Carcass Weight Research Articles

77 Differences in carcass quality and meat quality between cattle of different breed types

Abstract Crossbreeding cattle in the beef industry is a common practice to improve production and increase profitability. Introducing Bos indicus (BI) genetics into cattle herds is one potential method to improve production, as they are able to withstand higher temperatures, are better adapted to nutritional stress, and consume less water than Bos taurus (BT) cattle. However, introduction of BI genetics is known to decrease both carcass and meat quality compared with those from BT cattle. As such, the objective of this study was to determine how crossbreeding commercial Angus cows with Santa Gertrudis bulls to incorporate BI genetics impacts carcass and meat quality of the resultant offspring. This study utilized 38 steers of two different breeds: Angus (AN; n = 29; 100% BT) or Santa Gertrudis influenced (SG; n = 9; 19% BI, 81% BT). All steers were fed the same typical ration and harvested at a commercial facility once industry average body weight and backfat standards were met. Hot carcass weight (HCW), ribeye area (REA), yield grade (YG), and marbling scores were collected at harvest. Individual loins were collected for meat quality analysis. Meat quality data were collected after 14 d of wet aging at 4˚C. Meat color data was collected on d 0, 3, and 7. Statistical analysis was done using the MIXED procedure of SAS to assess the main effect of breed. Color analysis was conducted with day as a repeated measure. Least squares means were separated using Tukey-Kramer adjustments. Angus cattle had an increased (P = 0.009) REA and tended to have a reduced (P = 0.06) YG than SG cattle. However, no differences (P ≥ 0.13) between breeds were observed in HCW or marbling score. Additionally, no differences (P ≥ 0.08) were observed in meat quality (pH, drip loss, cook loss, Warner-Bratzler Shear Force, or Texture Profile Analysis) between breeds. There was not a day x breed (P > 0.65) or breed (P ≥ 0.57) effect for L*, a*, or b* color values. Day affected (P = 0.008) L*, a*, and b*, such that a* and b* both increased on d 3, then decreased on d 7, while L* increased on d 3 and remained consistent until d 7. These results are promising as they indicate there may not be differences in carcass quality and meat quality when utilizing this method to introduce BI genetics into a traditional BT production system. As such, this could be a useful tool in managing production systems in our beef herds. However, future research with a larger sample size will be necessary to gain more conclusive results.

349 The relationship of heart score with hot carcass weight and fat depth in Angus cattle

Abstract Congestive Heart Failure (CHF) is a cardiopulmonary condition observed in cattle raised in feedlots situated at elevations above 800 m. This condition leads to right-sided heart failure caused by increased pulmonary vessel pressures and cardiopulmonary remodeling, known as pulmonary hypertension (PH). In cattle experiencing PH, pulmonary arterial pressure (PAP) becomes abnormally high, increasing heart muscle load. This load stretches muscle fibers and enlarges the right side of the heart which can lead to heart failure and death. To assess the severity of PH, animals are assigned a heart score (HS) on a scale ranging from 1 to 5 at harvest. A score of 1 represents a normal heart, while a score of 5 indicates extreme heart remodeling. Understanding the relationship between hot carcass weight (HCW), fat depth (FD), and HS in Angus cattle will provide useful information on the impacts of this condition on feedlot performance and profitability. The objective of this study was to determine if a phenotypic relationship between HCW and FD with HS in Angus-influenced cattle. For this experiment, a total of 798 black, Angus-influenced cattle were used (245 steers, 553 heifers) that were fed near Greeley, CO. The HCW, FD, and HS data from each animal were recorded at harvest. Three general linear models were used to estimate the effects of HS on HCW and FD. Mean HCW and FD were 393.1 kg, (SD = 90.9) and 0.66 mm, (SD = 0.18), respectively, with an average HS of 2.08 (SD = 0.77). For all models, HCW and FD were fit as dependent variables, while lot and HS were included as fixed effects. Model 1 included all HS categories independently. Model 2 divided HS into 2 groups of normal (HS = 1 or 2) or remodeled (HS = 3+). For model 3 HS 3 was removed leaving only HS of 4 or 5 in the remodeled group. For both HCW and FD in Model 1, the overall effect of HS was not significant (P = 0.82 and P = 0.40, respectively). However, when comparing individual scores, animals with a HS = 4 were 15.0 kg lighter for HCW than individuals with a HS = 1 (P < 0.05). Conversely for FD, a non-significant difference (P = 0.74) of -0.33 mm was observed between animals with a HS = 4 versus a HS = 1. Grouping HS into 2 categories in Model 2 did change the outcome, yielding non-significant HCW and FD differences. However, when eliminating the HS = 3 data, a significant reduction in HCW of 16.9 kg (P = 0.05) was observed between the 2 HS groups, whereas non-significant effects on FD remained. These data suggest that at extreme levels of heart remodeling HCW may be extremely impacted negatively.

