Research Article

Reproduction Performance as a Basis for Selecting Female Balinese Cattle in Traditional Breeding in East Halmahera Regency

Sariffudin Fatmona*, Sri Utami, Gunawan

Department of Animal Science, Faculty of Agriculture, Universitas Khairun, Ternate, North Maluku, Indonesia, Jl. Yusuf Abdulrahman Campus II Gambesi, South Ternate District, Ternate City, North Maluku, Postal Code 97722, Indonesia.

Received | December 14, 2023; Accepted | February 04, 2024; Published | May 18, 2024

*Correspondence | Sariffudin Fatmona, Department of Animal Science, Faculty of Agriculture, Universitas Khairun, Ternate, North Maluku, Indonesia, Jl. Yusuf Abdulrahman Campus II Gambesi, South Ternate District, Ternate City, North Maluku, Postal Code 97722, Indonesia; Email: sariffudinunkhair2002@gmail.com

Citation | Fatmona S, Utami S, Gunawan (2024). Reproduction performance as a basis for selecting female balinese cattle in traditional breeding in east Halmahera regency. Adv. Anim. Vet. Sci., 12(7):1214-1222.

DOI | https://dx.doi.org/10.17582/journal.aavs/2024/12.7.1214.1222

ISSN (Online) | 2307-8316

Copyright: 2024 by the authors. Licensee ResearchersLinks Ltd, England, UK.

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

Introduction

Success in the ruminant farming business lies in the management of the five livestock businesses namely seed and mating management, feed, disease/health, housing systems and marketing management (Fatmona and Gunawan, 2022). In this case, the most important factor in the post-breeding business is the seed and marriage factors. Balinese cattle a cattle that are domesticated from Bos Sondaicus breed (bos banteng). Theoretically, Balinese cattle are originally from Bos Sondaicus due to their type, character, and appearance similarity (Hasnudi et al., 2016). Balinese cattle are originally from Indonesia and have been numerously bred by Eastern Indonesian breeders due to their high adaptation ability (Baco et al., 2020). Balinese cattle are spread and breed by small-scale breeders in almost all Indonesian regions (Prasetya et al., 2022).

Bali cattle (Bos javanicus) are domesticated cattle from banteng (Bos bibos) which have high potential genetic resources (1). The advantages of Bali cattle are fast breeding, easy adaptation to the environment, ability to life in critical land, and high carcass percentage (2), staying productive in low-quality feed, and good fertility (3). To improve the genetic quality of the Bali cattle selection program can be performed (4) which relies on the growth characteristic.(Setiaji et al., 2022).

Body condition scores (BCS) describe the relative fatness of a cow through the use of a nine-point scale and is an effective management tool to evaluate nutritional status of the herd (Rasby et al., 2014). The body condition scoring system allows producers to visually assess their cow herd using a number system that objectively describes the amount of condition or fat reserve of an animal. In this case, Body Condition Score (BCS) is one of the most important factors that affect cattle reproduction and further affects the post-partum interval (PPI), conception level (CR), and calving interval (CI) in beef cattle (Lan and Kenas, 2022). The success of a cattle breeding business is significantly related to the reproduction performance and mortality level of the female and calves (Rusdi et al., 2016; Ketut et al., 2016).

The development of Bali cattle farming can be designed if it is carried out based on the carrying capacity of the area. Balinese cattle breeding can be developed based on the carrying capacity of the area. The regional government of North Maluku has determined livestock production centers (livestock development areas) according to each condition for livestock development, including the East Halmahera district (Fatmona, 2007). In this case, the area to be developed significantly depends on the carrying capacity, potential area size, local human resources, and the existing livestock commodities potential (Fatmona and Gunawan, 2022). For the breeders, especially those in rural areas, beef cattle are an important asset, which cannot be separated from the agricultural system they own. Breeders also use beef cattle to pull plows to work in the fields and other workers. Cattle are also a source of additional income and savings for the farmers’ families which can be used whenever farmers need money.

