Carcass Quality Traits Research Articles

Carcass and meat quality of young Angus steers with different growth potential finished exclusively grass-fed or corn supplemented.

Beef cattle production has a large variety of systems with different performance and technology levels. This study compared young Angus steers carcass and meat quality traits of high growth potential early-finished animals fed exclusively on pasture with low growth potential late-finished animals. Besides the grazed forage, the low growth potential group received corn grain at 0.8% of their body weight right after the slaughtering of the first group. Following weaning, the 20 steers grazed pastures composed of oat, ryegrass, and clovers. At winter's onset, animals were moved to native pastures improved with fescue and clovers. The supplemented period of late steers began when the first group of ten early-finished animals reached the requirements for slaughter. Supplementation ended when the animals got the slaughter requirements. The high growth potential steers showed a ribeye area (P < 0.0001) and a Longissimus muscle width highly significantly (P < 0.0001) superior to the low growth group. However, corn-supplemented animals showed better dressing percentage (P < 0.0001), subcutaneous fat thickness (P < 0.0001), marbling (P < 0.0001), and muscle (P = 0.0033) scores, but lower shear force (P = 0.0001). The finishing system did impact fat lightness (L*; P = 0.0234) at the slaughter time. Grass-fed animals showed higher red-green color parameter (a*) values than corn supplemented on fat at 24h (P = 0.0439) but lower hue angle (P = 0.0418). The consumer panel showed better results for tenderness and general acceptability for supplemented animals beef compared to grass-fed. The supplementation resulted in a higher carcass standardization. It also provided higher PUFA: MUFA and n-6: n-3 ratios, and a higher amount of n-3. Supplemental corn grain did not have adverse effects upon the beneficial effects to human health of the grass-fed beef.

Time-based restriction and refeeding programmes in growing rabbits: Effects on feeding behaviour, feed efficiency, nutrient digestibility, and caecal fermentative activity

The present study evaluated the effect of five feeding programmes (AL, ad libitum feeding; DF, daylight access to feed followed by fast full refeeding; NF, nightly access to feed and fast full refeeding; NS, nightly access to feed and slow full refeeding; NI, night access to feed until the end of the trial) on growth, nutrient digestibility, caecal fermentative activity, and carcass and meat quality of 400 crossbred rabbits housed in 40 open-top pens (10 rabbits/pen) from weaning to slaughter (28–70 days of age). In all feed-restricted rabbits, feeding time decreased from 14 to 9 h/day during the 1st week, it stood at 8 h/day during the 2nd week, and it increased from the beginning of the 3rd week according to three refeeding systems: i) fast until ad libitum (+4 h/day until 24 h/day) for the DF and NF groups; ii) slow until ad libitum (+1 h/day until 24 h/day) for the NS group; and iii) very slow and until 12-h-restriction (+30 min/day until 12 h/day) for the NI group. During the restriction period, DF and NF programmes compared with the AL programme, improved the coefficient of total tract apparent digestibility (CTTAD) for crude protein (+4.6%) and ether extract (+2.7%) (P < 0.001); NF programmes increased caecal volatile fatty acids (VFA) (79.7 vs 67.7 mmol/L; P = 0.034) and decreased pH (5.32 vs 5.46; P = 0.013) compared with AL. During the refeeding period, the NI programme increased the CTTAD of dry matter (+2.9%; P = 0.001), crude protein (+3.9%; P = 0.003), and gross energy (+2.6%; P = 0.001) compared with the DF and NF groups. The AL, DF, and NF treatments decreased caecal VFA compared with NS and NI (81.0 mmol/L vs. 95.4 mmol/L; P < 0.001). In the whole trial, the NI programme decreased feed intake (−7.5%; P < 0.001) and feed conversion (−6.7%; P = 0.002) compared with the AL programme, without differences in growth, final live weight, and slaughter traits among groups. Compared to AL feeding, feed restriction increased the mortality rate due to digestive disorders (9.0 vs 1.6%; P = 0.036), without affecting morbidity and health risk index. Slaughter weight (on average: 2608 g), carcass yield (60.2 g/100 g live weight at slaughter), and carcass and meat quality traits were not affected. In conclusion, the NI programme improved feed efficiency without impairing growth, slaughter, and carcass traits.

