Growth regulators and their reflection on different hop genotypes cultivated under in vitro conditions

Hops is a new culture in Brazil. Tissue culture can be an important technique for rapid hop propagation. This paper aims to characterize responses from different genotypes under different growth regulators through the interrelationship of response variables important to hop in vitro growth. Three genotypes were cultivated in six culture media with different combinations of growth regulators, BAP (6-benzylaminopurine), IAA (3-indolacetic acid) and GA3 (gibberellic acid). The means were compared by orthogonal contrasts and the interrelationship of the response variables was performed by path analysis. American genotypes showed favorable root development under the BAP + IAA combination, while the use of IAA improved shoot development. The origin of genotypes was important for defining the best protocol for in vitro cultivation. The path coefficient showed that the variable number of shoots has stronger direct effect on the number of nodal segments. Additionally, in tissue culture assays, the use of a covariable and proper error distribution significantly increased experimental accuracy.

Does the Bleaching Gel Application Site Interfere With the Whitening Result? A Randomized Clinical Trial

SUMMARY This study aimed to evaluate the effect of the bleaching gel application site on chromatic changes and postoperative sensitivity in teeth. Thirty patients were selected and allocated to three groups (n=10 per group), according to the location of the gel: GI, cervical application; GII, incisal application; and GIII, total facial. The amount and time of application of the 35% hydrogen peroxide (H2O2) gel were standardized. Color changes were analyzed by ΔE and Wid (bleaching index), using the values obtained in the readings conducted on a digital spectrophotometer in the cervical (CRs) and incisal regions (IRs) of the teeth. Spontaneous sensitivity was assessed using the questionnaire, and the stimulated sensitivity caused by the thermosensory analysis (TSA). The analysis occurred in five stages: baseline, after the first, second, and third whitening sessions (S), and 14 days after the end of the whitening, using the linear regression statistical model with mixed effects and post-test by orthogonal contrasts (p<0.05). Although the IR was momentarily favored, at the end of the treatment, the restriction of the application site provided results similar to those obtained when the gel was applied over the entire facial surface. Regarding sensitivity, only the GI showed spontaneous sensitivity. In the TSA, GIII had less influence on the threshold of the thermal sensation. It was concluded that the chromatic alteration does not depend on the gel application site. Spontaneous sensitivity is greater when the gel is concentrated in the cervical region (CR), and the teeth remain sensitized by thermal stimuli even after 14 days.

The application of orthogonal contrasts to determine homogeneous groups

The paper presents a modified approach to analysis of data obtained from experiments carried out according to classical factorial designs. Four examples were discussed in order to present details of proposed method. Modification of the analysis of variance presented here enables more effective use of information on how studied factors affect the means of dependent variable. The specificity of this approach is based on alternative multiple comparison procedure incorporating orthogonal contrasts to determine homogeneous groups.

Does the Inclusion of Atrazine in S-Metolachlor/Mesotrione/Bicyclopyrone Improve Glyphosate-Resistant Canada Fleabane Control in Corn?