367 Changing the conversation: Evaluating feedyard closeouts and the beef system on a carcass basis

Abstract Beef cattle genetics, management, technologies and nutritional strategies are ever evolving, and current US trends favor feeding cattle to heavier carcass endpoints and optimizing quality grade. The average number of days on feed (DOF) in the US has increased year after year, averaging 195 and 183 DOF for steers and heifers, respectively, as reported by Elanco Benchmark data in 2021. As DOF increase, cattle live performance, including average daily gain and feed efficiency decline; however, hot carcass weight (HCW) becomes significantly heavier. Although a reduction in live feed conversion occurs as cattle are fed for extended DOF, the kilograms of additional live gain that result as kilograms of gain on the carcass, termed carcass transfer, increase linearly. As DOF are extended, carcass transfer has been reported to increase up to 88 %. As a result of genetic advancements, technologies, and feeding longer, HCW has trended heavier over the last 60 yr, with 2024 USDA HCW reported for April as 11.3 and 9.5 kg heavier for steers and heifers, respectively, year after year. According to mandatory price reporting data, approximately 74 % of fat cattle marketed in the US are sold as dressed beef. As we continue to feed to heavier endpoints and longer DOF, the profitability of selling on a carcass-basis increases. With the increase in carcass transfer as DOF extend, this presentation will attempt to address that cattle live performance should be adjusted to a carcass-basis for feedyards to appropriately capture the inflection point at which cost of additional gain equals the price received for the additional gain.

64 Effects of alternative finishing methods on performance and carcass quality of beef feeder steers

Abstract There has been an interest in directly locally marketing finished beef end products in Arkansas; however, most beef operations do not have the infrastructure to finish cattle conventionally. The objective of this study was to evaluate two non-traditional finishing methods (pasture-based with supplement) compared with a conventional finishing method on live performance and carcass quality of feeder steers. Crossbred beef steers (n = 63; 363.9 ± 28.7 kg) were blocked by body weight (BW) and assigned to pens (n = 3 steers/pen) with 7 pens randomly allocated to each treatment: conventional feedlot finishing diet with roughage included in the ration (FDLT); high starch supplement fed at 2 to 2.25% of BW with ad libitum access to bermudagrass pasture (STCH); or high by-product supplement fed at 2-2.25% of BW with ad libitum access to bermudagrass pasture (BYPD). Steers were fed their respective diets once daily and weighed on d 0, 28, 56, 84, 112, 140, and 161. Once cattle reached their targeted endpoint, they were transported to and harvested at a commercial slaughter facility in Arkansas City, Kansas. Carcass data were collected including hot carcass weight (HCW), preliminary yield grade (PYG), yield grade (YG), quality grade (QG), dressing percentage (DP), and final carcass value. Data were analyzed using PROC GLIMMIX and MIXED (SAS 9.4); pen was the experimental unit, treatment was a fixed effect, and block was considered a random effect. Cattle fed FDLT and BYPD had a greater BW on d 84, 112, and 140 (P ≤ 0.02) and greater overall carcass-adjusted BW (P = 0.03) compared with STCH. Average daily gain (ADG) was greater on d 84 (P = 0.03) for FDLT compared with STCH and BYPD. Overall carcass-adjusted ADG tended (P = 0.09) to be greater for FDLT and BYPD compared with STCH. As expected, cattle fed FDLT had greater dry matter intake (DMI) compared with STCH and BYPD for the entire study (P ≤ 0.0005). Both STCH and BYPD had a more efficient feed-only feed conversion on d 28, 56, 112, 140, and 0-161 (P ≤ 0.05) and were more economical (P < 0.0001) than FDLT. In this study, cattle fed BYPD were more profitable (P ≤ 0.04) compared with STCH and FDLT. Hot carcass weight tended (P = 0.13) to be greater and final carcass value (P = 0.01) was greater for BYPD and FDLT compared with STCH. No differences (P ≤ 0.78) were noted for PYG, YG, QG, or DP. Data from this study suggests feeding supplemental diets to beef cattle grazing pasture could successfully be used as an alternative finishing method without affecting carcass quality.

350 Awardee Talk: Beef cattle mineral nutrition: What do we know and where do we go from here

Abstract Trace minerals are pivotal in enhancing cattle growth and ensuring profitability in beef production. Historically, supplementation strategies have aimed at preventing deficiencies, significantly improving growth and reproductive performance. However, as cattle breeding has evolved to achieve remarkable growth rates, the challenges related to health and stress during the feeding period have intensified. This presentation explores refined trace mineral recommendations, focusing on zinc’s “stress requirement” for cattle undergoing transit and health challenges, and its impact on performance. The segmented nature of the beef industry, necessitating multiple transports, induces physiological stress and oxidative stress, highlighting the need for tailored mineral supplementation. Further, when recognizing feedlot cattle as the high-performing athletes they are, the potential benefits of adjusted trace mineral concentrations become apparent. Preliminary findings suggest that optimal zinc concentrations may exceed current National Academies of Sciences, Engineering, and Medicine (NASEM) 2016 recommendations, whereas for other minerals like copper and manganese, the existing guidelines remain appropriate. This presentation will explore the differential effects of increasing dietary zinc and copper in conjunction with various growth-promoting technologies. Preliminary data indicates that increasing zinc concentrations can linearly enhance average daily gain (ADG) and hot carcass weight (HCW), especially when using potent anabolic implants, while the response to increased copper concentrations exhibits a more quadratic relationship with performance. Building upon the foundational work of pioneering researchers in the field of mineral nutrition, this presentation advocates for the continuous refinement and optimization of trace mineral supplementation strategies. By integrating cutting-edge technologies and fostering collaborative research efforts, we aim to further enhance the sustainability of the beef industry. A deeper understanding of trace mineral requirements in the face of modern production challenges will pave the way for more precise and effective nutritional strategies.

