with supplemental methionine concentration on a weight basis, supplemental methionine intake on a weight basis, and supplemental methionine intake on a molar basis as the independent variable, respectively. Two of the models were sloperatio models with supplemental methionine intake on a weight basis or supplemental methionine intake above basal diet on a weight basis as the independent variable. The results of the regression analysis indicated average bioavailabilities were 122 (egg production), 109 (egg mass), and 89% (egg weight) on a weight basis or 139 (egg production), 124 (egg mass), and 101% (egg weight) on a molar basis. All bioavailability values were not different (P > 0.05) from 88% on weight basis or 100% on a molar basis but were different (P

SUMMARY Nutrient requirements for maximum profits are dependent on the production performance of the flock, egg and feed prices, and overall farm management. The production performance in turn is a function of many factors: nutrient density, TSAA levels, housing temperature, and feeding. For any viable layer operations, the above mentioned factors are the underpinning and need to be optimized. To optimize profits, all of the above factors must be optimized not maximized. For example, depending upon egg and feed prices, maximum performance may or may not result in maximum profits. In this project we found little or no effect on egg production, feed consumption, or egg specific gravity when various levels of TSAA were fed to laying hens. Hens housed in a cooler environment consumed significantly more feed and produced more and heavier eggs compared with those housed in a warmer environment. The TSAA requirement for maximum profits, therefore, varies with environmental temperature and market conditions (feed cost and egg price).

A study was conducted to determine if synthetic glycine could replace dietary protein and improve performance of commercial broilers. Nine diets were formulated per feed regimen (starter, finisher, and withdrawal). A commercial diet was used as control (Diet A). Amino acids were reduced by 15% from Diet A to obtain Diet B. Synthetic methionine and lysine were added to Diet B to bring their level equal to Diet A, and create Diet C. Three levels of synthetic glycine (0, 0.05 and 0.1%) were added to Diets A, B, and C to obtain the nine dietary treatments. Male chicks (n = 3,150) originating from Ross male x Hubbard female breeder flocks were randomly placed in 63 floor pens in an open-sided house with thermostatically controlled curtains. Floor pens were divided into 7 blocks, each block containing 9 pens. The nine dietary treatments in each feed regimen were randomly assigned to pens in each of the seven blocks on d 1 (starter), 22 (finisher), and 43 (withdrawal) of age. Mortality, feed consumption (FC), body weight (BW) and feed to gain ratio (FG) were determined. Supplementing glycine, or methionine and lysine had no effect on FC. Glycine had no influence on the BW of chicks. The BW decreased with the reduction in dietary amino acids, and increased with an increase in dietary methionine and lysine fed the amino acid deficient diet. Glycine had no beneficial effect on FG, and 0.05% glycine increased (P < 0.05) FG up to 3 weeks. Addition of synthetic glycine (0.05 to 0.1%) to the 15% amino acid deficient diet could not make up for the deficiency of dietary amino acids in broiler diets.

Calcium requirements of laying hens have been widely studied yet keep challenging nutritionists as a result of new genetic make-ups of commercial strains, farm management techniques, environmental concerns, and economics considerations. The present research was conducted to determine the calcium requirement of "Bovines" hens that represent about 17% of US layer industry. Increasing dietary level of calcium from 2.5 to 5.0% in hens' diets in increments of 0.5% had a significant positive linear effect on egg production and egg specific gravity. Increasing dietary calcium level from 2.5 to 5.0% increased egg production from 75.3 to 82.4% and egg specific gravity from 1.078 to 1.083 units. Calcium level had no effect on feed consumption or egg weight. "Bovines" hens required 5.57 g calcium/h/d for a maximum egg specific gravity index of 1.083 units (high shell quality). The decision to feed this level of calcium to achieve maximum shell quality however depends upon the nature and cost-benefits analysis of the layer operation.