One of the solutions in solving the problem in beef cattle population is by increasing and improving the performance of female cattle, considering their important role in population development. The performance of the cattle can be seen through several parameters including first calving, Post-Partum Estrus, Post-Partum Mating, Calving Interval, and Body Weight. Their performance can be improved by improving the feed, management and improving the genetic quality of cattle through artificial insemination technology. One of the problems in the society is the lack of identification of the reproductive performance of prospective Balinese female cattle to be inseminated (AI) (Irwansyah et al., 2021).

In this case, the novelty raised is that this study produces comprehensive data in East Halmahera Regency concerning the reproductive performance of Balinese cows breed traditionally. There has been no research regarding the reproductive performance of Balinese cows which were assumed to have experienced a decline in reproductive performance, so the results of this research are expected to be the basis selection and treatment to overcome these problems.

The objective of this research was to determine the performance of Balinese cattle breed traditionally with several parameters, including first calving age, post-partum estrus, post-partum mating, calving interval, and body weight.

Materials and Methods

This research site is East Halmahera Regency, North Maluku, Indonesia in three districts, namely Maba, South Wasile and North Maba Cities, which were determined through purposive sampling. This study was carried out or ninety days (three months) from May to July 2019. In this case, Balinese cattle was employed with the criteria that the cattle aged above two years old by looking at the teeth shape, then body measurements such as body weight using the jagra method, as well as body length, gumba height, and chest circumference using references (Heryani et al., 2018). Meanwhile, the measurement of first calving age, post-partum estrus, post-partum mating, and calving interval was conducted through interview and questionnaires distribution to 70 small-scale breeder families who own the livestock mentioned above. The age determination of the female cattle is carried out by looking at the composition of the number of incisors’ changes (source: Yuliantika et al., 2016) in Figure 1.

 

Next, the variables were measured: First calving age of cows, post partum estrus, post partum mating calving interval using the interview method with 70 traditional breeders using a questionnaire. The respondents’ criteria include: Natural livestock mating system, The natural mating system determines the research respondents using the criteria of breeders who have female Balinese cattle and have more than three years of breeding experience. The body length and gumba height was measured using a measuring stick (caliper), while chest circumference was measured using a butterfly brand measuring tape, and other equipment such as recording tools such as pens, camera paper and others.

The measurements of cows include the following: Body weight measurements follow the Djagra formula, namely measuring body weight based on calculations of body measurements quoted in the article (Heryani et al., 2018) dengan as follows:

Meanwhile, the cattle measurements also include the body weight measurements based on Djagra formula (Yuliantika et al., 2016) as follow:

Data analysis

The cattle measurement shall be carried out when the cattle is in a normal standing position and the legs support the body in a balanced manner. In this case, the measurement was done using the method proposed in article (Heryani et al., 2018) and (Galib et al., 2017). The measurements of the body sizes are seen in Figure 2.

 

The calculation of the average, standard deviation, and coefficient of diversity based on Steel and Torrie (1993) uses the following equation.

Average

Description: X̅= Average, Xi = ith data, N= Amount of data.

Standard deviation

Description: SD= Standard deviation, Xi= ith data, X̅= Average, N= Amount of data.

Coefficient of diversity

Description: KK = coefficient of diversity, SD= standard deviation, X̅= average value.

Research area

East Halmahera Regency is located in North Maluku, Indonesia and formed by Law no. 1 of 2003. Astronomically, East Halmahera Regency is located between 00⁰40’-01⁰04’ North Latitude and 126⁰45’-129⁰30’ East Longitude with total area of 6,538.10 km² consisting of 10 districts and 104 sub-districts or villages. The largest district is South Wasile by 1,175.48 km², while the smallest district is Wasile by 337.32 km². Data on each district area in the Regency are as follow.