361 Evaluating the effect of liver copper concentration on lubabegron fumarate-induced performance and carcass characteristics of finishing steers

Abstract The objective of this study was to evaluate the effect of copper (Cu) status on response to lubabegron fumarate (Experior, Elanco, Greenfield, IN). Angus crossbred steers [n = 48; body weight (BW) = 469 ± 31 kg] were enrolled in a 77-d finishing study, housed in pens of 6, with a GrowSafe bunk (GrowSafe Systems, Ltd, Airdire, AB, Canada) in each pen and implanted (Revalor-200, Merck Animal Health, Madison, NJ; 200 mg TBA + 20 mg E2) on d 0. A 2 × 2 factorial arrangement was applied to Cu status (deficient, DEF, no supplemental Cu; or adequate, ADE, 10 mg supplemental Cu/kg DM as CuSO4) and Experior (36 mg·steer⁻¹·d⁻¹, EXP; or no Experior, NOEXP). A prior trial resulted in steers with distinct liver Cu (DEF and ADE were 42 ± 21 and 193 ± 31 mg Cu/kg DM, respectively). Experior was fed from d 37 to d 73, and cattle harvested on d 78. Body weights were collected on d -1, 0, 37, 55 (mid-Experior), 76 and 77. Blood was collected on d 0, 37, 55, and 76 for serum urea nitrogen (SUN), non-esterified fatty acids (NEFA), glucose, and insulin. Data were analyzed in Proc Mixed of SAS as a factorial design, with steer as the experimental unit (n = 12 per treatment). From d 0-37, DEF daily gain and feed efficiency (G:F) were greater than ADE (P < 0.01), while dry matter intake (DMI) did not differ (P = 0.36). Overall DMI was greater in ADE than DEF (P = 0.04) and not affected by Experior (P = 0.13). Carcass-adjusted average daily gain was not affected by Cu or Experior (P ≥ 0.21). Deficient steers had greater carcass-adjusted G:F than ADE (P = 0.02). Hot carcass weight was greater in EXP (P = 0.04), but post-hoc analysis of the Cu x Experior effect (P = 0.2) reveals this was driven by DEF-EXP (15 kg over DEF-NOEXP) rather than ADE-EXP (4 kg over ADE-NOEXP). Marbling tended to be greater in ADE (P = 0.06) and was unaffected by Experior (P = 0.14). The revised quantitative insulin sensitivity check index displayed an EXP x Day effect (P < 0.01) where NOEXP was consistent across days and EXP had greater insulin sensitivity during the Experior period. Serum urea nitrogen was affected by Cu × Experior × Day (P = 0.01), where DEF-NOEXP had lesser d 0 SUN than all others, and EXP decreased on d 55 while NOEXP increased steadily during the finishing phase; by d 76 DEF-EXP remain lesser than NOEXP treatments with ADE-EXP being similar to all others. These data suggest Cu concentration influences steer response to lubabegron fumarate, and more research is needed to determine the cause of this.

51 Lean meat yield of Angus, Brahman and Charolais grain fed steers

Abstract Lean meat yield (LMY) is a key driver of profitability in the beef industry, and it is associated with muscling and feed efficiency (Pethick et al., 2021). No research has studied differences in LMY between British, Continental, and Tropical beef breeds fed for increasing days on feed. The objective of the present study was to compare LMY of Angus, Brahman and Charolais steers with increasing days on feed (DOF). The hypothesis was that Charolais have the greatest LMY throughout the feeding period due to being a later maturing, high muscling breed compared with Angus and Brahman. Angus (n = 30), Brahman (n = 30), and Charolais (n = 29) 12-18 mo-old steers were inducted with a body weight (BW) of 361 ± 5.3 kg, 355 ± 5.3 kg and 317 ± 5.3 kg, respectively. Six animals of each breed were randomly selected for slaughter at 50-d intervals until 200 DOF. Steers were allowed ad libitum access to water and feed (78% rolled barley, 13.76% CP, 12.15 ME MJ/kg DM). Body weight, hot carcass weight (HCW), and LMY were measured at slaughter. All components of the animal were collected, and carcass muscle, fat and bones physically dissected with knives and weighed separately. The LMY as % empty BW (EBW) was calculated as the weight of lean meat separated from the carcass divided by EBW. The LMY as % of HCW was calculated as the weight of lean meat separated from the carcass divided by HCW. Data was analyzed with a model containing the fixed effect of breed, DOF at slaughter, and their interaction. Breed, DOF and their interaction affected LMY expressed as both ratio to EBW and HCW (P < 0.05). Charolais steers had the greatest LMY (% HCW) at 50, 100, and 150 DOF, but similar to Brahman at 0 and 200 DOF (P < 0.05; Figure 1a). Angus steers showed the lowest LMY (% HCW) throughout all DOF (P < 0.05) except at 50 DOF being similar to Brahman (P > 0.05). Furthermore, Charolais had the greatest LMY (% EBW) from 50 to 200 DOF (P < 0.05) but it was similar to Brahman at 0 DOF (Figure 1b; P > 0.05). Angus had the least LMY (% EBW) throughout (P < 0.05) but was not different to Brahman at 50 DOF. Brahman had intermediate LMY (% EBW and % HCW) between Charolais and Angus. Differences between beef breeds suggest that LMY should be considered as another factor to establish an accurate carcass value.

