Impact of beef cattle diets containing corn or sorghum distillers grains on beef color, fatty acid profiles, and sensory attributes

Strip loins from 236 carcasses from crossbred yearling steers were collected on each of 2 slaughter dates (slaughter 1 or 2) to determine the effects of feeding corn or sorghum distillers grains (DG) on beef color, fatty acid profiles, lipid oxidation, tenderness, and sensory attributes. Dietary treatments consisted of a steam-flaked corn (SFC) diet without (control) or with 15% (DM basis) corn dry or wet DG (CDDG and CWDG) or sorghum dry or wet DG (SDDG and SWDG) and alfalfa hay (R). Additional treatments included SDDG or SWDG with no alfalfa hay (NR). In slaughter 2, steaks from steers fed SFC had lesser L*, but greater a* (P < 0.05) values than those from steers fed DG. When comparing sorghum and corn DG steaks, the same color differences were detected. Steaks from steers fed sorghum DG had lower L*, but greater a* (P < 0.05) values than those from steers fed corn DG. Also, L* values in steaks from steers fed SWDG with R were greater (P < 0.05) than those from steers fed SWDG with NR. In slaughter 1, feeding DG increased (P < 0.05) steak n-6 fatty acid concentrations compared with SFC. In both slaughter groups, feeding dry DG increased (P < 0.05) steak linoleic acid concentrations compared with wet DG. In slaughter 2, feeding corn DG diets increased (P < 0.05) linoleic acid concentrations of steaks compared with sorghum DG diets. In addition, increased (P < 0.05) concentrations of alpha-linolenic acid in steaks resulted from feeding SDDG or SWDG with R compared with those sorghum treatments with NR. In each slaughter group, feeding DG increased (P < 0.05) the n-6:n-3 ratio of steaks compared with SFC, and feeding corn DG increased (P < 0.05) this ratio compared with sorghum DG. Furthermore, steaks from steers fed corn DG had greater (P < 0.05) concentrations of trans-vaccenic acid than those from steers fed sorghum DG. In slaughter 1, the CLA isomer 18:2, trans-10, cis-12 was greater (P < 0.05) in steaks from DG diets. On d 1 of retail display, steaks from steers fed SDDG with R in slaughter 2 had greater (P < 0.05) thiobarbituric acid reactive substances values than those from steers fed SDDG with NR. Feeding DG at 15% of the dietary DM did not affect sensory attributes or Warner-Bratzler shear force values of steaks. Feeding DG from either corn or sorghum as either a wet or dry by-product had no effect on beef sensory attributes.     

Comparison of the mineral and fatty acid profiles of ostrich,turkey and broiler chicken livers

1. The aim of this study was to determine the mineral and lipid profiles in ostrich, turkey and broiler chicken livers.

2. The highest concentrations of phosphorus, potassium and magnesium were found in turkey livers, at 3751.50, 2153.05 and 363.98 mg/kg fresh weight (FW), respectively, whereas ostrich livers were the richest in calcium (82.77 mg/kg FW).

3. Ostrich liver was the richest source of iron, calcium, zinc and silicon, at 947.8, 82.77, 47.50, 36.69 mg/kg FW, respectively.

4. Ostrich livers proved to be the richest source of long-chain fatty acids (5.18% C20:4n+6, 0.48% EPA and 1.08% DHA)

     

Heterosis,sex and breed differences in the fatty acid composition of muscle phospholipids in beef cattle