SUMMARY Efficient phosphorus utilization and reduced excretion from poultry has been a matter of great concern due mainly to the detrimental effect on the environment. This research was conducted to analyze the effect of Allzyme 2x , a nongenetically modified phytase produced by solid-state fermentation on performance of commercial Leghorns. The experiment was designed using a factorial analysis with two lysine levels of 0.83 and 0.92% and three available phosphorus (aP) levels of 0.4% (control), 0.1% (without phytase), and 0.1% (with phytase). There were eight replicates of 20 hens (40 wk old) for each treatment, and the diets were fed for 8 wk. Results indicated that reducing the lysine level from 0.92 to 0.83% significantly reduced egg weight and feed consumption but had no influence on egg production. Reducing the aP level from 0.4 to 0.1% reduced egg production, egg weight and feed consumption. Supplementing 11,400 phytase units (PTU)/kg Allzyme 2x (phytase) to the phosphorus-deficient diet alleviated the drop in egg production and egg weight. These results indicate the nongenetically modified phytase completely reversed the negative effects of aP deficiency in commercial layers.

This study was conducted to determine the influence of a corn-soy enzyme, Avizyme 1500 (AZ1500) in hen diets on performance and profits of commercial Leghorns. A 3 × 2 × 2 factorial arrangement of treatments comprising three lysine levels (0.75, 0.83, and 0.92%), two energy levels (2,820 and 2,906 kcal ME/kg), and two AZ1500 levels (0 and 0.075%) were used. Hy-Line W-36 hens (n = 1,920) were randomly assigned in groups (20 hens/group) to the 12 dietary treatments for 16 wk. Feed intake (FI), egg production (EP), egg weight (EW), egg specific gravity (SG), and BW were determined. Inclusion of AZ1500 in the diet resulted in interactions with energy and lysine content of the diet, influencing FI, EP, and BW. AZ1500 increased FI of hens fed highenergy diet when lysine was 0.75 and 0.83%, but not at 0.92%. This increase in FI was not observed in hens fed the low-energy diet. AZ1500 increased EP at lower lysine levels but not at the higher level. AZ1500 also increased EP at the low-energy level but not at the high-energy level. Increasing dietary lysine from 0.75 to 0.92% linearly increased EW (P 0.05). A BW increase at 0.83% lysine due to AZ1500 was not observed at 0.75 or 0.92% lysine. Inclusion of AZ1500 in the diet increased the relative amount of bacteria (e.g., Lactobacillus spp.) in the caecum in the 30 to 40% range of guanine plus cytosine and decreased the relative amount of microbes (e.g. Bifidobacterium spp.) in the 60 to 70% range of guanine plus cytosine. These results indicate some positive influences of AZ1500 on energy and lysine (protein) utilization in hens, impacting EP, FI, and BW. However, more research is required to learn how to maximize the beneficial effects of AZ1500 on energy utilization in hens.

SUMMARY Anexperimentwasconductedtodeterminewhethersupplementaldietaryphytasecouldsupport egg production, egg shell quality, fertility, and hatchability in broiler breeder hens on a diet with marginal available phosphorus. During the production period, 27 to 60 wk of age, individually caged broiler breeder hens were fed four diets with two available phosphorus (AP) concentrations (0.1 and 0.3%) and two phytase levels [0 and 300 phytase units (FTU)/kg]. Phytase increased overall hen-day egg production by 9.8%, as compared with hens consuming a low phosphorus diet without added phytase. Addition of phytase significantly reduced hen mortality regardless of AP levels. Phytase improved bone mineral content and bone density of hens at both AP levels. Supplemental phytase had no significant effect on egg weight or egg specific gravity. The results suggest the possibility of a detrimental interaction of phytase with the 0.1 AP level on hatchability.