399 Effect of feeding palm oil products on finishing cattle performance, carcass characteristics, and methane production

Abstract The objectives of this experiment were to evaluate feeding palm oil products on feedlot cattle performance and methane production. Steers (n = 320; 380 ± 14.5 kg) were allocated to 40 pens in a randomized block design and assigned to 1 of 5 treatments consisting of different sources of supplemental fat: 1) No Oil; negative control containing 0.0% supplemental fat, 2) Corn Oil; positive control containing 4.0% supplemental corn oil, 3) Whole Palm; 4.0% supplemental whole palm oil, 4) Olein; 4.0% supplemental palm olein oil, or 5) Stearin; 4.0% supplemental palm stearin oil. Cattle consuming Corn Oil, Olein and Stearin all had greater (P = 0.04) final body weight (BW) and hot carcass weight (HCW) than cattle consuming no oil but were not different (P > 0.11) from each other or from Whole Palm, which was intermediate. Dry matter intake (DMI) of cattle consuming No Oil, Whole Palm and Stearin oil was not different from each other; however, cattle fed Corn Oil had greater intake than Whole Palm (P = 0.03). Corn Oil, Olein, and Stearin all had greater average daily gain (ADG) than cattle consuming No Oil (P = 0.04) but were not different (P > 0.12) from Whole Palm. Adding fat improved feed efficiency (gain to feed; G:F) as all diets including added fat had greater (P < 0.01) G:F than No Oil. Marbling scores were greater (P = 0.01) for Olein and Stearin than Corn and Whole Palm. There were no differences in backfat, ribeye area or liver abscess rate among any treatments (P > 0.74). Gas emissions were evaluated for only the No Oil and Whole Palm treatments. Total methane and methane produced per pound of dry matter intake was less for cattle consuming Whole Palm than No Oil by 14.8% (P < 0.04) while cattle were in the methane chamber. Methane produced per kilogram of ADG for Whole Palm was also reduced (P < 0.01) by 21.4% compared with No Oil. The results of this study indicate feeding palm oil products as a source of supplemental fat in finishing diets increases final BW, ADG, and HCW compared with feeding no supplemental fat, but had minimal impact on DMI resulting in an improvement in G:F. Adding supplemental fat reduced methane emissions in cattle when feeding Whole Palm compared with No Oil. The value of palm oil products in feedlot finishing diets is comparable with feeding corn oil.

22 Effects of trace mineral source and chromium propionate supplementation on rumen fermentation, growth performance, and carcass characteristics in finishing beef steers

Abstract Crossbred beef steers [n = 400; body weight (BW) = 370 ± 8 kg] were used to evaluate the effects of trace mineral (TM) source and chromium propionate (Cr) on rumen fermentation characteristics, plasma glucose and mineral concentrations, performance, and carcass characteristics in feedlot steers fed a steam-flaked corn-based finishing diet. Steers were blocked by initial BW and randomly assigned within block to 1 of 4 treatments (10 steers/pen) with 10 pens per treatment. The experimental design was a randomized complete block design with a 2 x 2 factorial arrangement of treatments. Factors included: 1) TM source [sulfate or hydroxychloride (IntelliBond] Cu, Mn, and Zn TM supplemented at 18, 40, and 90 mg/kg DM, respectively) and 2) with or without supplemental Cr (KemTRACE) at 0.0 or 0.25 mg/kg DM. Steers were individually weighed on d -1 and 0 and every 28 d throughout the experiment. Jugular blood samples and rumen contents were collected from 10 steers per treatment on d 28 and 84 of the experiment for plasma glucose and TM concentration and volatile fatty acid analysis, respectively. On d 154 of the experiment, steers were harvested at a commercial abattoir and carcass data was collected. Data were analyzed on a pen mean basis for a randomized complete block design using PROC MIXED of SAS. There was no TM source by Cr supplementation interactions for any of the response variables measured, therefore only main effects are reported. Overall ADG (P = 0.03) and gain:feed (P = 0.02) were greater in steers receiving supplemental Cr when compared with steers not supplemented with Cr. Hot carcass weight (P = 0.04), dressing percentage (P = 0.01), longissimus muscle area (P = 0.03), and USDA yield grades (P = 0.04) were greater in steers receiving hydroxychloride TM compared with steers receiving sulfate TM. Steers supplemented with Cr had a greater dressing percentage (P = 0.01) and longissimus muscle area (P = 0.04) compared with steers not supplemented with Cr. On d 28 of the experiment, ruminal acetate concentrations were lesser (P = 0.01) and ruminal propionate concentrations tended to be greater (P = 0.12) in steers receiving hydroxychloride TM compared with steers receiving sulfate TM. Steers supplemented with Cr had greater ruminal acetate concentrations (P = 0.04) and plasma glucose concentrations (P = 0.05) on d 28 of the experiment when compared with non-supplemented controls. These data indicate the Cr supplementation and TM source can influence feedlot steer performance, carcass characteristics, and rumen fermentation characteristics.

490 Lifetime growth performance and carcass composition of offspring when inactivated Saccharomyces cerevisiae was included in gestating and lactating gilt diets and/or offspring nursery diets

