Sustaining livestock: minimum technical requirements and quality standards for Angus Grade - Black Cattle in Sragen Regency in supporting livestock preservation

This research focuses on establishing the minimum technical requirements and quality standards for Angus Grade - Black Cattle, to promote sustainable livestock practices and support the preservation of genetic resources. The absence of standardized quality measures for Angus Grade - Black Cattle necessitates the use of data from field surveys in Sragen Regency as a baseline for initial quality standards until national standards are established. The study defines the minimum technical requirements for Angus Grade - Black Cattle breeding, with a special emphasis on sustainable production, encompassing both qualitative and quantitative criteria. the minimum requirements (in centimeters) of chest circumference, shoulder height, body length for male candidates aged 24-36 months are: Class 1 - 191, 139, 140; Class 2 - 187, 138, 137; Class 3 - 182, 137, 135, for female candidates aged 18-24 months are: Class 1 - 170, 127, 129; Class 2 - 168, 125, 126; Class 3 - 165, 124, 124, female candidates aged 24-36 months are: Class 1 - 178, 130, 131; Class 2 - 174, 129, 128; Class 3 - 170, 128, 126, respectively. These stringent requirements aim to select high-quality Angus Grade - Black Cattle for breeding, ensuring sustainable livestock production, genetic preservation, and overall productivity.


Introduction
The Angus Grade -Black Cattle that flourishes in the Sragen region is a product of a hybrid between Aberdeen Angus cattle and probably some local Indonesian cattle [1].Based on their observable characteristics, phenotypic characterization is used to identify and document diversity within and between different breeds [2], which can be used to characterize an animal population ethnologically and enable an evaluation of their productive potential by looking at the mechanical relationships that are inherently present in their morphological structure [3].
The distinctive attributes of individual breeds can serve as a basis for breeding programs, even though differentiating cattle breeds solely based on physical characteristics can be challenging due to the significant variation within each breed [4].Phenotypic characterization functions as indicators for assessing production performance and characterizing livestock populations.Utilizing these indicators allows for the evaluation, management, and conservation of livestock, considering their morphological relationships [5].Aberdeen Angus cattle are recognized for their black coats and inherent hornlessness (polled) [6].Interestingly, hornless cattle are preferred to be maintained in Angus Grade -Black Cattle that has the potential [7].Based on the information provided, a technical study is needed for Angus Grade -Black Cattle to facilitate their identification and further development processes, every ecological niche (also known as an ecological zone or habitat) is governed by its own unique variability in terms IOP Publishing doi:10.1088/1755-1315/1292/1/012005 2 of genetic improvement, which takes into account a range of traits that may be employed for selection purposes [1].This technical requirement is formulated and can be used as an initial quality standard before Angus Grade -Black Cattle attains a national quality standard.

Materials and methods
A total of 99 female and 15 male Angus Grade -Black Cattle were identified based on their age, determined by their birth records and tooth condition.The age determination based on permanent incisor teeth is as shown in Table 1 [8].This study utilized both a survey method and a literature review on Angus Grade -Black Cattle, involving direct observation of Angus Grade -Black Cattle at local smallholder farms.Measurements of the cattle's body dimensions, including chest circumference (CC), withers height (WH), and body length (BL), were conducted.Additionally, interviews were carried out with relevant stakeholders, such as historical livestock breeders, as well as representatives from the Animal Production and Fisheries Agency in Sragen Regency.The study was conducted over a 5-month period, from August to December 2022, in the subdistricts of Kedawung, Sidoharjo, Tanon, Plupuh, and Sragen City.These locations were selected due to their high population of Angus Grade -Black Cattle.Specific exterior characteristics of the Angus Grade -Black Cattle were documented, relying on direct observations and the preferences of livestock breeders regarding qualitative traits.Body measurements were taken using measuring tapes and sticks while the cattle stood in an upright position (in a parallelogram stance).The CC measurement was obtained by following the body's circumference just behind the shoulders, passing through the withers.WH was measured from the ground surface to the highest point of the withers, while BL was measured by drawing a horizontal line from the front edge of the shoulder joint to the back edge of the ischium.The data was tabulated, and the mean values were calculated, rounding off the decimal places without decimal values.

