Growth performance and gastrointestinal responses in heavy Tom turkeys fed antibiotic free corn-soybean meal diets supplemented with multiple doses of a single strain Bacillus subtilis probiotic (DSM29784)1.

Growth performance and gastrointestinal (GIT) responses to a single-strain of Bacillus subtilis (SSB) were investigated using 960 Hybrid Converter Toms. A total of 4 iso-caloric and iso-nitrogenous corn-soybean meal-based diets were allocated to 12 replicate cages/pens and fed (ad libitum) in a four-phase feeding program (starter; days 0 to 28, grower-1; days 29 to 56, grower-2; days 57 to 84, and finisher; days 85 to 126). The diets had either 0 (control), 1E+08 (low), 2E+08 (mid) or 1E+09 (high) cfu B. subtilis/kg. Feed intake (FI) and BW were recorded by phase. Excreta samples were collected towards the end of starter and grower-1 phases for apparent retention (AR) of components by marker method and litter moisture, respectively. Selected birds were necropsied on days 28 and 56 for GIT weight and samples for jejunal histomorphology and ceca digesta short chain fatty acids (SCFA). Supplemental SSB had linear and non-linear (P < 0.05) response on BW gain (BWG). Specifically, relative to the control, birds fed low SSB had higher BWG in starter and grower-1 phases whereas bird fed mid and high SSB had lower BWG in grower-2 and birds fed low and mid SSB had higher BWG in finisher phase. Consequently, birds fed low and mid SSB doses were heavier (P < 0.05) than control fed birds at the end of trial. The FCR response to SSB was linear and non-linear (P < 0.05) with birds fed low SSB showing lower FCR than control fed birds in starter, grower-1 and finisher phases. Supplemental SSB had linear and non-linear (P < 0.05) effects on AR of components (DM, ash, crude protein, crude fat, neutral detergent fiber, and gross energy), litter moisture, GIT weight, jejunal histomorphology, and SCFA. Relative to control, birds fed high SSB showed higher AR of components, villi height, day 56 ceca digesta total SCFA concentration, and lower litter moisture. In conclusions, under condition of the current study, growth performance was optimized by low to mid SSB. Improved nutrient retention and indices of gut health suggested higher SSB doses may optimize growth performance under challenging farm conditions.

Effect of dietary supplementation of Bacillus subtilis DSM29784 on hen performance, egg quality indices, and apparent retention of dietary components in laying hens from 19 to 48 weeks of age.

The aim of the current study was to evaluate egg production, quality, and apparent retention (AR) of components in response to a multi-dose application of a single strain Bacillus subtilis (SSB; DSM29784) in a corn-soybean meal basal diet fed to hens (19 to 48 wk of age). The treatments consisted of a basal diet with either no probiotic (control, CON), 1.1E+08 (low, LSSB), 2.2E+08 (medium, MSSB) or 1.1E+09 (high, HSSB) CFU/kg of diet. A total of 336, 19-wk old Shaver White layers were used at a stocking density of 7 and 6 hens/replicate-cage in layer I (week-19 to 28) and layer II (week-29 to 48) phases, respectively. Evaluated variables included feed intake (FI), body weight (BW), feed conversion ratio (FCR), egg production, weight, mass, and egg quality (shell thickness, shell breaking strength, albumen height (AH), and Haugh unit (HU)). Excreta was collected at the end of week-28 for AR of components and apparent metabolizable energy (AME). Supplementation of SSB increased (P = 0.008) FI during peak egg-lay (week-24) and BW increased linearly (P = 0.019) in early layer II (week-32). In layer I, LSSB compared with CON increased EM (g/egg) by 3.3% (P = 0.049). In layer II, SSB inclusion tended to improve FCR (linear, P = 0.094; g FI: g EM). Although shell breaking strength was lowest at week-20 with HSSB (4.518 vs. 4.889 kgf for HSSB vs. CON; P = 0.045), AH and HU were improved at higher dose of SSB, in both phases (P ≤ 0.005). Apparent retention of dry matter, AME, and minerals were improved (P < 0.0001) in a dose response. Hence, while the low dose of B. subtilis DSM29784 improved hen performance and maintained egg quality in both phases, a higher dose of SSB improved the interior protein quality of eggs (AH and HU).