Abstract Gilts [n = 90; initial body weight (BW) = 189.1 ± 3.9 kg] were used to determine the effect of feeding a yeast additive (Saccharomyces cerevisiae inactivated through hydrolyzation; HY) to gestating and lactating gilts and/or the offspring during the nursery period on lifetime offspring growth performance. Gilts were randomly assigned to one of three dietary treatments (n = 30/treatment): standard gestation and lactation diets (GHY0) or supplemented with 0.25% (GHY0.25) or 1% (GHY1.0) HY. Diets were fed between d 85 of gestation until weaning at d 21 (2.6 kg/d in gestation, ad libitum in lactation). At weaning, 8 piglets/litter were placed in nursery pens and pens were randomly assigned to a control (NO) or a HY-supplemented diet (NHY), apart from GHY1.0 offspring who were only provided NO during the nursery period (n = 12). In nursery phases 1, 2 and 3, HY was included at 0.75, 0.50, and 0.25% respectively. Thereafter, pigs received standard grower and finisher rations until slaughter (160 d of age). Data were analyzed in SAS using GLIMMIX with gilt treatment as the main effect (pre-weaning); post-weaning performance used gilt and nursery treatments as the main effects, and interactive effects were tested separately due to the incomplete 3 × 2 factorial design. Mean comparisons were conducted using the Tukey-Kramer test to separate LSmeans. Gilt BW was unaffected by gilt treatment, but gilts fed GHY1.0 had greater total lactation feed intake versus GHY0.25 (128.6 vs. 109.4 ± 7.7 kg; P < 0.01). At birth, GHY0.25 offspring were 70 g heavier than pigs from GHY0 (P < 0.001) with GHY1.0 intermediate. At weaning, GHY0.25 and GHY1.0 offspring were heavier than GHY0 offspring (5.9 vs. 5.6 kg; P < 0.001). After weaning, neither gilt nor nursery diet influenced offspring BW. Pigs fed GHY1.0-NO had greater ADFI versus all other treatments in the nursery (interaction; P < 0.001), GHY0.25-NHY had greater ADFI than GHY0.25-NO and GHY1.0-NO in the grower (interaction; P = 0.005), and NHY consumed more feed than NO in the finisher phase (main effect; P < 0.001). In the nursery, NHY had less average daily feed intake (ADFI) than NO (main effect; P < 0.05), but in grower and finisher, NHY had greater ADFI than NO pigs (main effect; P < 0.001). In the nursery, gain to feed (G:F) was greater for GHY0-NHY versus GHY0.25-NHY and GHY1.0-NO, and greater for GHY0-NO versus GHY0.25-NHY with all other treatments intermediate (interaction; P < 0.05). In the grower phase, G:F was unaffected by maternal or nursery diet, but in the finisher phase, G:F was less for pigs fed NHY versus NO during the nursery phase (main effect; P < 0.05). Slaughter BW, hot carcass weight, and fat and lean percents were not influenced by gilt or nursery diet. Therefore, HY provided to gilts during gestation and lactation, improved pre-weaning offspring growth, but HY supplemented to pigs during the nursery period had greater positive effects on lifetime growth performance.

Nutritional composition and technological properties determining the quality of different cuts of organic and conventional Turkey meat

The aim of this study was to evaluate the nutritional composition and technological properties of meat from turkeys produced under organic conditions and compare them with those of turkeys produced under conventional conditions. Twenty carcasses of female B.U.T. Premium turkeys (Aviagen Turkeys) were obtained directly from the abattoir ten h after slaughter time of animals. Ten carcasses originated from female turkeys reared under conventional intensive husbandry conditions for meat-type turkeys (on average, 5611.8 ± 196.2 g of carcass weight) and the other ten carcasses corresponded to female turkeys raised under certified organic free-range conditions (PavosBio, Ávila, Spain) (on average, 5528.5 ± 354.4 g of carcass weight). Breast, thigh and wing meat samples were analyzed from each turkey: Chemical composition, fatty acid profile, free amino acids, mineral and vitamins content, color, and texture. Meat from female turkeys reared under organic conditions presented higher fat content in breast (1.90 vs. 1.01%, P = 0.032), thigh (3.79 vs. 2.68%, P = 0.022) and wing (12.0 vs. 8.91%, P = 0.012) than meat of female turkeys reared under intensive conventional conditions. The proportion of saturated fatty acids was higher in the meat of intensively reared female turkeys than in those reared under organic conditions (42.8 vs. 38.1%, P = 0.017 in breast; 38.8 vs. 33.6%, P = 0.0053 in thigh and 40.2 vs. 33.9%, P < 0.001 in wing). On the contrary, the proportion of monounsaturated fatty acids was higher in meat of organic turkeys (41.4 vs. 35.6%, P = 0.012 in breast; 42.3 vs. 35.6%, P < 0.001 in thigh and 46.9 vs. 39.3%, P = 0.011 in wing). Concentration of riboflavin and pyridoxine was higher by 21.1% (P = 0.010) and by 154% (P = 0.006), respectively, in meat from organically raised female turkeys than in that of female turkeys reared under intensive conditions. The organic turkey meat analyzed contained a higher proportion B2 and B6, lipids and monounsaturated fatty acids, and a lower content of omega-3 polyunsaturated fatty acids.

Effects of replacing soybean meal with enzymolysis-fermentation compound protein feed on growth performance, apparent digestibility of nutrients, carcass traits, and meat quality in growing-finishing pigs

