Metabolic and endocrine profiles and reproductive parameters in dairy cows under grazing conditions: effect of polymorphisms in somatotropic axis genes

Characterization of polymorphisms in the follicle-stimulating hormone receptor and insulin-like growth factor-1 genes and their association with fertility traits in Jawa-Brebes cows

Background and Aim

The availability of fertility markers is crucial for maintaining, protecting, and improving the genetics of Jawa-Brebes (Jabres) cows. Follicle-stimulating hormone receptor (FSHR) and insulin-like growth factor-1 (IGF-1) play critical roles in female reproductive physiology. The single-nucleotide polymorphisms (SNPs) FSHR G-278A and IGF-1 C-512T correlate with cows' fertility traits. This study aimed to identify these SNPs and their potential associations with fertility parameters in Jabres cows.

Materials and Methods

Samples were collected from 45 heads of multiparous Jabres cows aged 3-10 years with body condition scores of 2.5-5.0 on a 5-point scale in Brebes Regency, Java, Indonesia. These cows were assigned to fertile (n = 16) and infertile groups (n = 29). Polymerase chain reaction (PCR) was carried out for DNA amplification of FSHR G-278A and IGF-1 C-512T fragments. Restriction fragment length polymorphism-PCR with the restriction enzymes FaqI for the product of FSHR G-278A and SnaBI for the product of IGF-1 C-512T was used to identify SNPs.

Results

The FaqI enzyme cut the 211 bp DNA fragment of FSHR G-278A in all samples into two bands of 128 bp and 83 bp (GG genotype). Meanwhile, the genotyping of amplicon products of IGF-1 C-512T generated a single 249 bp fragment (CC genotype) in both groups.

Conclusion

The results showed that the FSHR G-278A/FaqI and IGF-1 C-512T/SnaBI loci were monomorphic in Jabres cows. Thus, neither FSHR G-278A/FaqI nor IGF-1 C-512T/SnaBI is a possible genetic marker for fertility in Jabres cows.

Exploring the relationship between polymorphisms of leptin and IGF-1 genes with milk yield in indicine and taurine crossbred cows

Leptin an adipokine plays a significant role in several physiological processes and has been indicated as a candidate gene for marker-assisted selection for high-yielding cows. Insulin-like growth factor-1 (IGF-1) hormone plays an important physiological role in growth, development, metabolism, and lactation in bovines. It is believed to be one of the main mediators of energy balance effects on the reproductive performance of dairy cows after calving. The present investigation was carried out to identify the novel polymorphisms in exon 3 region of leptin and exon 3 partial intron 3 of IGF-1 genes and their association with the milk production performance in indicine and taurine crossbred (Karan Fries) cows. Blood samples were collected from 160 apparently healthy Karan Fries (KF) cows. Four SNPs (single-nucleotide polymorphisms) at positions rs29004508 (C > T), rs29004509 (C > T), rs29004510 (T > C), and rs29004511 (T > C) in leptin gene and two SNPs at positions rs133251968 (C > A) and rs137289661 (C > T) in IGF-1 gene were found in KF cows; however, rs29004509 (C > T) had a positive correlation (r = 0.376; P < 0.05) with milk yield. The genetic variants observed in exon 3 region of leptin gene and their association with milk yield traits revealed the importance of CT genotype, which had been useful for genetic improvement of KF cow for milk production traits and can also be utilized as a potential genetic marker to select appropriate animals.

Assessment of growth hormone gene polymorphism effects on reproductive traits in Holstein dairy cattle in Tunisia

Research to assess the effect of single genes on reproductive traits in bovine species is imperative to elucidate genes' functions and acquire a better perspective of quantitative traits. The present study was undertaken to characterize genetic diversity in the bovine growth hormone (GH) gene in a population of 410 Holstein dairy cows in Tunisia. The analyses were based on single nucleotide polymorphisms, and GH-AluI and GH-MspI detections and genotyping were carried out using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Data were analyzed using a mixed linear model with the MIXED procedure to reveal the possible effect of GH genotypes on reproductive traits. The frequency data of AluI(L//V) and MspI( + // - ) alleles were 87.04//12.96 and 70.06//29.94, respectively. The distribution of the frequency of GH genotypes for LL/LV/VV and ( - / - )//( + / - )//( + / + ) were 77.75//18.59//3.66 and 15.37//29.13//55.50, respectively. The results of the statistical analyses proved that GH-AluI showed a substantial favorable effect on exanimate traits except for the age at first calving; however, only a suggestive effect of GH-MspI on the calving interval (CI) and the days open (DI) was found. The homozygous LL genotype seemed to be advantageous with respect to the CI and the DI compared with LV and VV genotypes. Heterozygous MspI( + / - ) cows tended to have a longer CI and DI than MspI( + / + ) and MspI( - / - ) cows, but the difference was not statistically significant. A significant effect of different GH-AluI-MspI combined genotypes was found on the number of inseminations per conception, the CI and the DI, and the LL/- combined genotype seemed to be associated with better reproductive performance. Based on these results, the LL genotype of the GH locus can be considered to be a favorable genotype for reproductive traits in Holstein dairy cattle, although these findings need to be confirmed by further research before polymorphisms can be used in a marker-assisted selection program.

The effect of polymorphism in gene of insulin-like growth factor-I on the serum periparturient concentration in Holstein dairy cows

OBJECTIVE

To investigate the relationship between polymorphism within the 5'-untranslated region (5'-UTR) of IGF-I gene and its periparturient concentration in Iranian Holstein dairy cows.

