Identification of leptin gene polymorphisms associated with carcass traits and fatty acid composition in Japanese Black cattle

Previous studies have indicated that some leptin gene polymorphisms were associated with economically important traits in cattle breeds. However, polymorphisms in the leptin gene have not been reported thus far in Japanese Black cattle. Here, we aimed to identify the leptin gene polymorphisms which are associated with carcass traits and fatty acid composition in Japanese Black cattle. We sequenced the full‐length coding sequence of leptin gene for eight Japanese Black cattle. Sequence comparison revealed eight single nucleotide polymorphisms (SNPs). Three of these were predicted to cause amino acid substitutions: Y7F, R25C and A80V. Then, we genotyped these SNPs in two populations (JB1 with 560 animals and JB2 with 450 animals) and investigated the effects on the traits. Y7F in JB1 and A80V in JB2 were excluded from statistical analysis because the minor allele frequencies were low (< 0.1). Association analysis revealed that Y7F had a significant effect on the dressed carcass weight in JB2; R25C had a significant effect on C18:0 and C14:1 in JB1 and JB2, respectively; and A80V had a significant effect on C16:0, C16:1, C18:1, monounsaturated fatty acid and saturated fatty acid in JB1. The results suggested that these SNPs could be used as an effective marker for the improvement of Japanese Black cattle.     

Genomic imprinting variances of beef carcass traits and physiochemical characteristics in Japanese Black cattle

The objective of this study was to estimate variance components related to imprinting for carcass traits and physiochemical characteristics in Japanese Black cattle. The carcass records obtained from 4,220 Japanese Black feedlot cattle included carcass weight (CW), rib eye area (REA), rib thickness, subcutaneous fat thickness, and beef marbling score (BMS), and the physiochemical characteristics were fat, moisture, glycogen per proportion of moisture content, oleic acid, and monounsaturated fatty acids (MUFA). To detect gametic effects, an imprinting model was fitted. High additive heritabilities were estimated for all traits (from 0.516 for glycogen to 0.853 for fat) and were reduced in Mendelian heritability. The range of the differences was from 0.002 (CW) to 0.331 (fat and moisture), and the reductions were due to their imprinting variances. The ratio of the imprinting variance to the total additive genetic variance for REA (0.374), BMS (0.291), fat (0.387), moisture (0.388), and MUFA (0.337) were large (p < 0.05). These imprinting variances were due to the maternal contribution and suggested the existence of maternally expressed genomic imprinting effects on the traits in Japanese Black cattle. Therefore, maternal gametic effects should be considered in breeding programs for Japanese Black cattle.     

Genetic relationships between meat quality traits and fatty acid composition in Japanese black cattle

Genetic parameters were estimated to investigate the relationships between meat quality traits and fatty acid composition from 11 855 Japanese Black cattle. The meat quality traits included beef marbling score (BMS), beef color score, firmness of beef (FIR), texture of beef (TEX) and beef fat color score (BFS). The data on fatty acid composition included oleic acid and monounsaturated fatty acids (MUFA) contents, the ratio of MUFA to saturated fatty acids (MUS) and the ratio of elongation. The heritability estimates for meat quality traits ranged from moderate (0.30) to high (0.72). The strong genetic correlations between them were useful for simultaneous genetic improvement. In addition, high heritability estimates of fatty acid composition, ranging from 0.60 to 0.63, indicated that they could also be improved genetically. The genetic correlations of fatty acid composition with BMS, FIR and TEX were weak and negative. In contrast, positive and stronger genetic correlations were found between BFS and fatty acid composition, in particular, related to the level of unsaturation (0.77 and 0.79 for MUFA and MUS, respectively). This implies that improving the level of unsaturation makes fat darker (more yellow) and thus requires balancing with BFS.     