BackgroundAddressing the shortage of high-quality protein resources, this study was conducted to investigate the effects of replacing soybean meal (SBM) with different levels of enzymolysis-fermentation compound protein feed (EFCP) in the diets of growing-finishing pigs, focusing on growth performance, nutrients digestibility, carcass traits, and meat quality.MethodsSixty DLY (Duroc × Landrace × Yorkshire) pigs with an initial body weight of 42.76 ± 2.05 kg were assigned to 5 dietary treatments in a 2 × 2 + 1 factorial design. These dietary treatments included a corn-soybean meal diet (CON), untreated compound protein feed (UCP) substitution 50% (U50) and 100% SBM (U100) diets, and EFCP substitution 50% (EF50) and 100% SBM (EF100) diets. Each treatment had 6 pens (replicates) with 2 pigs per pen, and the experiment lasted 58 d, divided into phase I (1–28 d) and phase II (29–58 d). Following phase I, only the CON, U50, and EF50 groups were continued for phase II, each with 5 replicate pens. On d 59, a total of 15 pigs (1 pig/pen, 5 pens/treatment) were euthanized.ResultsDuring phase I, the EF50 group had a higher average daily gain (ADG) in pigs (P < 0.05) compared to the CON group, whereas the U50 group did not have a significant difference. As the substitution ratio of UCP and EFCP increased in phase I, there was a noticeable reduction in the final body weight and ADG (P < 0.05), along with an increase in the feed-to-gain ratio (F/G) (P < 0.05). In phase II, there were no significant differences in growth performance among the treatment groups, but EF50 increased the apparent digestibility of several nutrients (including dry matter, crude protein, crude fiber, acid detergent fiber, ash, gross energy) compared to U50. The EF50 group also exhibited significantly higher serum levels of neuropeptide Y and ghrelin compared to the CON and U50 groups (P < 0.05). Moreover, the EF50 group had higher carcass weight and carcass length than those in the CON and U50 groups (P < 0.05), with no significant difference in meat quality.ConclusionsThe study findings suggest that replacing 50% SBM with EFCP during the growing-finishing period can improve the growth performance, nutrient digestibility, and carcass traits of pigs without compromising meat quality. This research offers valuable insights into the modification of unconventional plant protein meals and developing alternatives to SBM.

Undegradable dietary protein limits growth and carcass yields in crossbred Boer kids fed Desmanthus hay or Rhodes grass (Chloris gayana) hay supplemented with urea and/or cottonseed meal

Context Low-protein tropical forages required protein supplementation, which might affect growth of meat goats. Aims This study was aimed to compare liveweight gain, carcass/non-carcass yields and meat quality in crossbred Boer kids fed isonitrogenous diets varying in undegradable (UDP) and rumen-degradable (RDP) dietary protein sources. Methods Twenty-five female crossbred Boer kids were randomly allocated into the following five dietary treatments: Rhodes grass (Chloris gayana) hay supplemented with urea (U), urea plus cottonseed meal (UCSM), cottonseed meal (CSM), gliricidia (Gliricidia sepium) (Gliri) or Desmanthus (Desmanthus leptophyllus) only (Desman). The diets were formulated to supply 135 and 195 g crude protein/kg DM for the two experiments. Experiment 1 lasted 78 days and the dietary UDP:RDP ratio (g/kg DM) was 35:102 (U), 37:100 (UCSM), 40:97 (CSM), 55:82 (Desman) and 46:91 (Gliri). Experiment 2 lasted 138 days and the dietary UDP:RDP ratio (g/kg DM) was 45:150 (U), 52:143 (UCSM), 58:137 (CSM), 83:112 (Desman) and 71:124 (Gliri) respectively. Data were subjected to one-way ANOVA and general linear model. Key results After 138 days of supplementation, the Desman goats had the highest liveweight gain (83 g/day) and heaviest cold carcass weight (12.1 kg) in Experiment 2. This was followed, in descending order, by CSM (58 g/day and 9.6 kg), UCSM (48 g/day and 7.8 kg), Gliri (41 g/day and 7.6 kg) and U (6 g/day and 6.0 kg). Heavier carcass weight was associated with larger eye-muscle area and fat depth at the 12th rib. Aus-meat Beef Colour Standard scores of 3–4 for the eye muscle of the Desman and CSM goats compared with scores of 1C-2 in the other goats meant that the darker meat in Desman and CSM diets was associated with heavier carcass weight and a more rapid rate of decline in carcass pH. Conclusions Crossbred Boer kids fed high dietary UDP had higher intakes of UDP, RDP, metabolisable protein (MP) and metabolisable energy (ME), even though an isonitrogenous diet was offered. The Desman kids had higher liveweight gain, heavier carcass yield, greater eye-muscle area, thicker fat depth and heavier mass of non-carcass components. Implications The higher liveweight gain and carcass/non-carcass yields for Desman goats than for others was associated with increased DM, UDP, RDP, MP and ME intakes.

Effects of a Bacillus-based direct-fed microbial on performance, blood parameters, fecal characteristics, rumen morphometrics, and intestinal gene expression in finishing beef bulls.

We evaluated the effects of supplementing direct-fed microbials (DFM), containing Bacillus licheniformis and Bacillus subtilis, on performance, rumen morphometrics, intestinal gene expression, and blood and fecal parameters in finishing bulls. Nellore × Angus bulls (n = 144; initial BW = 401 ± 45.5kg) were distributed at random in 36 pens (4 bulls/pen and 18 pens/treatment), following a completely randomized design. A ground corn-based finishing diet was offered for ad libitum intake twice a day for 84 d, containing the following treatments: 1) control (without DFM); 2) DFM (B. licheniformis and B. subtilis) at 6.4 × 109 CFU (2g) per animal. The data were analyzed using the MIXED procedure of SAS, with a pen representing an experimental unit, the fixed effect of the treatment, and the random effect of pen nested within the treatment. For fecal parameters (two collections made), the collection effect and its interaction with the treatment were included in the model. Bulls that received the DFM had a decreased dry matter intake (P ≤ 0.01), did not differ in average daily gain (2.05kg; P = 0.39), and had a 6% improvement in gain:feed (P = 0.05). The other performance variables, final BW, hot carcass weight, and hot carcass yield, did not differ (P > 0.10). Plasma urea-N concentration decreased by 6.2% (P = 0.02) in the bulls that received DFM. Glucose, haptoglobin, and lipopolysaccharides were not different between treatments (P > 0.10). Ruminal morphometrics were not affected by the treatment (P > 0.10). The use of DFM tended to reduce fecal starch (P = 0.10). At slaughter, bulls fed DFM had an increased duodenal gene expression of tryptophan hydroxylase-1 (P = 0.02) and of superoxide dismutase-1 (P = 0.03). Overall, supplementation with DFM based on B. licheniformis and B. subtilis to Nellore × Angus bulls in the finishing phase decreased dry matter intake, did not influence ADG, improved gain:feed, and increased the expression of genes important for duodenal function.