METHODS

Blood samples (5 mL, n = 37) were collected by caudal venipuncture from each animal into sample tubes containing the EDTA and DNA was extracted from blood. In order to measure IGF-I concentration the collection of blood samples (n = 111) was also done at 14 d before calving (prepartum), 25 and 45 d postpartum.

RESULTS

We found evidence for a significant effect of C to T mutation in position 512 of IGF-I gene on its serum concentration in dairy cows in Iran. Cows with CC genotype had significantly higher concentration (Mean±SD) of IGF-I at 14 d prepartum (91.8±18.1) µg/L compared to those with TT genotype (73.3±14.4) µg/L (P=0.04). A significant trend (quadratic) was found for IGF-I concentration, as higher in CC cows compared to ones with TT genotype, during the 14 d before calving to 45 d postpartum (P=0.01).

CONCLUSIONS

We concluded that C/T transition in the promoter region of IGF-I gene can influence the serum concentration of IGF-I in periparturient dairy cows.

A polymorphism in the insulin-like growth factor 1 gene is associated with postpartum resumption of ovarian cyclicity in Holstein-Friesian cows under grazing conditions

Background

Insulin-like growth factor 1 (IGF-1) gene is considered as a promising candidate for the identification of polymorphisms affecting cattle performance. The objectives of the current study were to determine the association of the single nucleotide polymorphism (SNP) IGF-1/SnaBI with fertility, milk production and body condition traits in Holstein-Friesian dairy cows under grazing conditions.

Methods

Seventy multiparous cows from a commercial herd were genotyped for the SNP IGF-1/SnaBI. Fertility measures evaluated were: interval to commencement of luteal activity (CLA), calving to first service (CFS) and calving to conception (CC) intervals. Milk production and body condition score were also evaluated. The study period extended from 3 wk before calving to the fourth month of lactation.

Results and discussion

Frequencies of the SNP IGF-1/SnaBI alleles A and B were 0.59 and 0.41, respectively. Genotype frequencies were 0.31, 0.54 and 0.14 for AA, AB and BB, respectively. Cows with the AA genotype presented an early CLA and were more likely to resume ovarian cyclicity in the early postpartum than AB and BB ones. No effect of the SNP IGF-1/SnaBI genotype was evidenced on body condition change over the experimental period, suggesting that energy balance is not responsible for the outcome of postpartum ovarian resumption in this study. Traditional fertility measures were not affected by the SNP IGF-1/SnaBI.

Conclusion

To our knowledge this is the first report describing an association of the SNP IGF-1/SnaBI with an endocrine fertility measure like CLA in cattle. Results herein remark the important role of the IGF-1gene in the fertility of dairy cows on early lactation and make the SNP IGF-1/SnaBI an interesting candidate marker for genetic improvement of fertility in dairy cattle.

Influence of fresh forage-based diets and αs₁-casein (CSN1S1) genotype on nutrient intake and productive, metabolic, and hormonal responses in milking goats

Polymorphism at the αS1-casein locus (CSN1S1) in goats influences several milk production traits. Milk from goats carrying strong alleles, which are associated with high αS1-casein (αS1-CN) synthesis, has higher fat and casein contents, longer coagulation time and higher curd firmness than milk from goats with weak alleles linked to low αS1-CN content. Nutrition also affects these milk properties; therefore, it is important to better understand the interaction between dietary characteristics and the CSN1S1 genotype in goats. This study aimed to investigate the effect of fresh forage based diet or energy supplement on feeding behavior, milk production, and metabolic and hormonal parameters of Girgentana goats with different genotypes at CSN1S1 loci. From a group of goats genotyped by PCR at the DNA level, 12 were selected because they had the same genotype for αS2-CN, β-CN, and κ-CN but a different genotype for αS1-CN: 6 were homozygous for strong alleles at the CSN1S1 loci (AA) and 6 were heterozygous for a weak allele (AF). Goats of each genotype were allocated to 3 subgroups and fed 3 diets ad libitum in a 3×3 Latin square design. The diets were sulla (Hedysarum coronarium L.) fresh forage, sulla fresh forage plus 800 g/d of barley meal (SFB), and mixed hay plus 800 g/d of barley meal (MHB). Diet had a stronger effect than CSN1S1 genotype. The SFB diet led to the highest energy intake, dry matter (DM) digestibility, and milk yield. The fresh forage diets (SFF and SFB) increased DM and crude protein (CP) intake, CP digestibility, and milk CN compared with the MHB diet. The diets supplemented with energy (SFB, MHB) reduced milk fat and urea, improved CP utilization for casein synthesis, and limited body fat mobilization, in accordance with a lower level of nonesterified fatty acids and higher levels of glucose and IGF-1. With regard to CSN1S1 genotype, AA goats showed higher CP digestibility and lower free thyroxine hormone and cholesterol levels than AF goats. Significant diet × genotype interactions indicated how AA goats, compared with AF goats, showed higher DM digestibility and milk yield when fed the SFB diet, which had more energy. A reduction in free triiodothyronine hormone occurred in AF goats fed the MHB diet, whereas no differences were observed in AA goats. These results demonstrate how goats with a higher capacity for αS1-CN synthesis exhibit more efficient energy and protein utilization, evident at the digestive level, and better productive responses to high-nutrition diets.