Digestibility,ruminal fermentation,nitrogen balance and methane production in Holstein steers fed diets containing soy sauce cake at 10 or 20%

Two feeding trials were performed to evaluate the effect of soy sauce cake (SSC) on digestibility, ruminal fermentation and nitrogen (N) balance as well as methane production in Holstein steers. Six animals received a diet without or with the SSC at 10% (Experiment 1) and 20% (Experiment 2) in a 2 × 2 crossover design with a balance trial and respiratory exchange measurement. The SSC feeding showed a strongly inhibitory effect on methane production when its proportion was elevated up to 20%. The digestibility of nutrients with the 10% SSC treatment was similar to that of the control, whereas that for the 20% SSC treatment was significantly decreased in comparison with the control. The 20% SSC treatment also inhibited ruminal fermentation. A lower N partition to urine and a higher N partition to retention were observed in the animals receiving the 20% SSC treatment. These results suggested that SSC feeding at 20% suppressed methane production and changed the N balance; however, the feeding level of 20% caused deterioration in some productive aspects, such as nutrient digestibility and ruminal fermentation. In addition, a feeding level of SSC at 10% of the diet should be considered a reasonable level in cattle.     

Effects of parent‐of‐origin models with different pedigree information on beef carcass traits and fatty acid composition in Japanese Black cattle

Genomic imprinting should be considered in animal breeding systems to avoid lead in bias in genetic parameter estimation. The objective of this study was to clarify the effects of pedigree information on imprinting variances for carcass traits and fatty acid composition in Japanese Black cattle. Carcass records [carcass weight, rib eye area, rib thickness (RT), subcutaneous fat thickness and beef marbling score (BMS)] and fatty acid composition were obtained for 11,855 Japanese Black feedlot cattle. To estimate and compare the imprinting variances for the traits, two imprinting models with different pedigree information [the sire–dam gametic relationship matrix (Model 1) and the sire–maternal grandsire (MGS) numerator relationship matrix (Model 2)] were fitted. The ratio of the imprinting variance to the total additive genetic variance for RT (6.33%) and BMS (19.00%) was significant in Model 1, but only that for BMS (21.09%) was significant in Model 2. This study revealed that fitting the sire–MGS model could be useful in estimating imprinting variance under certain conditions, such as when restricted pedigree information is available. Furthermore, the present result suggested that the maternal gametic effects on BMS should be included in breeding programmes for Japanese Black cattle to avoid selection bias caused by imprinting effects.     

Change of fatty acid composition of the lumbar longissimus during the final stage of fattening in the Japanese Black cattle

Consideration of the shortened fattening period seems to be worthwhile for the realization of profitable beef production. In this study, change of fatty acid composition of the lumbar longissimus during the final stage of fattening was investigated in Japanese Black cattle. Each of 110 fattening animals was sampled three times: the initial two samples were taken by biopsy (25.7 months and 27.5 months on average) and the final one was from carcasses (29.9 months on average). Preliminary analysis indicated that removing muscle tissues from the constant body position of the living animals should be essential for sampling. Average monounsaturated fatty acids (MUFA) at three sampling points were 58.1%, 58.5% and 60.5%, and the differences of the third sampling with the first and second samplings were significant. Both in steers and heifers, MUFA also increased as the fattening stage proceeded, and MUFA of the heifers at all the sampling points were significantly higher than those of the steers. The increasing rate of MUFA rose from 0.21 percentage points (pp)/month at period 1 (from the first sampling to the second sampling) to 0.84 pp/month at period 2 (from the second sampling to the slaughter).     

Effect of soy lecithin on total cholesterol content,fatty acid composition and carcass characteristics in the Longissimus dorsi of Hanwoo steers (Korean native cattle)

This study aims to investigate the effect of soy lecithin on the total cholesterol content, the fatty acid composition and carcass characteristics in the Longissimus dorsi in Hanwoo steers. Hanwoo steers (24 head) were fed two diets: Control (CON) (concentrate + alcohol‐fermented feed (AFF)) and soy lecithin treatment (CON + soy lecithin at 0.5% of the AFF). Soy lecithin treatment increased average daily gain, serum concentrations of triglyceride, total cholesterol and high‐density lipoprotein‐cholesterol in the blood. A lower cholesterol concentration was found in the Longissimus dorsi for the soy lecithin diet compared to the CON diet. With respect to the marbling score and quality grade of Longissimus dorsi, soy lecithin supplementation significantly increased the C20:5n3, C22:4 and polyunsaturated fatty acids contents compared to the CON diet. Soy lecithin supplementation would alter the total cholesterol content, polyunsaturated fatty acid profile and meat quality of Longissimus dorsi.     