Previous studies have indicated that hens fed diets formulated based on protein (FBP) produced more and heavier eggs compared with diets formulated based on lysine (FBL). It was hypothesized that this beneficial effect may be due to higher lysine or other amino acids rather then just protein per se. To test this hypothesis, fish meal (FM) which contains more lysine and has different amino acid ratios than soybean meal, was used to determine if the decline in performance associated with hens fed diets FBL could be prevented. Fish meal was used in diets FBL to supply the same quantity of TSAA and protein but more lysine (0.02 and 0.04%) than diets FBL. Three levels of FM (0, 2.5 and 5%) with three TSAA levels (0.65, 0.72 and 0.81%) were used to obtain the 9 dietary treatments. Three diets were also FBP to compare results. A total of 96 replicates of 16 hens each (n = 1536) were randomly assigned to 12 dietary treatments. Egg production (EP), feed consumption (FC), egg weight (EW) and egg specific gravity (ESG) were evaluated to determine hen performance. Hens fed diets FBP produced more (1.4%) and heavier (0.6g) eggs than hens fed diets FBL. Inclusion of FM (lysine) to diets FBL prevented the drop in EP and there was no significant difference (P > 0.05) in EP of hens fed diets FBP (90.4%) and hens fed diets FBL using FM (90.4%). However, FM (lysine) did not improve EW equal to hens fed diets FBP. Although FC was not influenced by FM (lysine), a TSAA effect was observed. Hens fed the higher TSAA levels consumed more feed than those fed the lower level. These results indicate that the difference in performance of hens fed diets FBP and FBL were not due to protein per se but at least partially due to lysine and other non-sulfur containing amino acids.

An experiment was conducted as a 2 x 5 factorial to determine if increasing dietary lysine in corn- soy diets formulated based on lysine improves egg weight (EW) and egg production (EP) in commercia l Leghorns. A set of five corn-soy diets with similar levels of energy were formulated based on lysine to contain 0.97, 0.92, 0.87, 0.83 and 0.79% lysine. These diets contained no synthetic lysine. A second set of five diets were formulated by supplementing 0.097% synthetic lysine to each diet in the first set. Hy-Line W36 hens (n=1,280; 21 wk of age) were randomly assigned in replicates of 16 hens to the ten dietary treatments for 16 weeks. Feed consumption (FC), EP, EW and egg specific gravity (ESG) were measured. Adding synthetic lysine to diets formulated based on lysine had no significant effect on EP, EW, ESG or FC of hens. Also, amino acid density had no effect (P > 0.05) on EP, FC, or ESG. However, EW linearly increased (P < 0.01) as amino acid density increased. These results indicate that adding 0.097% additional synthetic lysine to corn-soy diets formulated based on lysine containing 0.79 to 0.97% lysine had no significant influence on performance of commercial Leghorns.

A study was conducted to determine the effect of dietary supplementation of phytase on the incidence and severity of tibial dyschondroplasia (TD) in chickens selected for high (HTD) and low (LTD) incidences of TD for 11 generations. By feeding a phosphorus-deficient diet (0.1% nonphytate phosphorous; nPP), HTD and LTD chickens were further identified as high-sensitivity birds (HS) and low-sensitivity birds (LS) to phosphorus deficiency based on mortality. Two hundred forty 1-d-old chicks from HTD and LTD lines (five replications of four birds per treatment) were randomly assigned to a control diet with 0.5% nPP and two treatment diets (0.1% nPP) with and without 600 phytase units (FTU) Natuphos phytase/kg. Feed consumption and growth rate were measured for 3 wk, and both tibiae were scored for TD incidence, average TD score, and total number of TD lesions with the most severe form of the abnormality (lesions that were scored 3). The addition of phytase had no influence on TD incidence and lesion scores of 3 in HTD chicks. However, a nonsignificant reduction in TD incidence (P = 0.07), TD score, and no. 3 lesions (Por = 0.01) were observed in LTD chicks. Interactions between sensitivity (to P deficiency) and phytase (Por = 0.01) and sensitivity and nPP (Por = 0.01) were observed for no. 3 scores in LTD chicks. These results indicate that phytase was effective in reducing TD incidence and severity in LTD chicks but not in HTD chicks.

