Carcass Average Daily Gain Research Articles

218 Weaning weights associated with improved performance of grow-finish pigs

Abstract This study was conducted to evaluate the downstream impact of wean weight (WW) on finishing pig performance. Individual body weights (BW) were recorded at the time of weaning using the LeeO individual animal identification system. Finisher performance evaluation started at d 57 post-weaning. Pigs (n = 1,276; PIC 800 x DNA 241 F1) were blocked by wean age (20.6 ± 1.5 d) and sex, ranked in order of individual WW (6.05 ± 1.43 kg), and divided into BW quartiles to create four WW treatment groups [WW Quartile (Q) 1, 2, 3, and 4; Table 1]. Pigs (n = 21) in the same Q were housed in each pen yielding 15 replicate pens per quartile. Pigs were fed common diets formulated in a 4-phase sequence from the time of placement in the finisher through marketing, which occurred on a fixed-BW basis targeting 131.5 kg. Pen BW and feed disappearance were recorded every 3 wk and at marketing, and individual BW were recorded on d 134 post-weaning. Data were analyzed using linear mixed effects models in the lme4 package of R. Differences in mean BW of each Q were evident at weaning (P < 0.001), start of finisher evaluation (d 57, P < 0.001), and through d 121 (P < 0.001); by d 144, the BW between Q3 and Q4 did not differ (126.6 vs 129.0 kg, respectively, P > 0.05). Overall average daily gain (ADG) and average daily feed intake (ADFI) were greater (P < 0.001) for finishing pigs of either Q3 or Q4 compared with Q1, but no difference (P > 0.10) in gain to feed ratio (G:F) was observed between quartiles from 28.0 to 131.5 kg BW. Pigs in Q3 and Q4 required fewer (P < 0.001) days on feed than pigs in either Q1 or Q2, which culminated in an overall linear (P < 0.001) effect such that a 0.45-kg advantage in WW resulted in 2.25 d less to reach a market BW of 131.5 kg. Coefficient of variation (CV) in BW at d 134 post-weaning was greater (P < 0.001) for pigs in Q1 compared with pigs in Q2, Q3, or Q4. Backfat depth was thicker (P < 0.05) for Q1 pigs compared with Q4 pigs but did not differ from pigs in Q2 or Q3. A decrease (P < 0.001) in carcass ADG was seen for pigs in the lightest 50% of the population compared with those in Q4. In conclusion, even though feed efficiency was not impacted by WW, heavier WW resulted in fewer days to reach desired market weight while simultaneously resulting in improved carcass characteristics.

59 Effects of serial harvest on growth and carcass characteristics of beef x dairy crossbred steers

Abstract Beef x dairy crossbred feedlot steers [n = 707; body weight (BW) at initial processing = 148 kg] were utilized in a randomized complete block design to evaluate effects of three serial harvest endpoints on growth performance and carcass characteristics. Allocation to treatment occurred after 204 d-on-feed (DOF), at which point steers weighed 484 kg (SEM = 3.2 kg). Treatments consisted of three serial harvest endpoints: 326, 347, and 368 DOF, as measured from initial processing at 148 kg. Twelve pens, with approximately 59 steers/pen and four pens/treatment were utilized. Final BW measured 696, 730, and 744 kg at 326, 347, and 368 DOF, and increased (P < 0.01) with DOF. Dry matter intake (DMI) from allocation to harvest did not differ among treatments (11.4 kg/d; P = 0.36). Average daily gain (ADG) from allocation to harvest measured 1.82, 1.79, and 1.64 kg at 326, 347, and 368 DOF, respectively and was greater (P < 0.01) at 326 and 347 DOF than at 368 DOF. Feed efficiency (FE) from allocation to harvest measured 0.162, 0.151, and 0.143 at 326, 347, and 368 DOF, respectively and was greater (P < 0.01) at 326 and 347 DOF than at 368 DOF. Hot carcass weight (HCW) measured 438, 459, and 472 kg at 326, 347, and 368 DOF, respectively and increased (P < 0.01) with DOF. Across the 42-d serial harvest period live and carcass ADG averaged 1.09 and 0.78 kg, respectively, with a carcass transfer of 71.6%. Backfat thickness measured 1.35, 1.63, and 1.47 cm at 326, 347, and 368 d, respectively and was greater (P < 0.01) at 347 and 368 d than at 326 d. Marbling score measured 508, 529, and 550 at 326, 347, and 368 DOF, respectively and was greater (P = 0.03) at 368 and 347 DOF than at 326 DOF. Distribution of USDA quality grades (QG) did not differ (P = 0.45) among treatments and averaged 6.3% Prime and 83.1% Choice. Ribeye area and dressing percentage (P = 0.11) did not differ among treatments. Distribution of USDA yield grades (YG) was affected by treatment (P < 0.01), with a shift toward more YG 4 and 5 carcasses with increasing DOF. Liver abscess occurrence averaged 62.9% and did not differ (P = 0.61) among treatments. Results from this experiment indicate a BW gain of 1.09 kg/d and a HCW gain of 0.78 kg/d across the 42-d serial harvest period. There were no differences in DMI as DOF progressed but ADG and FE decreased in the longest-fed cattle. Distribution of QG was not affected by DOF, but YG increased with increasing DOF.