Growth performance,carcass characteristics,fatty acid composition and CLA concentrations of lambs fed diets supplemented with different oil sources

Quality food for human consumption will always be the aim for animal producers. Quantity and composition of fat deposits (fatty acid profile) strongly influences meat quality in ruminants, especially via increasing conjugated linoleic acid (CLA) concentration, which is known to have beneficial anticarcinogenic, antiatherogenic, antidiabetic and cholesterol reduction properties for human health. Awassi lambs are one of the main and most consumed meat sources in the Middle East area; however, studies addressing the fat content of CLA and methods to enhance its concentrations in this breed are still rare. For this reason, the aim of this study was to evaluate the effect of adding two different oil sources (soybean oil (SBO) and sunflower oil (SFO) at two levels (1.8 and 3%)) on growth performance, carcass characteristics and fatty acid profile of fat in Awassi lambs. Oil supplementation had no effect on growth performance or carcass characteristics, while fatty acid composition changed according to the site of extraction. CLA concentrations were increased in the tail fat deposit, with 1.8% SBO and in intermuscular fat deposit with 3% SFO. Intermuscular fat is the one most naturally consumed by humans, serving to improve food quality.     

Effects of GH gene polymorphism and sex on carcass traits and fatty acid compositions in Japanese Black cattle

To investigate the effects of bovine growth hormone (bGH) gene polymorphism on carcass traits and fatty acid compositions in Japanese Black cattle caused by nucleotide substitution of CTG (allele A)/GTG (allele B) at codon 127 and of ACG (allele A and B)/ATG (allele C) at codon 172 of bGH, GH genotypes of 135 cattle were determined using allele specific-multiplex polymerase chain reaction (PCR). Allele A gave greater rib thickness and lower melting point of fat (MP) while allele B gave higher C18:1% ( P  < 0.05). Allele C gave higher C18:1, monounsaturated fatty acid (MUFA), unsaturated fatty acid (USFA) percentages ( P  < 0.05). It also gave lower saturated fatty acid (SFA) percentages, higher MUFA/SFA and USFA/SFA ratios, and lower MP ( P  < 0.05). Interactions of sex and GH alleles were analyzed. In heifers, allele A gave higher carcass weight, daily carcass gain, rib eye area, rib thickness, subcutaneous fat thickness, and BMS while allele B gave greater rib eye area and rib thickness ( P  < 0.05). Allele C gave higher C18:1 ( P  < 0.01), MUFA ( P  < 0.01), USFA percentages ( P  < 0.05) and MUFA/SFA and USFA/SFA ratios ( P  < 0.01), and lower C16:0 and SFA percentages ( P  < 0.05) and MP ( P  < 0.01). GH gene polymorphism affected carcass traits and fatty acid compositions although the effects were more pronounced in heifers.     

Effect of SCD and SREBP genotypes on fatty acid composition in adipose tissue of Japanese Black cattle herds

Fatty acid composition of beef adipose tissue is one of important traits because high proportions of monounsaturated fatty acid are related to favorable beef flavor and tenderness. In this study, we investigated effects of genetic factors such as stearoyl-CoA desaturase (SCD) and sterol regulatory element binding protein (SREBP) on beef carcass traits including fatty acid composition using two cattle populations. Sire effect was significantly related to almost all traits except BMS, suggesting that the trait examined in this study is highly controlled by genetic factors. The effect of SCD genotype on fatty acid composition was detected remarkably in both cattle groups, especially on stearic and oleic acids. This result was consistent with our previous studies and suggests that SCD is associated with fatty acid composition. Unlike SCD genotyping, the effect of SREBP genotype was not identified in this study. Our results suggested that SCD genotype would contribute to improving beef quality in field populations. Further studies about the relationship among these factors will bring an insight into the molecular mechanism of fatty acid metabolism in cattle.     