162 Fetal Programming and Meat Quality

Abstract For many years, variation in carcass and meat quality traits was thought to result from actions taken throughout the animals’ life after birth. However, the quantity and quality of meat obtained at slaughter are not always as good as expected. The past decade has increased the number of evidence of the effects of intrauterine development of skeletal muscle on animal performance that affects the carcass and meat quality traits. The so-called “Fetal Programming” concept sheds light on the biology of skeletal muscle development in meat animals, revealing that this development stage appears to be a pivotal moment to invest efforts aiming to improve animal productivity and the quality of meat. Because most, if not all, of the muscle fibers are formed prenatally in livestock species, the impairment of muscle fiber formation at this stage will limit the overall muscle mass deposition throughout postnatal life. Intramuscular adipocytes also start their formation at the fetal stage. As such, since the intramuscular fat depot has a lower deposition rate than other fat depots, enhancement of intramuscular adipogenesis during the fetal stage may increase marbling deposition postnatally. Muscle fibers, adipocytes, and fibroblasts, which contribute to connective tissue formation, are derived from the same pool of mesenchymal stem (MS) cells. Depending on the insult suffered during intrauterine development, their commitment may shift from myogenic towards adipogenic/fibrogenic lineage. So far, most of the evidence in livestock animals has shown that maternal nutrition during gestation is the main factor that influences the mechanisms underlying the commitment of the MS cells. Although the majority of these studies have shown the consequences of maternal nutrition on myogenesis, adipogenesis, and fibrogenesis, the epigenetic markers that cause the programming of MS cells to undergo to one lineage or another needs to be further investigated.

53 Awardee Talk: Implications of the Gut Microbiome for Genetic Improvement of Swine

Abstract With the universal adoption of genomic selection as a breeding standard, livestock farming is about to enter a new chapter in which deep phenotyping and multi-omics technologies will enhance the use of molecular data in the selection process. Microbiome composition represents a promising tool in this arena, serving simultaneously as a benchmark of environmental challenge, a predictor of animal physiological status, and a direct target for host selection. Our group has been researching the application of the gut microbiome in swine production, with a particular focus on growth and feed efficiency. We investigated how the microbiome is shaped in different production systems by comparing the microbiome composition of growing/finishing pigs raised in bio-secure nucleus farms and commercial facilities. Results suggested a strong impact of gut microbiome composition on pork production efficiency and a consistent effect of several microbial features across different systems. We found that microbial features associated with animal growth are heritable and identified host genomic markers contributing to their relative abundance. We have found that the microbiota composition is different across breeds but stable within breeds (Duroc, Large White, Landrace). Taxa differently represented among the breeds are also associated with feed efficiency and behavior. We estimated the ‘microbiability’ of meat and carcass quality traits. We found that the gut microbiome composition leaves an identifiable ‘footprint’ on the animal tissue deposition. Following these findings, we elucidated the complex relationship between genomic and microbial variation using structural equation modeling to test a causal path between the host genotype, the gut microbiome composition, and fat deposition. We identified direct and mediated (through microbiome) genomic variants affecting host trait expression, highlighting the potential for the ‘second genome’ to contribute to the recovery of genetic variance.

221 Camelina Meal as an Alternative Ingredient in Growing-finishing Pig Diets

Abstract The objective of this experiment was to determine the most effective inclusion rate of camelina meal (CM) in growing-finishing pig diets. Pigs (n = 192; 11 wk old), balanced for sex and initial weight, were assigned to 4 dietary treatments (6 pens/treatment; 8 pig/pen). Treatments consisted of a non-GMO corn-soybean meal-based control diet (CON), and CON containing 5% CM (5%CM), 10% (10%CM), or 15% (15%CM) camelina meal. Feed deliveries and pigs were weighed every other week to calculate ADG, ADFI, and Gain:Feed on a pen basis. Focal pigs (5/treatment) were harvested at 23 wk of age at the University of Minnesota abattoir for meat quality analysis (drip loss, pH, fat depth, belly firmness, loin marbling score, shelf life) and the remaining pigs were harvested at a commercial abattoir. Before harvest, real-time ultrasonic measurements of back fat depth and loin eye area were collected on all pigs. Data were analyzed using Proc Glimmix with dietary treatment as a fixed effect and pen as the experimental unit with data collected over time considered as repeated measures. Pigs fed CON diet consumed more feed than pigs fed CM diets (P = 0.002; Table 1). Pigs fed CON diet exhibited higher (P = 0.002) ADG than pigs consuming 10%CM and 15%CM diets. These differences resulted in heavier (P = 0.003) CON-fed pigs at marketing than 10%CM or 15%CM-fed pigs. There were no significant differences in Gain:Feed, any carcass or meat quality traits analyzed (data not shown). These results suggest that supplementing 5% CM in corn-soybean meal-based diets will not negatively influence growth performance, carcass traits, or meat quality of growing-finishing pigs.

