Development of an X-band Photoinjector at SLAC

As part of a National Cancer Institute contract to develop a compact source of monoenergetic X-rays via Compton backscattering, we have completed the design and construction of a 5.5 cell Photoinjector operating at 11.424 GHz. Successful completion of this project will result in the capability of generating a monoenergetic X-ray beam, continuously tunable from 20 - 85 KeV. The immediate goal is the development of a Photoinjector producing 7 MeV, 0.5 nC, sub-picosecond electron bunches with normalized RMS emittances of approximately 1 pi-mm-mR at repetition rates up to 60 Hz. This beam will then be further accelerated to 60 MeV using a 1.05 m accelerating structure. This Photoinjector is somewhat different than the traditional 1.5 cell design both because of the number of cells and the symmetrically fed input coupler cell. Its operating frequency is also unique. Since the cathode is non-removable, cold-test tuning was somewhat more difficult than in other designs. We will present results of "bead-drop" measurements used in tuning this structure. Initial beam measurements are currently in progress and results will be presented as well as results of RF conditioning to high gradients at X-band. Details of the RF system, emittance-compensating solenoid, and cathode laser system as well as PARMELA simulations will also be presented.Comment: 3 pages, 6 figures, 1 Table, LINAC 200

Weed control in "LL" maize tolerant to glufosinate-ammonium.

The glufosinate-ammonium is an herbicide with contact action and, when used in tolerant LL maize, requires associations with other products to improve the weed control spectrum and increase the residual period in the area. The aim of this work was to evaluate the efficacy and selectivity of glufosinate-ammonium, applied alone and in combination with other herbicides, for weed control in maize crops. The treatments consisted of two strategies. In the first one, the following herbicides were applied in pre-emergence conditions: atrazine, [atrazine + simazine], [atrazine + oil], [atrazine + S-metolachlor], and S-metolachlor; with the subsequent application of glufosinate-ammonium in post-emergence condition of maize. The second application method corresponded to the use of glufosinate-ammonium, alone and combined with nicosulfuron + mesotrione and the other products used in the first strategy, in addition to two control areas, being one weed-infested and the other weed-free. Phytotoxicity on maize and weed control were assessed. Ear insertion height, number of rows per ear, number of grains per row, thousand grain weight and maize yield were determined upon harvesting. The herbicides were effective and did not cause yield loss to the crop. The herbicides applied in combination with glufosinate-ammonium were efficient in regard to weed control and selective to maize

Effect of Phase-Feeding Strategies on Growth Performance and Carcass Characteristics of Growing-Finishing Pigs: Strategies to Reduce Dietary Phases Using a Field Approach on Lysine Levels

The objective of this study was to evaluate whether simplification of phase-feeding strategies using a field approach with lysine specifications slightly below the estimated requirement for maximum growth rate is possible without compromising overall performance and carcass characteristics of grow-finish pigs. A total of 1,188 pigs (PIC; 359 × 1050; initially 63.5 lb body weight (BW)) were used in a randomized complete block design with 27 pigs per pen and 11 pens per treatment under commercial research conditions. Treatments consisted of four feeding programs with lysine specifications set at 98.5% of estimated requirements for maximum growth rate and 97.5% of maximum feed efficiency (F/G) for the weight range in each phase, except for the last phase of one of the 2-phase feeding programs which the lysine specifications were set for 100% of estimated requirements of maximum growth rate. Treatments were: a 2-phase feeding program with 0.91 and 0.72% standardized ileal digestible (SID) lysine (Lys) from 60 to 220 and 220 to 280 lb BW, respectively (2-phase Lys 98%); a 2-phase feeding program with 0.91 and 0.77% SID lysine from 60 to 220 and 220 to 280 lb BW, respectively (2-phase Lys 98%/100%); a 3-phase feeding program with 0.99, 0.79, and 0.72% SID lysine from 60 to 160, 160 to 220, and 220 to 280 lb BW, respectively (3-phase Lys 98%); and a 4-phase feeding program with 1.07, 0.91, 0.79, and 0.72% SID lysine from 60 to 110, 110 to 160, 160 to 220, and 220 to 280 lb, respectively (4-phase Lys 98%). The experimental diets were based on corn, distillers dried grains with solubles (DDGS), and soybean meal. Overall, from d 0 to 114, no evidence (P \u3e 0.05) for difference was observed in growth performance across feeding programs. There was no evidence for difference (P \u3e 0.05) for hot carcass weight and carcass yield, backfat thickness, loin depth, or percentage lean. Consequently, no evidence (P \u3e 0.05) for difference was observed in economics, with all phase-feeding programs resulting in similar income over feed cost (IOFC). In conclusion, simplification of phase-feeding strategies to fewer dietary phases in the grow-finish period with lysine set slightly below the requirements seems to be feasible. However, along with findings from our previous study, in feeding programs with fewer dietary phases and lysine set slightly below the requirements, growth performance can be compromised if initial BW and feed intake in the grow-finish period are lower than expected