 

In general, the area of East Halmahera Regency varies, from lowlands along the coast to highlands in the mountains. The altitude of areas in East Halmahera Regency also varies. The lowest altitude is in South Wasile District with an area height of 8 meters above sea level, while the highest altitude is in Central Maba District with an area height of 82 meters above sea level.

Results and Discussion

First calving age

Bali cattle in East Halmahera Regency have an average maternal age of 5.44 years has a fairly good Standard Deviation (SD) value of 0.28 and an average first calving age of 32.97 months, has a Standard Deviation (SD) value 1,03, which ranges from 30 to 36 months with a percentage of 88.3%, so the average first calving age is 33 months. Meanwhile, those aged more than 36 months is at the percentage of 11.7% of 230 respondents. Compared to the other research, this region is slower than West Java, which is 31.48 months (Wimbavitrati et al., 2020). Hence, it is necessary to carry out artificial insemination to improve production performance. Contribution to the development and application of artificial insemination (AI) in beef cattle is very important to improve genetics and livestock productivity (Pernas et al., 2023). Other factors in livestock selection are also important, such as genomic and phenotypic selection criteria are very important (Guti et al., 2023).

The advantages of Bali cattle, especially their productivity, are quite high. This can be seen from several indicators of productivity, including birth weight, weaning weight, adult weight, rate of increase in body weight, as well as reproductive characteristics such as sexual maturity, puberty age, calving interval, and percentage of births. Bali cattle also have the advantage of a high level of adaptation (Zafitra and Gushairiyanto, 2020). In addition, other indicators, such as production and reproductive characteristics, are very important and economical that can be used as selection parameters (Fatmona and Putranti, 2021).

Based on the research data in this first sub-discussion, namely the age of the mother, the age at first calving and the weaning age of Bali cattle in this region, it is important to serve as a reference or have implications in other places, that the importance of this data is so that we can know and select livestock whose performance It is good to use as a further nursery and try to overcome the problems experienced by Balinese livestock parents, for example management and environmental problems.

Female Balinese Cattle Performance in East Halmahera Regency is shown in Table 1.

Aspect of female cattle reproduction

Reproduction is a process to produce new individuals. This can occur sexually and asexually in animal. The asexual reproduction process will occur through division, fragmentation or budding, while sexually it begins with the formation of gametes, fertilization and embryo development until a new individual appears (Mastrodonato et al., 2022). Reproduction in female livestock is a complex process that will involve the entire animal’s body. The reproductive system can function if female livestock have entered sexual maturity. The reproductive aspect variables of Bali cattle breeds consist of post partum estrus, post partum mating, calving interval which are discussed in the following sub-chapter.

Post-partum estrus of female balinese cattle in east halmahera regency

Post-partum estrus (PPE) was obtained by determining the time span between the calving and the first estrus after giving birth (Riyanto et al., 2017). The time span between calving and first estrus ranges from 50 to 60 days or 1.5 months – 2 months. The expected time for uterine involution in cattle ranges from 30 to 50 days or 1 – 1.5 months. Estrus involution generally occurs before the first estrus period after parturition (Riyanto et al., 2017). The cause of the high PPE is believed to be because the estrus period occurs after giving birth and breeders are not careful in detecting the estrus. Breeders cannot distinguish estrus specifically; they only pay attention to estrus through behavior and sounds. Genuine estrus is clearly described by the vulva and vagina being enlarged and reddish in color as well as discharge from the vagina (Riyanto et al., 2017).

 

Table 1: Age, first calving age, and weaning age.

No	Variable		Average	N	Standard deviation	Coefficient of diversity (%)
1.	Age (years old)		5.44		0.28	5.14
2.	First calving age (Months)		32.97		1.03	3.12
	a.	30-36 month		203
	b.	> 36 months		27
Total				230
3	Weaning age (Months)		6.01		0.83	13.80
	a.	6-8 months		3
	b.	> 8 months		227
Total				230

 

Table 2: Post-partum estrus, post-partum mating, calving interval of Balinese female cattle in east Halmahera regency.