PSXIII-17 Supplementing organic-complexed or inorganic Co, Cu, Mn, and Zn to beef cows during gestation: post-weaning responses of offspring reared as replacement heifers or feeder cattle

Abstract Beef cows and their progeny were used to evaluate the effects of supplementing organic-complexed or inorganic Co, Cu, Mn, and Zn during gestation: on offspring reared as replacement heifers or feeder cattle. Non-lactating, pregnant beef cows (n = 190) were ranked by parity, pregnancy type, body weight (BW) and body condition score (BCS), at 117 ± 2.2 d of gestation (d 0) and assigned to receive a supplement containing: 1) sulfate sources of Cu, Co, Mn, and Zn (INR; n = 95) or 2) an organic complexed source of Cu, Mn, Co, and Zn (AAC; Availa®4; Zinpro Corporation, Eden Prairie, MN; n = 95). From d 0 to calving, cows were maintained in a single pasture and individually offered treatments three times a week. Calves were weaned at 6 mo of age (d 367) and preconditioned for 45-d. Heifer puberty status was verified weekly (d 437 to d 619) based on plasma progesterone concentrations. Steer calves were shipped to a commercial feedlot on d 493, where they were managed as a single group until slaughter (d 724). Plasma cortisol concentration was greater (P = 0.05) in AAC calves at weaning but tended to be less (P = 0.10) on d 370 compared with INR calves. Mean plasma haptoglobin concentration was greater (P = 0.03) in INR vs. AAC calves during preconditioning, and no treatment effects were noted (P = 0.76) for preconditioning average daily gain (ADG). Puberty attainment was hastened in AAC heifers during the experiment (treatment × day; P &amp;lt; 0.01), despite similar (P = 0.39) ADG between treatments from d 412 to 620. No treatment effects were detected (P ≥ 0.24) for steer ADG from d 412 until slaughter, nor for carcass quality traits. Therefore, supplementing Co, Cu, Zn, and Mn as organic complexed instead of sulfate sources to beef cows during the last 5 mo of gestation did not improve performance of steer progeny until slaughter, but hastened puberty attainment in female progeny reared as replacement heifers.

Comparison between two multivariate analyses for the evaluation of genetic divergence for carcass and meat quality traits in alternative lines of chicken

The univariate analysis is becoming harder to use due the increasing number of characteristics of economic importance in agricultural industry. The multivariate approach provides an answer to this issue, allowing to analyze several traits when comparing different methodologies, genetics and products. This study aimed to use and compare the canonical variable analysis (CVA) and principal component analysis (PCA) to evaluate 7 genotypes of alternative lines of chicken (Caboclo, Carijó, Colorpak, Gigante Negro, Pesadão Vermelho, Naked Neck and Tricolor). The study evaluated 840 male chicks reared at 91 days from these genotypes, in a completely randomized design with 4 replicates per genotype. Different traits (23) were measured, and only 7 remained relevant after the multivariate approach: Carcass yield, Breast Yield, Back Yield, Cooking Loss, lightness, yellowness and water holding capacity. Both analyses remained with two variables explaining the variating. The Pearson correlation was used to measure the traits responsible for the most variance between genotypes. On the principal component cooking loss, carcass and breast yields, and the color parameters lightness and yellowness were the most relevant, while on canonical variables it was carcass yield, breast yield, lightness, yellowness and back yield. Both analysis resulted in similar conclusion, allowing to classify the genotypes in three major groups: 1 (Pesadão vermelho, Carijó, Colorpak, Nacked Neck), 2 (Gigante Negro and Caboclo) and 3 (Tricolor). PCA and CVA facilitate the interpretation of data with several traits of importance, showing the main traits responsible for genetic divergence.

