Breeding Value of Sires Based on Offspring Weaning Weight as a Recommendation for Selecting Kebumen Ongole Grade Cattle

The objective of study was to estimate breeding value of sires of Kebumen Ongole grade cattle based on offsprings weaning weight. This research was carried out from August to December 2015 in Urut Sewu area, Kebumen. The calculation of genetic parameter estimation was heritability of weaning weight. The value of heritability was used to calculate the breeding value of sires based on offsprings weaning weight. Heritability was calculated using paternal half-sib correlation with the direct pattern variance analysis. Breeding Value (BV) of sire was calculated by absolute estimated breeding value. The materials used in this study included were data record during the last three years (2013-2015) consisted of 41 sires, 51 dams and 244 calves. Weaning weight data had been corrected based on age of dams, sex and weaning age of 120 days. The results showed that the heritability value of weaning weight was included in high category (0.36 ± 0.21). The highest BV was KJ.J608 (49.76) with a ratio of 231.45%. The results of this study were expected to be the basis recommendation for selecting sires in Kebumen.


INTRODUCTION
One of national assets in the field of animal husbandry in Kebumen that very potential to be developed is the Kebumen Ongole grade cattle. It is one of a good meat producers animal. Sutarno and Setyawan (2015) reported that the carcass of males and females cattle can reach more than 50%. Agung et al. (2015) and Haryoko and Suparman (2009) reported that the percentage of the carcass reach 51.42±2.27% and 47.78±2.82%. Kebumen Ongole grade cattle has been established as a new cattle strains in Indonesia through Decision Letter of Minister of Agriculture No. 358/Kpts/PK. 040/6/2015 on June 8 th 2015 (Kementrian Pertanian, 2015).
The potential of Ongole grade cattle as one of livestock genetic resources and sources of animal protein should be increased, including through the selection. Growth traits like weaning weight is an economical trait that can be one of consideration as selection criteria in selecting animals. Weaning weight is a weight at the time of calf separated with the dam. It was obtained through the weighing at the age of six to eight months or 205 days (Hardjosubroto, 1994). The weaning weight can be used to know the ability of milk production of the dam, mothering ability of the dam and also the genetic growth information of the calf.
Selection is the act of choosing males and females cattle that will be developed in the breeding area based on its genetic quality. Selection in cattle is usually based on a combination of several traits of economic importance which may be phenotypically and genetically related (Tsvetanova, 2004). Genetic progress in economic characters such as weaning weight cannot be measured directly, but it can be estimated on the basis of phenotypic (Lodhi et al., 2016). The information on genetic parameters, such as heritability, repeatability, and genetic correlation is a prerequisite for making efficient selection strategies by the geneticists and breeders (Toghiani, 2012). Heritability is a ratio of variances as the total proportion of variances in a population for a particular measurement, taken at a particular time or age, that attributable to variation in additive genetic (Visscher et al., 2008). The concept of heritability is commonly used in human, animal genetic or sub-population samples based on genetics (Hansen et al., 2011). Several studies showed that the heritability of weaning weight of Ongole grade cattle 0.48±0.58 (Putra, 2014) and 0.24 (Paputungan et al., 2015), Friesian cattle 0.74±0.19 (Ramatsoma et al., 2015), Nellore cattle 0,45 (Lobo et al., 2003), Hanwoo cattle 0.17 (Roh et al., 2015). The others publication also showed that repeatability of Ongole grade cattle in weaning weight reached 0.64 and 0.42 ± 0.11 (Dib, et al., 2009) which higher than Friesian 0.15 (VecihiAksakal et al., 2009). Both values will be used to calculate the breeding value of cattle. One of the organizations that work in the selection of the cattle or the breeding of the cattle is the ASPOKEB (Association of Kebumen Ongole Grade Farmer). The aim of this study was to calculate the estimated breeding value of sires based on the offsprings weaning weight. This research was very important to choose sires that will be used as pemacek in Kebumen area. The results of this research are expected to help ASPOKEB in selecting sire. This research was still rarely done in Kebumen so it was very interesting to do.