Different dietary branched-chain amino acid ratios, crude protein levels, and protein sources can affect the growth performance and meat yield in broilers

Balanced ratios of branched-chain amino acids (BCAAs) can enhance chicken growth, immunity, and muscle synthesis. However, these ratios can be affected by changes in crude protein (CP) levels or the substitution of protein sources, leading to BCAA antagonism. This, in turn, can have a negative impact on chicken growth. In Experiment 1, a total of 960 0-d-old male Cobb 500 broilers were divided into 6 treatments with 8 replicates. Three different BCAA ratios were used in High or Low CP diets as follows: 1) Low Leu group (Low level of leucine with increased valine and isoleucine levels), 2) Med Leu group, and 3) High Leu group (High level of leucine with reduced valine and isoleucine levels) for a total of 6 diets. In Experiment 2, a total of 640 0-d-old male Cobb 500 broilers were divided into 4 treatments with 8 replicates. The four diets had either High or Low CP and one of two protein sources with the same medium levels of BCAAs: 1) the soybean meal (SBM) group, which had SBM as the main protein source (protein bound AA), and 2) the wheat middlings with non-bound AAs (WM+AA) group (non-bound AA), which had additional non-bound AAs to replace SBM. The High Leu diet had a negative effect on overall growth performance, carcass weight, breast muscle weight, and body mineral composition compared to the Low Leu and Med Leu groups, particularly in the High CP diet (P < 0.05). The SBM group showed increased growth performance, breast muscle weight, expression levels of genes promoting muscle growth, and improved bone mineral composition compared to the WM+AA group, and the High CP group intensified the negative effect of the WM+AA diet (P < 0.05). In summary, balanced BCAA ratios and SBM-based diets have positive effects on chicken growth and muscle accretion, whereas excessive leucine and non-bound AA levels in the diets may negatively affect growth performance and meat yield in chickens.

Genetic parameter estimation and genetic evaluation of important economic traits in white and yellow broilers

ABSTRACT 1. This study calculated descriptive statistics for the production traits of two broiler populations: 1) the Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF white broilers), including fat and lean lines; and 2) the Guangxi yellow broilers. Their genetic parameters were estimated, including (co)variance components, heritability (h 2 ) and genetic correlations (rg), using the REML method. 2. Heritability estimates (h 2 ) for NEAUHLF white broilers ranged from 0.07 to 0.61. Traits with high heritability (h 2 >0.3) included body weight at 3, 5 and 7 weeks of age (BW3, BW5, BW7), carcass weight (CW), metatarsal circumference (MeC), liver weight (LW), gizzard weight (GW), spleen weight (SW) and testis weight (TeW), while in Guangxi yellow broilers, heritability estimates ranged from 0.18 to 0.76, with every trait exhibiting high heritability, except for SW (0.18). 3. Positive genetic correlations for NEAUHLF were found (rg >0.3, ranging from 0.31 to 0.84) between BW7 and metatarsal length (MeL), MeC, body oblique length (BoL), chest angle (ChA), LW, GW, heart weight (HW) and SW. Genetic correlations between abdominal fat weight (AFW) and BW1, BW3, BW5, CW, MeL, keel length (KeL), BoL and LW were positive (rg >0.3, ranging from 0.31 to 0.58). 4. Among the Guangxi population, BW (125 d of age) showed strong positive genetic correlations with all other traits (rg >0.3, ranging from 0.30 to 0.99), while AFW displayed strong positive genetic correlations with leg muscle weight (LeW), CW, BW and thigh diameter (TD) (rg >0.3, ranging from 0.44 to 0.51). 5. It was concluded that the characteristics of the two populations were different, which means there is a need to use different strategies when performing the breeding work to improve productivity and efficiency in both broiler populations.

Effects of protein grass hay as alternative feed resource on lamb's fattening performance and meat quality

Protein grass hay (PGH) was used as a new feed source for lambs to study its effect on fattening performance and meat quality. Fifty-six male lambs were allotted to four experimental groups and fed for eight weeks either alfalfa hay (AH)-based diet (control) or diets in which AH was replaced with 33 %, 66 %, or 99 % PGH. The inclusion of PGH did not affect final body weight, dry matter intake, average daily gain, feed conversion ratio, or carcass weight. Moreover, substituting AH with PGH at any level did not influence the ruminal fermentation or serum biochemical parameters, meat color, water holding capacity, shear force, or amino acid profile. However, relative liver weight was increased with 66 % substitutions. Furthermore, replacing 99 % AH with PGH decreased the meat's pH at 24 h. Higher levels of C18:3n-3, C20:5n-3, and total n-3 PUFA and a lower ratio of n-6: n-3 PUFA were also observed in meat from lambs fed PGH at 99 %. These findings suggest that PGH could be incorporated into the lamb's diet up to 99 % without compromising fattening performance and body health while improving their meat n-3 PUFA deposition.