A total of seven field studies were conducted in southwestern Ontario from 2018 to 2020 to evaluate S-metolachlor/mesotrione/bicyclopyrone (Acuron Flexi®) and S-metolachlor/atrazine/mesotrione/bicyclopyrone (Acuron®) for the control of glyphosate-resistant (GR) Canada fleabane in corn. Acuron Flexi® and Acuron® applied preplant (PP) controlled GR Canada fleabane 90-97% and 99-100%, respectively. Commonly used PP herbicides in Ontario, dicamba/atrazine + glyphosate and tolpyralate + atrazine + glyphosate controlled GR Canada fleabane 97-99%. Acuron Flexi® and Acuron® applied postemergence (POST) provided 75-92% and 92-99% control of GR Canada fleabane, respectively. Dicamba/atrazine + glyphosate and tolpyralate + atrazine + glyphosate applied POST provided 84-97% and 94-98% control of GR Canada fleabane, respectively. Glyphosate applied POST at 900 ae ha-1 provided only 35-38% control of Canada fleabane in corn. Orthogonal contrasts indicated that herbicides applied PP provided up to 10% greater control of GR Canada fleabane than POST. There was no significant difference between the low and high rates of Acuron® or Acuron Flexi® in controlling GR Canada fleabane. Acuron® controlled GR Canada fleabane 14, 9 and 7% greater than Acuron Flexi® at 4, 8, and 12 WAA, respectively. GR Canada fleabane interference with corn reduced yield up to 42%. However, there was no difference in corn yield between herbicides treatments evaluated. Orthogonal contrasts indicated that reduced GR Canada fleabane interference with PP herbicides evaluated provided 0.9 t ha-1 greater corn yield than the POST herbicides evaluated. There was no significant difference in corn yield with Acuron® or Acuron Flexi® at the lower rate or higher rates. Additionally, Acuron Flexi® applied PP provided a similar corn yield as when applied POST. Based on these results, the use of Acuron® results in improved GR Canada fleabane control than Acuron Flexi® but this did not result in an increase in corn yield. The study concludes that there is potential for Acuron Flexi® for GR Canada fleabane control in corn especially in areas where atrazine use is restricted, however additional weed control tactics may be required for acceptable control.

Extrusion Processing Modifications of a Dog Kibble at Large Scale Alter Levels of Starch Available to Animal Enzymatic Digestion

The objective of the present work was to produce dog foods from a single recipe at three levels of resistant starch (RS). The low (LS), medium (MS), and high shear (HS) foods were produced on a single-screw extruder at target screw speeds of 250, 375 and 460 rpm, respectively, and with increasing in-barrel moisture as shear decreased. Post-production, kibble measurements and starch analyses were conducted. Kibble parameters were compared by ANOVA with significance noted at p < 0.05 with a single degree of freedom orthogonal contrasts for extrusion outputs, starch analyses, and viscosity (RVA). The MS and LS kibbles exiting the extruder were denser and less expanded (p < 0.05) than the HS treatment. Resistant starch, starch cook, and raw:cooked starch RVA AUC increased linearly as shear decreased. These results confirmed that lower mechanical energy processes led to decreased starch gelatinization and greater retention of in vitro RS.

PSXVI-25 25-hydroxy-vitamin-D3 improves productive performance of grazing Nellore cattle during dry season

The aim with this trial was to evaluate three nutritional plans with the addition of 25-hydroxy-vitamin-D3 (HyD®) on performance of grazing Nellore steers in dry season. One hundred and twenty Nellore calves (iBW ± 267 kg; age, 9 mo) were randomly allocated to six paddocks (n = 20/paddock), in the following nutritional plans: mineral-proteic supplementation (PS; Fosbovi® Proteico 35; at 0.1% BW); PS with sodium monensin (PSM; Fosbovi® Proteico 35 M; at 0.1% BW); and mineral-protein-energetic supplementation (PES; Fosbovi® Proteico-Energético 25; at 0.3% BW); all three fed with or without addition of 1 mg/animal/d of 25-hydroxy-vitamin-D3 (HyD®), totaling six treatments. Both HyD® and supplements were provided by DSM Nutritional Products Brasil S.A. The intake and animal weight were collected daily and individually using an automatic feeder/scale system located in each paddock. Data were analyzed using the mixed procedure of SAS and means were compared by orthogonal contrasts (P &lt; 0.05). Animals fed PSE, when compared to PSM and PS, presented higher ADG (PSE = 0.290 vs. PSM= 0.130 and PS = 0.030 kg/day; P &lt; 0.01), FBW (PSE = 302.5 vs. PSM = 282.6 and PS = 271.7 kg; P &lt; 0.01) and supplement intake (PSE = 1.640 vs. PSM = 0.190 and PS = 0.210 kg/day; P &lt; 0.01). Additionally, regardless of nutritional strategy, HyD® supplementation increased ADG in 32 g/day (0.165 vs. 0.133 kg/day; P = 0.05) and FBW in 3.9 kg (287.5 vs. 283.6 kg; P = 0.05), compared to not-supplemented calves. No effects on supplement intake (either expressed in kg/day or %BW) were observed for HyD®. We conclude that 1 mg of HyD® can optimize performance of protein and protein-energetic supplemented cattle raised in tropical conditions during dry period.

