INTISARIPenelitian ini bertujuan untuk mengestimasi parameter genetik sifat produksi, nilai pemuliaan (NP), hubungan rasio berat sapih (RBS) dengan nilai pemuliaan serta estimasi terhadap kemampuan berproduksi induk (MPPA) sapi Simmental yang dipelihara di Balai Pembibitan Ternak Unggul Sapi Potong Padang Mengatas. Data yang digunakan adalah recording berat lahir (BL), berat sapih (BS), pertambahan berat badan harian (PBBH) lepas sapih dan berat setahunan ( Dari 18 ekor pejantan, 10 ekor (55,56%) memiliki NP lebih tinggi dari nilai rata-rata populasi yaitu 142,21 kg dan sisanya 7 ekor (44,44%) berada di bawah rata-rata populasi. Frekuensi NP calon pejantan dan calon induk yang berada di atas rata-rata berat sapih adalah sebanyak 210 ekor (44,68%), sedangkan 260 ekor (55,32%) berada di bawah rata-rata berat sapih populasi yang terkoreksi terhadap umur induk, yaitu 130,21 kg. Sebaran NP absolut berkisar dari 112,77 kg hingga 155,91 kg. Nilai pemuliaan jantan memiliki frekuensi di atas rata-rata lebih besar dari betina yaitu 149 ekor (66,22%) jantan dan 61 ekor (24,90%). Frekuensi MPPA di atas rata-rata berat sapih populasi adalah sebanyak 150 ekor (41,67%) dan sisanya sebanyak 210 ekor ( 58,33%) berada di bawah rata-rata. Rasio berat sapih memiliki korelasi positif dan signifikan (1,00 ** ) dengan NP. Dari penelitian disimpulkan jika seekor sapi memiliki RBS tinggi diharapkan akan memiliki NP yang tinggi pula, sebaliknya, jika RBS rendah maka NP yang diharapkan juga rendah sehingga dapat dijadikan sebagai kriteria seleksi.(Kata kunci: Sapi Simmental, Parameter genetik, Nilai pemuliaan, Daya produksi induk, Rasio berat sapih) , WW, YW and ADG were 0.11±0.09; 0.39±0.16; 0.43±0.19; and 0.46±0.20, respectively. The r of BW, WW, YW and ADG, were 0.25±0.16; 0.32±0.18; 0.25±0.22; and 0.34±0.16, 0.46±0.33; 0.2 ±0.39; 0.68±0.16; 0.006±0.30 and 0.57±0.21, respectively. From 18 Bulls, 10 bulls (55.56%) ABSTRACT The objectives of this research were to estimate the genetic parameters of production characteristics, breeding value (BV), weaning weight ratio (WWR) correlation with BV and most probable producing ability (MPPA) of Simmental cattle reared at Balai Pembibitan Ternak Unggul Sapi Potong Padang Mengatas. Research was based on records of birth weight (BW), weaning weight (WW), post weaning average daily gain (ADG) and yearling weight (YW) from 2002 to 2007. Heritability value (h 2 ) was estimated for BV, WW, ADG and YW using paternal-half sib correlation and repeatability value (r) of characteristics of both using intra class correlation. The genetic correlation (r G ) of BW-WW, WW-YW, WW-ADG, WW-YW, WW-ADG and YW-ADG were analyzed by variance and covariance. BV and MPPA estimation was base on record of weaning weight. The h 2 value of BW

This study is proposed to determine the heritability of growth traits of Simmental cattle in BPTU-HPT Padang Mengatas, West Sumatra. Data were collected by observations and measurements of the cattle in the field, completed by the secondary data from BPTU-HPT recorded from 2010 to 2016. Data for heritability were collected from 455 offsprings belonged to 15 sires. Weight and body size are two parameters used to estimate the heritability and breeding value, the heritability was analyzed between weaning and yearling age and breeding value was only calculated for weaning age. The data were analyzed by using paternal half-sib correlation method. The heritability between bulls and offspring was varied in weaning age, ranged from 0.24 to 0.97, and yearling age was showed high heritability in all parameters, ranged from 0.56 to 0.64. The heritability of weaning weight was 0.50 ± 0.19, weaning body size (shoulder height, body length and heart girth) was 0.97 ± 0.31; 0.24 ± 0.13; 0.44 ± 0.19, yearling weight was 0.56 ± 0.08 and yearling body size was 0.58 ± 0.08; 0.64 ± 0.09 and 0.56 ± 0.08 respectively. This result found that the highest heritability was shoulder height and the lowest heritability was body length. Relative breeding value above 0 represented by six sires with the highest breeding value was 37.12. Sires with the highest BV can be selected for future breeding in BPTU-HPT Padang Mengatas, while the lowest BV is recommended to be culled.

This study was aimed to analyse the genetic polymorphism of Growth Hormone (GH) polymorphism of Simmental cattle using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method and its relation to average daily gain. The research was conducted in the Padang Mangatas Breeding Centre, Limapuluh Kota district, West Sumatera Province and Biotechnology Laboratory of Faculty of Animal Husbandry, Andalas University. The research used 100 Simmental calves. DNA were isolation from blood sample using DNA purification Kit from Pomega. The PCR procedure was used to amplify 591-bp of bGH exon 1 (GH1) and 694-bp exon 2 (GH2). The PCR product were digested by restriction enzymes MspI and AluI. Digestion of 591-bp GH gen PCR product with enzyme restriction MspI reveal allele A(+) and B(-) with frequency 0.875 and 0.125 respectively and digestion with restriction enzyme AluI revealed allele C(+) and D(-) with frequency 0.95 and 0.05 respectively and. Digestion of 694-bp PCR product by MspI represent allele P(+) and Q(-) with frequency 0.88 and 0.12 respectively and digestion with AluI enzyme represent allele R(+) and S(-) with frequency 0.94 and 0.06 respectivly. The observed heterozygosity, effective allele numbers and polymorphism information content of GH1/MspI, GH2/MspI, GH1/AluI, and GH2-AluI were 0.11/0.1948, 0.04/0.1889, 0.00/0.0927, and 0.00/0,1096 respectively. Using GLM, there was no relation between these polymorphic and avarage daily gain of calve.