No	Variable	Average (days)	Amount of sample (Cattle)	Standard deviation	Coefficient of diversity (%)
1	Post-partum estrus (days)	44.66	N	1.08	2.43
2	Post-Partum Mating (days)	45.13	N	0.026	0.06
3	Calving Interval (days)	13.02	N	0.65	4.97

 

Description: Amount of sample N=320.

 

Results of previous research show that the average Post-Partum Estrus (PPE) of Balinese cattle in East Halmahera is 44.66 days, according to the standards, the Standard Deviation value is quite good, 1.08. It takes longer compared to the results of previous studies ranging from 28-43 days. It was stated (Laksmi et al., 2019) that the average time of first and second ovulation of primiparous cattle is 27.67 and 47.67 days postpartum, while the average time of first and second ovulation of pluriparous cattle is 28.33 and 43.33 days postpartum. This showed a correlation between body condition scores and hormone levels, namely Leptin levels of 0.861; LH level of 0.960; FSH level of 0.799; and Estrogen level of 0.761 (Laksmi et al., 2019).

There is a need to address reproductive performance problems caused by genetic or seed factors as well as environmental factors, for example feed factors, temperature and humidity factors, as well as artificial insemination management factors.

Poor reproductive performance is one of the most common reasons for the slaughter of female cattle (Temesgen et al., 2022).

One effort to improve the reproductive performance of cows is artificial insemination (AI), which has been widely used to increase productivity and improve genetic quality. (Ramadhan et al., 2022). Efforts to detect methods from the start of pregnancy are an important management factor in cattle reproduction and production programs (Yakobus et al., 2023). In the previous research, during the first ovulation, all cattle do not show any signs of estrus. However, in the second ovulation 2 primiparous cows and 1 pluriparous cattle show less obvious signs of estrus, 1 primiparous cattle and 1 pluriparous cattle show moderate signs of estrus, and 1 pluriparous cattle show clear signs of estrus (Yuliantika et al., 2016).

The average duration of pregnancy is 324.2 days, the first calving age is 3.7 years, calving period is 1.1 times, calving interval is 467.1 days, and post-partum mating is 128.5 days The condition of low postpartum estrus is also influenced by the amount of nutrients in the ration, where the higher the protein, the better the reproductive performance. In this case, the protein levels increases natural estrus by 66.05% and produce natural mating by 91.65% (Sonjaya et al., 2020). Estrus needs to be synchronized to improve the reproductive performance of cattle, in Madurese cattle, it affects the form of estrus symptoms and pregnancy (Luthfi and Efendy, 2019).

Post-partum mating of Balinese cattle in East Halmahera Regency

Parity is a period in the animal reproductive cycle process that shows the number of births of the parent animal. Parity can provide an idea of the cow’s actual physical maturity. Primiparas or mother cows that have experienced one parturition have a physical maturity level of around 82-90%, meaning that the mother cow has not yet reached optimal growth levels (Muslimin et al., 2022).

Post-Partum Mating (PPM) is the time interval between the first mating and calving (Riyanto et al., 2017). Female cattle should be bred 60–80 days or 2–2.5 months after calving because it takes a minimum of 50–60 days or 1.5–2 months to achieve complete uterine involution in the female cattle (Setiawan et al., 2021). This aims to ensure that breeders do not wait for the next estrus which will increase the maintenance costs if they are not mated and produce offspring immediately. Previous research showed that post-partum mating took too long due to delays in mating after giving birth. In general, post-partum estrus (PPE) was delayed due to inaccurate detection of estrus by breeders (Muslimin et al., 2022).