Effects of BIOWISH MultiBio 3P on Growth Performance and Carcass Characteristics of Grow-Finish Pigs

This study was conducted to determine the effects of a multi-species direct-fed microbial product based on lactic acid bacteria and Bacillus subtilis on growth performance and carcass characteristics of grow-finish pigs. A total of 1,188 pigs (PIC 359 × 1050; initially 57 lb BW) were used in a 121-d growth trial with 27 pigs per pen and 22 pens per treatment. Pigs were allotted to treatments based on initial body weight (BW) in a randomized complete block design. The two experimental diets were Control and Biowish (BIOWISH MultiBio 3P, BIOWISH Technologies Inc., Cincinnati, OH). The diets were based on corn, distillers dried grains with solubles, and soybean meal, and fed in four dietary phases. The probiotic BIOWISH MultiBio 3P was included in the diet at 1.1 lb/ton at the expense of corn. Overall, from d 0 to 121, pigs fed the control diet had greater average daily gain (ADG) (P \u3c 0.024) and final BW (P \u3c 0.001) compared to pigs fed the Biowish diet. There was no evidence for differences in average daily feed intake (ADFI) and feed efficiency (F/G) between dietary treatments. The difference in final BW resulted in heavier (P \u3c 0.026) hot carcass weight (HCW) in control pigs compared to Biowish pigs, but no evidence for differences was observed in carcass yield, backfat, loin depth, and lean percentage between dietary treatments. In conclusion, the inclusion of BIOWISH MultiBio 3P in growing-finishing diets reduced ADG in this commercial study. This response was not expected, but could be related to inclusion rate or other factors not identified in this study. This warrants further research to better characterize the effects of this probiotic on pig performance

The Effect of Phase-Feeding Strategies on Growth Performance and Carcass Characteristics of Growing-Finishing Pigs: II. Field Approach on Lysine Levels

The objective of this study was to evaluate phase-feeding strategies for grow-finish pigs under commercial research conditions and using a field approach with lysine levels slightly below the pig’s requirement estimates for maximum growth performance. A total of 1,100 pigs (PIC 359 × 1050; initially 57 lb body weight (BW)) were used in a randomized complete block design with 25 pigs per pen and 11 pens per treatment. Treatments consisted of four feeding programs: a 1-phase feeding program with 0.79% standardized ileal digestible (SID) lysine from 60 to 280 lb BW; a 2-phase feeding program with 0.91 and 0.72% SID lysine from 60 to 220 and 220 to 280 lb BW, respectively; a 3-phase feeding program with 1.07, 0.85, and 0.72% SID lysine from 60 to 110, 110 to 220, and 220 to 280 lb BW, respectively; and a 4-phase feeding program with 1.07, 0.91, 0.79, and 0.72% SID lysine from 60 to 110, 110 to 160, 160 to 220, and 220 to 280 lb, respectively. The lysine levels were determined based on the estimated lysine requirements to achieve 98.5% of maximum growth rate for the weight range in each phase, using an equation developed by the genetic supplier. The experimental diets were based on corn, distillers dried grains with solubles (DDGS), and soybean meal. Overall, from d 0 to 119, pigs fed the 1-phase feeding program had decreased (P = 0.009) average daily gain (ADG) compared to those fed the 4-phase feeding program, with 2- and 3-phase feeding programs intermediate. The 1-, 2-, and 3-phase feeding programs resulted in poorer (P \u3c 0.001) feed efficiency (F/G) compared to the 4-phase feeding program, with the poorest F/G observed in pigs fed the 1-phase feeding program. Final BW and hot carcass weight (HCW) were lower (P \u3c 0.05) in pigs fed the 1-phase program compared to the 4-phase program, with 2- and 3-phase programs intermediate. No evidence for differences was observed across the feeding programs for average daily feed intake (ADFI), carcass yield, backfat thickness, loin depth, or percentage lean. For economics, income over feed costs (IOFC) per pig was increased (P = 0.018) in the 4-phase program compared to the 1-phase program, with the 2- and 3-phase feeding programs intermediate. In conclusion, phase-feeding strategies provide advantages in growth performance and economics over feeding a single diet throughout the grow-finish phase. Moreover, simplification of feeding programs to two or three dietary phases with lysine levels slightly below the requirement estimates (98.5% of maximum growth rate) have negative implications on overall feed efficiency compared to a feeding program with four dietary phases

The Effect of Phase-Feeding Strategies on Growth Performance and Carcass Characteristics of Growing-Finishing Pigs: I. Lysine Levels at the Estimated Requirement