Polymorphisms of Candidate Genes Associated with Growth and Carcass Traits in Canadian Duroc Pigs

Background: Selection based on traits such as average daily gain (ADG) and carcass quality in commercial pig populations have drawn attention of swine breeders due to the correlation with growth and consumer preference for carcass composition, respectively. The association between melanocortin 4 receptor (MC4R) gene, which encodes the G-protein-coupled receptor and ADG and carcass quality, have been well documented. The study was conducted to determine the effects of MC4R/TaqI and PIT-1/RsaI polymorphisms on growth and carcass quality traits in total of 576 Duroc pigs at national breeding farms of Vietnam. Methods: After the performance test, the desired traits including ADG, IF and LD were measured. ADG (g/day) was calculated as the live weight divided by the number of days from birth to 100 kg, BF and LD can be captured at position P2 (6-8 cm away from body midline at the last rib level) with Ultrasound machine Aloska SSD 500V. Genomic DNA were collected and genotyped to observe the polymorphism of MC4R and PIT-1. Result: Three genotypes AA, AG andGG of MC4R gene and AA, AB and BB of PIT-1 gene were found in the studied pig population. The observed frequencies of AA, AG and GG were 0.09, 0.41 and 0.50 (MC4R gene) and for AA, AB and BB were 0.37, 0.47 and 0.16, respectively. The G allele (MC4R) and B allele (PIT-1) have more positive effects on traits of ADG, BF and LD. Specifically, in MC4R gene, the individuals carrying GG genotype had higher ADG by 50 gram and lower BF by 1.4 mm than AA genotype. In PIT-1 gene, pigs carrying BB genotype had higher ADG and LD than AA genotype by 37 gram and by 1.9 mm, respectively. Therefore, the increased selection of G allele, GG genotype (MC4R) and of B allele, BB genotype (PIT-1) should be considered to contribute to the improvement of ADG, BF and LD traits in Duroc population in current study

Comparative evaluation of carcass characteristics and meat quality attributes of Japanese quail among different lines

The present study evaluated the carcass and meat quality traits of three groups of Japanese quails. These groups {i.e. selected for 4-week body-weight group (WBS), selected for egg number (EBS), and random-bred control (RBC)}, were selected for three consecutive generations from a base population of 1125 quails. In total, 2700 four-week-old quails from three selected lines (225 birds per group per generation) were slaughtered in a total of four generations (G0 to G3). The effects of selection were evaluated on the carcass and meat quality traits in four generations. WBS in G3 presented significantly highest dressing yield, breast yield, thigh yield, percentage of liver, heart, and gizzard than RBC and EBS groups. The ultimate pH of breast meat was higher in G2 of the WBS group. Breast meat lightness was also significantly higher in G2 of the WBS group, while redness was higher in G0 (at 20 min post-slaughter) and G3 (at 24 h post-slaughter) of the RBC group. The quails from G3 of WBS had more tender meat than all EBS and RBC groups. Percentage of drip loss and cooking loss were significantly higher in quails of G3 from the WBS group. It was concluded that body weight and egg based selection practices in Japanese quail had a positive influence on meat yield and quality.

Effects of production system and feeding regimen on carcass and meat quality traits of Naked Neck chicken

To evaluate the effect of a production system and feeding regimen on meat quality attributes of Naked Neck chickens, a total of 150 cockerels at 18 weeks old (1625 ± 70 g) were collected from 10 treatment groups with five replicates of three birds. The factorial arrangement of treatments consisted of two production systems (intensive and free-range) and five nutritional regimens, namely 100% commercial feed; 75% commercial feed plus 25% kitchen waste; 50% commercial feed plus 50% kitchen waste; 25% commercial feed plus 75% kitchen waste; and 100% kitchen waste. Carcass traits, meat quality, and meat organoleptic were found to differ significantly among production systems, feeding regimens, and their interaction. Higher liver weight was observed in birds reared under an intensive system. Higher gizzard weight was noted in birds fed with 100% kitchen waste, whereas lower gizzard weight was observed in birds fed the commercial diet. The meat from cockerels fed with 75% kitchen waste was most yellow, whereas the meat from the birds fed with 100% kitchen waste was least yellow. At two hours after slaughter, pH of the meat was highest in birds fed 50% kitchen waste and lowest in birds fed 100% kitchen waste. The interaction of production system and feeding regimen was significant for overall acceptability score. In conclusion, Naked Neck chickens performed equally well under intensive and free-range systems, irrespective of the level of kitchen waste that they were fed.

