Genotype and site differences in the fatty acid composition of muscle phospholipids in cattle

Phospholipid data from the Longissimus dorsi (eye muscle) and M. brachii (shoulder muscle) of Jersey and Limousin cattle were used to study the effects of genotype, anatomical site and their interactions on fatty acid composition. Results indicated that phospholipids of the two muscles did not differ in total saturated, monounsaturated and polyunsaturated fatty acids. However, they differed in specific fatty acids 18:0 and 22:5. Genotype was a significant source of variation for the individual fatty acids 18:2 and 18-di-methyl-aldehyde (18-DMA). Significant genotype by anatomical site interactions were observed in the levels of 18-DMA, 18:0, 18:2 and 20:5 fatty acids. It was concluded that the fatty acid composition of phospholipids from biopsy samples of the L. dorsi and M. brachii muscles were similar, but there were significant differences in some individual fatty acids. Furthermore, attention should be paid to genotype by anatomical site interactions that can exist in some individual fatty acids

Breed and sire effects on fatty acid composition of beef fat

The fat content of muscle and the fatty acid profile and melting point of subcutaneous fat was examined in the progeny of three years of crossbreeding Angus, Belgian Blue, Hereford, Jersey, Limousin, South Devon and Wagyu sires with Hereford cows. Significant cohort and sire breed effects were recorded for most traits. Heritability was moderate in most cases. As expected, significant breed differences were noted in the fat content of muscle, but also apparent was the difference in the degree of unsaturation in Jersey and Wagyu progeny. Angus, Hereford, Belgian Blue, South Devon and Limousin animals varied in some fatty acid measures. Jersey and Wagyu had fat with lower melting point (a function of fatty acid composition) and South Devon and Limousin had higher melting point than the remaining breeds

Sex and breed differences in the fatty acid composition of muscle phospholipids in crossbred cattle

Phospholipid data from the Longissimus dorsi (eye muscle) of 117 weaners across 7 cattle genotypes were analysed. The aim was to investigate sex and breed differences in fatty acid composition of muscle phospholipids in an entirely grass-fed management situation. Results showed that sex was a significant source of variation in the levels of 18: ln-9, total monounsaturated fatty acids (MUFA) and calculated Δ9-desaturase enzyme activity index. Heifers had higher percentages in all cases than steers. All the other individual fatty acids and the summations of their proportions did not differ between the sexes. Significant breed differences were apparent in 18: ln-9, 18:3n-3, MUFA and Δ9-desaturase enzyme index. Wagyu and Belgian Blue crosses had the highest proportion of 18: ln-9 and Hereford the lowest. Jersey crosses and Hereford breeds had the highest 18:3n-3 levels and Belgian Blue the lowest. Δ9-desaturase enzyme index was highest in the Wagyu crosses. There were no other breed differences detected in all the other individual fatty acids and their summations. This study suggests that in weaners, the fatty acid composition of muscle lipids differs between breeds and sexes. The magnitude of the differences is, nevertheless, more reflected in the adipose tissue than in the muscle phospholipids. Also, Wagyu and Belgian Blue genotypes produced muscles with the most monounsaturated fatty acids

Genetic variation between crossbred weaner calves in triacylglycerol fatty acid composition

This study compared the fatty acid composition of subcutaneous biopsies of 324 weaner progeny by Angus, Belgian Blue, Hereford, South Devon, Wagyu, Jersey and Limousin sires mated to Hereford dams. The aim was to investigate sire genotype and sex differences in triacylglycerol fatty acids in a grass-fed management system. Results indicated that sire genotype and sex were significant sources of variation in individual fatty acids and summations of their proportions, while the effects of sire genotype by sex interaction and sire nested within sire genotype were not significant. Limousin crosses had the highest proportion of 18:0 and total saturated fatty acids, but the lowest proportion of 16: 1 and total monounsaturated fatty acids. Jersey crosses had the highest percentage of 16: 1 while Wagyu crosses had the highest proportions of 18: ln-9 and total monounsaturated fatty acids. Total polyunsaturated fatty acids did not differ between genotypes. Heifers contained higher 16: 1, 18: ln-9 and total monounsaturated fatty acids but lower proportions of 18:O and total saturated fatty acids than steers

Heritabilities of triacylglycerol fatty acids from the adipose tissue of beef cattle at weaning and slaughter