Several studies have shown that microbial phytase improved bioavailability of phytate phosphorus and reduced the need for inorganic phosphorus in layer diets. However, limited work is available concerning the influence of phytase on availability of other nutrients, especially Ca. The objective of this study was to determine the influence of phytase on Ca utilization in Hy-Line W-36 hens. This experiment utilized three levels of dietary Ca (3.1, 3.4, and 3.7%) and two levels of phytase (0 and 300 phytase units/kg diet) with 0.3% nonphytate phosphorus (NPP). Three additional treatments with 3.4, 3.7 and 4.0% Ca with 0.4% NPP were also included in this study to compared results. Increasing dietary Ca from 3.1 to 3.7% resulted in a significant linear increase in eggshell and bone quality. Phytase supplementation (300 phytase units/kg) significantly increased egg specific gravity (ESG) during the first 6 wk. Subsequently, phytase significantly increased ESG of hens fed 3.4% Ca, but not of those fed 3.1 and 3.7%. Phytase improved bioavailability of Ca and eggshell quality at the marginal Ca level of 3.4% as indicated by improved ESG.

Nutrient equivalency of Natuphos Phytase for minerals, amino acids, and energy has been estimated elsewhere for broiler chickens. The current study was to evaluate equivalent values of 600 FTU/kg Natuphos Phytase for amino acids and energy in 3,150 broiler chicks from hatch to 7 wk of age. Treatments consisted of a 3 x 3 factorial arrangement of three levels of dietary amino acids (AA; 100, 92.5, and 85% of Illinois Ideal Protein for Broiler Chickens) and three phytase inclusion approaches (positive control: 0 FTU/kg with no reduction of Lys, TSAA, and ME; negative control: 0 FTU/kg with reduction of 2% Lys, 1% TSAA, and 0.5% ME; and reformulation with phytase: 600 FTU/kg with reduction of 2% Lys, 1% TSAA, and 0.5% ME). The effect of AA was linear on BW gain and feed conversion (FC); a greater AA level improved performance. No interaction of AA and phytase inclusion approach was significant in terms of BW gain, feed intake (FI), and FC of growing and finishing broilers. Birds fed the positive control diet had greater BW gain than those fed the negative control diet. Body weight gain of birds fed the diet reformulated with phytase did not differ from those of birds fed the positive control. Feed conversion was not affected by phytase inclusion approaches. Effects of phytase supplement on apparent ileal digestibilities (AID) of CP and AA were not significant. Restoring BW gain lost in the negative control by reformulated feed with 600 FTU/kg phytase indicates that equivalent values estimated elsewhere might be adequate.

In vivo mineral source solubilization is determined by a decanting procedure in which unsolubilized mineral sources are recovered from the excreta. These studies were conducted to improve the accuracy and broaden the use of this procedure. These studies examined the influence of excreta sample wet weight on percentage mineral source recovered; compared results from wet samples and dried, ground samples of comparable original wet weights, and evaluated the influence of three P sources on percentage in vivo P source solubilization in broilers and layers. Reducing sample weights significantly (P

Continued genetic selection for improved BW gain has met an obstacle of skeletal disorders in broiler chickens. Two broiler chicken lines (HTD and LTD) were developed by 10 generations of divergent selection for tibial dyschondroplasia (TD) incidence originating from commercial primary breeders. The reference population was a randombred control line maintained along with the selected lines. Relationships of TD incidence with BW, egg production (EP), and hatchability were assessed using these lines. The response of TD to selection was asymmetric, favoring an increased TD incidence. Mean TD incidence increased 7.6 percentage points per generation during Generation 1 through 10 in males and 9.1 percentage points in females of the HTD line but did not change significantly in the LTD line at 4 wk of age. Responses of the HTD line in early (1 to 4) generations were greater than in later (6 to 10) generations, in contrast to nonsignificant responses for both durations in the LTD line. The 4-wk BW of the HTD line was slightly heavier than or similar to that of the LTD line within generations. The HTD line birds tended to decrease 7-wk BW with advancing generations. The trend of changes in BW was not as clear in the LTD lines as in the HTD line. The variability of 7-wk BW had an increased trend with advancing generations in the HTD line, accompanied by a decreased additive genetic variability of TD due to continued selection. The average EP in the LTD hens was 7.6 percentage points higher than in the HTD from Generations 1 through 10. Mean hatchability in the LTD line did not differ from that in the HTD line within generation. Responses of EP and hatchability, components associated with fitness, appeared slower towards increased fitness than towards decreased fitness.