The history of Angus Grade -Black Cattle, from introductions to current challenges
The historical timeline of Angus Grade -Black Cattle in Sragen Regency began in 1976 with the introduction of frozen semen from American Brahman and Aberdeen Angus bulls imported from New Zealand, Australia, Germany, and Canada.This initiative was carried out through the Balai Inseminasi Buatan Lembang (Lembang Artificial Insemination Center) to implement Artificial Insemination (AI) reproductive technology in Central Java Province.Sragen Regency was chosen as one of the regions to implement AI using frozen semen from American Brahman and Aberdeen Angus bulls.Before 1976, the majority of cattle in Sragen Regency were of the Peranakan Ongole (PO) breed, along with some Javanese cattle.Between 1976 and 1982, the AI program using frozen semen from American Brahman bulls was implemented in the subdistricts of Tangen, Tanon, Jenar, and Gondang.During the same period, the AI program utilizing frozen Aberdeen Angus semen took place in the subdistrict of Masaran.
From 1982 to 2001, the use of frozen Aberdeen Angus semen expanded to include the subdistricts of Karangmalang, Gondang, Plupuh, and Sambungmacan.As a result, a considerable population of black cattle was already present in Sragen Regency.In 1988 and 1989, the Lembang Artificial Insemination Center imported Brangus bulls from Tri S Ranch Tapos and began producing frozen semen from these bulls, which was used to support the development of the existing black cattle population in Sragen Regency.Based on its initial formation, Angus Grade -Black Cattle is suspected to have a genetic composition derived from its parent cattle breeds, namely Aberdeen Angus, American Brahman, and Peranakan Ongole (PO) cattle [9].In a previous study utilizing Cytochrome b analysis, it was observed that the Cytochrome b gene in most Angus Grade -Black Cattle shared similarities with Bos javanicus, while a minority displayed similarities with Bos indicus and Bos taurus [10].
Since 2001 until the present, the development of Angus Grade -Black Cattle has experienced fluctuations in population due to the dynamics of demand exceeding production capacity and negative promotion, resulting in reduced interest in raising Angus Grade -Black Cattle.However, efforts to increase population and productivity continue to be carried out, such as organizing competitions and contests for Angus Grade -Black Cattle.

Technical requirements and quality standards for Angus Grade -Black Cattle
Ensuring the quality of products that meet the demand requires high-quality livestock, and to achieve this, the cattle must adhere to the following minimum technical and general requirements: Firstly, the cattle must be in a healthy condition and devoid of any physical defects, including eye defects, lameness, paralysis, abnormal hooves, and other body abnormalities.Secondly, male cattle should be suitable as studs, free from physical and genital defects, exhibit good libido, and possess good quality and quantity of semen.Thirdly, female cattle should be free from physical and reproductive organ defects, abnormal udders, and should not show any signs of infertility.Lastly, to further ensure the health aspect, certification of health and freedom from contagious animal diseases must be issued by an authorized government official responsible for animal health actions.
The specific qualitative requirements for male Angus Grade -Black Cattle include a thin and black coat, absence of horns and humps, and a relatively large head that is shorter than female Angus Grade -Black Cattle.Additionally, males should have a prominent muzzle, small eyelids, and medium-sized, actively moving ears that are not drooping.Their back should be straight and broad, and they should possess a dewlap of medium size, extending from the jaw to the front of the chest.Furthermore, male Angus Grade -Black Cattle should exhibit a relatively wide and deep chest, larger than that of females, as well as a convex and long body, which is larger than the female counterparts.They should have relatively small and short legs, round buttocks, and a medium-sized and long tail with thick tail fur.Notably, males should have a large prepuce and penis, with a slightly drooping scrotum [9].
The specific qualitative requirements for female Angus Grade -Black Cattle include a thin and black coat, absence of horns and humps, and a relatively long and large head.Similar to males, females should possess a relatively large muzzle, small eyelids, and medium-sized, actively moving ears that are not drooping.Their back should be straight and broad, and they should have a dewlap of small to medium size, extending from the jaw to the front of the chest.Additionally, females should exhibit a relatively wide and deep chest, and they should have a convex and long body.Their legs should be relatively small and short, and their buttocks should be round.Furthermore, female Angus Grade -Black Cattle should have a medium-sized and long tail with thick tail fur, as well as a large udder [9].
These specific qualitative requirements are crucial for maintaining the quality of Angus Grade -Black Cattle for breeding purposes.
Specific Quantitative Requirements: the quantitative requirements for Angus Grade -Black Cattle can be found in Table 2 and 3.The body measurements can be used to estimate body weight, that's a critical factor in assessing the cattle's production capacity [11], To modify cattle size, one can opt for either selective breeding over generations or crossbreeding smaller frame-size cattle breeds with larger frame-size cattle breeds [12].Chest Circumference is related to body weight and indicates the ability of feed intake [13]  The minimum quantitative requirements for Angus Grade -Black Cattle have significantly different values compared to the national standard values in Indonesia for Simmental [14], Limousin [15], PO [8], and Brahman cattle [16], respectively.These distinct values indicate the identity and differences in breeds of the cattle, and they can be used for estimating body weight to evaluate the production capacity ability of the cattle [17].In Figure 1 and 2 showing a male and a female Angus Grade -Black Cattle, illustrated that this catlle is a derivative of Aberdeen Angus Catlle.These cattle are famous for their good quality meat [18].Therefore, a breeding program is needed to maximize the potential of the Angus Grade -Black Cattle, Previously, a strong relationship between morphometrics and production potential was reported [19].Aberdeen Angus Cattle exhibited higher productivity and economic efficiency [20].

Conclusion
Specific qualitative requirements for male and female Angus Grade -Black Cattle were identified, along with quantitative measurements for chest circumference, withers height, and body length based on different age groups.Additionally, cattle age was determined using birth records and permanent incisor teeth replacement.This research provides valuable insights for the livestock industry and breeding programs in supporting livestock preservation in Sragen Regency.

Table 1 .
Age determination based on permanent incisor teeth

Table 2 .
Quantitative requirements for male Angus Grade -Black Cattle

Table 3 .
Quantitative requirements for female Angus Grade -Black Cattle.