Methodology affects measures of phosphorus availability in growing broilers. 2. Effects of calcium feeding strategy and dietary adaptation period length on phytate hydrolysis at different locations in the gastrointestinal tract1.

An experiment was conducted to determine the effects of dietary adaptation period length (DAPL; 0, 24, and 48 h) and Ca feeding strategy (0.35% or 1.4:1 Ca:P ratio) on apparent phytate P (myo-inositol 1,2,3,4,5,6 hexakis dihydrogen phosphate; IP6) hydrolysis (AIP6H) and apparent digestibility (AΣIPD) of the sum of all inositol phosphate esters (ΣIP) of corn-titration diets at 3 locations (proventriculus/gizzard [Pro/Giz], jejunum, and distal ileum) in the gastrointestinal tract (GIT). Four hundred thirty-two Ross × Ross 708 male broilers were placed into 36 battery cages and fed a common starter diet until 18 d of age. Eight semipurified diets and a control diet for DAPL were fed from 19 to 21 d of age. Digesta were collected at each location from 4 birds per pen after each DAPL. Diets formulated with a 1.4:1 Ca:P ratio had higher (P < 0.001) AIP6H and AΣIPD when measured in the jejunum and ileum, but no differences were observed in the Pro/Giz. No interaction effects between DAPL and sampling location were observed for AIP6H and AΣIPD of the control diet. Conversely, interactive effects (P < 0.05) were measured for AIP6H and AΣIPD of the corn-titration diets. The highest values for both AIP6H (73.9%) and AΣIPD (80.7%) were measured in the Pro/Giz after 24 h. Phytate hydrolysis and AΣIPD were similar regardless of DAPL when sampled from the distal ileum. Concentrations of TiO2, IP6 and ΣIP also varied (P < 0.05) in response to DAPL and sampling location. Variability was likely due to inconsistencies in the flow of inositol phosphate esters and TiO2 through the GIT, specifically the Pro/Giz. Therefore, the use of TiO2 as an inert marker may have limitations when determining the hydrolysis and digestibility of phytate esters.

Methodology affects measures of phosphorus availability in growing broilers: Effects of calcium feeding strategy and dietary adaptation period length on true ileal phosphorus digestibility and predicted endogenous phosphorus losses1.

An experiment was conducted to determine the effects of Ca feeding strategy and dietary adaptation period length (DAPL) on the apparent ileal P digestibility (AIPD) and apparent ileal myo-inositol 1,2,3,4,5,6 hexakis dihydrogen phosphate (IP6) hydrolysis (AIIP6H) of corn titration diets. Nine hundred sixty Ross × Ross 708 male broiler chicks were placed into 80 battery cages. Broilers received a common starter diet until 18 d of age and then were fed one of 10 experimental treatments from 19 to 21 d of age. Nine diets were formulated to evaluate 5 corn inclusion concentrations (15, 30, 45, 60, or 75%) and 2 Ca feeding strategies (fixed at 0.35% or 1.4:1 Ca:P) after 3 DAPL (zero, 24, and 48 h). As a control for DAPL, one treatment group received the common starter diet for the duration of the experiment. Broilers consuming the control diet had higher (P < 0.001) BW gain and feed intake than broilers fed the corn titration diets. Apparent ileal P digestibility of the control diet was affected (P = 0.038) by DAPL. For diets formulated with a 1.4:1 Ca:P ratio, negative linear effects (P < 0.05) on AIPD and AIIP6H were observed with increasing corn. Conversely, for diets formulated with 0.35% Ca, positive linear effects (P < 0.05) were measured for AIPD after a 48 DAPL while no linear or quadratic effects (P > 0.05) were measured for AIPD or AIIP6H for other DAPL. Broilers fed diets formulated with 1.4:1 Ca:P had variable (P < 0.05) true ileal P digestibility (TIPD; 32.2, 15.1, and 35.4%) and negative endogenous P losses (EPL; -190, -499, and -262 mg/kg DM intake) for zero, 24, and 48 h DAPL, respectively. Conversely, TIPD values (41.2, 39.1, and 47.3%) were similar (P > 0.05) and EPL were positive (102, 197, and 154 mg/kg DM intake), regardless of DAPL, for broilers fed diets formulated with 0.35% Ca. These data demonstrated that formulating diets with a 1.4:1 Ca:P ratio affected AIPD of the titration diets, shifting the regression line and predicted negative EPL and an underestimation of TIPD.