Ability to utilize dietary phytate P was evaluated in 1,387 broiler chicks of 45 sire and 180 dam families, by feeding a corn-soybean base diet supplemented with no inorganic P and a low level of Ca. These chicks were the progeny of high and low incidence of tibial dyschondroplasia (TD) selected divergently for 11 generations and a nonselected control line. Chicks from the control line utilized phytate P better than those from the high or low lines in terms of livability, mortality, and growth performance. Chicks did not differ in mortality and body weight between the high and low lines. Variation in livability and mortality was greater among lines than among families, whereas families accounted for a greater part of variation than lines in body weight. Dams accounted for a slightly larger proportion of variation than sires in traits studied. Genetic selection for improved utilization of dietary phytate P could be effective.

Light and methionine supplementation for molting hens have been the focus of attention in may different research papers. The present experiments examined the combined effects of additional light prior to molting and methionine supplementation in molt feed on the performance of molted hens. Additional light or methionine supplementation in molt feed had no significant effect on most of the performance criteria observed in the two experiments. However, the did increase feed cost, utility cost, and incidence of body-checked eggs in both experiments. These result give reason to question the efficiency of supplying 24 hr light for 7 days prior to molt and using TSAA levels greater than 0.60% or protein levels greater than 15.90% in molt feed.

Producers commonly feed commercial leghorns based on flock average feed intake to control egg size and nutrient intake. However, results of these experiments indicate that this procedure may not yield maximum profits. Results indicate that hens house in the bottom row of cages have significantly greater egg size and feed consumption than those on the top row. Most of the differences associated with cage row level cannot be explained by variation in temperature. Our results suggest that most commercial leghorns are either overfed or underfed depending on cage row position and that profits could be increased by feed hens based on feed intake as determined by cage row position rather than by average flock intake.

An experiment was conducted to evaluate the response of heat-stressed hens to increases in dietary calcium at two protein levels. Criteria evaluated included feed consumption, energy consumption, egg weight, egg production, egg specific gravity, and calcium and phosphorus solubilization and excretion. There were no effects of different calcium levels on egg production or egg weight. Increasing dietary calcium from 3.5% (2.9 g/hen/day) to 3.9% (3.2 g/hen/day) significantly increased egg specific gravity. Further increases in calcium intake however, did not improve egg shell quality. Protein level had no influence on egg production or egg specific gravity.

Two experiments were conducted to determine whether 1) serum Si and Al is increased in hens intubated with sodium zeolite A (SZA); and 2) dietary cholecalciferol (vitamin D3) influences the absorption of Si or Al by hens fed SZA. In Experiment 1, hens were intubated at oviposition with 0, 1, or 2 g of SZA. Blood samples were collected from the brachial vein at oviposition, and 4, 8, 12, 16, and 20 h postoviposition. Serum samples were analyzed for Si and Al. Peak serum Si and Al were observed at 4 and 8 h postoviposition, respectively. In Experiment 2, hens consumed commercial layer diets ad libitum containing five levels of dietary cholecalciferol (100 to 500 IU/kg) with or without .75% SZA for 6 wk. Blood samples were collected at the end of the 6-wk period by cardiac puncture at oviposition. When dietary cholecalciferol was increased from 100 to 200 IU/kg of diet there was an increase (P < .05) in serum Si but not Al. Levels of cholecalciferol above 200 IU/kg did not produce an additional increase in serum Si. The results showed increased (P < .01) serum concentrations of Si and Al for hens intubated with or fed SZA. It was concluded that Si and Al from SZA are absorbed by commercial Leghorn hens, and a possible involvement of Si or Al should be considered in the mechanism of action of SZA associated with improved eggshell quality and bone development.