Probiotics effects on the growth performance and meat quality of broiler chickens

Context In the limited field of research on Kazakhstan’s poultry, this study explores a new area by investigating the lack of studies on the impact of probiotics from camel milk and mare’s milk. This study provides valuable knowledge about an important aspect of poultry production in the region. Aims The purpose of the study was to investigate the effect of probiotics isolated from traditional fermented dairy products, fermented camel milk (shubat) and fermented mare’s milk (koumiss) on the growth performance and meat quality of broiler chickens. Methods In total, 240 1-day-old Ross 308 chicks were randomly separated into four treatment groups of three replicates (20 birds per replicate). Three experimental groups were fed by basal diet plus drinking water containing 0.25 mL, 0.5 mL, and 1.0 mL of probiotics per bird (Pro1, Pro2, and Pro3 respectively). The control group was fed by basal diet plus drinking water. The carcass characteristics included the weights of the body and carcass rate. Organoleptic analysis, proximate composition, pH, drip loss, cook loss and were used to determine meat-quality properties. Key results According to the study results isolated probiotics Lacticaseibacillus paracasei subsp. paracasei SH1, Enterococcus faecalis SH6, and Kazachstania unispora Y 2.2 had a significant effect on body and carcass weight (P &lt; 0.05). Average daily gain and feed conversion ratio were also improved in probiotics groups (P &lt; 0.05). Additionally, Pro 2 group had increased meat protein contents (P &lt; 0.05). No significant differences in organoleptic quality between the control and experimental groups fed with the probiotics were determined. Conclusions Traditional fermented dairy products could become a source of new effective probiotics useful to improve broiler production. Implications The readily available shubat and koumiss in Kazakhstan present a promising opportunity for establishing localised probiotic production for poultry, indicating a viable path for promoting sustainable and tailored approaches to poultry farming in the region.

Evaluation of Dietary Supplementation of a Multi-Carbohydrase Enzyme Complex on Growth Performance and Carcass Traits of Pekin Ducks Fed Corn–Soy Based Diets

The present study investigated the effect of supplementing a multi-carbohydrase enzyme complex (MCE) in corn–soy-based diets of Pekin ducks. The treatments were as follows: positive control (PC, 2980 and 3120 kcal/kg for starter and grower, respectively); negative control (NC, −132 kcal/kg energy reduction to PC achieved by reduction of fat and wheat middlings as filler); NC + MCE at 75 ppm (E75); 100 ppm (E100); and 125 ppm (E125) randomly distributed in 10 replicate pens with 25 birds each. Performance was evaluated after 14 and 35 d. On day 36 of the trial, five ducks/pen were processed to evaluate carcass traits. During days 1–14, the PC had a lower (p &lt; 0.01) feed intake compared to all other treatments. At 14 and 35 d of age the NC decreased (p &lt; 0.001) the body weight (BW) of the ducks compared to the PC by −8.3% and −5.3%, respectively. The NC BW was lower (p &lt; 0.001) compared to all MCE-supplemented treatments at 14 and 35 d. The BW of E75, E100, and E125 treatments was not different (p &gt; 0.05) from the PC at both evaluation periods. Cumulatively (1–35 d), the NC resulted in a weight-adjusted FCR increase (p = 0.001) of 9.9% compared to the PC, and the FCR of E75, E100, and E125 were able to recover 72.3%, 66.4%, and 63.5%, respectively, compared to the PC. The carcass and breast weights were lower (p &lt; 0.001) in the NC compared to all other treatments, and no differences (p &gt; 0.05) were observed between the MCE-supplemented treatments and the PC. In conclusion, these results suggest that the MCE supplementation can maintain duck growth performance with no negative effects on carcass traits in energy-reduced corn–soybean meal-based diets. From the results of the trial, 75 ppm MCE delivered the best performance recovery and 125 ppm MCE supplementation had the best % breast yield.

Development of selected performance, dressing and meat quality traits of Pekin ducks in relation to genotype and phytogenic feed additives

Abstract The aim of this study was to determine the effect of the genetic origin of ducks and the use of phytogenic additives in their feeding on performance indices, slaughter value and dressing percentage, as well as meat quality. The experimental material consisted of three genetic groups of Pekin ducks: Polish Pekin P-33 (P), Dworka D-11 (D) and Star 53 H.Y. (S). A 7-week experimental rearing of 216 commercial hybrids (3 × 72 animals) was carried out. Within each genetic line, three feeding groups were established, differing in the use of plant-based additives in the feed mixture (5% herb mixture or 5% black cumin seed). To assess slaughter value and meat quality of the ducks, 18 birds from each group were selected, including 9 males and 9 females. It was shown that the basic performance and slaughter value traits of Pekin ducks depend (p≤0.05) on their genetic origin. The most favourable (p≤0.05) rearing efficiency and slaughter value (body, carcass and meat weight) were found for commercial Star 53 HY ducks. Their breast muscles were characterized by higher (p≤0.05) cooking loss and lower (p≤0.05) collagen content. The genetic origin of the ducks was shown to influence (p≤0.05) economic efficiency of rearing, dressing percentage and chemical indicators of meat (except for water content in breast muscles) and some physical characteristics (pH24, cooking loss, colour lightness of leg muscles and electrical conductivity in breast muscles). Supplementation of the standard diet of ducks with phytogenic additives (mixture of herbs, black cumin seeds) at a level of 5% had (p≤0.05) a negative effect on body, carcass and meat weight, and a positive effect on the physical characteristics of meat related to water loss (pH24 and cooking loss).