Growth performance, apparent retention of components, and excreta dry matter content in Shaver White pullets (5 to 16 week of age) in response to dietary supplementation of graded levels of a single strain Bacillus subtilis probiotic.

Administered in adequate amounts, probiotics can be an alternative to antibiotic growth promoters in poultry production. This study evaluated dose response of a single strain of Bacillus subtilis (SSB, DSM29784) on growth performance, apparent retention (AR) of components, and excreta DM content in pullets. A basal corn-soybean meal diet was formulated to meet the specifications for grower (week 5 to 10) and developer (week 11 to 16) phases. In each phase, SSB was added to the basal diet to create 4 test diets: 0 (control, CON), 1.1E+08 (low; LSSB), 2.2E+08 (medium; MSSB), or 1.1E+09 (high; HSSB) CFU of SSB/kg of feed. All diets had TiO2 (0.5%) as a digestibility marker. A total of 720 day-old Shaver White chicks were placed in 48 cages (15 pullets per cage) and reared on a commercial antibiotic free diet for a 4-wk period. At the beginning of week 5, treatments were allocated based on cage BW (n = 12). Birds had free access to feed and water throughout. The BW, BW uniformity, feed intake (FI) and FCR were obtained weekly. Excreta was collected at the end of each phase for AR of DM, organic matter, CP, neutral detergent fiber, minerals, and AME, as well as excreta DM content. In response to SSB inclusion, BW improved in a linear (P < 0.005) and quadratic (P < 0.0001) manner in grower. FI decreased in a linear and quadratic pattern (P < 0.05, week 8 to 10) in grower, and linearly (P < 0.05) across the developer phase. Overall FCR improved in linear and quadratic pattern (P < 0.01) in the grower phase. In both the phases, AME improved in a quadratic pattern (P < 0.05). Inclusion of SSB had a linear reduction (P < 0.0001) in excreta moisture content in the grower phase. In summary, these results demonstrate that B. subtilis probiotic improved performance through enhanced nutrient utilization and reduced excreta moisture content indicating improved pullet gut health.

Evaluation of different dietary alterations in their ability to mitigate the incidence and severity of woody breast and white striping in commercial male broilers.

The following study was conducted to define how multiple nutritional strategies affect broiler performance, meat yield, and the presence and severity of white striping (WS) and woody breast (WB) in high-yielding broilers. Relative to a commercial set of reference broiler diets (Commercial reference diet; Trt 1) that were fed in a 4-phase program, the following nutritional strategies were investigated: increasing the ratio of digestible arginine: digestible lysine (dArg: dLys ranged from 113 to 126; Trt 2), supplementing Trt 1 with 94.4 mg vitamin C/kg feed (Trt 3), doubling the vitamin pack inclusion rate (Trt 4), reducing the digestible amino acid density (dAA) of only the grower phase by 15% and feeding the same Trt 1 starter, finisher, and withdraw diets (Trt 5), and combining the 4 strategies just mentioned (Trt 6). There was no difference in performance at the end of the starter phase (P = 0.066); however, at the end of the grower and finisher phases, feeding lower dAA grower diets suppressed BW (Trts 5 and 6; P < 0.001) and increased FCR. Differences in performance amongst all treatments disappeared at day 49 (P = 0.220). No differences were observed in average breast weight (P = 0.188); however, breast yield (as a % of live weight) was greatest for Trt 1 and least for Trt 6 (P = 0.041). The WB score dropped from 1.83 in Trt 1 to 1.49, 1.27, 1.74, 1.53, and 1.43 in treatments 2 to 6, respectively (P = 0.018). These changes were the result of a shift in WB score, where the WB class that contained scores of 2 and 3 shifted from 61.3% in Trt 1 to 49.3, 35.9, 60.0, 50.8, and 38.7 in treatments 2 to 6, respectively. Given the FCR, breast weight data and the fact that high WB scores result in a devaluation of breast meat, feeding a higher ratio of dArg: dLys, higher vitamin C, or lower dAA in the grower phase results in better breast meat quality and value.