Longissimus dorsi muscle tissue was biopsied between the 12th and 13th ribs of 96 purebred Jersey, purebred Limousin and Jersey × Limousin crossbred calves at the age of 9–10 months. Fatty acids of the phospholipid fraction were extracted and analysed for sex and breed differences. Heterosis, additive and maternal variances were estimated. All calves grazed pasture in a single management group and were biopsied from the same anatomical site. Steer calves had significantly higher proportions of the 14 : 0, 14 : 1, 18 : 2, 20 : 3 fatty acids and less of the 16‐di‐methyl‐acetal than heifer calves. Significant breed differences were observed: Limousin calves had the highest proportions of 16 : 0, 24 : 0 and saturated fatty acids (SFA), whereas Jersey×Limousin calves had the most 18 : 0 and elongation index. Dominant effects were evident in the proportions of 16 : 0, 18 : 0, SFA and elongation index. Additive genetic effects were significant in the proportions of 16 : 0, 18 : 0, 18 : 1n‐9, total SFA and desaturation and elongation indices. Combined maternal and additive effects were significant for long chain polyunsaturated fatty acids 18 : 2, 20 : 3 and 20 : 4.     

Trona and sodium bicarbonate in beef cattle diets: effects on pH and volatile fatty acid concentrations

A study was conducted to evaluate the effectiveness of NaHCO3 and trona in beef cattle diets. Trace element (n = 28) analysis revealed no toxicological or safety concerns with the use of trona. Trona was more (P less than .05) soluble in ruminal fluid than Na2CO3, and NaHCO3 and had greater (P less than .05) buffering capacity (9.6 meq/g) than NaHCO3 (6.1 meq/g) but less (P less than .05) than Na2CO3 (11.1 meq/g). Calcium carbonate was insoluble and did not buffer ruminal fluid. Six yearling (avg 272 kg) Hereford X Angus steers, each with ruminal, duodenal and ileal cannulas, were fed 50:50 (cracked corn-based concentrate:cottonseed hulls) or 90:10 concentrate diets with no buffer, 1% NaHCO3 or with 1% trona. Intake, across all treatments, averaged 2.4% of body weight. Propionate (mmol/liter) increased (17.6 vs 13.5; P less than .05) and butyrate decreased (3.5 vs 5.2; P less than .05) with trona in the 90:10 diet as compared with no buffer. Propionate (16.8) increased (P less than .05) with NaHCO3 in the 90:10 diet. Average ruminal pH was greater (P less than .05) in 90:10 diets with trona or NaHCO3 than with no buffer (5.61, 5.61 vs 5.55); duodenal pH was greater (P less than .01) with trona than with no buffer (2.66 vs 2.55). Trona reduced ruminal pH-hours (P less than .05) and pH-area (P less than .12; time and area below mean pH of control) below control for both concentrate levels.(ABSTRACT TRUNCATED AT 250 WORDS)     

Serologic prevalence of toxoplasmosis in cattle, sheep, goats, pigs, bison, and elk in Montana

Serum samples from 2,539 cattle, 649 sheep, 123 goats, 413 pigs, 93 bison, and 56 elk from Montana were examined for antibody to Toxoplasma gondii in the Sabin-Feldman dye test or the modified agglutination test (MAT). Cattle, bison, and elk serum samples were treated with 0.2 M-mercaptoethanol before examination in MAT. In the dye test, 13.2% of sheep, 5.0% of pigs, and 22.7% of goats had antibody at a dilution of greater than or equal to 1:16. In the MAT, 3.2% of cattle, 3.1% of bison, and none of the elk were positive at a dilution of greater than or equal to 1:128.     

Comparison between haplotype-based and individual snp-based genomic predictions for beef fatty acid profile in Nelore cattle