Interactive effects of dietary adaptation period length and titration diet type on apparent ileal phosphorus digestibility and phosphorus retention in growing broilers.

Two experiments were conducted to examine the effects of different corn titration diets and dietary adaptation period length (DAPL) on intestinal histology, apparent ileal P digestibility (AIPD), and apparent P retention (APR) in Ross × Ross 708 male broilers from 20 to 24 d of age. It was hypothesized that purified ingredients in nutrient-deficient titration diets may affect P availability with varying DAPL. In experiment 1, 1,152 broilers were utilized in a 3 × 3 factorial treatment structure with 3 diets (control, 25% corn titration diet [25CTD], or 75% corn titration diet [75CTD]) and 3 DAPL (0, 24, or 72 h). Experiment 2 was conducted with 576 broilers as a 4 × 3 factorial arrangement with 4 diets (control, 25CTD, 75CTD, or nitrogen-free diet [NFD]) and 3 DAPL (24, 48, or 72 h). All diets contained purified ingredients except for the control diet, which had the same formulation as the common starter and served as a control for DAPL. The NFD diet was fed as a highly purified protein-free diet. Broilers were fed a common diet until 19 d of age and then transferred to experimental diets at 20 d of age. In experiment 1, diet type did not affect (P > 0.05) intestinal histology. However, diet type and DAPL each influenced (P.≤.0.001) diet AIPD. Higher (P.≤.0.001) AIPD was measured for the control diet compared with the 75CDT, and the 25CTD had the lowest AIPD. Following a 24 h DAPL, AIPD was higher (P.≤.0.001) than after a DAPL of 0 or 72 h. In experiment 2, diet type × DAPL interactions (P.≤.0.001) were observed for APR of the control diet, 75CTD, and NFD, but not the 25CTD. Because APR of the control diet was affected by varying DAPL, factors other than differences in diet type may have been responsible for inconsistencies in the measure of P availability. Furthermore, no clear evidence was observed that broilers were able to adapt to P-deficient diets by increasing APR or AIPD. In conclusion, a standard DAPL should be established as a means to reduce variability associated with measuring of feedstuff P availability.

Effects of calcium feeding strategy on true ileal phosphorus digestibility and true phosphorus retention determined with growing broilers.

An experiment utilizing 960 Ross × Ross 708 male broilers was conducted to determine the effects of Ca feeding strategy on true ileal (prececal) P digestibility (TIPD) and true P retention (TPR) of corn. Experimental diets were formulated with 1 of 3 dietary Ca feeding strategies (0.95%, 0.13%, or variable Ca concentrations to maintain a 2.1:1 Ca:P ratio) and contain 0, 25, 50, or 75% corn. A practical corn-soybean meal diet (1.4:1 Ca:P ratio) was fed as a control. After receiving a common starter diet, experimental diets were fed from 19 to 26 d of age. After a 48-h dietary adaptation period, a 48-h retention assay was conducted. At 25 and 26 d of age, ileal digesta were collected from 8 birds per cage. Broilers consuming the control diet had higher (P<0.001) BW gain, feed intake, digesta P, and excreta P than broilers consuming the corn titration diets. Digesta and excreta P increased (linear, P<0.05) with graded increases of corn. True ileal P digestibility and TPR were highest (P<0.05) for diets with 0.13% Ca (57.3 and 69.5%, respectively) compared with diets formulated with a 2.1:1 Ca:P ratio (41.2 and 37.8%, respectively) or 0.95% Ca (25.4 and 39.0%, respectively). Values for TPR were higher (P<0.05) than those for TIPD except when the dietary Ca:P ratio was fixed. Additionally, negative endogenous P losses were predicted by regression equations when TPR was estimated for birds fed titration diets with the fixed Ca:P ratio. Changing the Ca concentration of the diets to maintain a fixed Ca:P ratio influenced (P<0.001) apparent P retention, which affected the estimate for TPR due to the prediction of negative endogenous P losses. These data demonstrated that regression analysis may have limitations when estimating the TIPD or TPR of corn when formulating diets with different Ca feeding strategies. More research is necessary to elucidate the factors that contributed to regression equations predicting negative endogenous P losses.

Apparent ileal amino acid digestibility of reduced-oil distillers dried grains with solubles fed to broilers from 23 to 31 days of age.

