Study association of bPRL (Bovine Prolactin) gene and milk production trait in Indonesian Holstein dairy cattle

This study was aimed to analyze the genetic variation of bPRL (Bovine Prolactin) gene and its association to milk production in Indonesian Friesian Holstein (IFH) dairy cattle. In total 49 DNA from whole blood were extracted and followed with PCR-RFLP to distinguish the genotype difference between individual samples. The fragment of bPRL gene was amplified using pair of primer forward 5’-GAGTCCTTATGAGCTTGATTCTT-3’ and reverse 5’-GCCTTCCAGAAGTCGTTTGTTTTC-3’, resulting in 156 bp PCR product size. DNA digestion then performed using RsaI restriction enzyme that recognizes 5’-GT↓AC-3’ sites with blunt-end termini. According to the study, two genotypes were discovered that are AA and AB, with respective frequencies of 0.84 and 0.16. Based on the genotype grouping of milk production data, AB genotype yielded 4016.63±1344 kg while AA genotype yielded 3314.32±1153 Kg of milk per lactation. However, there is no statistical (P>0,05) difference between both genotypes on the amount of milk yielded. It is concluded that bPRL gene was not associated with milk production traits in the studied Indonesian Dairy Cattle population.

Correlations of Animal Welfare Scores with First Lactation Milk Yield of Dual Purpose Cows

The objective of this study was to determine the relationships between animal welfare scores (AWS) and milk production in dairy cattle. AWS traits on locomotion ability (LA), social interaction (SI), flooring (F), indoor conditions (IC) and stockmanship effect (SE) were scored by a 100 points scale in a total of 51 farms in Samsun region of Turkey. First lactation milk yield (FLMY) records of Brown Swiss and Simmental cows were used as milk production trait. All components were assessed by t-test to determine the effects of the welfare traits on FLMY. The overall mean of AWS was calculated to be 74.05±1.69, and therefore the farms were founded within a “suitable” class. It was estimated moderate correlations among the parameters except for AWS and SI, however, no statistically significant difference was estimated between AWS and FLMY of the cows. SE was revealed the most important factor on AWS of the farms. Finally, routine scoring cattle farms to decide their suitability for animal needs is advised to herd owners for managing rentable populations in the farms.

Efficiency of bovine IGF-i gene in the improvement of milk productivity using marker-assisted selection (MAS)

Because of insulin-like growth factor-I (IGF-I) gene plays an important regulatory function in milk secretion in cattle, IGF1 gene is potential quantitative trait locus and genetic marker (i.e, SNP) associated with milk production trait in cattle. Consequently, marker-assisted selection (MAS) will be useful to increase and accelerate the rate of genetic improvement on milk productivity. In this study, 48 female Holstein cattle reared under Egyptian conditions were selected based on their milk productivity and DNA from blood was extracted to amplify 249-bp of the gene encoding IGF-I. According to the breeding value, PCR products of IGF-I gene (249-bp) were sequenced only in the 15 highest and lowest milk productivity animals (GenBank accession numbers from gb|HQ183710| to gb|HQ183724|, sequentially). The result indicated that two single nucleotide polymorphisms (SNP?s) at two different positions were observed in one of the highest milk productivity animals. Where, all 15 animals have adenine (A) and cytosine (C) bases at the positions 33 and 63, respectively, except, one animal (GenBank Acc. No. gb|HQ183711|) has thymine (T) and guanine (G) bases at the same positions (33 and 63, respectively). Thus, this finding can be used as marker-assisted selection (MAS) for high milk productivity in Holstein cattle.

Genetic trends for production and non-production traits in Simmental breed in Slovenia

The main part of Slovenian Simmental breed is selected for milk production. Genetic changes in a population should be checked in the case of selection on more traits at the same time. The estimation of genetic trend is the best tool to follow genetic changes in a population. In this paper we present the estimated genetic trends for traits with high economic weight in total selection of Slovenian Simmental breed. Results show that the greatest genetic progress was attained for milk production trait and conformation traits for udder. In other traits not so high genetic progress was attained. In the case of muscularity significant negative genetic progress was attained in the last 12 years.