The aim of this study was to evaluate the genomic predictions using the single-step genomic best linear unbiased predictor (ssGBLUP) method based on SNPs and haplotype markers associated with beef fatty acids (FAs) profile in Nelore cattle. The data set contained records from 963 Nelore bulls finished in feedlot (±90 days) and slaughtered with approximately 24 months of age. Meat samples from the Longissimus dorsi muscle were taken for FAs profile measurement. FAs were quantified by gas chromatography using a SP-2560 capillary column. Animals were genotyped with the high-density SNP panel (BovineHD BeadChip assay) containing 777,962 markers. SNPs with a minor allele frequency and a call rate lower than 0.05 and 0.90, respectively, monomorphic, located on sex chromosomes, and with unknown position were removed from the data set. After genomic quality control, a total of 469,981 SNPs and 892 samples were available for subsequent analyses. Missing genotypes were imputed and phased using the FImpute software. Haplotype blocks were defined based on linkage disequilibrium using the Haploview software. The model to estimate variance components and genetic parameters and to predict the genomic values included the random genetic additive effects, fixed effects of the contemporary group and the age at slaughter as a linear covariate. Accuracies using the haplotype-based approach ranged from 0.07 to 0.31, and those SNP-based ranged from 0.06 to 0.33. Regression coefficients ranged from 0.07 to 0.74 and from 0.08 to 1.45 using the haplotype- and SNP-based approaches, respectively. Despite the low to moderate accuracies for the genomic values, it is possible to obtain genetic progress trough selection using genomic information based either on SNPs or haplotype markers. The SNP-based approach allows less biased genomic evaluations, and it is more feasible when taking into account the computational and operational cost underlying the haplotypes inference.     

Adiposity, fatty acid composition, and delta-9 desaturase activity during growth in beef cattle

Oleic acid (18:1n‐9) is the most abundant fatty acid in bovine adipose tissue. Because most of the lipid in bovine muscle is contributed by intramuscular adipocytes, oleic acid also is the predominant fatty acid in beef. In many species, the concentration of oleic acid in adipose tissue is dictated by the average concentration of oleic acid in the diet, but in ruminant species such as beef cattle, oleic acid is hydrogenated largely to stearic acid by ruminal microorganisms. In these species, the concentration of oleic acid in adipose tissue is dependent upon the activity of Δ⁹ desaturase, encoded by the stearoyl coenzyme A desaturase (SCD) gene. Expression of the SCD gene is essential for bovine preadipocyte differentiation, and desaturase gene expression and catalytic activity increase dramatically as adipose tissue mass increases after weaning. Feeding a hay‐based diet to American Wagyu steers to a typical Japanese bodyweight endpoint (650 kg) markedly stimulated desaturase enzyme activity as well as the accumulation of both oleic acid and intramuscular lipid, but the increase in oleic acid and intramuscular lipid was much less in hay‐fed Angus steers. Increasing the concentration of oleic acid improves the palatability and healthiness of beef, and Korean Hanwoo and Japanese Black (and American Wagyu) seem especially well adapted to accumulate oleic acid in their adipose tissue.     

Coyote as a final host for Sarcocystis species of goats, sheep, cattle, elk, bison, and moose in Montana

Tissues (1 kg) from sheep, goats, cattle, moose, bison, or elk naturally infected with Sarcocystis species were fed to one to four Sarcocystis-free coyotes and the number of sporocysts in feces and intestines were counted. All 12 coyotes fed naturally infected tissues shed Sarcocystis in feces, with a prepatent period of 9 to 15 days. The four coyotes fed infected beef had 15, 25, 113, and 201 million sporocysts in their feces and intestines. The coyotes fed elk, moose, or bison had 2.5, 15, and 2.5 million sporocysts in their intestines, respectively. Sporocysts in feces of coyotes fed musculature of cattle, sheep, goats, and elk were structurally similar to those described previously from the feces of dogs. This is evidently the first report of the completion of life cycle of Sarcocystis species in moose and bison. Cross-transmission experiments indicated that one species of goat Sarcocystis completes its life cycle in both dog and coyote and that the ovine Sarcocystis is not transmissible to goats.     