A first attempt at estimating the heritabilities of total saturated (SFA), monounsaturated (MUFA)and polyunsaturated (PUFA) fatty acids from the triacylglycerol fraction of adipose tissues is presented. The data were from subcutaneous fat biopsies of 324 weaner steers and heifers across 7 genotypes and 26 sires. These animals all went into the feedlot postweaning, but the carcases of 150 at slaughter were sampled for fatty acid analysis. Results showed that weaner SFA, MUFA and PUFA had heritability estimates of 15, 16 and 0% respectively. At slaughter, estimates of heritabilities were 23, 57 and 15% for SFA, MUFA and PUFA respectively. Since monounsaturated fatty acids are highly desirable given their cholesterollowering ability, this study suggests that selective breeding for MUFA has a good prospect of making genetic progress given the high hL of 57%. A larger data set would shed more light on the precision and accuracy of the estimates presented since these are based on a small data set

Breed differences and genetic parameters for fat traits of crossbred cattle

Sires representing seven diverse breeds were mated to Hereford cows over four years and the progeny slaughtered. Highly marbled Jersey and Wagyu crossbred cattle had softer fat (6% lower melting point) than the other breeds. The Angus crosses marbled like Jersey and Wagyu, but had harder fat similar to the very lean Belgian Blue. Hereford, South Devon and Limousin crosses had harder fat than Angus crosses. The South Devon had similar marbling to the Hereford (moderate), but with much less P8 fat (similar to Limousin). Heritabilities were low (e.g. marbling 18%) to moderate (e.g. carcass weight 36%) for the various carcass traits measured

Placental restriction in multi-fetal pregnancies increases spontaneous ambulatory activity during daylight hours in young adult female sheep

Intrauterine growth restriction (IUGR) has adverse effects on metabolic health and early life, whereas physical activity is protective against later development of metabolic disease. Relationships between birth weight and physical activity in humans, and effects of IUGR on voluntary activity in rodents, are mixed and few studies have measured physical activity in a free-ranging environment. We hypothesized that induced restriction of placental growth and function (PR) in sheep would decrease spontaneous ambulatory activity (SAA) in free-ranging adolescent and young adult progeny from multi-fetal pregnancies. To test this hypothesis, we used Global Positioning System watches to continuously record SAA between 1800 and 1200 h the following day, twice during a 16-day recording period, in progeny of control (CON, n=5 males, 9 females) and PR pregnancies (n=9 males, 10 females) as adolescents (30 weeks) and as young adults (43 weeks). PR reduced size at birth overall, but not in survivors included in SAA studies. In adolescents, SAA did not differ between treatments and females were more active than males overall and during the day (each P&lt;0.001). In adults, daytime SAA was greater in PR than CON females (P=0.020), with a similar trend in males (P=0.053) and was greater in females than males (P=0.016). Adult SAA was negatively correlated with birth weight in females only. Contrary to our hypothesis, restricted placental function and small size at birth did not reduce progeny SAA. The mechanisms for increased daytime SAA in adult female PR and low birth weight sheep require further investigation.</jats:p

Genetic and phenotypic correlations between triacylglycerol fatty acids at weaning and slaughter in beef cattle

Predicting fatty acid composition of beef cattle at slaughter using weaner data would enable an early selection decision thereby saving time and costs associated with progeny testing. The aim of this study was to examine genetic and phenotypic correlations between triacylglycerol fatty acid composition at weaning and slaughter. Subcutaneous fat between the 12th and 13th rib interface was biopsied from 324 weaner calves sired by Angus, Belgian Blue, Hereford, Jersey, Limousin, South Devon and Wagyu. Fat from the same anatomical site was sampled from their carcasses at slaughter and analysed for fatty acids by gas-liquid chromatography. Statistical analysis was by Mixed Model and Maximum Likelihood procedures of Harvey (1990) after adjusting for genotype, sire nested within genotype, sex and location. Results indicated strongly positive genetic correlations between biopsy and carcass stearate (18:0), oleate (18:1n-9), total monounsaturated fatty acids (MUFA) and delta-nine desaturase enzyme index of 0.84, 0.99, 0.93 and 0.82 respectively. However, biopsy and carcass palmitate (16:0) had a low genetic correlation of 0.15. Phenotypic correlations were relatively low and ranged from 0 to 0.67. The highly significant genetic correlations obtained suggest that selection decisions for fatty acid composition in the adipose tissue of cattle could be made at weaning

Genetic variation in the fatty acid composition of cattle fat and muscle

Genetic variation in the fatty acid composition of meat and fat biopsy samples collected from 89 Jersey and Limousin cows in a single management group was studied. The animals were part of the J.S. Davies Bovine Gene Mapping Herd. Results indicated that differences between Jersey and Limousin fats (triglycerides) in the percentages of saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids were highly significant (P<0.01). Limousin cows contained higher percentages of SFA than the Jerseys (46 vs 41% respectively). Jerseys on the other hand exhibited higher levels of MUFA (43 vs 38%) and PUFA (15 vs 9%) than Limousins. There were no breed differences in the fatty acid composition of the meat samples (phospholipids)