Several studies have demonstrated the influence of dietary calcium level on feed and energy intake. Because egg size is influenced by feed or energy intake, two experiments were conducted to determine if egg size can be increased by feeding diets marginal to deficient in calcium. Hens were fed six levels of calcium ranging from 2.5 to 4.5% in isocaloric and isonitrogenous diets (Experiment 1) and in diets not isocaloric and isonitrogenous (Experiment 2). Results indicated that as dietary calcium level decreased, egg specific gravity decreased and feed consumption and/or energy consumption increased. However, the increased energy consumption had no effect on egg weight or production. Because there were no adverse effects from feeding higher levels of dietary calcium and there were adverse effects (reduced egg specific gravity and increased feed cost) from feeding low dietary calcium levels, it was concluded that the increased feed and/or energy intake of hens fed the lower calcium levels was not beneficial. Therefore, poultry growers should end the practice of feeding marginal dietary calcium levels to stimulate feed and/or energy intake.

The purpose of this study was to compare the rates of separation of 0.04 taper nickel titanium (NiTi) rotary instruments using two different instrumentation techniques. Twenty sets of 0.04 taper Profile Series 29 rotary instruments, sizes 2 to 6 were used in the mesial (mandibular) or buccal (maxillary) canals of extracted human molars with a 20 to 30 degree root curvature according to the Schneider classification. The rotary instruments were used up to 20 times either with the crown-down technique recommended by the manufacturer or with a combination of preflaring with hand files in a passive step-back technique followed by rotary instrumentation. Statistical analysis of the data showed that the combination technique allowed more uses before separation compared with the crown-down technique recommended by the manufacturer p < 0.0001.

Modeling a North American Free Trade Area: Estimation of Flexible Functional Forms, - This paper provides estimates of the almost ideal demand system as applied to U.S. imports from Canada, Mexico, the rest of the world, and competing domestic output. Quarterly data over 1980-88 and for 19 mining and manufacturing sectors are used. Implications of adding up, homogeneity, symmetry, and negativity are considered. The econometric results should guide applied general equilibrium modeling of a North American Free Trade Area, especially with regard to potential terms-of-trade effects.

An experiment with a 2 × 2 factorial arrangement of treatments was used to determine differences in responses of early-maturing (EM) and late-maturing (LM) pullets fed low dietary P (.4% total P; LP) and normal dietary P (.7% total P; NP) levels. Six hundred pullets (18-wk-old) were equally and randomly allocated to the LP and NP treatments. Egg production, egg weight, egg specific gravity, and eggshell breaking strength were measured at 26 and 28 wk. When pullets were 28 wk of age, plasma total Ca (TCa), ionic Ca (Ca++), and inorganic P (Pi) concentrations, urine Ca concentrations, and urine pH, bone mineral content (BMC), bone density, total kidney weight, and kidney weight ratio (heavier kidney ÷ lighter kidney) were determined from 15 pullets each from EM-NP, EM-LP, LM-NP, and LM-LP treatments. The pullets with osteoporosis and pullets that died during the experiment were categorized into EM and LM groups. Results showed that LP caused severe adverse effects on LM pullets. The LM pullets fed the LP diet had high plasma Ca++ concentration, low plasma Pi concentration, increased urine Ca concentration, a high incidence of osteoporosis, mild kidney lesions, and elevated mortality compared with pullets subjected to the other treatments. The EM pullets fed the LP diet were also adversely effected by LP, but were less susceptible to osteoporosis and mortality. The LP diet improved eggshell quality, but this beneficial effect was only temporary. The severity of adverse effects of low dietary P was greater for LM than the EM pullets.