Effect of long-term corn by-product feeding on beef quality, strip loin fatty acid profiles, and shelf life

The objective of this study was to evaluate the meat quality and shelf life of steaks from steers fed dried distillers grains with solubles (DDGS) or dried corn gluten feed (CGF) compared with soybean meal with corn (SBM) as a protein supplement from weaning to slaughter. Angus cross steers (n = 81; BW = 306 ± 26.1 kg) were randomly assigned to pens (n = 9) and fed a stocker diet of corn silage (75% of DM) with DDGS, CGF, or SBM and ground ear corn. After 84 d of stockering, 12 steers (BW = 397 ± 15.3 kg) were randomly selected from each treatment and finished using the same protein supplement at 25% of DM for 100 d. Carcass data were collected (24 h) and the longissimus lumborum was fabricated into steaks at 48 h postmortem. Steaks were assigned to proximate analysis, Warner-Bratzler shear force (7-, 14-, or 21-d aging), and retail display (1, 3, 6, or 9 d). Protein source did not affect carcass yield, quality, or longissimus lumborum composition (P > 0.05). After 7 d of aging, DDGS and CGF steaks were more tender (P < 0.01) than SBM, but were similar (P = 0.30) after 14 and 21 d of aging. Feeding corn by-products did not influence subjective overall color acceptance (P = 0.17) in this study, but acceptance declined over time (P < 0.01). Subjective redness was similar (P > 0.05) among diets except SBM steaks were more red (P < 0.01) than DDGS after 9 d. On d 3 and 6 of retail display, CGF steaks exhibited more discoloration (P < 0.04) than SBM or DDGS steaks. However, after 9 d DDGS steaks were more discolored (P < 0.01) than CGF or SBM. Objective L* was lighter for CGF (P < 0.04) over 9 d of display, and all treatments became darker (P < 0.01) as time increased. Redness (a*) declined (P < 0.01) over time with SBM steaks maintaining more color in the red spectrum than CGF and DDGS after 6 d of display. Protein source did not affect (P > 0.05) the rate of lipid oxidation. Total SFA concentrations were similar (P > 0.05) among treatments; however, total MUFA were less (P < 0.05) and total PUFA concentrations were greater (P < 0.05) in DDGS steaks compared with SBM or CGF steaks. These data show that DDGS or CGF can be fed as a protein supplement at 25% DM from weaning until slaughter while maintaining meat quality when compared with steers fed soybean meal as a protein supplement.     

牦牛、犏牛及黄牛肉脂肪酸和风味物质的分析

随机选取青海省果洛州同一放牧群体的1.5岁牦牛（♂）和犏牛（♂）各3头,与青海省湟中县1.5岁的3头黄牛（♂）做比较研究,利用气质联用仪对牦牛、犏牛和黄牛肉中脂肪酸组成及含量进行分析,利用高效液相色谱法对其肉中的肌苷、肌苷酸和硫胺素进行测定,采用高氯酸滴定法测定其肉中谷氨酸钠的含量。结果表明：①牦牛、犏牛和黄牛肉中饱和脂肪酸和单不饱和脂肪酸的含量无显著差异（P〉0.05）;多不饱和脂肪酸在犏牛肉中含量最高,明显高于牦牛和黄牛肉（P〉0.05）。②牦牛肉肌苷的含量明显高于同龄黄牛（P〈0.05）;三种牛肉中肌苷酸的含量无显著差异（P〉0.05）;犏牛肉硫胺素的含量最高,明显高于同龄黄牛（P〈0.05）;犏牛与黄牛肉谷氨酸钠的含量明显高于同龄牦牛（P〉0.05）。     

Effects of supplemental rumen-protected conjugated linoleic acid or linoleic acid on feedlot performance, carcass quality, and leptin concentrations in beef cattle