The Implications of Changing Age and Weight at Slaughter of Heavy Pigs on Carcass and Green Ham Quality Traits.

Simple SummaryConventional rearing systems for heavy pigs intended for Italian dry-cured ham production require pigs to be slaughtered at 160 ± 16 kg and a minimum age of 9 months. With the current animal genetic trends providing progressively leaner animals, the conventional rearing system fails to provide pigs with optimal characteristics for the dry-cured ham industry. In this research, new combinations of age and weight at slaughter were explored, using different feeding conditions, as possible alternative rearing strategies for heavy pigs. Such alternative rearing strategies aimed to manipulate the growth rate of pigs, first allowing them to reach 160 ± 16 kg slaughter weight at a younger age; second, allowing pigs to maximize their slaughter weight at 9 months of age; and third, inducing slow growth in the pigs to reach the 160 ± 16 kg body weight at an older age. The first two strategies were the most promising alternatives as they improved the rate of gain, feed efficiency, and ham adiposity of the pigs. While the first strategy was the most economically convenient, the second produced the hams with the highest quality.Italian dry-cured ham production requires pigs to be slaughtered at 160 ± 16 kg at 9 months of age (control, C). The study explored three alternatives, based on different feeding conditions: (1) allowing pigs to express their growth potential by letting them reach 160 ± 16 kg slaughter weight (SW) at younger slaughter age (SA) (younger Age, YA); (2) allowing pigs to express their growth potential by maximizing their SW at 9 months SA (greater weight, GW); (3) increasing the SA required to reach 160 ± 16 kg SW (older age, OA). Pigs (336 C21 Goland, 95 kg initial body weight) were slaughtered on average at 257, 230, 257, and 273 d SA and 172.7, 172.3, 192.9, and 169.3 SW kg for the four treatments, respectively. C pigs had an average daily gain (ADG) of 715 g/d and feed efficiency (FE) of 0.265 (gain to feed). Compared to C, YA pigs had higher ADG (+32%), FE (+7.5%), and better ham adiposity; GW pigs had higher carcass weight (+12%), ADG (+25%), trimmed ham weight (+10.9%), and better ham adiposity. OA treatment affected ADG (−16.4%), FE (−16.6%), and trimmed ham weight (−3.6%). YA and GW could be promising alternatives to C as they improved FE and ham quality traits.

Genome‐wide association study and pathway analysis for carcass fatness in Nellore cattle measured by ultrasound

Identifying genes or genomic regions influencing carcass-quality traits such as fatness (FTN) is essential to optimize the genetic selection processes in beef cattle. The aim of this study was to identify genomic regions associated with FTN in Nellore cattle as well as to elucidate the metabolic pathways related to the phenotypic expression. Ultrasound-based measurements of FTN were collected in 11750 animals, with 39903 animals in the pedigree file. Additionally, 1440 animals were genotyped using the GGP-indicus 35K SNP panel, which contained 33623 SNPs after quality control. Twenty genes related to FTN were found on 11 chromosomes, explaining 12.96% of the total additive genetic variance. Gene ontology revealed seven genes: NR1L2, PKD2, GSK3β, EXT1, RAD51B, SORCS1 and DPH6, associated with important processes related to FTN. In addition, novel candidate genes (MAATS1, LYPD1, CDK5RAP2, RAD51B, c13H2Oorf96 and TRAPPC11) were detected and could provide further knowledge to uncover genetic regions associated to carcass fatness in beef cattle.