青贮艾草对肉牛生长性能、胴体品质及肌肉脂肪酸组成的影响

文章旨在研究育肥期肉牛日粮中添加不同水平的青贮艾草对生长性能、胴体品质及肌肉脂肪酸组成的影响。试验选择15月龄平均体重为(326±22)kg的肉牛24头,随机分为4组,每组6个重复,每个重复1头牛。试验分为育肥前期和育肥后期两个阶段,对照组饲喂基础日粮+水稻秸秆,试验组在基础日粮中分别补充5%、10%和15%的青贮艾草,两个阶段精料补充料干物质、粗蛋白质、粗脂肪、中性洗涤纤维、酸性洗涤纤维、脂肪酸组成及主要脂肪酸含量相近。结果 :精料摄入量随日粮青贮艾草添加水平的升高表现为显著二次曲线效应(P <0.05);随着日粮艾草添加水平的升高,肉牛末重和平均日增重表现为显著二次曲线效应(P <0.05),而料比线性降低(P <0.05)。牛的屠体重、眼肌面积和大理石纹评分随日粮青贮艾草添加水平的升高表现为显著二次曲线效应(P <0.05),而背膘厚度表现为显著二次曲线降低(P <0.05)。眼肌C18:0、C18:1和单不饱和脂肪酸含量显著线性降低(P <0.05),亚麻油酸、C18:3、C20:4、C22:0和C24:1脂肪酸含量显著线性降低(P <0.05),多不饱和脂肪酸和多不饱和脂肪酸与饱和脂肪酸比值表现为显著二次曲线增加(P <0.05)。结论 :日粮青贮艾草添加水平对肉牛生长性能、肌肉脂肪酸含量的影响表现为二次曲线效应,但高水平青贮艾草降低了肉牛生长性能、屠宰性能及肉品质。肉牛育肥期日粮中适宜的青贮艾草添加水平为10%。     

Effects of the fattening period on the fatty acid composition of fat deposits and free amino acid and inosinic acid contents of the longissimus muscle in carcasses of Japanese Black steers

The effects of the fattening period on carcass characteristics, fatty acid composition of fat deposits, and muscle free amino acid (FAA) and inosinic acid (IMP) contents were evaluated in Japanese Black steers. Ten castrated, 10-month-old calves derived from the same sire were divided into five to be slaughtered at the age of 30 months after a 20-month fattening period (20-month group) and five to be slaughtered at the age of 34 months after a 24-month fattening period (24-month group). Concerning the fatty acid composition of subcutaneous fat, the percentage of palmitoleic acid was higher ( P  < 0.05) in the 24- than in the 20-month group, but no difference was noted in any other fatty acids. For intermuscular fat, no difference was observed in any fatty acids. The percentages of oleic acid and total monounsaturated fatty acid of intramuscular and perinephric fat were higher ( P  < 0.05) in the 24- than in the 20-month group. Of the FAAs in the longissimus thoracis muscle, the threonine and tyrosine contents were lower ( P  < 0.05) in the 24- than in the 20-month group. The IMP content was higher ( P  < 0.05) in the 24- than in the 20-month group, suggesting an effect of prolongation of the fattening period.     

Effect of ruminal dosing of mechanical stimulating brush on carcass characteristics and fatty acid composition of dressed carcass fat in fattening Holstein steers fed with high-concentrate diets

This experiment was undertaken to examine the effect of dosing of a mechanical stimulating brush (RF) in the rumen on dressed carcass characteristics and on the fatty acid composition of dressed carcass fat in fattening beef cattle. The fattening trial was carried out with high-concentrate diets (organic cell wall contents: 27.5% on a dry mater basis) in eight Holstein steers (12 months of age). Four of the experimental animals were orally dosed with three RF/head (RF group); the other four animals without RF dosing were allotted as the control group. Grass hay was fed to the animals (0.2 kg/head/day) until 19 months of age. Concentrate diet was given ad libitum during the experiment. There were no statistical differences between the RF group and the control group in yield score and meat quality score of dressed carcass characteristics. Regarding fatty acid composition of dressed carcass fat, the proportion of C18 : 2 fatty acids in subcutaneous fat in the RF group was greater ( P  < 0.05) than that in the control group. C16 : 0 fatty acids in kidney fat in the RF group was lower ( P  < 0.05), and C18 : 2 fatty acids and total unsaturated fatty acids of 18 carbon number in kidney fat in the RF group were higher ( P  < 0.05) compared with the control group. The proportion of C18 : 2 fatty acids in rib eye fat in the RF group was greater ( P  < 0.05) than that in the control group. C18 : 1 fatty acids, C18 : 2 fatty acids and total unsaturated fatty acids of 18 carbon number in rib fat in the RF group were greater ( P  < 0.05) than those in the control group. The results suggest that in fattening Holstein steers fed with high-concentrate diets, the effect of ruminal RF dosing on dressed carcass characteristics is not significant, but the proportion of unsaturated fatty acid of carcass fat is increased.     