Thirty-six Angus x Hereford heifers (365 kg) were used to determine effects of dietary lipid supplementation from two sources during the final 32 or 60 d of feeding on serum and adipose tissue leptin concentrations, animal performance, and carcass characteristics. Following an initial feeding period of 56 d, heifers were fed one of three diets in a 3 x 2 factorial arrangement: 1) basal diet, 2) basal diet plus 4% (DM basis) corn oil, or 3) basal diet plus 2% (DM basis) rumen-protected conjugated linoleic acid (a mixture of Ca-salts of palm oil fatty acids with 31% conjugated linoleic acid). Jugular blood samples were collected at 28-d intervals (d 28 to 118) and serum subsequently harvested for leptin quantification via RIA. Real-time ultrasound measurements were collected at 28-d intervals across time on feed. At slaughter, samples were obtained from various adipose depots. Data were analyzed with dietary treatment, length of supplementation, adipose depot (when appropriate), and all two- and three-way (when appropriate) interactions in the repeated measures model. Measures of feedlot performance, including ADG, DMI, and gain:feed did not differ (P > 0.23) with dietary treatment or supplementation length. Heifers supplemented with corn oil tended (P < 0.07) to have higher marbling scores following 32 d of treatment than those supplemented with rumen-protected conjugated linoleic acid, with controls intermediate. Quality grade and hot carcass weight did not differ (P > 0.15) with treatment or length of supplementation. Leptin concentrations were higher (P < 0.05) from d 57 to 118 on feed than the initial period (d 0 to 56) of dietary adaptation when all animals received the basal diet. Circulating leptin concentrations were not affected by dietary treatment. However, leptin concentrations in adipose tissues were greater (P < 0.05) for heifers supplemented with corn oil than either control or rumen-protected conjugated linoleic acid diets, which did not differ. Compared with adipose tissues from rumen-protected conjugated linoleic acid-supplemented animals, tissues from heifers fed corn oil contained 68% greater leptin concentration. Correlations between performance, carcass traits, and serum leptin concentrations were low. Serum leptin concentrations across time on feed were not associated with carcass and performance data, including ADG, DMI, and gain:feed. Based on these data, concentrations of leptin are not related to indices of feedlot performance and carcass quality in beef cattle.     

Transplacental transfer and colostral concentrations of selenium in beef cattle

Three groups of 20-month-old pregnant Hereford heifers received 3 regimens of selenium (Se) supplementation. Group 1 received pelleted alfalfa hay, soybean meal, which contained Se (0.313 mg/kg), and 90 mg of Se as sodium selenite/kg of salt-mineral mix ad libitum. Group 2 received the pelleted hay and soybean meal, and group 3 received only the pelleted alfalfa hay. At time of parturition, the mean whole blood Se concentrations were: group 1 = 0.250 mg of Se/kg of blood, group 2 = 0.162 mg/kg, and group 3 = 0.052 mg/kg, whereas the respective mean blood glutathione peroxidase (GSH-Px) values were 144, 80, and 30 mU/mg of hemoglobin. In comparison, the mean whole blood Se values for the calves were 0.242, 0.175, and 0.81 mg/kg, respectively, and their blood GSH-Px values were 154, 113, and 50 mU/mg of hemoglobin, respectively. Thus, the blood Se and GSH-Px values for each group reflected dietary intake of Se. The calf blood GSH-Px values were similar to their dams for group 1, but were 41% higher in group 2 and 67% greater in group 3. The data suggested that the fetus can sequester blood Se, accumulating values greater than the dam, and that larger amounts were concentrated in the fetus when smaller amounts were available from the dam. The colostrum contained modest to low amounts of Se proportionate to dietary intake of this element. However, milk 7 days after parturient contained inadequate amounts of Se to sustain blood Se values in calves and the milk from heifers with low normal blood Se was essentially void of Se (0.009 mg/kg). (ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of high-oil corn on feedlot performance, carcass characteristics, fatty acid profiles, beef palatability, and retail case life traits of beef top loin steaks

