Genetic variation in the first intron and exon of the myostatin gene in several Indonesian cattle populations

Background and Aim

Myostatin (MSTN), a member of the transforming growth factor-b family, is a negative regulator of muscle mass. This study aimed to detect the genetic variation of the 1160 bp fragment of exon 1 and part of intron 1 of the MSTN gene in several cattle populations raised in Indonesia.

Materials and Methods

Polymerase chain reaction products of the MSTN gene amplified from 92 animals representing 10 cattle populations (Peranakan Ongole [PO], Belgian Blue x PO cross, Rambon, PO x Bali cross, Jabres, Galekan, Sragen, Donggala, Madura, and Bali) were sequenced, compared, and aligned with bovine MSTN of Bos taurus (GenBank Acc. No. AF320998.1) and Bos indicus (GenBank Acc. No. AY794986.1).

Results

Four nucleotide substitutions (nt 1045 and 1066 in intron 1; nt 262 and 418 in exon 1) and two indels (nt 807 and 869 in intron 1) were synonymous mutations. Among these substitutions, only the nt 262G>C and nt 418A>G loci were polymorphic in all populations, except Bali cattle. The frequencies of the nt 262C (0.82) and nt 418A (0.65) alleles were highest. For the nt 262G>C locus, the CC genotype had the highest frequency (0.66) followed by GC (0.30) and CC (0.03). For the nt 418A>G locus, the AG genotype had the highest frequency (0.52) followed by AA (0.39) and GG (0.09).

Conclusion

The results, showing genetic variations in exon 1 and intron 1 of the MSTN gene, might be helpful for future association studies.

Associations between UASMS2 polymorphism in leptin gene and growth, carcass and meat quality traits of cattle: a meta-analysis

Although numerous studies investigated the effect of UASMS2 polymorphism in leptin gene on cattle production, a consensus has not yet been reached. Therefore, we reviewed and meta-analyzed the effects of UASMS2 on cattle. We searched potentially relevant studies from seven databases (to December 25, 2019). Standard mean difference along with 95% confidence intervals was calculated to assess the strength of association through the random-effects model. Six published articles containing 1378 cattle samples were included in our meta-analysis. We found UASMS2 was not related to carcass weight, dressing percentage and loin muscle area in the recessive genetic model, but there was a significant association between UASMS2 and average daily weight gain, dry matter intake, body weight, marbling score, and backfat thickness. This meta-analysis indicated that UASMS2 was associated with growth and meat quality traits of cattle, implying that this SNP can be used reliably in beef cattle breeding. This study may provide valuable information on improving beef yield and quality in cattle production.

Feedlot performance and immune function analysis of implanted and non-implanted steers selected for alcohol dehydrogenase 1 C (ADH1C) genotype and fed a low vitamin A diet

Previous studies have shown that the interaction between limiting vitamin A (VA) and an alcohol dehydrogenase 1 C (ADH1C) variant in beef cattle results in increased intramuscular fat in the longissimus thoracis muscle in one genotype when fed low dietary VA. Although quality grade is important for increased profitability and improving taste characteristics of beef products, limiting VA too drastically can impair animal welfare. The objectives of this study were to determine if this marker-assisted management strategy would be effective, and whether any impairment in immune function would occur in a feedlot setting. Mixed breed beef steers (n=2000) were sorted into 40 feedlot pens so that all combinations of ADH1C genotype (TT or CT), VA level (50% or 100% of recommended) and hormonal implant status (implanted (IMP) or non-implanted (NI)) were equally represented within the population. The VA×ADH1C interaction was not observed. An implant status × ADH1C interaction was observed with average daily gain (ADG; P=0.03). Steers that were IMP and CT had higher ADG than IMP TT (CT=1.69 and TT=1.62 kg/day), whereas both genotypes in the NI steers were lower (CT=1.29 and TT=1.32 kg/day). Implant status was shown to affect dry matter intake (DMI; IMP=8.55 and NI=7.87 kg; P<0.01), total days-on-feed (IMP=164.4 and NI 210.5 days; P<0.01), USDA yield grade (YIELD; IMP=2.40 and NI=2.77; P<0.01), marbling score (MARB; IMP=392 and NI=455; P<0.01), longissimus thoracis area (LTA; IMP=85.0 and NI=80.7 cm2; P=0.01) and backfat thickness (FAT; IMP=8.0 and NI 10.0 mm; P<0.01). Overall, IMP animals finished on fewer total days-on-feed with higher ADG, DMI, larger LTA, and lower YIELD, MARB and FAT. To investigate immune function parameters, crossbred steers (n=18) were selected from a prior feeding trial so that all combinations of ADH1C (TT, CT and CC) and VA (25% or 75%) were equally represented. Blood cell count analysis and peripheral blood mononuclear cell proliferation and stimulation assays were conducted. None of these immune parameters were affected by VA level. Treatment and mortality records were examined in the 2000 steer population, where no correlations with ADH1C, implant status or VA level were observed. Due to no VA × ADH1C interaction, this nutrigenetic marker-assisted management strategy is not effective at this time in commercial beef cattle feedlots, however, supplementing VA at a level as low as 25% of recommended in finishing rations would likely not result in signs of immune dysfunction.