Effect of supplementation of soy sauce oil and Ca salts of fatty acids on rumen fermentation,milk production and conjugated linoleic acid in milk of dairy cows

Eight cows were used to evaluate the effects of supplementation of soy sauce oil (SO) or Ca salts of fatty acids (FA) on rumen fermentation and milk production. The control diet (CO) consisted mainly of hay, corn silage and a concentrate. In the experimental diets, 400 g/day per cow of SO or FA (soybean oil and rapeseed oil) was supplemented to the CO diet. Experimental period for the three treatments was 14 days, and milk samples were taken during the last 2 days and rumen sample was taken on the last day. Dry matter intake was not affected by the treatments. The number of rumen protozoa at 0 h increased by SO and FA diets. Total volatile fatty acids at 2 h after feeding of SO diet was decreased compared to CO. The milk composition yield did not differ among treatments, although the percentages of fat and protein were decreased by SO and FA diets. The proportions of C8–C16 fatty acids in milk fat decreased, and those of C18 increased by SO and FA diets. The proportion of cis‐9, trans‐11 conjugated linoleic acid in milk fat by SO and FA diets increased by 120% and 135%, respectively. In spite of the slight suppression of rumen fermentation by SO diet, negative effects on feed intake and milk production were not detected.     

低蛋白质日粮对育肥绵羊生长性能、胴体性状及肌肉脂肪酸组成的影响

本研究旨在研究降低全混合日粮蛋白质水平对育肥期绵羊生长性能、胴体性状及肌肉脂肪酸组成的影响.试验将32只平均体重为(38.14±0.45)kg的育肥期绵羊随机分为2组,每组8个重复,每个重复2头.两组绵羊在为期10周的试验期中分别饲喂蛋白质水平为13.5％和8.5％的全混合日粮.结果:将全混合日粮蛋白质水平从13.5％...     

Carcass characteristics,chemical and fatty acid composition and oxidative stability of meat from broiler chickens fed black cumin (Nigella sativa) seeds

A study was conducted to investigate the dietary supplementation of black cumin seeds (BCS) on carcass characteristics, chemical and fatty acid (FA) composition and antioxidant properties of thigh and breast meat of broiler chickens at 42 days of age. Three hundred sixty 1‐day‐old broiler chickens were allocated to five dietary treatment groups (each group containing eight replicate pens with each pen containing nine broiler chickens): basal diet (control; CON), CON + 0.05 g/kg of bacitracin methylene disalicylate (AB), CON + 5 g/kg of BCS (low dose of BCS), CON + 10 g/kg of BCS (medium dose of BCS) and CON + 20 g/kg of BCS (high dose of BCS). Weight (g) of slaughtered birds (p = .03), hot carcass (p = .007), breast (p = .03), thigh (p < .001), wing (p = .06), neck (p = .01), liver (p = .09), abdominal fat (p = .01) and total edible parts (p = .01) increased or tended to increase due to BCS supplementation compared with the CON. The concentrations of dry matter, crude protein and ether extract in chicken thigh and breast meat increased (p = .038 to <.001) with increasing doses of BCS in diets. The ferric reducing antioxidant activity in blood and meat increased linearly with increasing doses of BCS in the diets. However, peroxide values in meat were not affected by BCS and AB on both days 1 and 7 of storage at 4°C. Supplementation of BCS increased the concentrations of C14:1, C18:3n‐6, C20:1, C20:2 FA and PUFA linearly (p < .05) and tended to increase (p = .098) the concentration of C18:2cis linearly. However, the concentrations of C16:0 and C16:1 FA decreased linearly with increasing doses of BCS in the diets. In conclusion, dietary supplementation of BCS at 20 g/kg diet may improve slaughter body weight, beneficial FA concentrations and antioxidant properties of broiler chicken meat.     