Research Site and Data Collected
This research has been carried out from August until December 2015 in Urut Sewu, Kebumen. Urut Sewu is lowland and coastal area in Kebumen. Kebumen Regency geographically located at 7 o 271 to 7 o 501 109 o 331 to South latitude and 109 o 501 East longitude. The materials used in the study was the growth record data of last 3 years i.e. 2013 to 2015. This data include the pedigree, cattle performances, weaning age and the age of the dams. Pedigree data consists of 41 Sires, 51 dams and 244 offsprings.

Data Analysis
Standardization of data. Data correction was used to minimize variations in the environment. Weaning weight was corrected to weaning age of 120 days, sex and the age of dams based on Hardjosubroto ( 1994)  Where CF dams age = correction factor of dams age, WW 5 = the weight of the dams at 5 years , and WW a = weaning weight at the actual age -Corrected weaning weight Where WW 120 as corrected weaning weight at 120 days of age, WW = actual weaning weight, BW = birth weight and WA = actual weaning age.
Heritability. The data were analysed by least squares analysis of variance by R progam v. 3.3.2 to identify the fixed effects with significance (P<0.05). Heritability estimation used paternal half sib correlation data with the following model : Y ik = µ + α 1 + e ik Where µ as the average of the population, α 1 as the effect of sire, e ik as the effect of environmental and genetic deviation related to the individual in a group of sire. h 2 = 4t Where h 2 = heritability, σ S 2 = variance of sire, σ D 2 = variance of dams, SE = standard error, k = constanta, S = number of sire, N as total of progeny or number of progeny per sire Estimated Breeding Value. The estimation of breeding value for sires was calculated based on the progeny performance data with the following equation according to Hardjosubroto (1994) (Warwick et al., 1990) : t = 0.25h 2 Where RA = relative accuracy, n as number of progeny per sire, and t (0,25h 2 ) paternal half-sib correlation.

Weaning Weight
The weaning weight of the cattle was corrected to 120 days according to environmental conditions in the field. The farmer in Kebumen do weaning at the age of 120 days so this research correspond with the weaning age that used by them. The average of WW 120 in Kebumen Ongole grade cattle in this study was 119.40±36.61 kg. This result was higher than the weaning weight of several Indonesian native cattle are Bali 90.5±15.46,Sumba Ongole 113.67±25.24 kg, Brahman cross 107.13+19.25 kg and 44.68+11.00 kg for Aceh (Praharani, 2009;Kaswati et al., 2013;Putra et al., 2014). It was also lower than weaning weight of Charolais 229.10±12.73 kg, Hungarian Grey 191±5.05 kg, Hungarian Simmental 236±3.40 kg, Angus 212±3,61 kg, Hereford 204±5.06 kg, Blonde d'Aquitaine 242±7.95 kg, Limousin 203±2.99 kg, Angus-Nellore 247.74±5.63 and Simmental-Nellore 248.16±7.31 (Contreras et al., 2015;Szabó et al., 2012;Szabó et al., 2013 andÍtavo et al., 2014). The difference in the weaning weight was caused by the difference of the weaning ages and breeds. Kebumen Ongole grade cattle have lower weaning weight than the others because they are weaned at the age of 120 days, while the other at the age of 205 days. Sutarno and Setyawan (2015) reported