A novel production profile classification system for incoming calves that predicts feedlot growth performance

Context Mitigating financial risk in the feedlot environment is an ongoing occurrence, and good production is a key risk mitigator. However, production protocols are based on historic averages because of the inability to predict growth potential of incoming calves. Production profiling of individual incoming feeder calves could address these limitations. Aims The aim of this study was to establish criteria for optimal sorting of incoming feeder calves into various cattle groups in a feedlot that maximises feedlot profit. Methods South African feeder calves (n = 436) were classified into four production-profile (PP) categories according to a predetermined set of phenotypic traits: PP 3 (n = 72) representing feeder calves with the poorest feedlot growth potential, PP 2− (n = 191) with below-average potential, PP 2+ (n = 139) with above-average potential and PP 1 (n = 34) with above-average feedlot growth potential. After combining the data of PP 2− and PP 2+ into PP 2, mixed modelling of economically important feedlot growth traits (average daily gain (ADG), carcass ADG, and carcass exit weight) was performed to evaluate the effect of PP classification (PP 1 and PP 3), while adjusting for potential confounding effects such as starting weight (entry weight) and gender. Key results Carcass weights for calves with a PP classification of 3 and 1 were 15.54 kg less (P < 0.000), and 11.34 kg more (P = 0.007) respectively, than those with a PP classification of 2 (261.27 kg, 95% CI 257.94–264.57), after adjusting for entry weight, calf gender and the random effect of the feeding pen. Similar to carcass weight, calves with a PP 3 classification were outperformed by other classifications in all the measured traits (P < 0.05). Conclusions This is the first report demonstrating the ability of subjective production-profile classification to predict growth performance of individual feeder calves. Implications The opportunity of the PP classification system lies in value-based procurement of incoming feeder calves based on their growth potential at the start of the feeding period, and then to use technology to improve and finalise the current subjective PP classification system.

41 Growth Performance and Carcass Characteristics of Beef-Sired Steers Born to Holstein Dams

Abstract The objective of this study was to compare feedlot growth performance and carcass characteristics of F1 beef × Holstein steers (n = 124) sired by commercially available Angus (n = 19 from 7 sires), Charolais (n = 79 from 3 sires), SimAngus (n = 16 from 3 sires), or Wagyu (n = 10 from 2 sires) bulls. Male calves born from May to August of 2021, were sourced from 8 Pennsylvania dairy herds. Steers were raised by a commercial calf grower until April of 2021 (10.5 ± 1.5 months of age). Steers were then moved to the PA Department of Agriculture’s Livestock Evaluation Center (LEC) and transitioned to a high-energy ration. Individual feed intake was monitored using the GrowSafe Feed Intake Monitoring System (Model 4000E, Vytelle, Calgary AB, Canada). Steers were slaughtered after 90, 118, or 153 days on feed at the LEC. Pulls were based on a combination of visual appraisal and body weight. Linear models of growth performance traits and carcass characteristics included the fixed effects of sire breed, herd of origin, and birthdate. Binomial models of USDA Quality Grades and Yield Grades included a fixed effect of sire breed. Angus-sired steers were heaviest at feedlot entry (P < 0.01) and were on feed for the fewest days (P < 0.01). Angus × Holstein steers were heavier at slaughter (P < 0.01) than SimAngus and Wagyu-sired steers. Wagyu-sired steers had the least dry matter intake (DMI), average daily gain (ADG), and carcass ADG (P < 0.01) when compared with progeny of other sire breeds. No differences in gain to feed intake (G:F(; P = 0.90), back-calculated carcass G:F (P = 0.62), net energy of metabolism (P = 0.70) and net energy of gain (P = 0.70), nor hip height at harvest (P = 0.14) were detected between sire breeds. Wagyu × Holstein carcasses were the lightest (P < 0.01) and had the least amount of backfat (P = 0.01). Dressing percentage tended to be least (P = 0.10) in Charolais × Holstein carcasses (60.5%) and greatest in SimAngus × Holstein carcasses (61.7%); carcasses from Angus and Wagyu-sired steers were intermediate and not different. About 84% of Angus × Holstein carcasses graded Choice while only 31% of SimAngus × Holstein carcasses graded Choice (P = 0.03). However, there were no differences in called marbling scores between sire breeds (P = 0.15). Charolais × Holstein tended to have the lowest proportion (4%) of Yield Grade 1 carcasses (P = 0.05). Angus-sired steers were on feed for the fewest days when compared with steers sired by other beef breeds. Wagyu × Holstein steers had reduced ADG, DMI, and subsequent carcass weight in comparison with compared steers of other sire breeds.