Effects of adding poultry fat in the finishing diet of steers on performance, carcass characteristics, sensory traits, and fatty acid profiles

Use of poultry fat in the finishing diets of steers has not been studied as a potential source of added energy. Therefore, 60 Angus crossbred steers were fed 1 of 3 dietary treatments consisting of 1) a corn-soybean meal control diet devoid of added fat; 2) the control diet formulated with 4% tallow; or 3) the control diet formulated with 4% poultry fat. Addition of fat did not (P = 0.17) affect ADG for the 112-d study. The inclusion of tallow in the diet reduced (P < 0.05) ADFI of steers compared with those on the control diet; however, ADFI of steers fed poultry fat did not differ from those fed the control (P = 0.06) or the tallow (P = 0.36) diets. At d 55, steers consuming either fat source had improved (P < 0.05) G:F compared with steers fed the control diet. For the entire 112 d, steers consuming the poultry fat diet gained more efficiently (P < 0.05) than the control steers, and the tallow-fed steers were intermediate and not different from the other groups (P > or = 0.14). The inclusion of fat in the diet did not (P > or = 0.15) affect carcass characteristics. Steaks from the steers consuming diets with added fat were darker (lower L* value; P < 0.05) than the controls; however, dietary treatments did not (P > or = 0.10) affect any other objective color measurements or discoloration scores during retail display. Thiobarbituric acid reactive substances for LM steaks did not differ (P = 0.21) by dietary treatment. The cooked LM steaks from steers fed poultry fat did not (P > or = 0.80) differ in juiciness or flavor intensity from steaks of steers fed the control or tallow diets. There were also no differences (P = 0.18) in off flavors as a result of added dietary fat. In the LM and adipose tissue, percentages of total SFA were increased (P = 0.05) by adding supplemental fat to the diet, regardless of source. In the LM, total MUFA were decreased (P = 0.02) by adding supplemental fat. Conversely, diet did not (P > or = 0.14) affect the proportions of total PUFA in either tissue or total MUFA in the adipose tissue. Results indicated that replacing beef tallow in finishing diets with poultry fat, a more economical energy source, had no detrimental effects on growth performance, carcass characteristics, retail display life, fatty acid profiles, or palatability.     

Genome‐wide association study for carcass traits,fatty acid composition,chemical composition,sugar, and the effects of related candidate genes in Japanese Black cattle

We performed a genome‐wide association study (GWAS) and candidate gene analysis to: (i) evaluate the effectiveness of the GWAS in our small population by performing GWAS for carcass weight (CW) and fatty acid composition; (ii) detect novel candidate regions affecting non‐CW carcass traits, chemical composition and sugar; and (iii) evaluate the association of the candidate genes previously detected in CW and fatty acid composition with other economically important traits. A total of 574 Japanese Black cattle and 40 657 Single nucleotide polymorphisms were used. In addition, candidate gene analyses were performed to evaluate the association of three CW‐related genes and two fatty acid‐related genes with carcass traits, fatty acid composition, chemical composition and sugar. The significant regions with the candidate genes were detected for CW and fatty acid composition, and these results showed that a significant region would be detectable despite the small sample size. The novel candidate regions were detected on BTA23 for crude protein and on BTA19 for fructose. CW‐related genes associated with the rib‐eye area and fatty acid composition were identified, and fatty acid‐related genes had no relationship with other traits. Moreover, the favorable allele of CW‐related genes had an unfavorable effect on fatty acid composition.     

Effects of a DHA‐rich unextracted microalgae as a dietary supplement on performance,carcass traits and meat fatty acid profile in growing‐finishing pigs

Two 125‐day experiments of the same design were conducted to evaluate the effects of a heterotrophically grown microalgae (AURA) containing docosahexaenoic acid (DHA) on pig performance, carcass traits and the fatty acid composition of lean and adipose tissue. In each experiment, 144 Hypor pigs were blocked by sex, allocated to three treatment groups, and fed 0, 0.25% or 0.50% AURA in isonutritive, isocaloric diets. Pigs were weighed on days 0, 28, 56, 84 and 112. Feed and water intakes were measured every 28 days. Pigs were slaughtered on day 125. Data from the two studies were analysed as a single data set. Performance and carcass traits did not differ between treatments. Both microalgae treatment levels enriched (p < .05) Longissimus lumborum (LL) and backfat in DHA and improved (p < .05) their ratios of n‐6 to n‐3 fatty acids.