The objective of this study was to evaluate phase-feeding strategies for grow-finish pigs under commercial research conditions and using lysine levels closely set to the pig’s requirement estimates for maximum growth performance. A total of 1,188 pigs (PIC 359 × 1050; initially 60.4 lb body weight (BW)) were used in a randomized complete block design with 27 pigs per pen and 11 pens per treatment. Treatments consisted of four feeding programs: a 1-phase feeding program with 0.82% standardized ileal digestible (SID) lysine from 60 to 280 lb BW; a 2-phase feeding program with 0.96 and 0.77% SID lysine from 60 to 220 and 220 to 280 lb BW, respectively; a 3-phase feeding program with 1.13, 0.89, and 0.77% SID lysine from 60 to 110, 110 to 220, and 220 to 280 lb BW, respectively; and a 4-phase feeding program with 1.13, 0.96, 0.82, and 0.77% SID lysine from 60 to 110, 110 to 160, 160 to 220, and 220 to 280 lb, respectively. The lysine levels were determined based on the estimated lysine requirements to achieve 100% of maximum growth rate for the weight range in each phase, using an equation developed by the genetic supplier. The experimental diets were based on corn, distillers dried grains with solubles (DDGS), and soybean meal. Overall, from d 0 to 121, pigs fed the 1-phase program had decreased (P = 0.007) average daily gain (ADG) compared to 2- and 4-phase feeding programs, with the 3-phase feeding program intermediate. There was no evidence for difference on average daily feed intake (ADFI) and feed efficiency (F/G) across the feeding programs. Final BW was lower (P = 0.050) in pigs fed the 1-phase program compared to the 4-phase program, with pigs fed 2- and 3-phase programs intermediate. Similarly, hot carcass weight (HCW) was decreased (P = 0.014) in pigs fed the 1-phase program compared to 2- and 4-phase programs, with the 3-phase program intermediate. No evidence for differences was observed across the feeding programs for carcass yield, backfat thickness, loin depth, or percentage lean. For economics, the 1-phase feeding program resulted in the lowest (P \u3c 0.001) feed cost per pig and feed cost per lb of gain, but also in the lowest (P = 0.013) revenue per pig. The 2-, 3-, and 4-phase feeding programs resulted in similar feed cost per pig, feed cost per lb of gain, and revenue per pig. The income over feed cost (IOFC) was similar across all phase-feeding programs. In conclusion, phase-feeding strategies provide advantages in growth performance over feeding a single diet throughout the grow-finish phase. However, simplification of feeding programs to two dietary phases with lysine levels closely set to requirement estimates to maximize growth performance does not compromise overall growth performance, carcass characteristics, and IOFC

Evaluation of Phase Feeding Strategies and Lysine Specifications for Grow-Finish Pigs on Growth Performance and Carcass Characteristics

The objective of this study was to compare phase feeding strategies for grow-finish pigs using the estimated lysine requirements for optimal growth and feed efficiency compared to a standard strategy. A total of 1,188 pigs (PIC 359 × 1050; initially 61.5 lb BW) were used in a randomized complete block design with 27 pigs per pen and 11 pens per treatment. The treatments consisted of: MAX, a 4-phase feeding program with lysine levels for maximum growth (1.13, 0.96, 0.82, and 0.77% SID Lys in Phases 1 to 4, respectively); STD, a standard 4-phase feeding program for optimal income over feed cost (1.02, 0.87, 0.76, and 0.67% SID Lys in Phases 1 to 4, respectively); STD/ MAX, a 4-phase feeding program based on standard lysine levels in early finishing and lysine levels for maximum growth in late finishing (1.02, 0.87, 0.82, and 0.77% SID Lys in Phases 1 to 4, respectively); and 2-PHASE, a 2-phase feeding program based on the average estimated lysine requirements for maximum growth with 0.96% SID lysine for Phases 1 to 3 and 0.77% SID lysine during Phase 4. The four phases were from approximately 60 to 110, 110 to 160, 160 to 220, and 220 to 280 lb, respectively. The experimental diets were based on corn, distillers dried grains with solubles, and soybean meal. Lysine levels were achieved by manipulating the ratio of corn to soybean meal. Overall, from d 0 to 117, pigs fed the 2-PHASE regimen had increased ADG (P \u3c 0.05) compared to pigs fed the STD regimen, and feeding either the MAX or STD/MAX regimen resulted in intermediate ADG. There was no evidence for differences in ADFI, F/G, or final BW among dietary regimens. Also, no evidence for differences was observed across the dietary treatments for the carcass traits HCW, yield, backfat, loin depth, or lean percentage. For economics, the STD feeding program resulted in the lowest (P \u3c 0.001) feed cost per pig and feed cost per lb of gain compared to the other 3 programs. Revenue and income over feed costs per pig were similar across the feeding programs. In conclusion, feeding lysine levels for maximum growth and efficiency in either a 2- or 4-phase feeding program results in the same growth performance and feed cost. A broad range of lysine specifications within the levels tested herein can be utilized in grow-finish diets without compromising income over feed cost