Random-effect meta-analysis of genetic parameter estimates for carcass and meat quality traits in beef cattle

Considerable variability of genetic parameter estimates is observed among different studies for the same trait, which is associated with the distinct effects included in the statistical model, population breed, and sample sizes. The random-effect meta-analysis summarizes genetic parameters considering the heterogeneity among studies. Therefore, the aim of this study was to perform a random-effect meta-analysis of heritability and genetic correlation estimates for carcass and meat quality traits in beef cattle. A total of 152 estimates of heritability and 83 genetic correlations for longissimus muscle area (LMA), back fat thickness (BFT), and marbling score (MRB) were used. High heterogeneity among published studies was observed for all traits, indicating the need of a random-effects model to perform the analysis. Estimates of heritability through the meta-analysis using the random-effects model were high (0.30 to 0.34), indicating that fast genetic progress can be obtained for these traits. However, genetic correlations had low magnitude (lower than 0.25), which suggested that all three traits should be included in the selection scheme.

Performance and carcass quality traits of Iberian × Duroc crossbred pig subject to gender and age at the beginning of the free-range finishing phase

The traditional production of the Iberian breed pig involves a long production cycle. It might be shortened by using Iberian pigs crossed with Duroc and by reducing the growing phase, but the age-related changes on productive performance and carcass quality should be addressed. Thus, productive performance, live measurements and carcass and primal cut traits were evaluated on Iberian × Duroc 50:50 crossed pigs according to animal age at the beginning of the free-range finishing phase (Montanera): 10, 12 and 14 months old (IBxD10 (n = 15), IBxD12 (n = 17) and IBxD14 (n = 18) animal batches, respectively) and gender (immunologically castrated female -consisted of the Improvac® vaccination- and surgically castrated males). During the growing period, animals were fed with restrictions; 1.49, 1.29 and 1.20 ± 0.023 (mean ± SEM) kg/day of commercial feeds to start Montanera with similar BW; 103.9, 102.9 and 102.1 ± 0.22 kg, for IBxD10, IBxD12 and IBxD14, respectively. IBxD14 animals yielded the highest average daily gain (ADG) and BW after Montanera, as well as larger rump height and croup width. In contrast, these animals had the lowest carcass yield. Although animals from IBxD10 yielded hams of inferior size, this could be of interest to the sector, as there is a certain segment of the market that demands hams of smaller size and, generally, this is difficult to obtain with the traditional Montanera production system. The gender had no major effects on performance and carcass and primal cut traits, so both immunologically castrated female and surgically castrated males are suitable for finishing in Montanera.

Current Knowledge on River Buffalo Meat: A Critical Analysis.

Simple SummaryBuffaloes are reared for different purposes, primarily for milk and dairy products. Meat is often a secondary product and mainly derives from old animals at the end of their productive or working life. However, in recent years buffalo meat has gained increased popularity due to its nutritional properties. Therefore, a huge economic potential might arise from the development of the meat sector in buffalo breeding. This review provides an overview of the recent advances in the knowledge on river buffalo meat, with a special focus on quality traits, and offers insights for future research aimed at improving the meat sector in this species.The estimated world population of water buffalo counts around 204 million head, mostly reared for milk production. However, buffaloes also largely contribute to the meat sector, with around 4.3 million tonnes produced in 2019, mainly derived from old animals at the end of their productive or working life and only to a small extent from young animals. Therefore, buffalo meat production has been generally considered unsatisfactory for both quantity and quality. In fact, the dressing percentage is generally lower than 50% and the meat is considered of poor quality mainly due to its dark colour and reduced tenderness. However, in recent years, the healthy properties highlighted by some studies have led to a renewed interest in buffalo meat, with a parallel increase in research. Therefore, this review aims at providing an updated picture on carcass and meat quality traits in river buffalo, with special attention to the intrinsic and extrinsic factors contributing to their variability. The research done so far has demonstrated that river buffaloes can efficiently contribute to the quanti-qualitative production of meat, provided that the meat supply chain is specifically organised for this purpose. The analysis of the available data also showed that further research is needed on the factors affecting meat production in order to gain greater knowledge essential for planning more targeted interventions.

Validation of the Prediction Accuracy for 13 Traits in Chinese Simmental Beef Cattle Using a Preselected Low-Density SNP Panel.