An experiment was conducted using male Ross×Ross 708 broiler chicks to determine the effect of oil extraction from corn distillers dried grains with solubles on apparent ileal amino acid digestibility from 23 to 31 d of age. On an as-fed basis, ether extract concentrations were determined as 5.4% (L-distillers dried grains with solubles), 7.9% (M-distillers dried grains with solubles), and 10.5% (H-distillers dried grains with solubles) for the 3 experimental distillers dried grains with solubles sources. Prior to experimentation, each sample (H-distillers dried grains with solubles (control), M-distillers dried grains with solubles and L-distillers dried grains with solubles) was analyzed on an as-fed basis for crude protein (29.2, 27.6, and 27.9%), starch (4.4, 5.2, and 6.1%), neutral detergent fiber (29.5, 33.2, and 29.9%), and total dietary fiber (31.4, 36.6, and 33.6 %). Four hundred and thirty-two male chicks (12 birds per cage; 0.04 m2 per bird) were randomly assigned to 36 battery grower cages. Broilers were fed one of 3 semi-purified diets, which were comprised of 76% L-distillers dried grains with solubles, M- distillers dried grains with solubles, or H-distillers dried grains with solubles as the sole amino acid source from 23 to 31 d of age. Apparent ileal amino acid digestibility coefficients were negatively affected (P<0.05) by oil extraction for Met (0.722, 0.788, and 0.791), Lys (0.504, 0.510, and 0.552), Thr (0.563, 0.566, and 0.612), Trp (0.708, 0.733, and 0.767), and Arg (0.762, 0.776, and 0.799) for L-distillers dried grains with solubles, M-distillers dried grains with solubles, and H-distillers dried grains with solubles, respectively. Conversely, no differences in apparent amino acid coefficients were reported for Ile, Leu, and Val. These results indicated that L-distillers dried grains with solubles had lower apparent amino acid digestibility coefficients for Met, Lys, Thr, Trp, and Arg compared with H-distillers dried grains with solubles.

Effects of hydroxy trace minerals on oxidative metabolism, cytological endometritis, and performance of transition dairy cows.

Multiparous Holstein cows (n=60) were used to determine effects of supplementing hydroxy forms of Zn, Cu, and Mn compared with 2 other common supplementation strategies on oxidative metabolism, cytological endometritis, and performance of transition cows. After a 1-wk pretreatment period, cows were assigned randomly to 1 of 3 dietary treatments from 21 d before expected calving through 84 d postcalving. Dietary treatments administered by daily top-dressing included (1) inorganic sulfate forms of Zn, Cu, and Mn (ITM); (2) a blend (75:25) of sulfates and organic complexes of Zn, Cu, and Mn (ITM/OTM); and (3) hydroxy trace minerals (HTM) of Zn, Cu, and Mn. The resulting dietary concentrations of supplemental Zn, Cu, and Mn were similar among treatments and averaged 40, 10, and 27 mg/kg, respectively, before calving and 59, 15, and 40 mg/kg, respectively, after calving. Total concentrations of Zn, Cu, and Mn averaged 80, 16, and 62 mg/kg during the prepartum period and 102, 23, and 75 mg/kg, respectively, during the postpartum period. Overall, effects of treatment on milk yield and milk composition were not significant. Cows fed HTM during the prepartum period had higher body weight (BW) than those fed ITM during the prepartum period and had higher BW during the postpartum period than those fed the other treatments; however, BW change, body condition score, and body condition score change were not affected by treatment. Plasma total antioxidant capacity was lower in cows fed HTM than ITM but was not different from cows fed ITM/OTM. Cows fed HTM tended to have lower concentrations of plasma thiobarbituric acid reactive substances than those fed ITM during the whole study period, but plasma thiobarbituric acid reactive substances were not different between HTM and ITM/OTM. Plasma haptoglobin was lower in cows fed HTM than ITM/OTM at 1 wk postpartum. Endometrial cytology 7d postcalving and cytological endometritis as assessed on 1d between 40 and 60 d postcalving was not affected by treatment. In conclusion, supplementation with HTM sources of Zn, Cu, and Mn modulated plasma variables related to oxidative metabolism compared with supplementation with ITM; however, HTM and ITM/OTM resulted in similar responses. Furthermore, the source of trace minerals did not affect performance or uterine health in this experiment.

Growth performance and meat yields of broiler chickens fed diets containing low and ultra-low oligosaccharide soybean meals during a 6-week production period.