Dietary limestone solubilization in laying hens improves if retention time is prolonged in the gizzard. To determine the minimum dietary particle size of limestone that can be retained in the gizzard, equal quantities of four different sizes of limestone particles were mixed with a layer diet devoid of limestone and fed to molted hens for 1h. Limestone particles retained in crop, gizzard and intestine were recovered and separated into the four test particle sizes. A greater (P

Experiments were conducted to determine if the high ion-exchange capacity of sodium aluminosilicate (ZA) marketed as ETHACAL Feed Component or its aluminum content or both are related to the beneficial effect of ZA on egg specific gravity (ESG). In Experiments 1 and 2, ZA was compared with hydroxy-sodalite (HS) and carnegieite, which have the same chemical formula as ZA but little or no ion-exchange capacity. Two levels of ZA (0 and 1.5% of the diet) and three levels of HS (0, .75, and 1.5%) were fed in Experiment 1. In Experiment 2, 0, .75, and 1.5% of ZA and carnegieite were fed. In Experiment 3, ZA, carnegieite, aluminum sulfate, and aluminum phosphate were fed at levels calculated to contain .148 and .101% aluminum. Criteria evaluated were ESG, egg production, feed consumption, and egg weight. Egg specific gravity was significantly improved by ZA in all experiments and was not affected by HS, carnegieite (Experiments 1 and 2), aluminum sulfate (.148% Al), or aluminum phosphate (Experiment 3). Carnegieite and aluminum (.101%) from aluminum sulfate increased ESG in Experiment 3. In Experiments 1 and 3, egg production and feed consumption were not influenced by various treatments. Carnegieite and ZA reduced egg production and feed consumption in Experiment 2. It was concluded that the ion-exchange capacity and aluminum content of ZA may contribute to its beneficial effect on ESG.

To determine the influence of sodium aluminosilicate (SA) on hens (7 mo of age) fed different levels of phosphorus, 1,920 hens were fed diets containing .70, .57, .43, and .30% total phosphorus with and without the inclusion of 1.0% SA for 6 wk. Egg production, egg weight, egg specific gravity, and feed conversion were determined weekly. Birds fed .30% phosphorus with 1% SA had a much faster and greater decline in production than the hens fed .30% phosphorus without SA. For hens fed diets containing more than .43% phosphorus, egg production was not affected by level of phosphorus in the diet with or without SA. The inclusion of 1.0% SA improved egg specific gravity; also, the degree of improvement was unrelated to level of dietary phosphorus when the proportion of phosphorus was greater than .30%. Sodium aluminosilicate significantly reduced feed consumption when the level of dietary phosphorus was .30%. Hens fed diets containing .30% phosphorus with or without SA had significant reductions in egg size. However, hens fed SA at phosphorus levels above .30% had eggs that were .5 g heavier than those from hens fed the same level of phosphorus without SA. The author concluded that SA improved egg specific gravity, but had no effect on egg production when total phosphorus intake was 668 mg/hen per day or higher. Because of the strong interaction of SA by phosphorus for egg production, the level of dietary phosphorus must be considered when using SA.

Two experiments of 4 x 2 x 2 factorial arrangements of 4 dietary energy levels, 2 molting methods (feed withdrawal and no salt diet), and 2 strains (Bovans White and Dekalb White) were conducted to determine the effect of dietary energy and molting method on long-term postmolt performance of 2 strains of commercial Leghorns. In experiments 1 and 2, Bovans White hens (n = 576) and Dekalb White hens (n = 576) were randomly divided into 16 treatments (6 replicates of 12 birds per treatment). Experiment 1 lasted from 86 to 96 wk of age, and experiment 2 lasted from 100 to 110 wk of age. Bovans White hens had significantly higher egg production than Dekalb White hens, whereas Bovans White hens had significantly lower egg weight, percentage of eggshell, and egg specific gravity than Dekalb White hens. Based on improved feed conversion, dietary energy of 2,846 kcal of ME/kg appeared to be enough for optimal performance during second cycle phase 2. Based on BW of hens, dietary energy level for optimal performance should be less than 2,936 kcal of ME/kg during second cycle phase 3. There can be no fixed ideal dietary energy level for optimal profits for postmolt egg production. Molting method had no effect on egg production and egg mass during the early and middle stages of the postmolt production period. However, hens molted by feed withdrawal had significantly higher egg production and egg mass during the later stage of the postmolt production period compared with hens molted by a no salt diet. There was no significant difference in egg specific gravity due to molting method. Feeding a no salt diet resulted in reasonable long-term postmolt performance and eggshell quality, rather than optimal performance and eggshell quality.