Simple SummaryTo reduce the breeding costs and promote the application of genomic selection (GS) in Chinese Simmental beef cattle, we developed a customized low-density single-nucleotide polymorphism (SNP) panel consisting of 30,684 SNPs. When comparing the predictive performance of the low-density SNP panel to that of the BovineHD Beadchip for 13 traits, we found that this ~30 K panel achieved moderate to high prediction accuracies for most traits, while reducing the prediction accuracies of six traits by 0.04–0.09 and decreasing the prediction accuracy of one trait by 0.2. For the remaining six traits, the usage of the low-density SNP panel was associated with a slight increase in prediction accuracy. Our studies suggested that the low-density SNP panel (~30 K) is a feasible and promising tool for cost-effective genomic prediction in Chinese Simmental beef cattle, which may provide breeding organizations with a cheaper option and greater returns on investment.Chinese Simmental beef cattle play a key role in the Chinese beef industry due to their great adaptability and marketability. To achieve efficient genetic gain at a low breeding cost, it is crucial to develop a customized cost-effective low-density SNP panel for this cattle population. Thirteen growth, carcass, and meat quality traits and a BovineHD Beadchip genotyping of 1346 individuals were used to select trait-associated variants and variants contributing to great genetic variance. In addition, highly informative SNPs with high MAF in each 500 kb sliding window and in each genic region were also included separately. A low-density SNP panel consisting of 30,684 SNPs was developed, with an imputation accuracy of 97.4% when imputed to the 770 K level. Among 13 traits, the average prediction accuracy levels evaluated by genomic best linear unbiased prediction (GBLUP) and BayesA/B/Cπ were 0.22–0.47 and 0.18–0.60 for the ~30 K array and BovineHD Beadchip, respectively. Generally, the predictive performance of the ~30 K array was trait-dependent, with reduced prediction accuracies for seven traits. While differences in terms of prediction accuracy were observed among the 13 traits, the low-density SNP panel achieved moderate to high accuracies for most of the traits and even improved the accuracies for some traits.

Spatial distribution of genetic values of Nelore breed in Brazil

This aim of this study was to analyze the influence of socieoconomic, environmental and farm variables on the existing genetic values (Expected Progeny Differences - EPDs) of the different clusters of Nelore animals in Brazil. The data evaluated included EPDs of 1,462,485 animals, males and females born between 2000 to 2011, same period of the compiled variables used (socieoconomic, environmental and farm), distributed in 171 municipality from 15 Brazilian states by GENEPLUS (Genotype Breeding Program of Embrapa Beef Cattle). The municipality averages of sixteen variables were used for weight traits (maternal and direct genetic effects for weight at 120 days, maternal and direct genetic effects at birth and weaning weight, post-yearling weight and average daily gain post-weaning), carcass quality (carcass conformation at weaning, carcass conformation at post-yearling, eye muscle area, subcutaneous fat thickness and marbling) and reproductive traits (scrotal perimeter at weaning, scrotal perimeter at post-yearling, age at first calving and cow weight at weaning) as well as their respective accuracies. The data were spatialized in the ArcGIS program along with environmental factors and human development indicators. The statistics included clustering, discriminant and canonical analyzes using the SAS® program. Three clusters for weight traits, five for carcass quality, four for reproductive traits and five for accuracy were formed. The clusters showed good distribution across the country, highlighting the clusters with highest genetic values for each trait type. Discrimination was seen among environments for beef cattle at pasture, depending on climatic conditions. The spatial distribution of the Nelore cattle breed may provide a better understanding of the real situation of the breed in different Brazilian climates and environments. The results of this study can be used to correct possible errors of genetic selection programs that use the same breeders and females for different environments.