Impacts of a leptin SNP on growth performance and carcass characters in finishing steers studied over time

A total of 2,948 steers (mean initial BW = 568.9 ± 49.4 kg) were used to evaluate the effect of the LEP R25C SNP genotype on feed intake, growth performance, and carcass characteristics over time. Steers were grouped into 5 blocks, each consisting of 10 pens initially, and then at approximately 24 d prior to the assigned slaughter date, cattle in each pen were randomly selected either to remain in the pen they were in (group A) or to be assigned to a new pen (group B). Steers were allocated to 5 blocks and 6 harvest weeks (-3, -2, 0, 2, 3, and 4 wk) relative to the projected end point. Steers were weighed and ultrasound scanned at 60 and 1 d prior to harvest. Leptin genotype affected ( ≤ 0.011) 12th-rib fat and i.m. fat percentage (IMF) for each slaughter group at both 60 and 1 d prior to slaughter, although rib eye area (REA) was not affected ( = 0.773) by leptin genotype 60 d prior to slaughter in any group. Time affected ( < 0.001) live BW as well as 12th-rib fat, REA, and IMF measured 60 and 1 d prior to each slaughter time. Dry matter intake was also higher ( = 0.003) for cattle of the animals homozygous for the T allele (TT) genotype compared to those with the animals homozygous for the C allele (CC) genotype (9.59 vs. 9.29 ± 0.075 kg). The LEP R25C genotype affected key traits related to carcass fatness; specifically, compared to cattle of the CC genotype, cattle of the TT genotype had a higher ( = 0.016) calculated empty body fat (29.1 vs. 28.8 ± 0.133%) and higher ( = 0.020 calculated yield grade (2.62 vs. 2.52 ± 0.035). Additionally, like for live measures, TT cattle tended ( = 0.093) to have a higher 12th-rib fat (13.2 vs. 12.8 ± 0.26 mm). However, the LEP R25C genotype did not affect KPH ( = 0.854) or marbling score ( = 0.240), nor did it affect any USDA quality measure ( ≥ 0.350). The leptin genotype also affected ( = 0.048) HCW, which was highest for steers of the TT genotype (400.9 vs. 403.5 ± 3.41kg). Results indicate that the leptin R25C genotype and time impacted most traits associated with fatness.

Performance and carcass characteristics when sorting feedlot cattle on the basis of phenotype, and leptin genotype along with differential use of β-adrenergic agonists

Kononoff, P. J., Defoor, P. J., Engler, M. J., Swingle, R. S., James, S. Y., Deobald, H. M., Deobald, R. L., Woronuk, G. N. and Marquess, F. L. S. 2015. Performance and carcass characteristics when sorting feedlot cattle on the basis of phenotype, and leptin genotype along with differential use of β-adrenergic agonists. Can. J. Anim. Sci. 95: 455–463. Crossbred steers were used in a randomized complete block design to evaluate a feedlot cattle sorting system. The sorting system combined information on live body weight, ultrasound fat thickness, coat color, and genotype on the leptin R25C genotype. Using described sorting criteria, a total of four groups (Groups 1–4) of cattle were created along with a randomly selected unsorted control (Group 5), with Groups 1 through 5 representing experimental treatments, and placed in one of five pens within each block. Block was replicated 10 times thus n equaled 50. All cattle were administered zilpaterol hydrochloride except Group 3, which we hypothesized would have a greater proportion of cattle reaching a higher value Quality Grade, and as a result administered ractopamine hydrochloride. The initial body weight of cattle was similar (P=0.426) between the control Group and Groups 1–4. Initial fat, as measured by ultrasound, was also observed to be similar (P=0.256) between these two groups. Overall, when cattle included in Groups 1–4 were compared with Group 5, hot carcass weight was greater (P=0.040), while the proportion of excessively heavy weight carcasses was less (P=0.049). Additionally, hot carcass weight gain tended (P=0.096) to be higher for Groups 1–4 compared with Group 5. No differences (P≥0.129) were observed for calculated yield grade. On average, cattle included in the Sorting Groups 1–4 returned $23 more per head than those in Group 5.