213 Increased Standardized Ileal Digestible Isoleucine to Lysine Ratio Improved Feed Efficiency in Pigs Fed Distillers Dried Grains with Solubles from 11 to 80 kg

An experiment was conducted to determine the impact of dietary SID Ile to Lys ratio on the performance pigs from 11 to 80 kg of BW. A total of 1,092 pigs (initial BW = 11.1, SEM = 0.6 kg; 14 pens/treatment; 13 pigs/pen) were used in an 80d trial with a randomized complete block design. Dietary treatments were in a 2 x 3 factorial arrangement containing 2 levels of DDGS (0 and 25%) and 3 levels of SID Ile/Lys (0.54, 0.58, and 0.62). Energy and nutrient levels of all treatments were formulated at equal levels that met or exceeded NRC (2012) requirements. The SID Ile/Lys ratio was controlled by crystalline Ile. The MIXED procedures of SAS 9.4 were employed for statistical analysis. Orthogonal contrasts were used to test for main effects of DDGS and SID Ile/Lys. In the results, formulating with 25% DDGS decreased FBW, ADG, and ADFI (P &lt; 0.05) of growing pigs. The average FBW of treatments without and with 25% DDGS were 81.7 and 78.6 kg, respectively. The ADG of diets without and with DDGS were 0.88 vs 0.84 kg/d, respectively. The ADFI of treatments without DDGS were 1.85 kg/day, while the counterparts of treatments fed diets containing 25% DDGS were 1.79 kg/d. Feeding diets containing 25% DDGS tended to decrease Gain:Feed (0.477 vs. 0.472; P &lt; 0.10). Increasing the level of SID Ile/Lys (from 0.54 to 0.62) linearly increased Gain:Feed in pigs fed diets containing 25% DDGS (0.467, 0.471, 0.477, respectively; P &lt; 0.05). In summary, this study demonstrated feeding diets containing 25% DDGS decreased the performance of growing pigs by reducing ADG and ADFI. Greater SID Ile/Lys in diets may help reduce the negative impact of DDGS diets in grow-finishing pigs by improving feed efficiency.

PSIII-22 Impact of a Dietary Phytogenic Feed Additive on Growth Performance of Growing Finishing Pigs

Abstract: Two experiments were conducted involving a total of 1560 pigs (25.82 kgs, PIC and Hypor) to evaluate if phytogenic feed additive (PFA), containing essential oils and pungent substances, has positive impact on growth performance of growing finishing pigs. Pens in each experiment (Study 1: 11 pens, 20 pigs per pen; Study 2: 15 pens, 20 pigs per pen) were randomly allocated to one of 3 dietary treatments containing 0, 68, or 136 g/ton of the PFA. Feeding program consisted of 3 feeding phases of 21 d each. Body weight (BW), average daily gain (ADG), average daily feed intake (ADFI) and gain to feed (GF) were measured for each phase and overall. Performance data were analyzed using PROC MIX of SAS using RCBD design with dietary inclusion of PFA, pen location blocked within a study and initial BW as covariate. Orthogonal contrasts were used to determine linear or quadratic effect of PFA. No significant differences (P&gt;0.20) were observed in ADG, ADFI or GF during the first 2 phases of the study. During phase 3 however, increasing the level of PFA resulted in a linear increase in ADG (P&lt; 0.001) and a quadratic response in ADFI (P&lt; 0.05) and GF (P&lt; 0.05). Overall, linear improvements in ADG (P&lt; 0.001) was observed with addition of PFA in the diets (+2.5%, +3% vs. NC). Similarly, increasing the level of PFA in the diet tended to linearly improve final BW (P&lt; 0.10, +0.9%, +1.6% vs. NC). The results of this study indicate a positive impact of feeding a PFA on growth of growing-finishing pigs.