Comparison of hydrated sodium calcium aluminosilicate and yeast cell wall on counteracting aflatoxicosis in broiler chicks.

The objective of this research was to determine the efficacy of 2 types of adsorbents [hydrated sodium calcium aluminosilicates (HSCAS) vs. a combination of clay and yeast cell wall] in preventing aflatoxicosis in broilers. A total of 275 one-day-old birds were randomly divided into 11 treatments, with 5 replicate pens per treatment and 5 chicks per pen. The 11 treatments included 3 diets without any adsorbent containing either 0, 1, or 2 mg/kg of aflatoxin B1 (AFB1) plus 8 additional treatments employing 2 dietary levels of AFB1 (1 or 2 mg/kg), 2 different adsorbents [Solis (SO) and MTB-100 (MTB)], and 2 different levels of each absorbent (0.1 and 0.2%) in a 2×2×2 factorial arrangement. Solis is a mixture of different HSCAS and MTB is a combination of clay and yeast cell wall. Feed and water were provided ad libitum throughout the 21-d study period. Body weight gain and feed intake were depressed and relative liver weight was increased in chicks fed AFB1 compared with the positive control (P<0.05). Severe liver damage was observed in chicks fed 2 mg/kg of AFB1 with lesions consistent with aflatoxicosis, including fatty liver and vacuolar degeneration. Serum glucose, albumin, total protein, Ca, P, and alkaline phosphatase concentrations were reduced by AFB1 (P<0.05). The addition of either SO or MTB ameliorated the negative effects of 1 mg/kg of AFB1 on growth performance and liver damage (P<0.05). However, supplemental MTB failed to diminish the negative effects of 2 mg/kg of AFB1, whereas SO was more effective compared with MTB at 2 mg/kg of AFB1 (P<0.05). These data indicate that the HSCAS product effectively ameliorated the negative effect of AFB1 on growth performance and liver damage, whereas the yeast cell wall product was less effective especially at the higher AFB1 concentration.

Graded levels of phytase past industry standards improves broiler performance.

This study evaluated the overall performance of 0-to-16-d-old, mixed-sex, Cobb x Cobb broiler chicks when dietary phytase levels were supplemented in excess of industry standards. The experimental diet used consisted of a basal corn-soybean meal diet that contained an analyzed 22.2% CP, 0.88% Ca, a deficient total P (tP) level of 0.46% (phytate P = 0.272%), and calculated ME of 3.123 kcal/g diet on an as-is basis. In addition to a positive control diet [0.70% tP], the dietary phytase levels evaluated were 0, 93.75, 187.5, 350, 750, 1,500, 3,000, 6,000, and 12,000 U/kg of diet. Supplementing phytase from 0 to 12,000 U significantly increased body weight gain from 287 to 515 g/chick, feed intake from 381 to 595 g/chick, gain to feed from 0.755 to 0.866, plasma P from 2.5 to 7.1 mg/100 mL, tibia ash from 26 to 41%, tibia ash weight from 0.200 to 0.601 g/tibia, tP retention from 51 to 80%, phytate P disappearance from 40% to 95%, apparent N retention from 58 to 78%, AMEn from 3,216 to 3,415 kcal/kg diet, and reduced P rickets from 80 to 3%. Using nonlinear regression analysis on log-transformed phytase levels, gain to feed, apparent N retention, and AME, responded linearly with respective R2 values of 0.76, 0.82, and 0.72, whereas body weight gain, feed intake, plasma P, P rickets, tP retention, phytate P disappearance, tibia ash percentage, and tibia ash weight responded quadratically with respective R2 values of 0.93, 0.88, 0.85, 0.84, 0.91, 0.96, 0.96, and 0.98. Few statistical differences existed between response data for broilers consuming the positive control diet or diets containing 1,500 to 12,000 U of phytase (P > 0.05). This finding indicates that broilers consuming a tP-deficient corn-soybean meal diet can achieve maximum performance when phytase is supplemented to 12,000 U/kg diet and that current phytase supplementation levels within the poultry industry may need to be reevaluated.