Two experiments were conducted to determine the effects of diets containing low oligosaccharide soybean meals (SBM) on growth performance, meat yields, and physiological variables of broilers during a 6-wk production period. In experiment 1, six hundred Ross × Ross 708 male chicks were randomly distributed to 24 floor pens (25 birds per pen; 0.09 m(2) per bird at 1 d of age). Birds were fed corn-soybean meal-poultry by-product meal-based diets with either low oligosaccharide (LOSBM) or control SBM (CSBM) from 1 to 40 d of age. In experiment 2, one thousand five hundred Ross × Ross 708 male chicks were randomly distributed to 60 floor pens (25 birds per pen; 0.09 m(2) per bird at 1 d of age). Broilers were fed corn-soybean meal-poultry by-product meal-based diets containing 1 of 3 SBM sources [CSBM, LOSBM, or ultra-low oligosaccharide SBM (ULSBM)] and formulated with moderate or reduced AMEn concentrations (25 kcal/kg reduction) resulting in a 3 × 2 factorial design. Diets were formulated using AMEn and digestible amino acid values determined from previous research utilizing the same SBM types. Variables measured consisted of BW gain, feed intake, feed conversion ratio, mortality, carcass weight and yield, abdominal fat percentage, total breast meat weight and yield, digesta viscosities and pH, plasma nonesterfied fatty acids, plasma glucose, and plasma triglycerides. In experiment 1, broilers fed diets containing LOSBM had increased BW gain (P = 0.020) and decreased (P < 0.001) feed conversion from 1 to 14 d of age. Abdominal fat percentage was higher (P < 0.001) for birds fed LOSBM vs. CSBM. In experiment 2, no differences were observed for interaction effects or main effects of energy concentration. Feed conversion ratio was lower (P < 0.001) for broilers fed diets containing ULSBM vs. LOSBM and CSBM from 1 to 28 and 1 to 42 d of age. Broilers fed diets formulated with ULSBM had higher (P < 0.05) carcass yield vs. birds fed diets with CSBM. Total breast yield was higher (P = 0.021) for birds fed diets containing LOSBM and ULSBM vs. CSBM. Abdominal fat percentage was higher (P = 0.027) for broilers fed diets containing LOSBM vs. CSBM. Diets formulated with LOSBM and ULSBM required approximately 45% less supplemental fat, and broilers fed these diets exhibited no adverse effects on growth performance and meat yields compared with broilers fed diets containing CSBM.

Apparent metabolizable energy and apparent ileal amino acid digestibility of low and ultra-low oligosaccharide soybean meals fed to broiler chickens.

Four experiments were conducted using 1,992 Ross × Ross 708 male broilers to determine AME(n) and apparent ileal amino acid digestibility (AIAAD) of low-oligosaccharide (LOSBM), ultra-low oligosaccharide (ULSBM), and control soybean meal (CSBM) fed to broilers from 20 to 31 d of age. An AME(n) assay was conducted in experiments 1 and 2, whereas AIAAD was determined in experiments 3 and 4. Chicks were randomly assigned to 3, 4, 2, or 3 dietary treatments, respectively, for experiments 1, 2, 3, or 4. The additional treatment in experiments 2 and 4 was to evaluate ULSBM. In the AME(n) assays, treatments were fed from 20 to 29 d of age and a 48-h excreta collection period was conducted from 27 to 29 d of age. Treatment 1 consisted of a basal diet and treatments 2, 3, and 4 consisted of 70% of the basal diet plus 30% CSBM, LOSBM, or ULSBM, respectively. The difference method was used to determine AME(n) utilizing an N correction factor to account for N retention. To determine AIAAD, broilers were fed semi-purified diets with CSBM, LOSBM, or ULSBM as the sole source of amino acids (AA) from 26 to 31 d of age with digesta collection occurring at 31 d of age. In experiment 1, LOSBM had 194 kcal/kg more AME(n) compared with CSBM (P = 0.011). Apparent ME(n) value of LOSBM was 141 and 134 kcal/kg higher (P = 0.012) compared with CSBM and ULSBM, respectively, in experiment 2. Digestible Lys, Met, Ile, and Val concentrations were higher (P < 0.001) for LOSBM vs. CSBM in experiment 3 even though digestibility coefficients were lower (P < 0.001) for LOSBM. In experiment 4, higher (P < 0.001) concentrations of digestible Met, Lys, Thr, Val, and Ile were observed for ULSBM and LOSBM compared with CSBM. In conclusion, genetically selected soybean meals with reduced stachyose and raffinose concentrations had higher AME(n) and AIAAD values compared with CSBM.