Heritability
The result of heritability of weaning weight using paternal half sib correlation data was in high category (h 2 >0.3). Estimated value of heritability calculated based on variance component in Table  1. These values may indicate that the diversity of weaning weight in a population of 36% was influenced by the additive genes and 64% was influenced by environmental factors and nonadditive. The value of standard error (SE) which obtained in this study were lower than its heritability, its can indicate that the value of heritability was accurate. The heritability value of this research was lower than Sumba Ongole and Aceh cattle at 0.77± 0.68; 0.49±0.59 respectively (Said et al., 2016;Putra et al., 2014) and also higher than several research of Indonesian cattle such as Ongole-crossbreed and Bali at 0,24; 0.27±0,16; 0.09±0.15 and 0.33±0.09, respectively (Paputungan et al., 2015;Gunawan and Jakaria, 2011). Some research has also been done on Asturiana de los Valles cattle, Northeastern Thai Indigenous Cattle, Hanwoo, Friesian and Charolais cattle at 0.29; 0.27±0.06; 0.15; 0.13±0.09 and 0.36 ± 0.01 (Goyache et al., 2003;Intaratham et al., 2008;Park et al., 2001;Atil et al., 2005;El-Saied et al., 2006). Environmental conditions and management of maintenance in research site were estimated in compliance with the status of physiology so that environmental condition alleged to be relatively uniform. The difference in these value caused by the genetic variety and different environments. The value of certain properties of a heritability in a population is the population of a specific character (Kurnianto, 2009). This heritability value can be used as a basis of selection for Kebumen Ongole grade cattle by ASPOKEB in Urut Sewu. Furthermore, this value also can be used to calculate the breeding value (BV) for sires based on offsprings weaning weight.

Estimated Breeding Value
The completeness of animal recording, which includes pedigree and performance recording, is advisable for all breeds to allow for accurate estimates of breeding values (Abin et al., 2016). Estimated breeding values (EBVs) is important to selecting animals for a range of traits that have direct impacts on productivity (Johnston et al., 2007). EBVs can also be used to determine genetic trends by regressing the average EBVs on birth year (Enns et al., 2008). Parameters for population structure also provide important insights for monitoring maintenance of genetic variation (Groeneveld et al., 2009) (Said et al., 2016;Paputungan et al., 2015;Rodriguez and Guerra, 2013). The sire breeding values based on the offsprings weaning weight can be used as one of the selection criteria for choosing the superior sire. The breeding value based on birth weight in this study do not calculate because birth weight is not a good selection criteria because it can cause distoxia and also it still largely influenced by the dams environment (Hardjosubroto, 1994). In the previous study, weaning weight had negative genetic gain due to a negative genetic correlation, especially between cow weight and weaning rate, a complex trait that includes fertility, maternal ability and survival (Laske et al., 2012). The proposed index and the relative economic importance of the identified traits can guide selection decisions in selecting their replacement animals (Laske et al., 2012). These top ten sires then can be recommended as the best sire Kebumen Ongole grade cattle. Furthermore, the sire with a lower BV can be culled in order to keep livestock productivity.
Relative Accuracy (RA) RA was useful for selecting sires based on number of progeny. It was calculated to support the result of estimated breeding value for sires. Because of there was no correlation between fenotype that caused by non genetic factor or environmental factor so the value of t = h 2 /4 (Warwick et al., 1990). The results of RA estimation are presented in Table 3. The highest RA of sires in this research was 0.80 (JIMIN) and the lowest was 0.48 (MRJ17638). JIMIN has the highest value of RA because of offsprings number. The previous studies showed the RA values on Aceh Cattle of BB 205 , BB 365 , BB 550 , respectively was 0.95, 0.98, and 1.15 . Based on the results, it can be concluded that the higher value of offsprings number per sire will deliver a higher value of RA. Therefore, Hardjosubroto (1994) stated that to increase the value of RA, the number of observations (data) should also be improved. JIMIN, MRN and KJ.J608 have the top three of RA value with the higher value of EBV, so they can be the main recommendation for selecting sire.

CONCLUSION
The highest breeding value of the top ten sires was KJ.J608 (49.76) with a ratio of 231.45%. The results of this study can be used as a basic reference in selecting sires of Kebumen Ongole grade cattle. In addition, the results of this research can be used as a material for the evaluation of the activities of the livestock breeding, primarily for repair the recording by ASPOKEB. Further research needs to be done about the response selection to find out the result of the selection is based on this breeding values.