Power of two methods for the estimation of bone ash of broilers.

An experiment was conducted to compare two common methods of estimating bone ash from growing broiler chicks (A = autoclaving; B = boiling/extracting). Ross x Ross 1-d-old broiler chicks were fed a corn-soy, phosphorus-deficient diet (22.7% CP, 1% calcium, 0.22% non-phytate phosphorus), with 0, 750, 1,500, 3,000, or 6,000 units of phytase (FTU) to produce bones with a range of ash. The methods were compared with bones from chicks at 7, 14, and 21 d of age. Left legs were used for method B, and right legs were used for method A. Data was analyzed by the general linear models procedure of SAS software, and differences between means were detected using the Duncan's new multiple range test at the 0.05 level. Variance estimates were the mean square errors (from SAS outputs). Sample sizes needed to detect a 2% difference in bone ash were calculated using the method of Zar. The addition of 6,000 FTU/kg increased tibia ash from 26 to 37%, 29 to 41%, and 33 to 43% on Days 7, 14 and 21, respectively (method B). With bones from 7-d-old chicks, the same number of samples was necessary to detect a 2% difference using methods A and B. With bones from 14- and 21-d-old chicks, approximately 50 and 150% more samples were necessary, respectively, using method A. The autoclaving method is less labor-intensive and requires no toxic solvents, but for older birds, many more samples or replications are needed to detect the same treatment differences.

The expression of calbindin in chicks that are divergently selected for low or high incidence of tibial dyschondroplasia.

Three experiments were conducted with broiler chicks that were divergently selected for low or high incidence of tibial dyschondroplasia (LTD and HTD, respectively) to determine if the expression of intestinal calbindin-28 kD mRNA and protein differed between the 2 strains. In addition, levels of intestinal vitamin D receptor mRNA and plasma thyroid hormone concentrations were also examined. In experiment 1, LTD and HTD chicks were fed a corn-soybean meal diet that was adequate in all nutrients except cholecalciferol (D3), which was titrated to 5 or 40 microg/kg diet in a completely randomized 2 x 2 factorial arrangement. At 4 and 8 d of age, HTD chicks fed 5 microg of D3/kg of diet had a lower (P < 0.05) expression level of calbindin-28 kD mRNA than the LTD chicks fed the same diet. At 4 and 8 d of age, HTD chicks fed 5 microg of D3 had the lowest intestinal expression of calbindin-28 kD protein. Expression of vitamin D receptor mRNA did not differ for broiler strains at either level of D3 supplementation. In experiment 2, there was no significant difference in the expression of calbindin-28 kD mRNA or vitamin D receptor mRNA between day-of-hatch LTD, HTD, and commercial broiler chicks. Experiment 3 was similar in design to the first experiment except that the birds were fed for 18 d. Calbindin-28 kD and vitamin D receptor mRNA expression levels at 18 d were similar to those observed in experiment 1. Plasma triiodothyronine and free-triiodothyronine concentrations were greater for LTD chicks, regardless of dietary D3 supplementation levels. These results suggest that divergent selection of broilers for LTD or HTD alters the physiological response to nutritionally inadequate levels of dietary D3.

Quantitative evaluation of 1-alpha-hydroxycholecalciferol as a cholecalciferol substitute for broilers.