Effect of a Bacillus probiotic strain on Nellore cattle finished on pasture during the dry season

The objective of this study was to evaluate the productive performance of Nellore bulls raised under grazing conditions during the dry season and fed a diet supplemented with a Bacillus probiotic strain, and its influence on ruminal and intestinal mucosa development. In addition, the probiotic effects on digestibility and ruminal fermentation were determined. The experiment was conducted between July and November 2017, corresponding to the dry period in the state of Goias, Brazil. Eighty-four animals (approximately 24 months old) were included in the study. Four animals were randomly slaughtered at the beginning of the experiment to assess carcass yield. The remaining animals (80 Nellore bulls, initial body weight (BW) of 354 ± 3.4 kg) were blocked based on their initial BW and assigned to one of two treatments: concentrate with probiotics and concentrate without probiotics (control). Bulls were divided into 16 paddocks of palisade grass (Urochloa brizantha spp.) pasture, supplemented with concentrate at 2% BW. After 133 days, the animals were slaughtered, and carcass traits were measured. Tissues from the ruminal ventral sac and jejunum were collected to evaluate the morphology of the rumen papillae and intestinal villi. No differences were detected in performance data; a tendency was found in improving the dressing percentage, carcass average daily gain (ADG), and gain to feed ratio based on carcass ADG. The 12th rib fat thickness was significantly lower in animals fed probiotic than in control group (4.06 vs. 2.97 mm, p < 0.05). No significant effect on the development of the ruminal and intestinal epithelia was observed with the use of probiotics. Later, an in vivo digestibility trial was carried out to investigate the influence of the Bacillus probiotic strain on rumen fermentation, with the same treatments, using eight rumen-cannulated steers in a cross-over design. Fecal output and forage intake were estimated using titanium dioxide and indigestible neutral detergent fiber (iNDF), respectively. Administration of the probiotics did not improve dry matter (DM) intake or nutrient digestibility. Isovalerate levels were higher in animals fed probiotics (2.01 vs. 1.55, p < 0.05), and no other differences were observed in the rumen fermentation parameters. The tested Bacillus probiotic strain significantly reduced carcass fat deposition in Nellore bulls finished in tropical grass pastures supplemented with a high-concentrate diet during the dry season.

Stylosanthes silage as an alternative to reduce the protein concentrate in diets for finishing beef cattle

The objective of this study was to evaluate the effects of silage and concentrate on nutrients digestibility, ruminal fermentation, efficiency of nitrogen use and animal performance of feedlot beef cattle. Two experiments were conducted simultaneously evaluating the same diets. The forage: concentrate ratio was 50:50 and diets consisted of Stylosanthes (StS) or corn (CS) silages in combination with two concentrates: without (C1) or with soybean meal (C2). In experiment 1, four rumen and abomasum fistulated bulls with an average initial body weight (BW) of 200 ± 15.7 kg were distributed to a Latin square design with a 2 × 2 (S × C) factorial arrangement (experiment 1). Experiment 2 was conducted using 48 Nellore bulls with an average initial BW of 358 ± 30 kg, distributed to a complete randomized design with a 2 × 2 factorial arrangement and 12 replicates. In experiment 1, there was an S × C interaction tendency (P ≤ 0.09) for DM, OM, CP and NDF intakes. Greater intake of DM, OM, CP and NDF was observed for CS with C2. The intake of iNDF was greater (P = 0.01) for StS-based diets. There was a decrease tendency (P = 0.06) on the total CP digestibility in StS-based diets. Nitrogen balance was greater for CS-based diet (P = 0.04). There was an S × C interaction tendency (P = 0.10) for microbial synthesis efficiency (MSE). In experiment 2, C2-based diets showed greater (P < 0.01) intakes of DM, OM and CP. The average daily gain (ADG) and carcass average daily gain (CADG) were greater (P < 0.01) for diets containing the C2. Thus, it is concluded that StS can replace CS in diets of feedlot beef cattle. However, the concentrate source affects animal performance. Stylosanthes silage represents a sustainable alternative for animal production.

Effects of mixing Stylosanthes conserved as hay or silage with corn silage in diets for feedlot beef cattle

The objective of this study was to evaluate the total and partial digestibility, ruminal pH and ammonia nitrogen (NH3-N) concentration, nitrogen balance (Experiment 1) and performance (Experiment 2) of beef cattle fed diets containing corn silage (CS) and Stylosanthes (silage or hay) as forage source. Treatments were: 1) CS; 2) Stylosanthes silage (StS); 3) Stylosanthes hay (StH); 4) CS + StS (StS-mixed diet); and 5) CS + StH (StH-mixed diet). Experimental diets (125 g CP/kg DM) consisted of 50% forage and 50% concentrate (DM basis). Five cannulated bulls (251 ± 42.6 kg of body weight) were distributed to a 5 × 5 Latin square (Experiment 1). The trial lasted 80 d. The experiment 2 was performed with 40 bulls (360 ± 2.7 kg of body weight) in a completely randomized design and eight replicates during a 99-days period. In experiment 1, CS diet showed greater (P ≤ 0.02) total digestibility of DM, OM, CP and NDF than other diets. Mixed diets had greater (P = 0.02) total NDF digestibility compared to StS and StH. Corn silage showed greater total digestibility of DM, OM, NDF and CP (P ≤ 0.03) compared to mixed diets. Ruminal NDF digestibility was greater (P = 0.03) for CS than other diets. Ruminal pH was greater (P < 0.01) for StS and StH compared to mixed diets. There was a treatment × hour interaction (P = 0.02) for ruminal NH3-N. In the experiment 2, animals fed CS presented lower (P ≤ 0.03) intake of DM, OM, EE, NDF, iNDF, but greater (P ≤ 0.01) intake of TDN, DOM and NFC than animals fed other diets. The intake of all nutrients, except for NDFi, was greater for mixed diets than StS and StH (P < 0.01). Mixed diets showed greater (P < 0.01) intake of most nutrients compared to CS diet, except for the intake of TDN and DOM, which were similar (P > 0.60). Corn silage showed greater (P < 0.01) digestibility of all nutrients than other diets. Stylosanthes silage and StH had greater (P ≤ 0.03) digestibility of DM, CP and NFC than mixed diets. Average daily gain (ADG) and carcass average daily gain (CADG) were greater (P ≤ 0.03) for CS diet than others, but mixed diets were similar (P ≥ 0.67) to CS. Mixed diets had greater (P < 0.01) ADG and CADG than StS and StH, while StS showed greater (P = 0.05) ADG compared to StH. Carcass yield was greater (P = 0.02) for StH compared to StS. Diets containing 50% CS and 50% StS or StH are alternatives to CS in ration of finishing beef cattle.