Evaluación de dos fuentes suplementarias de clorhidrato de zilpaterol sobre la calidad de la carne y los rasgos de la canal de toros Bos indicus cruzados en los trópicos

It was studied the effect of two zilpaterol hydrochloride (ZH) brands on carcass and meat quality traits of crossbred Bos indicus young bulls under tropical conditions. The patented ZH formulation (Zilmax®, ZHp) and a generic brand (Zipamix®, ZHg) were added to the feed (6 ppm) for 30 d before slaughter. Animals (n= 288) were randomly assigned to 1 of 3 diets, with 32 animals per pen and 3 replicates, for a total of 96 bulls per treatment: 1) basal diet without ZH (Control), 2) basal diet supplemented with Zipamix® at 6 ppm in the diet, as fed-basis (ZHg), and 3) basal diet supplemented with Zilmax® at the same concentration in the feed (ZHp). Carcass yield traits were significantly improved by ZH supplementation. Carcasses of ZH-treated bulls were 6-9 kg heavier (P=0.0023) and produced about 8-10 kg more of lean tissue (P&lt;0.0001) as compared to the Control group. Carcass quality traits were less affected by ZH supplementation. Among meat quality attributes, ultimate pH of ZHg (5.81) and ZHp (5.89) was higher (P=0.0022) than that of the Control (5.78). Results showed both ZH brands, when administered for 30 d before slaughter, as recommended by the manufacturer, improve most carcass yield traits without compromising carcass or meat quality attributes. Hence, tropical beef producers may use the ZH formulation of lowest cost to improve their productivity.

Feeding strategies impact animal growth and beef color and tenderness

The impact of growth rate (GR) and finishing regime (FR) on growth and meat quality traits of Angus x Nellore crossbred steers, harvested at a constant body weight (530 ± 20 kg) or time on feed (140 days), was evaluated. Treatments were: 1) feedlot, high GR; 2) feedlot, low GR; 3) pasture, high GR and 4) pasture, low GR. Live body composition, carcass and meat quality traits were evaluated. High GR had greater impact on muscle and fat deposition in feedlot-finished, but not in pasture-finished animals. Feedlot animals had higher Longissimus muscle area, backfat thickness, meat luminosity and tenderness when compared to pasture groups. Moreover, pasture- and feedlot-finished animals with similar GR did not differ in the chromatic attributes of non-aged meat, regardless of endpoint. Thus, GR appeared to be the main factor driving beef chromatic parameters, while FR had a major impact on achromatic attributes and tenderness of meat.

Detection of Genomic Regions with Pleiotropic Effects for Growth and Carcass Quality Traits in the Rubia Gallega Cattle Breed.

Simple SummaryThe breeding scheme in the Rubia Gallega cattle population is based upon traits measured in farms and slaughterhouses. We have developed a ssGWAS by backsolving the SNP effects after implementing a ssGBLUP. The results showed an apparent heterogeneity of the additive genetic variance across the genome. Some of the genomic regions explaining the most of this additive variance were shared across traits, indicating the presence of pleiotropic effects, which were reflected in their genetic correlations.The breeding scheme in the Rubia Gallega cattle population is based upon traits measured in farms and slaughterhouses. In recent years, genomic evaluation has been implemented by using a ssGBLUP (single-step Genomic Best Linear Unbiased Prediction). This procedure can reparameterized to perform ssGWAS (single-step Genome Wide Association Studies) by backsolving the SNP (single nucleotide polymorphisms) effects. Therefore, the objective of this study was to identify genomic regions associated with the genetic variability in growth and carcass quality traits. We implemented a ssGBLUP by using a database that included records for Birth Weight (BW-327,350 records-), Weaning Weight (WW-83,818-), Cold Carcass Weight (CCW-91,621-), Fatness (FAT-91,475-) and Conformation (CON-91,609-). The pedigree included 464,373 individuals, 2449 of which were genotyped. After a process of filtering, we ended up using 43,211 SNP markers. We used the GBLUP and SNPBLUP model equivalences to obtain the effects of the SNPs and then calculated the percentage of variance explained by the regions of the genome between 1 Mb. We identified 7 regions of the genome for CCW; 8 regions for BW, WW, FAT and 9 regions for CON, which explained the percentage of variance above 0.5%. Furthermore, a number of the genome regions had pleiotropic effects, located at: BTA1 (131–132 Mb), BTA2 (1–11 Mb), BTA3 (32–33 Mb), BTA6 (36–38 Mb), BTA16 (24–26 Mb), and BTA 21 (56–57 Mb). These regions contain, amongst others, the following candidate genes: NCK1, MSTN, KCNA3, LCORL, NCAPG, and RIN3.