Our objective was to compare the effects of feeding steam-flaked, high-oil corn with normal steam-flaked corn to which yellow grease was added to equalize dietary fat on performance and carcass characteristics of finishing beef steers, and palatability, retail case life, and fatty acid composition of strip loins. Angus steers (n = 120; initial BW = 288 kg) were allotted to dietary treatments consisting of 1) normal mill-run, steam-flaked corn plus added fat (NMR) or 2) high-oil, steam-flaked corn (HOC) and assigned randomly to pens (12 pens/treatment with 5 steers/pen). Performance (ADG, DMI, and G:F) was measured over time, and cattle were shipped to a commercial abattoir for collection of carcass data after 165 d on feed. Carcass data were collected at 48 h postmortem on all carcasses, and 2 carcasses from each pen were selected randomly for collection of strip loins (IMPS #180A). At 14 d postmortem, 4 steaks (2.54 cm thick) were removed for retail display, trained sensory panel analysis, Warner-Bratzler shear force determination, and fatty acid analysis. Daily BW gain was greater (P = 0.03) and G:F was increased 8.4% (P = 0.01) for steers fed NMR compared with HOC, but DMI was not affected (P > 0.10) by treatment. No treatment differences were observed (P > 0.10) for HCW, 12th-rib fat, KPH, and yield grade. Marbling scores were greater (P = 0.01) for NMR than for HOC, and LM area tended (P = 0.07) to be greater in NMR than in HOC carcasses. The proportion of carcasses grading USDA Choice did not differ (P = 0.77) between treatments, but a greater (P = 0.04) proportion of carcasses graded in the upper two-thirds of Choice for NMR vs. HOC. Trained sensory panel traits and Warner-Bratzler shear force values did not differ between treatments (P > 0.10), and no differences (P > 0.10) were detected for purge loss or fatty acid composition. Overall, ADG and G:F were less and marbling score was decreased, but there were no differences between treatments in beef palatability, retail case life, or concentrations of fatty acids in strip loins.     

Effect of endophyte type on carcass traits, meat quality, and fatty acid composition of beef cattle grazing tall fescue

Fourteen Hereford steers were used to compare carcass traits, meat quality, and fatty acid composition of beef from cattle grazing tall fescue infected with either wild-type (E+; n = 6) or novel, nil ergot alkaloid (AR542; n = 8) endophyte for 209 d. Average daily gain, live weight, and HCW were greater (P < 0.05) for AR542 cattle than for E+. No differences in LM color or pH were observed between AR542 and E+. Steaks from E+ cattle tended (P = 0.10) to have higher L* and b* than those from AR542 cattle at 0 d of display. Ground beef from E+ cattle also had higher (P < 0.05) L* than AR542 cattle, with no differences in a* or b* at 0 d of display. Color changes during display did not differ for both steaks and ground beef from E+ and AR542. Lipid oxidation levels increased (P < 0.05) during simulated retail display, but they did not differ between endophyte treatments. Adipose tissues from E+ cattle had a higher (P < 0.05) percentage of SFA, and a lower (P < 0.05) percentage of MUFA than adipose from AR542 cattle. Ground beef and i.m. fat had higher (P < 0.05) concentrations of SFA, MUFA, and cis-9, trans-11 isomer of conjugated linoleic acid, and lower (P < 0.05) concentrations of PUFA and PUFA:SFA ratio than s.c. fat. The n-6:n-3 fatty acid ratio did not differ among fat depots. Ergot-alkaloids were detected in s.c. adipose tissues, and alkaloid concentration was greater (P < 0.05) for E+ than AR542. Warner-Bratzler shear force values did not differ between endophyte types, but it decreased (P < 0.01) across the postmortem aging period. Conversely, sensory panel evaluation detected greater (P < 0.01) chewiness and lower (P < 0.05) juiciness for AR542 than for E+ steaks aged for 14 d. Although grazing cattle on tall fescue pastures infected with nil ergot alkaloid endophyte improved cattle performance, these results suggest that endophyte type has minor effects on carcass traits and meat quality of pasture-fed beef. Moreover, finishing cattle on tall fescue pastures showed the potential to enhance the fatty acid profile of beef from a human health perspective. Alkaloid concentration was greater (P < 0.05) in s.c. fat from E+ than AR542 (2.81 vs. 0.92 ppb; fresh-tissue basis). This is the first published report demonstrating the presence of alkaloids in beef tissues.     