Effect of inoculants in corn silage on dry matter digestibility, ingestive behavior, performance and carcass of heifers

We aim to evaluate inoculants with different strains of lactic acid bacteria (LAB) in corn silage on ingestive behavior, apparent digestibility of diet, performance and carcass traits of heifers. The treatments were: corn silage without inoculant (control); with 11CFT inoculant (strains of Lactobacillus buchneri and Lactobacillus casei) and with 11C33 inoculant (Lactobacillus buchneri, Lactobacillus plantarum and Enterococcus faecium) with six repetitions each. Ingestive behavior, weight gain and daily dry matter intake was not affected by the use of inoculants in corn silage. The apparent digestibility of diet was higher to silage with 11C33 inoculant, not differing from the diet with silage with 11CFT (73.30% and 71.99%, respectively). The animals fed silage inoculated with 11CFT obtained greater values of carcass gain and average daily carcass gain (86.33 kg and 0.833 kg day-1, respectively). The use of these inoculants in corn silage shows promising results regarding the gain of animals in feedlot.

Dose-response effect of encapsulated nitrate replacing soybean meal on growth performance, ingestive behavior, and blood metabolites of feedlot finishing bulls

ABSTRACT This study addressed the dose-response effect of an encapsulated nitrate product (ENP) replacing soybean meal (SBM) in the finishing period (87-d) of feedlot bulls. One hundred twenty Nellore bulls (340 ± 28 kg of body weight, BW; mean ± SD) were allotted to 20 outdoor pens (6 animals/pen) and assigned to a randomized complete block design with 5 blocks based on initial BW and 4 dietary treatments: SBM, as control; ENP-10, 10 g ENP/kg dry matter (DM; 6.5 g NO3−/kg DM); ENP-20, 20 g ENP/kg DM (13 g NO3−/kg DM); and ENP-30, 30 g ENP/kg DM (19.5 g NO3−/kg DM). Finishing diets (90:10 concentrate to roughage ratio) were formulated to provide similar amounts of nutrients. Animals were gradually and simultaneously adapted over 14 d to ENP and concentrate. Dry matter intake (DMI) reduced linearly (from 9.6 to 8.4 kg/d; P = 0.02) with ENP inclusion. Final BW, average daily gain (ADG), carcass ADG, hot carcass weight, dressing percentage, and fat thickness were not affected (P ≥ 0.12) by treatments. There was a quadratic trend for increased carcass gain:feed (0.121, 0.130, 0.128, 0.127, respectively; P = 0.07). Nitrate concentration in meat increased linearly (3.48, 2.73, 3.98, 6.59 mg NaNO3/kg meat; P = 0.02) with ENP addition, although nitrite was not detected. Time spent eating (min/d) was similar (P ≥ 0.16) among treatments, whereas a linear increase (P = 0.02) was observed for time spent eating per unit of DMI when ENP was fed. There was a trend (P = 0.07) for a quadratic effect in ruminating time per unit of DMI according to ENP increments. Blood methemoglobin before morning feeding increased linearly (P

73 Effects of dietary neutral detergent fiber and standardized ileal digestible lysine levels on growth performance and carcass characteristics of growing-finishing pigs

Abstract Our objective was to determine the effects of feeding different neutral detergent fiber (NDF) and standardized ileal digestible (SID) lysine (Lys) levels on performance of growing-finishing pigs from 30- to 130-kg. A total of 2,016 barrows and gilts (PIC 280×Camborough, initial BW of 29.6±0.53 kg) were allotted to a randomized complete block design with a 2×2 factorial arrangement. Dietary treatments (Table 1) consisted with two NDF levels (13% or 20%) and two SID Lys curves (PIC2008 or PIC2016). There were 21 mixed-sex pigs per pen, and 24 pens per treatment. The experiment diets were fed in 3 phases. Wheat, wheat by-products, peas, and canola oil were used with NRC (2012) loading values to achieve treatments, and all diets were formulated to be iso-caloric (2,420 kcal NE/kg). Experimental data were analyzed using generalized linear mixed models with pen as the experimental unit. Increasing NDF level resulted in a reduction (P&amp;lt; 0.05) in average daily gain (ADG), average daily feed intake, hot carcass weight, carcass yield, carcass ADG, and backfat depth (Table 2), and tended to decrease percentage of removals and mortality (P=0.10). Pigs fed PIC2016 Lys curve had greater ADG and carcass ADG as compared to those fed PIC2008 Lys curve (P&amp;lt; 0.05). There were NDF×Lys interactions (P&amp;lt; 0.10) for ADG, gain to feed ratio (G:F), carcass ADG, and carcass G:F. These response criteria were improved for pigs fed PIC2016 Lys curve compared to those fed PIC2008 Lys curve when NDF level was 13%; while no evidence of differences was observed at 20% NDF. Results indicate that increasing NDF level from 13 to 20% deteriorate performance of 30- to 130- kg pigs; and the improved growth performance of pigs fed PIC2016 Lys curve as compared to those fed PIC2008 Lys curve was only observed when lower NDF level was presented.