Two experiments were conducted using a corn-soybean meal diet that meets or exceeds the NRC (1984) requirements for all nutrients except cholecalciferol (D3) to determine the effectiveness of 1-alpha-hydroxycholecalciferol (1alpha-OHD3) as a substitute for D3 in the diet of young broilers. Ross x Ross mixed-sex, 1-d-old chicks were reared in Petersime battery brooders not exposed to ultraviolet light with feed and water supplied ad libitum for 16 d. In Experiment 1, D3 was fed at 0, 2.5, 5, 10, 20, and 40 microg/kg and one source of 1alpha-OHD3-(Hoffmann-LaRoche, Inc.; HLR) was fed at 0.625, 1.25, 2.5, 5, and 10 microg/kg of diet. In Experiment 2, the D3 was fed at 0, 2.5, 5, and 10 microg and two sources of 1alpha-OHD3-[HLR and Majestic Research Inc. (MRI)] were fed at 0, 0.625, 1.25, and 5 microg/kg of diet. Slope ratio analysis of data from the measurement of 16-d body weight, plasma Ca, rickets, and bone ash indicated bioavailability of the 1alpha-OHD3 as compared to D3 from 1.88 to 21.2. Percentage bone ash gave the most precise values in both experiments. Considering all the data from both experiments, the 1alpha-OHD3 appears to be approximately eight times as effective as D3 for satisfying the requirements of several criteria in two experiments with broiler chickens.

Effect of ash content on protein quality of meat and bone meal.

The effect of ash concentration on amino acid (AA) composition, true AA digestibility, and protein efficiency ratio (PER; weight gain per unit of protein intake) of meat and bone meal (MBM) was evaluated. Commercially rendered MBM samples containing 16 to 44% ash were obtained from two sources. Additional samples of MBM varying in ash from 9 to 63% were obtained by chloroform floatation or lab screening of a beef crax sample. Protein quality of selected MBM samples was assessed by determining true AA digestibility using the precision-fed cecectomized rooster assay and by a PER chick growth assay wherein chicks were fed 10% CP diets containing a MBM as the only source of dietary protein from 8 to 18 d of age. Increases in Ala, Pro, Gly, and Arg as a percentage of CP were observed in all MBM samples as ash percentage increased, with Pro and Gly accounting for most of the increase. In contrast, the levels (% of CP) of all essential AA, other than Arg, decreased as ash level increased. For example, Lys concentrations per unit of CP decreased from 5.7 to 4.0% as ash increased from 9 to 63%. There was little or no effect of ash content on AA digestibility of MBM varying in ash from 9 to 44%. The PER of MBM markedly decreased from 3.34 to 0.72 as ash increased from 16 to 44%, and most of the effects of ash on PER were not due to differences in dietary Ca and P levels. The results indicate that the reduction in protein quality of MBM as ash content increases is almost entirely due to a decrease in analyzed essential AA per unit of CP, not a decrease in digestibility of AA.

The effects of various dietary levels of phytase and available phosphorus on performance of laying hens.

Data previously obtained from our laboratory indicated that addition of 300 U of phytase/kg diet supported optimal long-term performance of laying hens (20 to 70 wk) fed a corn-soybean meal (SBM) diet containing 0.10% available phosphorus (AP). Our primary objective was to determine if a phytase level lower than 300 units/kg is adequate for a commercial strain of Single Comb White Leghorn laying hens (n = 504) fed a corn-SBM diet containing no supplemental P (0.10% AP). Dietary treatments consisted of the corn-SBM basal diet (0.10% AP, 3.8% Ca, and 17% CP) supplemented with 0, 100, 200, 250, or 300 U of phytase/kg, 0.05% inorganic P (0.15% AP), and a positive control diet containing 0.45% AP. Each of the seven dietary treatments was fed to six replicate groups of 12 hens from 20 to 60 wk of age. No significant differences in performance were observed among treatments during the first 8 wk of the experiment. By 28 wk of age, the 0.10% AP diet, with no supplemental phytase or P, resulted in significantly lower (P < 0.05) egg production and body weight compared with all other dietary treatments. Feed consumption, feed efficiency, and egg yield were subsequently depressed by 32 wk of age in hens fed the 0.10% AP diet. No other significant differences among treatments were observed for performance averaged over the entire 40-wk experimental period. The mean daily AP intake of hens fed the 0.15% AP, 0.45% AP, and 0.10% AP + phytase diets was 155, 474, and 103 mg, respectively. The results of this study indicate that phytase improves the utilization of P in corn-SBM diets for laying hens and that corn-SBM diets containing 0.10% AP + 100 units of phytase/kg diet or 0.15% AP supported egg production performance that was not significantly different (P > 0.05) from that of hens fed a corn-SBM diet containing 0.45% AP.