Determinants of success in treating cervical intraepithelial neoplasia.

OBJECTIVE: To determine the important factors affecting the long-term failure rate of treatment for cervical intraepithelial neoplasia (CIN). DESIGN: Multivariate analysis of prospectively collected clinical data. SETTING: Colposcopy clinic in a university teaching hospital. POPULATION: A total of 2455 consecutive women treated for CIN for the first time between 1 January 1989 and 31 December 2004 using excisional techniques. METHODS: The data were obtained from a clinical database into which information had been entered prospectively. Data on community follow-up were obtained from the national Exeter database of cervical screening results. The parameters studied were age, parity, severity of the lesion, extent to which the lesion involved the endocervical canal, seniority of the surgeon, type of treatment, anaesthesia used, dimensions of the treatment biopsy specimen, number of treatment biopsy fragments and completeness of excision. MAIN OUTCOME MEASURES: High-grade post-treatment cervical disease detected by biopsy or cytology. RESULTS: Univariate analysis eliminated several potential factors and identified interactions between some factors. Multivariate analysis identified the grade of disease (P < 0.001) and the extent to which the lesion involved the endocervical canal (P =0.008) as the most important determinants of high-grade post-treatment disease. Of the factors which the surgeon could control, depth of biopsy (P =0.002) and completeness of excision (P = 0.007) were the most important. CONCLUSIONS: This study confirms that clear margins are important to reduce the failure rate of excisional treatment for CIN. An adequate depth of treatment is important when the lesion involves the endocervical canal.

A long-term study of women with normal colposcopy after referral with low-grade cytological abnormalities.

BACKGROUND: About 50,000 women are referred annually to colposcopy in England because of a low-grade smear. About 35% of these women have no colposcopic abnormality but are followed up in the colposcopy clinic because of uncertainty about the risk of significant pathology. OBJECTIVE: This study determined the 5-year rate of disease when initial colposcopy was normal and smear was non-dyskaryotic. DESIGN: Retrospective study. SETTING: Colposcopy clinic of an inner city postgraduate teaching hospital. Population Two thousand one hundred and fifty seven women referred between January 1990 and December 2001 with mild dyskaryosis (Low Grade Squamous Intraepithelial Lesion [LSIL]) or borderline nuclear changes (Abnormal Squamous Changes of Uncertain Significance [ASCUS]). METHODS: Information was obtained from the colposcopy clinic database and Open-Exeter. Time plots of the disease-free rates were generated using the Kaplan-Meier method, and statistical comparisons were performed using Cox regression. MAIN OUTCOME MEASURES: Cumulative rates of cytological and histological abnormalities. RESULTS: High-grade or invasive disease was diagnosed histologically in 12.8% of 805 women referred with borderline nuclear changes and in 35.8% of 1352 referred with mild dyskaryosis. Among 620 women with normal colposcopy and a negative or borderline repeat smear, high-grade disease was found after 5 years of follow up in 1.3% of women originally referred with a borderline smear and in 8.5% referred because of mild dyskaryosis. CONCLUSION: Women referred to colposcopy with borderline nuclear changes or mild dyskaryosis whose colposcopy findings are normal and whose repeat smear in the clinic is non-dyskaryotic may be discharged for routine 3-yearly screening in the community because the risk of high-grade disease in the next 5 years is small.

Estimation of the true ileal digestible lysine and sulfur amino acid requirement and comparison of the bioefficacy of 2-hydroxy-4-(methylthio)butanoic acid and DL-methionine in eleven- to twenty-six-kilogram nursery pigs.