79 Effects of dietary net energy and neutral detergent fiber levels on growth performance and carcass characteristics of growing finishing pigs

Abstract Our objective was to determine the effects of feeding different net energy (NE) and neutral detergent fiber (NDF) on performance of growing-finishing pigs from 30- to 135-kg. A total of 2,058 barrows and gilts (PIC 380×Camborough, initial BW 33.4±0.60 kg) were used in a 97-d growth trial with 21 pigs per pen and 14 pens per treatment in a randomized complete block design. Treatments were formulated to contain 2.11, 2.21, 2.32, 2.42, 2.53, 2.63, and 2.73 Mcal NE/kg; and 24.2, 19.7, 15.1, 10.6, 10.2, 9.8, and 9.5% NDF throughout the experiment. Wheat, wheat byproducts, barley, rye, peas, fababeans, and canola oil were used with NRC (2012) loading values to achieve the treatments. Dietary lysine levels were set to meet PIC2016 lysine requirements for finishing gilts. Experimental data were analyzed using generalized linear mixed models and linear and quadratic polynomial contrasts were built with pen as the experimental unit. Increasing NE or decreasing NDF improved (linear and quadratic, P&amp;lt; 0.05) average daily gain (ADG), gain-to-feed ratio (G:F), carcass ADG, and carcass G:F (Table 1); but reduced (linear and quadratic, P&amp;lt; 0.05) average daily feed intake (ADFI). Comparing to pigs fed 2.42 Mcal/kg diet (energy equivalent to a corn-soybean meal diet), even though those fed 2.11 Mcal/kg diet had 8.7% increment on ADFI, daily NE intake was still 5.4% less. Hot carcass weight, backfat depth, and carcass yield increased (linear and quadratic, P&amp;lt; 0.05) and lean yield decreased (linear and quadratic, P&amp;lt; 0.05) with increasing dietary NE and decreasing NDF. No evidence for differences (P &amp;gt;0.10) were observed for loin depth. Removal and mortality rate was reduced (quadratic, P&amp;lt; 0.05) with increasing dietary NE and decreasing dietary NDF. In summary, increasing dietary NE while reducing dietary NDF resulted in improvements on growth performance, carcass characteristics, and removal and mortality rate.

Calcium salts of fatty acids with varying fatty acid profiles in diets of feedlot-finished Bos indicus bulls: impacts on intake, digestibility, performance, and carcass and meat characteristics.

We hypothesized that the inclusion of calcium salts of fatty acid (CSFA) into the diets and the fatty acid (FA) profile of the supplements would impact performance and meat characteristics of Bos indicus bulls. Hence, the objective was to evaluate the effects of CSFA profiles on intake, body weight (BW), carcass, and meat characteristics of feedlot-finished B indicus bulls. Fifty-three Nellore bulls [initial BW 315 ± 5.9 kg and 20 ± 2 mo] were used. At the beginning, 6 bulls were randomly chosen and slaughtered for determination of their BW composition, and the remaining 47 bulls were evaluated during a 140-d experimental period. The bulls were placed in individual pens, blocked according to initial BW and randomly allocated to 1 of the 3 following treatments: (1) control diet containing sugarcane bagasse, ground corn, citrus pulp, peanut meal, and mineral-vitamin mix (CON), (2) CON with the addition of 3.3% of CSFA from soybean oil (CSO), or (3) CON with the addition of a mixture of 3.3% of CSFA from palm, soybean, and cottonseed oils (CPSCO). Diets were offered ad libitum and formulated to be isonitrogenous. Bulls supplemented with CSFA had a greater (P < 0.01) final BW, dry matter intake, average daily gain (ADG), feed efficiency (FE), and FA intake vs. CON. Among carcass parameters, CSFA-supplemented bulls had greater (P < 0.01) carcass ether extract concentration vs. CON bulls. When the CSFA profile was evaluated (CSO vs. CPSCO), CPSCO bulls had a better (P ≤ 0.03) FE, carcass ADG, and hot carcass weight (HCW) vs. CSO bulls. The FA intakes differed among CSFA treatments, as the total saturated, palmitic, and oleic FA intakes were greater for CPSCO (P < 0.01), whereas lower intakes of total unsaturated and polyunsaturated FA (P < 0.01) were observed for CPSCO vs. CSO. Samples from the Longissimus muscle contained greater palmitoleic (P = 0.01) and reduced linoleic (P = 0.02) FA concentrations in CSFA-supplemented bulls vs. CON bulls. In agreement with the FA intakes, CPSCO-supplemented bulls had a greater (P ≤ 0.05) unsaturated FA concentration vs. CSO in Longissimus muscle. In summary, CSFA supplementation improved the performance of finishing B. indicus bulls vs. CON. Moreover, the inclusion of CSFA from palm, soybean, and cottonseed oil benefited the FE, carcass ADG, and HCW compared with the inclusion of CSFA from soybean oil, demonstrating the potential of specific FA for improving the performance and meat quality of B. indicus bulls.