Improving beef hamburger quality and fatty acid profiles through dietary manipulation and exploitation of fat depot heterogeneity

Background:Hamburger is the most consumed beef product in North America,but lacks in nutritional appeal due to its high fat content and high proportion of saturated fatty acids(SFA).Objectives of the present study were to improve the FA profiles of hamburgers made with perirenal fat(PRF) and subcutaneous fat(SCF) when feeding steers different diets along with examining differences in sensory attributes and oxidative stability.Diets included a control diet containing 70:30 red clover silage:barley based concentrate,a diet containing sunflower-seed(SS)substituted for barley,and diets containing SS with 15%wheat dried distillers' grain with solubles(DDGS-15) or30%DDGS(DDGS-30).Hamburgers were made from triceps brachii and either PRF or SCF(80:20 w/w).Results:Perirenal fat versus SCF hamburgers FA had 14.3%more(P 0.05) 18:0,11.8%less cis(c)9-18:1(P 0.05),and 1.82%more total trans(f)-18:1 mainly in the form of t11-18:1.During sensory evaluation,PRF versus SCF hamburgers had greater(P 0.05) mouth coating,but the difference was less than one panel unit.Examining effects of steer diet within PRF hamburgers,feeding the SS compared to the control diet increased(P 0.05) t-18:1by 2.89%mainly in the form of t11-18:1,feeding DGGS-15 diet led to no further changes(P 0.05),but feeding DDGS-30 diet reduced the proportions of(P 0.05) of f-18:l chiefly t11-18:1.Feeding SS and DDGS diets had small but significant(P 0.05) effects on hamburger sensory attributes and oxidative stability.Conclusions:Feeding high-forage diets including SS and 15%DDGS,and taking advantage of the FA heterogeneity between fat depots offers an opportunity to differentially enhance beef hamburgers with 18:2n-6 biohydrogenation products(i.e.,t11-18:1) with potential human health benefits without compromising their sensory attributes and oxidative stability during retail display.     

Improving beef hamburger quality and fatty acid profiles through dietary manipulation and exploitation of fat depot heterogeneity

Background

Hamburger is the most consumed beef product in North America, but lacks in nutritional appeal due to its high fat content and high proportion of saturated fatty acids (SFA). Objectives of the present study were to improve the FA profiles of hamburgers made with perirenal fat (PRF) and subcutaneous fat (SCF) when feeding steers different diets along with examining differences in sensory attributes and oxidative stability. Diets included a control diet containing 70:30 red clover silage: barley based concentrate, a diet containing sunflower-seed (SS) substituted for barley, and diets containing SS with 15% wheat dried distillers’ grain with solubles (DDGS-15) or 30% DDGS (DDGS-30). Hamburgers were made from triceps brachii and either PRF or SCF (80:20 w/w).

Results

Perirenal fat versus SCF hamburgers FA had 14.3% more (P <0.05) 18:0, 11.8% less cis (c)9-18:1 (P <0.05), and 1.82% more total trans (t)-18:1 mainly in the form of t11-18:1. During sensory evaluation, PRF versus SCF hamburgers had greater (P <0.05) mouth coating, but the difference was less than one panel unit. Examining effects of steer diet within PRF hamburgers, feeding the SS compared to the control diet increased (P <0.05) t-18:1 by 2.89% mainly in the form of t11-18:1, feeding DGGS-15 diet led to no further changes (P >0.05), but feeding DDGS-30 diet reduced the proportions of (P <0.05) of t-18:1 chiefly t11-18:1. Feeding SS and DDGS diets had small but significant (P <0.05) effects on hamburger sensory attributes and oxidative stability.

Conclusions

Feeding high-forage diets including SS and 15% DDGS, and taking advantage of the FA heterogeneity between fat depots offers an opportunity to differentially enhance beef hamburgers with 18:2n-6 biohydrogenation products (i.e., t11-18:1) with potential human health benefits without compromising their sensory attributes and oxidative stability during retail display.     

