Background and Aim: Myostatin (MSTN), a member of the transforming growth factor-β 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.

Information on the genetic diversity of native and local cattle in Indonesia is vital for the development of breeding and conservation strategies. This study was aimed to assess the genetic diversity and phylogenetic relationship of the Indonesian native (Bali) and local [(Donggala, Madura, Sragen, Galekan, Rambon, dan Peranakan Ongole Grade x Bali (POBA)] cattle populations. Genomic DNA was extracted from blood samples (n= 75). Partial sequences of mtDNA cyt<em> b</em>, 464 bp, were amplified using the polymerase chain reaction technique (forward primer: L14735 and reverse primer: H15149). Thirty-four reference sequences of <em>Bos taurus</em>, <em>Bos indicus</em>, and <em>Bos javanicus</em> were included in the phylogenetic analyses. A total of 55 polymorphic sites and 13 haplotypes were observed in the whole breeds. No variable sites of mtDNA cyt<em> b</em> were observed in Galekan (kept in BCRS) and Rambon cattle. Overall haplotype diversity and nucleotide diversity were 0.515 ± 0.070 and 0.0184 ± 0.0045, respectively. The highest (0.092) and the lowest (0.000) genetic distances were between Bali and Donggala cattle populations and among Galekan (kept in BCRS), Rambon, and POBA cattle populations, respectively. Both mtDNA network and phylogenetic analyses revealed two major maternal lineages (A and B) of the studied population. Most of the sampled individuals (69.33%, present in haplotype H8-H19) were linked to lineage B, which belonged to the same cluster with <em>Bos javanicus</em>. Overall, most of the Indonesian native and local cattle populations had a considerable genetic diversity and shared a common maternal origin with <em>Bos javanicus</em>.

This study aimed to determine the efficiency and effectiveness of the use of PGF2α and ovsynch (PGF2α and GnRH) estrous synchronization hormones on their ability to have an impact in the form of estrous and pregnancy symptoms in Madura cow. The material used were 182 Madura cows, was consisted by three treatments, namely A treatment with 62 cows; first day (H-0) was injected with PGF2α dose of 2 ml; 11th day (H-11) injected with the same hormone and dosage; then 3-4 days after the second AI (Artificial Insemination) injection directly; treatment B of 60 cows; first day (H-0) injected PGF2α dose 3 ml; 11th day (H-11) is injected again with the same hormone and dosage; then 3-4 days after injection of the second hormone directly AI; C treatments were 60 cows; given ovsynch treatment; that is, on the first day (H-0) injected with a 2.5 ml dose of the GnRH hormone; 8th day (H-8) injected with PGF2α dose 2 ml; the 10th day was injected again with the second GnRH hormone (2.5 ml dose), then the 11th day was directly AI. Sampling was done by purposive sampling method, which was choosing a cow that has a body condition score (BCS) between 5-7, normal reproductive organs and not in a state of pregnancy. The study design used a completely randomized design; Data were analyzed using the Kruskal Wallis test. The results showed that the administration of synchronous hormones to the percentage of estrous and pregnancy rate in all treatments showed no significantly different results (P > 0.05). The average percentage of estrous Madura cows in all treatments was 94.50%, while the average pregnancy rate was 68.66%, the highest yield in treatment C was 73.33%; followed by treatments A and B respectively 70.97% and 61.67%.

<p><strong>Objective:</strong> To determine the natural mating behavior pattern of PO bulls with Bali cows in the cattle breeding system using freestall housing of “Litbangtan Model”.</p><p><strong>Methods:</strong> The materials were 63 livestock; 3 PO bulls and 60 Bali cows. The study was designed with a randomized block design (RBD) with three treatments based on the physiological status of Bali cows; namely Treatment A: 20 heifers, Treatment B: 10 heifers and 10 cows, and Treatment C: 20 cows. The parameters observed were the pattern of estrous behavior, the length of time from estrus to mating, the phenomena that occurred during pregnancy and the birth process, and the pregnancy rate.</p><p><strong>Results:</strong> The estrous intensity in the +++ category was higher than + or ++ in all treatments. The shortest average time interval between estrus and mating occurred in treatment A with a pregnancy rate of 83.33%. The phenomena that occur during pregnancy and at birth are abortion, dystocia and calf death at birth. Abortion occurs at 4-6 months of gestation, dominated by heifers; the incidence of dystocia is entirely experienced by heifers.</p><p><strong>Conclusion:</strong> Cows with estrus were 86.67% with various expressions starting from silent heat (+), medium (++) and visible (+++). There are 42 Bali cows that show normal behavior in a series of reproductive activities (estrus and mating) with a time interval estrus and mating between 0.67-14.75 hours. Pregnancy rate 83.33%; the phenomena that occur during pregnancy and childbirth include abortion, calf death at birth and dystocia.</p>

Abstract. The study was conducted to determine the correlation between the body morphology size of PO steers and heifers which kept in the group housing of Litbangtan Models. The materials of this study used 24 PO steers and heifers (each cow was 15 to 18 months old). The data were analyzed using descriptive statistics and correlation analysis. Due to the significant value, it stated that the body length and chest circumference influenced positively to the gain of the weight body of PO steers and heifers . The value of determination analysis (R 2 ) both PO steers and heifers was 92.70% and 86.80%; It indicated that the gain of the body length size and chest circumference would increase the body weight. The result of calculation shown that the average of body weight of PO steers and heifers after having used two body morphological measurement (body length and chest circumference) was relativeely close to the real measurement. This phenomenon indicated that the body length and chest circumference had a close relationship with the body weight either in PO steers and heifers.Key words: PO steers and heifers, body morphological size, body weight Abstrak. Penelitian ini dilaksanakan untuk menentukan korelasi antara ukuran morfologi tubuh PO steers dan heifer yang dipelihara di kandang kelompok Litbangtan Model. Materi yang digunakan dalam penelitian ini adalah 24 PO steer dan heifer (masing-masing berumur 15 sampai 18 bulan). Data dianalisis menggunakan deskriptif statistik dan analisis korelasi. Berdasarkan nilai signifikan, dinyatakan bahwa panjang badan dan lingkar dada berpengaruh positif terhadap peningkatan bobot badan PO steer dan heifer. Nilai koefisien determinsasi (R 2 ) PO steer dan heifer adalah 92,70% dan 86,80%; mengindikasikan bahwa peningkatan ukuran panjang badan dan lingkar dada akan meningkatkan bobobt tubuh. Hasil perhitungan menunjukkan bahwa rataan bobot tubuh PO steer dan heifer setelah menggunakan dua ukuran morfologi tubuh (panjang badan dan lingkar dada) serupa dengan ukuran nyata. Fenomena ini menunjukkan bahwa panjang badan dan lingkar dada berkaitan erat dengan bobot tubuh pada PO steer maupun heifer.Kata kunci: PO steer dan heifer, ukuran morfologi tubuh, bobot tubuh