278 Effect of Feeding CARS on Digestibility in Finishing Cattle Diets

An experiment was conducted to evaluate the digestibility of a novel liquid feed, Condensed Algal Residue Solubles (Veramaris, Blair, NE) in finishing cattle diets. Mass production of algae to harvest omega-3 fatty acids results in byproduct production of CARS (25.4% DM, 19.3% CP, 8.3% Fat, 9.96% Na on DM basis), made up of the de-oiled algae cells and residual fermentation substrates. The CARS product has generally recognized as safe (GRAS) status. Six ruminally and duodenally cannulated crossbred steers were assigned randomly to 1 of 3 treatments over 3 collection periods, for a 3 x 3 replicated Latin Square design. Treatments differed by increasing inclusion of CARS (0, 2.5, and 5% of diet DM) fed with CARS replacing steam flaked corn (72, 69.5, and 67% of diet DM as CARS inclusion increased). All diets contained 15% dry distillers grains, 8% alfalfa haylage, and 5% supplement. Cattle were dosed with 10 g of titanium dioxide per day. Duodenal and fecal samples were collected four times per day across four days and composited by period for each animal. Fecal samples were analyzed for titanium dioxide concentration to determine fecal output and diet digestibility. Data were analyzed with CARS inclusion and period as fixed effects and animal as a random effect. Orthogonal contrasts were used to test linear and quadratic effects of CARS inclusion. There were no significant differences for DM intake and OM intake between the different CARS inclusions (P ≥ 0.17), averaging 7.76 kg DM/d and 6.94 kg OM/d. Total tract DM digestibility was not affected by treatment (P ≥ 0.71) and averaged 73.0%. Total tract OM digestibility was also not different between treatments (P ≥ 0.93) and averaged 71.1%. Replacing steam flaked corn with CARS up to 5% of diet DM in finishing cattle diets did not affect diet digestibility.

PSIII-21 Optimum SID Threonine to Lysine Ratio in Nursery Pigs

A total of 270 pigs (PIC 1050 x DNA 600, 6.0 kg) were used in a 42-d nursery trial to determine the optimum SID threonine to SID lysine (SID Thr/Lys) ratio for young pigs. Pigs were sorted by sex and initial BW, and were allotted to each pen (3 barrows, 3 gilts). Pens were then randomly assigned to diets containing incremental levels of SID Thr/Lys ratio (0.55, 0.60, 0.65, 0.70, 0.75), achieved using THRPRO 80 (CJ America, CA) as the source of L-threonine. Each treatment consisted of 45 piglets and 9 replicates per treatment. There were 3 dietary phases (2 weeks each) and the same levels of SID Thr/Lys were tested for each phase. All performance data (ADG, ADFI, and Gain to Feed (G:F)) were analyzed using Proc Mixed in a RCBD model with SID Thr/Lys ratio as fixed effect and weight block as random effect. Orthogonal contrasts were performed to test for linear and quadratic effects of SID Thr/Lys ratio on all performance parameters. Final BW averaged around 20.8 kg (±0.6) and was not influenced by SID Thr/Lys ratio (P&gt;0.20). It was however lower than previously observed from previous nursery batches and might be due to pig infection with Lawsonia intracellularis and Streptococcus suis. A linear trend on ADG was observed during the last phase of nursery (P=0.10) but this response was not significant for the overall study (P&gt;0.15). SID Thr/Lys ratio had no significant effect on ADFI during any phase or overall experimental period (P&gt;0.20). Increasing SID Thr/Lys ratio, however, linearly increase G:F of nursery pigs overall (P&lt; 0.05). The results of this study suggest that there is value in terms of increasing efficiency of gain with higher level of SID Thr/Lys as compared to current NRC recommendation (0.59), especially under disease challenge conditions.