Estimation of breed and heterosis effects for cow productivity, carcass traits and income in beef × beef and dairy × beef crosses in commercial suckler cow production

ABSTRACT This study aims to investigate calving difficulties, birth-, weaning- and carcass weight, herd life of cow, age at slaughter, average daily carcass gain, carcass conformation, carcass fatness and carcass income per carcass, kg or day, in Aberdeen Angus (A), Hereford (H), Charolais (C), Limousin (L), Simmental (S), Norwegian red (N) and their crosses, in order to evaluate crossbreeding strategies. Direct and maternal breed additive and heterosis effects and predicted phenotypic means were estimated with multiple regression using SAS. Crosses with N resulted in higher weaning weight and less calving difficulties than beef purebreds. Due to favourable maternal additive effects of N on carcass weight and -income, crosses with British breeds had higher performance than the purebreds. (A × C) × C had overall high performance due to beneficial maternal heterosis effects on calving difficulties and carcass weight. In conclusion, utilising profitable heterosis effects have potential in commercial production, but are dependent on production systems.

Supplementation with calcium salts of cottonseed oil improves performance of Bos indicus animals consuming finishing diets.

Lipid ingredients are often used into feedlot cattle diets, primarily to increase energy density and improve efficiency parameters of the herd. Therefore, this study was designed to evaluate the effects of including calcium salts of fatty acids (CSFA) and increasing levels of cottonseed byproducts into feedlot diets. On day 0 of the study, 96 Bos indicus bullocks were individually weighed twice and initial body weight (BW) was considered the average of both measurements (initial BW = 287 ± 22.4 kg). Bulls were ranked by initial BW, allocated into 1 of 12 feedlot pens (eight bulls per pen), and pens randomly assigned to one of three treatments: 1) inclusion of 15.0% [dry matter (DM) basis] of cottonseed byproducts into the finishing diet (CTS-15; n = 4), 2) inclusion of 22.0% (DM basis) of cottonseed byproducts into the finishing diet (CTS-22; n = 4), and 3) inclusion of 2.7% (DM basis) of CSFA of cottonseed oil into the finishing diet (CSFA; n = 4). The experimental period lasted 135 d and consisted of 5 d of preadaptation, 15 d of adaptation (ADP), 31 d of growing (GRO), and 84 d of finishing (FIN). Performance and carcass characteristics data were evaluated at the end of the experimental period. A treatment × period interaction was observed on total DM intake (DMI; P < 0.0001), given that no treatment differences were observed during ADP (P > 0.33), whereas CSFA-supplemented animals had a reduced DMI during GRO and FIN phases (P < 0.05). When individual mean nutrient intake was evaluated, CSFA supplementation caused a reduction in crude protein and physically effective neutral detergent fiber intake (P ≤ 0.05), and tended to reduce metabolizable energy, net energy for maintenance and gain intake (P = 0.06). Additionally, CSFA inclusion or CTS increase into the diet did not affect final BW, BW change, average daily gain (ADG), hot carcass weight, carcass ADG, and yield gain (P ≥ 0.11). On the other hand, CSFA reduced DMI as percentage of BW and improved feed efficiency (FE; P < 0.02) and also tended to improve biological conversion (BC; P = 0.07) versus CTS. Similarly, increasing CTS byproducts in the diet improved FE and BC (P = 0.02) but also tended to increase dressing percentage (DP; P = 0.08). In summary, including CSFA into feedlot diets reduced DMI but improved FE and BC of beef cattle, demonstrating the efficacy of this technology on feedlot beef cattle diets. Moreover, increasing cottonseed byproducts into the diets also benefited FE, BC, and DP of finishinw B. indicus cattle.

The effect of preconditioning on production and antibiotic use in a South African beef feedlot

Context There is pressure on production veterinarians to reduce the use of antibiotics in intensive beef production systems. Aims The present study investigated whether preconditioning – the process whereby weaned calves destined for the feedlot are prepared over a period of time – reduced antibiotic treatment events, and improved health and production of calves in a South African feedlot. Methods Preconditioned calves (n = 301) and control calves (n = 332) were sourced from the same origin on two occasions, and arrived at the feedlot on the same day. Bovine respiratory disease (BRD) was defined as the ‘pulling’ of clinically sick calves from feedlot pens, followed by the standard protocol for treatment of BRD (including antibiotic treatment). Outcome variables related to health were BRD overall incidence (pulling), BRD re-pulling and lung lesion scores. Production outcome variables measured were carcass weight, carcass average daily gain (ADG) and days on feed (DOF). Initial carcass weight was estimated from shrunk liveweight in order to estimate the effect of preconditioning on carcass gain, the most economically relevant outcome. Statistical analyses were done using multiple linear, logistic and Cox regression. Predictor variables were preconditioning vs control, gender, starting weight, DOF, pulling for BRD and carcass ADG. Key results A lower proportion of preconditioned calves were pulled and a lower proportion of pulled calves were re-pulled for BRD compared with control calves (8 vs 17% and 8 vs 16%, respectively, P &amp;lt; 0.01). A higher proportion of preconditioned calves compared with control calves were market ready at 90 DOF (89 vs 67%, P &amp;lt; 0.01). In the multivariable models preconditioning was associated with a 200 g/d increase in carcass growth rate (P &amp;lt; 0.01) and with a 17.7 kg increase in overall carcass gain (P &amp;lt; 0.01) after adjusting for gender and DOF. Conclusions Preconditioning reduced the incidence and severity of BRD and feedlot standing time and improved production of calves in South African feedlots. Implications Preconditioning has the potential to add value to the beef feedlot by reducing the formation of antimicrobial resistance while improving the profitability of the feedlot.