Three experiments were conducted to determine the true ileal digestible (TID) Lys and sulfur AA (SAA) requirement and to compare the bioefficacy of 2-hydroxy-4-(methylthio)butanoic acid (HMTBA) and dl-MET as Met sources in nursery pigs. Experiment 1 included 2 studies: 1 was 662 nursery pigs (Triumph 4 x PIC C22; initial BW 12.2 +/- 0.18 kg) allotted to 1 of 5 dietary treatments with TID Lys concentrations ranging from 1.10 to 1.50%; and the second study was 665 nursery pigs (Triumph 4 x PIC C22; initial BW 12.3 +/- 0.18 kg) allotted to 1 of 5 dietary treatments with TID SAA concentration ranging from 0.63 to 0.90%. In Exp. 2, 638 nursery pigs (Triumph 4 x PIC C22; initial BW 13.0 +/- 0.16 kg) were allotted to the same 5 SAA dietary treatments as in Exp. 1. In Exp. 3, 1,232 pigs (Triumph 4 x PIC C22; initial BW 11.0 +/- 0.30 kg) were allotted to 1 of 7 dietary treatments. The basal diet (diet 1) was supplemented with high concentrations of synthetic AA but no Met; this resulted in a dietary concentration of TID Lys of 1.30% and TID SAA of 0.50%. Diets 2 to 7 were the basal diet supplemented with 3 equimolar levels of HMTBA or dl-MET to provide TID SAA concentrations of 0.56, 0.62, and 0.68%, respectively. In Exp. 1, increasing TID Lys from 1.10 to 1.50% increased ADG (quadratic; P < 0.05) and improved G:F (linear; P < 0.002). The pooled data of Exp. 1 (SAA study) and Exp. 2 indicated that increasing TID SAA from 0.63 to 0.90% increased ADG (quadratic; P < 0.01) and improved G:F (quadratic; P < 0.01). Various methods of analyzing the growth response surface indicated that the optimal TID Lys concentration ranged from 1.28 to 1.32% for ADG (Exp. 1), and the optimal TID SAA concentration ranged from 0.73 to 0.77% for ADG and 0.80 to 0.83% for G:F (pooled Exp. 1 and 2), respectively. In Exp. 3, increasing TID SAA concentrations from 0.50 to 0.68% resulted in a linear improvement of ADG (P < 0.001), ADFI (P < 0.05), and G:F (P < 0.001). The best fit comparison of HMTBA and dl-MET was determined by the Schwartz Bayesian Information Criteria index, which indicated the average relative efficacy of HMTBA vs. dl-MET was 111%, with 95% confidence interval of 83 to 138%, within the range of TID SAA tested. Thus, the TID Lys and SAA requirements of modern lean-genotype pigs from 11- to 26-kg were greater than the 1998 NRC recommendations, and both HMTBA and dl-MET as Met sources can supply equimolar amounts of Met activity.

Estimation of the ideal ratio of true ileal digestible sulfur amino acids:lysine in 8- to 26-kg nursery pigs.

Four experiments were conducted to determine the ideal ratio of true ileal digestible (TID) sulfur AA to Lys (SAA:LYS) in nursery pigs at two different BW ranges using both DL-Met and 2-hydroxy-4-(methylthio)-butanoic acid (HMTBA) as Met sources. In Exp. 1, 1,549 nursery pigs (Triumph 4 x PIC Camborough 22; initial BW 8.3 +/- 0.08 kg) were allotted to one of nine dietary treatments. The basal diet (Diet 1) was a semicomplex corn-soybean meal-based diet (1.32% TID Lys) with no supplemental HMTBA or DL-Met (47.7% TID SAA:LYS). Diets 2 to 9 consisted of the basal diet supplemented with four equimolar levels of DL-Met or HMTBA (52.7, 57.7, 62.7, and 67.7% TID SAA:LYS). In Exp. 2, 330 nursery pigs (Triumph 4 x PIC Camborough 22; initial BW 11.4 +/- 0.10 kg) were allotted to one of nine dietary treatments. The basal diet (Diet 1) was a corn-soybean meal-based diet (1.15% TID Lys) with no supplemental HMTBA or DL-Met (49% TID SAA:LYS). Diets 2 to 9 consisted of the basal diet supplemented with four equimolar levels of DL-Met or HMTBA (54, 59, 64, and 69% TID SAA:LYS). In Exp. 3, 1,544 nursery pigs (Triumph 4 x PIC Camborough 22; initial BW 12.4 +/- 0.13 kg) were allotted to one of nine dietary treatments as in Exp. 2. In Exp. 4, 343 nursery pigs (Genetiporc; initial BW 12.8 +/- 0.56 kg) were allotted to one of six dietary treatments. The basal diet (Diet 1) was a corn-soybean meal-based diet (1.05% TID Lys) with no supplemental DL-Met (49% TID SAA:LYS). Diets 2 to 5 consisted of the basal diet supplemented with four levels of DL-Met (54, 59, 64, and 69% TID SAA:LYS), and Diet 6 was the basal diet supplemented with one equimolar level of HMTBA to satisfy 59% TID SAA:LYS ratio. In all experiments, increasing the TID SAA:LYS ratio resulted in quadratic improvements in ADG (P < or = 0.09) and G:F (P < or = 0.05). Three different methods were used to estimate the optimal TID SAA:LYS ratio for each experiment. The two-slope broken-line regression model, x-intercept value of the broken-line and quadratic curve, and 95% of upper asymptote across the four experiments indicated that the average optimal TID SAA:LYS ratios were 59.3, 60.1, and 57.7% for ADG and 60.6, 61.7, and 60.1% for G:F, respectively. Thus, the optimal TID SAA:LYS ratio for 8- to 26-kg pigs based on the average value of these three estimates was 59.0% for ADG and 60.8% for G:F.