Effect of pressure processing on amino acid digestibility of meat and bone meal for poultry.

In the future, it may become desirable or required to process meat and bone meal (MBM) under pressure to reduce human health concerns associated with bovine spongiform encephalopathy (BSE). Therefore, three experiments evaluated the effects of different processing pressures on the digestibility of amino acids (AA) in MBM when the pressure processing was done after typical rendering (Experiments 1 and 2) or during the initial rendering process of raw materials (Experiment 3). Processing pressures varied from 0 to 60 psi in experimental or commercial feather meal cookers. Increasing pressure during processing reduced MBM Cys concentrations in Experiments 1 and 2. True digestibilities of most AA were significantly decreased by increasing pressures in Experiments 1 and 2, and reductions were generally largest for Cys and Lys, particularly Cys, and increased with severity as pressure increased. For example, in Experiment 1, Cys digestibility decreased from 65 to 50 to 15%, and Lys digestibility decreased from 76 to 68 to 41% as the MBM was processed at 0, 30, and 60 psi, respectively, for 20 min. When the pressure processing occurred during the initial rendering of the MBM raw material (Experiment 3), a significant reduction in digestibility of most AA was observed only at 60 psi, and the decrease was much less than that observed in Experiments 1 and 2. Our results indicate that pressure processing of MBM decreases the digestibility of AA for poultry. Thus, pressure processing of MBM to reduce potential BSE infectivity will likely decrease the nutritional value of the MBM.

Effect of interval from melengestrol acetate to prostaglandin F2 alpha on timed and synchronized pregnancy rates of beef heifers and cows.

The objective of this experiment was to determine the optimal interval from the last day of melengestrol acetate (MGA) feeding to prostaglandin F2 alpha (PGF2 alpha) treatment on pregnancy rates of beef heifers and cows. All females (149 heifers and 399 postpartum cows) were fed MGA (.5 mg) daily for 14 d and then administered PGF2 alpha (25 mg Lutalyse) 13, 15, and 17 d (Groups 1, 2, and 3, respectively) after the last day of MGA feeding. Females not in estrus the first 52 h after PGF2 alpha treatment were artificially inseminated 72 h after PGF2 alpha treatment. Females in estrus 0 to 52 h and 78 h to 6 d after PGF2 alpha treatment were inseminated at estrus. Blood sera (collected immediately before and 3 d after PGF2 alpha treatment) were assayed for progesterone concentrations. Pregnancy was determined 44 to 47 d after the 72-h AI by rectal examination. The intervals from MGA feeding to PGF2 alpha that had the highest 72-h AI pregnancy rates were 17 d for heifers (43%) and 15 d for cows (43%). Heifers with a 17-d interval had a higher (P < .05) 72-h AI pregnancy rate than heifers with 13-d and 15-d intervals, and cows with a 15-d interval had a higher (P < .05) 72-h AI pregnancy rate than cows with a 17-d interval. The 4-d synchronized pregnancy rates (the 72-h AI and the succeeding 3 d inseminations) for both heifers (44%) and cows (53%) were not different (P > .05) among groups. Fewer (P < .05) cows with a 17-d interval from MGA to PGF2 alpha had corpora lutea regression (by 72 h) after PGF2 alpha treatment than cows with 13-d and 15-d intervals. We interpret the results to indicate that the interval from MGA to PGF2 alpha treatment may influence 72-h AI pregnancy rates, that optimal intervals are 17 d for heifers and 15 d for cows, and that pregnancy rates are improved by insemination for 3 d after the 72-h AI.