Effects of Standardized Ileal Digestible Tryptophan:Lysine Ratio on Growth and Carcass Performance of Finishing Pigs Fed Ractopamine HCl

Recent research has reported that increasing standardized ileal digestible (SID) Trp:Lys ratio above 20% in finishing pigs fed ractopamine HCl (RAC) resulted in improved growth and carcass performance, however, this response has been inconsistent. Therefore, the objective of this study was to evaluate the effects of feeding high SID Trp:Lys ratios with RAC on growth and carcass performance. A total of 1,791 finishing pigs (PIC 1050 × 337, initially 245.1 lb BW) were used in a 27-d study to evaluate the effects of feeding high SID Trp:Lys ratios on growth and carcass performance of pigs fed ractopamine HCl (RAC, Paylean, Elanco Animal Health, Greenfield, IN). Pens of 25 or 26 pigs were allotted by initial body weight (BW) and randomly assigned to 1 of 5 dietary treatments with 14 replications per treatment. The dietary treatments included 5 SID Trp:Lys ratios (20, 22, 24, 26, and 28% of Lys). All diets were formulated to 0.90% SID Lys and contained 10 ppm ractopamine. At d 27, pigs were transported to a commercial packing plant (JBS Swift and Company, Worthington, MN) for processing and carcass data collection. For overall growth performance, increasing SID Trp:Lys ratio increased (linear; P = <0.0001) SID Trp intake and Trp g/kg of gain; however, there was no evidence of a treatment difference (P > 0.10) for average daily gain (ADG) or feed efficiency (F/G). For carcass characteristics, increasing SID Trp:Lys decreased (linear; P = 0.002) carcass yield and tended to decrease (P = 0.078) lean percentage. There was no evidence of treatment differences (P > 0.10) for hot carcass weight, loin depth, carcass ADG, or carcass feed efficiency. The results from this study showed that grams per day of SID Trp intake ranged from 5.5 to 7.5. Greater feed intakes observed in this study resulted in increased Trp g/d of intake and could potentially be a reason why no evidence for treatment differences was observed. In summary, increasing SID Trp:Lys ratios above 20% (approximately 5.4 g SID Trp intake per day) in pigs fed RAC did not improve growth or carcass performance.

How do animal performance and methane emissions vary with forage management intensification and supplementation?

Context Yields from Brazilian beef-production systems do not always match the expected potential of a forage-based beef-production system. This efficiency is dependent on adjustments of grazing intensity and supplement utilisation to achieve higher bodyweight gain and lower methane emission. Therefore, more studies are necessary to evaluate the association between pasture management and supplement doses. Aims The aim of the present study was to determine nutrient intake, nutrient digestibility, animal performance, carcass characteristics and enteric methane emissions of young Nellore bulls grazing Urochloa brizantha cv. Marandu pastures. Methods One hundred and forty-eight yearling bulls (230 ± 17 kg) were randomly assigned to a grazing-by-supplementation strategy that was designed to allocate three different sward heights with differing levels of supplementation during the wet season. Treatment combinations were (1) low sward height with high supplementation (LH-HS, 15-cm sward height and supplementation at 0.6% of bodyweight (BW)); (2) low height with moderate supplementation (LH-MS, 15 cm and 0.3% BW); (3) moderate height with moderate supplementation (MH-MS, 25 cm and 0.3% BW); (4) moderate height with low supplementation (MH-LS, 25 cm and 0.1% BW); (5) high height with low supplementation (HH-LS, 35 cm and 0.1% BW); and (6) high height with no supplementation (HH-WS, 35 cm). Key results Bulls in the HH groups had a greater herbage intake than did those in the LH groups (P &amp;lt; 0.01). Bulls in the LH-HS treatment resulted in a greater (P &amp;lt; 0.01) carcass average daily gain than that obtained with LH-MS, MH-LS or HH-WS treatment. Higher stocking rate with the LH treatment resulted in greater gains per hectare in terms of both BW and carcass (P &amp;lt; 0.01). Carcass yield was greater for bulls maintained with the LH-HS treatment (54.3% BW). Higher enteric methane emissions were observed from bulls under the HH treatments (P &amp;lt; 0.01). Conclusions Comparing carcass gains per hectare and low methane emissions, the present study indicated that pasture management towards a low sward height combined with 0.3% or 0.6% BW supplementation can result in a greater nutrient utilisation efficiency of bulls. Implications Results provided information to obtain better gains per animals and area, also decreasing methane emission of beef cattle production system.