Route learning performance in Alzheimer disease patients.

OBJECTIVE: To examine performance on an objective measure of route learning in Alzheimer disease (AD) patients. BACKGROUND: Topographic disorientation (TD) is a common problem among AD patients. The underlying cognitive deficits that contribute to TD in AD patients are not well understood. METHOD: This study examined 19 healthy older individuals (controls) and 16 AD patients who were administered a comprehensive neuropsychological battery along with a novel Route Learning Test (RLT). Areas assessed included incidental learning, spatial relations. recall of the walking route, and recognition of landmarks. RESULTS: Despite comparable performance on basic visuospatial ability measures, AD patients performed significantly worse than controls on the RLT and evidenced poor incidental learning for environmental details. A measure of egocentric and allocentric orientation ability was the best predictor of RLT performance in AD patients. Among RLT subtests, AD patients performed best on recognition of landmarks compared with recognition and recall of spatial layout or recognition of incidental items in the environment. CONCLUSIONS: Our findings suggest that poor performance on the RLT in AD patients is characteristic of poor spatial orientation or spatial reasoning. Therefore, episodes of TD in AD patients may occur secondary to poor spatial orientation.

Effects of muscarinic and adrenergic agonism on auditory P300 in the macaque.

Homologs of human endogenous evoked potentials are known in several species of nonhuman primates, but the neurotransmitter substrates of these potentials remain uncertain. In particular, the role of central cholinergic and adrenergic systems is not yet clearly defined. We recorded cognitive evoked potentials from the scalp in four adult bonnet macaque monkeys during a passive version of the auditory oddball paradigm with unique novel stimuli under saline control conditions. In two subjects each, cognitive evoked potentials were also recorded following intramuscular administration of the m1 muscarinic agonist AF102B or of the alpha-2A noradrenergic agonist guanfacine. On saline, large positivities resembling the human P300 were recorded over midline sites in response to rare or novel auditory stimuli in all four monkeys. The amplitude of these positivities was sensitive to the delivery of fruit-juice reward in association with rare stimuli in three monkeys tested. At cognition-enhancing doses, AF102B enlarged the amplitude of P300-like positivities in both monkeys tested; guanfacine enlarged the amplitude of P300-like positivities in one of two monkeys tested. These results add to existing evidence of human-like endogenous late positivities in monkeys that are influenced by the cholinergic and adrenergic systems, and suggest a possible role of m1 muscarinic and alpha-2A noradrenergic receptor subtypes.

Eye movement abnormalities during reading in patients with Alzheimer disease.

OBJECTIVE: This goal of this study was to evaluate reading ability by assessing eye movements during reading among patients with Alzheimer disease (AD) compared with normal elderly controls. BACKGROUND: Reading is disturbed in patients with AD. These patients may have changes in reading ability early in the course of their disease before clinical alexia or abnormalities are apparent on standard reading tasks. METHOD: Reading competence was evaluated by recording eye movements during reading in 14 patients with mild to moderate clinically probable AD and 14 age- and education-matched controls. RESULTS: All patients with AD could recognize letters and words and could understand written material of similar difficulty. Despite successful reading comprehension among the patients with AD, their oculographs showed slowed reading and irregular eye movements. Compared with controls, the patients with AD did not differ in saccadic duration; however, they had significantly longer fixation times, more forward saccades per line of text, and more saccadic regressions. In addition, increased reading difficulty significantly correlated with a scale of dementia severity in the patients with AD. CONCLUSIONS: This pattern of eye movements corresponds to increased text difficulty and probably represents difficulty with lexical-semantic access in AD. These results suggest that disordered eye movements can signal difficulties in reading ability in AD even before complaints of reading difficulty or abnormalities on reading tests and may be a means of identifying linguistic impairment early in this disorder.