UTS2R gene polymorphisms are associated with fatty acid composition in Japanese beef cattle

Fatty acid composition of beef adipose tissue is one of its important traits because a high proportion of monounsaturated fatty acid is related to favorable beef flavor and tenderness. In this study, we searched polymorphisms in full length coding DNA sequence of urotensin 2 recepter and investigated the effects on fatty acid composition (C14:0, C14:1, C16:0, C16:1, C18:0, C18:1, C18:2, monounsaturated fatty acid, saturated fatty acid). Eight single nucleotide polymorphisms (SNP) were identified by sequence comparison among eight animals, including five Japanese Black and three Holstein cattle. One of these SNP (c.866C>T) was predicted to cause amino acid substitutions (P289L) and the other seven synonymous SNP, including c.267C>T, were presumed to be in linkage disequilibrium. Therefore we selected two SNP (c.267C>T and c.866C>T) for further analysis. We investigated associations between these genotypes and fatty acid composition in three Japanese Black populations (n = 560, 245 and 287) and a Holstein population (n = 202). Tukey‐Kramer's honestly significant difference test revealed that CC genotype in c.267C>T indicated lower C14:0 and higher C18:1 than the other genotypes in Japanese Black cattle and CC genotype in c.866C>T showed lower C16:1 than CT genotype in Holstein cattle (P < 0.05). These results suggested that these genotypes would contribute to production of high‐grade meat as selection markers in beef cattle.     

Mineral and amino acid composition of beef cattle hooves

Twenty-three Hereford X Shorthorn cattle were used to evaluate the effects of seasonal and dietary changes on the mineral composition (Ca, Mg, Cu, Zn, and S) of hooves. A seasonal pattern was found in the Ca, Mg, and Zn composition of hooves in the 12 cattle evaluated in 1982 and in the 11 cattle evaluated in 1983, with the concentrations of 3 minerals decreasing in winter when dietary change did not occur. Copper concentrations significantly decreased during the 1st year (1982) and had a tendency to decrease during the 2nd year. During the 1983 pasturing season, when effects of seasonal vs dietary change could not be distinguishable, hoof concentrations of Ca and Mg decreased, whereas the inverse trend was observed for Cu and Zn. Seasonal patterns for hoof concentrations of S were not found. Results of mineral analysis of hooves indicated strong correlations between calcium and the other minerals (except S), and between Zn and Cu. Amino acid analyses of hooves of the 11 cattle in 1983 indicated differences in their composition related to dietary changes (winter feeding vs pasture) or to management.     

Comparison of milk fatty acid profiles measured on Kouri cows near Lake Chad and on dairy cattle as reported by meta-analytical data

Kouri (Bos taurus) is a breed aboriginal from Lake Chad and threatened with extinction. This study aimed to compare milk fatty acid profiles measured on Kouri cows and on high-yielding dairy cattle in Europe and elsewhere as reported by meta-analytical data (22 experimentations). Milk samples were collected from 14 Kouri dairy cows in dry season (March to June) and fatty acids (FA) were determined by gas chromatography. Overall, 32 FA have been identified. Kouri showed lower values (P < 0.001) in the sum of saturated FA (SFA, ?10.9 pts), cis-9, cis-12 18:2 (?1.00 pt) (P < 0.01, higher values (P < 0.001) in the sum of monounsaturated FA (MUFA, +15.3 pts), C18:0) (+3.5 pts), cis-9, trans-11 C18:2-CLA (+1.00 pts), trans-11 18:1 (+1.4 pts) and (P < 0.01) in cis-9, C18:1 (+3.00 pts) acids. The differences between the milk FA profile of the Kouri cows and that obtained from meta-analytical data could be the possible consequence of the use of particular lake pastures by Kouri cows.