214 Correlation among host gut microbiome and their relationship with meat quality and carcass composition traits of swine

Abstract Study on correlation among host gut microbiome and their relationship with meat quality and carcass composition traits remains limited. The objectives of this study were 1) to estimate the microbial correlation between meat quality and carcass traits; and 2) to estimate the genetic correlation between microbial alpha diversity, and meat quality and carcass traits in commercial swine population. Data were collected from Duroc sired three-way cross individuals (n = 1,123) genotyped with 60K SNP chips. Fecal 16S microbial sequences for all individuals were obtained at three different stages: weaning (WEAN: 18.64 ± 1.09 days); week 15 (W_15: 118.2 ± 1.18 days); and off test (OT: 196.4 ± 7.80 days). Alpha diversity was measured at each stage [WEAN (alpha_w), W_15 (alpha_15) and OT (alpha_off)] using the Shannon index, which was computed as: ∑ ni=1piln(pi) where pi was the proportional abundance of ith operational taxonomic unit. Microbial correlations were estimated using multi-trait model, which included fixed effects of dam line, contemporary group and sex, as well as random effects of pen, additive genetic and microbiome. Bivariate analyses were conducted between different traits and alpha_w, alpha_15 and alpha_off with the same fixed effects and random pen and additive genetic effect. Analyses were conducted in ASREML v.4. Microbial correlations ranged from -0.93 ± 0.11 between firmness and slice shear force to 0.97 ± 0.02 between carcass average daily gain (CADG) and loin weight. For meat quality traits, correlations were weak, except for alpha_15 with Minolta a* (-0.45±0.19). Alpha_15 showed weak correlations except with CADG (-0.43±0.19). All correlations between alpha_ot and growth, carcass and meat quality traits were weak. These results may establish a newer approach of genetic evaluation process by utilizing gut microbiome information.

PSXIV-11 Supplementation of 25-hydroxy-vitamin-D3 and increased vitamin E as a strategy to increase carcass weight of feedlot beef cattle

Abstract Our objective was to evaluate the effects of supplementing 1mg of 25-OH vitamin D3 (HyD®) and increased vitamin E amount (2000 mg/animal/d) on cattleˈ performance and carcass characteristics when fed a 90-d feedlot finishing diet. A total of 140 Nellore bulls (IBW = 387 ± 28 kg) were distributed in 14 pens (10 animals/pen) in a randomized complete block design (7 pens per treatment). The basal diet was composed by 15% sugarcane bagasse, 72.8% ground corn, 7.6% soybean meal and 4.6 % mineral-vitamin premix (DM basis). The dietary treatments were: 1) Control: No addition of 25-hydroxy-vitamin-D3 (HyD®) and basal Vit. E amount (520 mg/animal per day); 2) HyD+Vit.E: Addition of 1 mg of HyD® plus increased Vit. E amount (2000 mg/animal per day). The animals were fed once daily and had free access to fresh water. Statistical analysis was performed using the MIXED procedure of SAS 9.4. Means comparison was evaluated by tukey test and declared significant at P &amp;lt; 0.05, and tendencies considered when 0.05 &amp;lt; P &amp;lt; 0.10. There was no difference on final body weight (~522.8 kg, P = 0.11), ADG (~1.54 kg/d, P = 0.17), DM intake (~9.9 kg/d, P = 0.41) and G:F (~0.156, P = 0.28) between treatments. Likewise, no differences were observed (P &amp;gt; 0.10) for dressing (~53.5%), REA (~65.5 cm²) and SFT (~4.10 mm). However, feeding HyD+Vit.E tended to increase (P = 0.07) carcass average daily gain (0.993 vs. 0.953 kg/d) and increased (P = 0.04) carcass weight by 4.2 kg compared with control (281.6 vs. 277.4 kg). In conclusion, the combination of HyD and increased vitamin E increases carcass production in feedlot cattle.

212 Genomic prediction of carcass average daily gain, fat and loin depth in three-way crossbred pigs including information collected on purebreds

Abstract The purpose of this study was to predict three-way crossbred performance for carcass traits using different crossbred/purebred reference populations. Carcass measures (average daily gain, back-fat and loin depths) were collected in 4,893 three-way-cross individuals (CB individuals, 1,252 being genotyped). Live measures of body weight and tissue deposition were collected on 3,050 purebred Duroc individuals (PB individuals, 941 being genotyped), paternal-half-sibs (PHS) of the CB individuals. Models’ predictive performance was tested via 4-fold cross-validation. The basic model included CB phenotypes from the training set without inclusion of genomic information (i.e. pedigree BLUP). We also sequentially included: 1) CB genotypes; 2) PB phenotypes and genotypes for the training families (PBt); 3) PB phenotypes and genotypes for the validation families (PBv). Variance components (heritabilities and genetic correlations between CB and PB traits) were not estimated but fixed at different values within a plausible interval, the combination of such parameters that gave the best predictive ability was considered for that model. Results reported pedigree prediction of CB traits to show about 0.25 accuracy (correlation between breeding value and adjusted phenotype) for the three traits. The inclusion of CB genotypes was beneficial, with an increase ranging from 25 to 50% (depending on the trait) compared to pedigree prediction. When PBt genotypes and phenotypes were included, prediction accuracy dropped to almost null accuracy. When PBv genotypes and phenotypes were included, predictive performance was better than models that included CB information only. Results suggest that PB information can improve selection accuracy for CB traits, with the condition PB are PHS of the CB in validation. Otherwise, inclusion of PB information from the training set can be detrimental. CB genotypes, on the other hand, always improve prediction accuracy. We can conclude that reference populations aimed at improving CB performance should include phenotypes and genotypes from these individuals.