Dementia with leukoaraiosis: clinical differentiation by temporoparietal hypometabolism on (18)FDG-PET imaging.

Patients with dementia and leukoaraiosis may have either Alzheimer's disease (AD) with cerebrovascular changes or a form of vascular dementia (VaD). The presence or absence of the characteristic AD pattern of bilateral temporoparietal hypometabolism on (18)FDG-PET was used to differentiate 30 patients with progressive dementia and severe leukoaraiosis. Compared to 18 patients with the typical AD pattern (group I), the remaining 12 (group II) had better recognition memory, and greater difficulty with sustained attention and serial reversals. Better recognition memory, confluent periventricular leukoaraiosis, and poorer sustained attention distinguished all group II patients from group I. Dementia patients with severe leukoaraiosis and bilateral temporoparietal hypometabolism may have predominant AD; those who lack this pattern and have confluent leukoaraiosis may have a greater contribution from VaD. Copyrightz1999S.KargerAG,Basel

Follicle-stimulating hormone and testosterone stimulation of immature and mature Sertoli cells in vitro: inhibin and N-cadherin levels and round spermatid binding.

The in vitro response of Sertoli cells isolated from adult rat testes to testosterone (T) and follicle-stimulating hormone (FSH) treatment was investigated. Sertoli cells from >70-day-old Sprague-Dawley rats were isolated by a combined enzymatic treatment followed by the removal of the majority of contaminating germ cells with immobilized peanut agglutinin lectin. Sertoli cells were then cultured for 6-10 days, forming a confluent layer with a cell viability of >83% and 74-77% purity. The contaminating cells were peritubular cells (4-6%), pachytene spermatocytes (4-5%), round spermatids (<2%), elongated spermatids (<1%), and degenerating germ cells (14.8%). The proportion of degenerating germ cells decreased from 14.8% to 8.6% between days 6 and 10 in culture. After a prestimulation culture period of 4 days, FSH treatment over a 2-day period resulted in a dose-related increase of inhibin with a median effective dose (ED50) value of 36.7+/-20.4 ng/ml in comparison with an ED50 value of 4.4+/-0.9 ng/ml obtained with immature Sertoli cell cultures from 20-day-old rats. Mature Sertoli cells, in contrast to immature Sertoli cells, were unresponsive to combined FSH + T treatment for the production of the cell adhesion protein N-cadherin. FSH treatment promoted the in vitro binding of round spermatids isolated from adult testis to adult Sertoli cells in coculture. It is concluded that mature Sertoli cells in culture are responsive to FSH in terms of inhibin production and round-spermatid binding. The lack of an FSH + T-induced increase in N-cadherin or round spermatid binding is attributed to either a reduced sensitivity, or an alteration in the regulation of mature Sertoli cells by FSH + T.

Performance on the Rey-Osterrieth Complex Figure Test in Alzheimer disease and vascular dementia.

BACKGROUND: Alzheimer disease (AD) and vascular dementia (VaD) are the two most common age-associated dementias. Neuropsychologic studies have demonstrated visuoconstructional impairment in AD and in VaD. OBJECTIVE: This study used the Rey-Osterrieth Complex Figure to assess and compare specific aspects of visuoconstructional deficits in patients with AD, patients with VaD, and normal age-matched subjects. METHOD: Thirteen normal controls, 20 patients with AD, and 20 patients with VaD were given a neuropsychologic battery as part of a comprehensive evaluation for dementia. The groups were similar in age and education, and the VaD and AD groups had comparable levels of dementia. Based on their previous research on visual deficits in AD, the authors devised a new scoring system that divided the Rey-Osterrieth Complex Figure into six perceptual categories: right, left, upper, lower, basic gestalt, and inner detail. RESULTS: Patients with AD and patients with VaD had significant deficits in all six Rey-Osterrieth Complex Figure scoring categories compared with normal controls. Patients with AD exhibited a pattern of deficits similar to that of patients with VaD, with one significant exception: The patients with AD had increased left-sided errors or inattention. CONCLUSIONS: These results suggest that left hemispatial inattention contributes to impaired performance on visuoconstructional tasks in AD.