The average Post-Partum Mating (PPM) in East Halmahaera Regency is 45.13 days, ranging from 30 to 90 days of 230 female cattle. Post-Partum Mating is greatly affected by Post-Partum estrus and the estrus detection accuracy by breeders. The data involved in this research are lower than previous research data, where there was an emergence of post-partum estrus in less than or equal to 3 months in the highlands. This is statistically higher (80%; p <0.05) compared to cattle in the lowlands (20%). Estrogen levels in post-partum estrus were 502.84 ± 232.20 pg/ml and 272.95 ± 184.43 pg/ml in the highlands and lowlands, respectively, showing statistically significant differences (p<0.05). The increased post-partum estrogen levels that occurred every month in the two groups showed a significant difference (p<0.05). It can eventually be concluded that Balinese cattle raised in the highlands show better reproductive performance than those in the lowlands (Pemayun et al., 2020). The reasons might be in the forms of low reproductive rate and others (Hamid, 1975). One of the important goals of cattle breeding is to increase the lifespan of cattle, which is also most important economic traits (Strapáková et al., 2023). Hence, these cattle need intensive reproductive management (Praxitelous et al., 2023). Meanwhile, cattle parasites live inside or on the body of beef cattle (Strydom et al., 2023).

Calving interval of Balinese female cattle in east Halmahera regency

The research results on the calving interval show above 13 months. In terms of time efficiency, it is detrimental to farmers. Calving interval is the distance between one calving to the next calving. The optimal calving interval is around 12 months or 365 days (Ananda et al., 2020), with a pregnancy period of nine months and a breastfeeding period of three months (Atha et al., 2020).

Previous research results showed that in female cattle, the first mating age is 26.87 months, the S/C value is 1.64, re-breeding after calving is 4.52 months, weaning age is 3.97 months, calving interval is 14.32 months, and the calving rate in the population is 45.5%. The reproductive efficiency value obtained was 91.8%, the natural increase was 44.68%, the net replacement rate for males and females was 1,207% and 253% respectively and the potential output is 44.11% (Rohyan et al., 2016). It was further stated that the highest and lowest average duration of pregnancy was 235 days and 224 days, respectively. The highest and lowest average S/C is 5.5 times and one time. The average calving interval in Senggreng, Trenyang, Sambigede and Jatiguwi villages is 440 days, 399 days, 420 days and 403 days. In addition, the number of pregnant cattle in the first AI, second AI, and more than the second AI was 27 cattle, 32 cattle, and 24 cattle (Yuliantika et al., 2016).

Calving Interval (CI) is the period of time between one calving and the next. Calving records are directly related to the calving period. The shorter the calving period, the more ideal the number of children conceived within the calving period. The calving interval will be shorter when estrus appears quickly after calving (Budiyanto et al., 2023).

The best calving interval (CI) is one year that is nine months of pregnancy and ninety days of breastfeeding. Theoretically, it would be good if a female cattle can produce one calf every year. The long Calving interval value is caused by the length of the Open Days, which is caused by calf who are not weaned (Prasetiyo et al., 2015). The average calving interval of the Balinese cattle in East Halmahera Regency, North Maluku is shown in Table 3.

 

Table 3: Average of calving interval in 320 female Balinese cattle.

Calving	Body condition score	Mating system	Average calving interval (months) Average ± KK
1	3	Natural	13.02± 1.54
2	3	Natural	13.00± 1.49
3	3	Natural	13.03±1.42

 

To achieve a calving interval of 12 months, a female cow must be pregnant again at maximum of 85 days after the previous calving so that the calving interval can be optimal (Juliantari et al., 2021). The calving interval is often used as a measure of reproductive efficiency, because a long calving interval can be detrimental to the farmer and indicates poor reproductive function so that fewer calf are produced during the productive period. The results of the research sub-discussion of Post Partum Estrus, Post Partum Mating, Calving Interval of Bali Cattle in this region are important to be used as a reference or have implications in other places, that the importance of this data is so that we can know and select livestock that perform well which will be used as seeds for subsequent breeding and trying to overcome the problems experienced by Balinese parent livestock, for example management and environmental problems.

Body weight of female Balinese cattle in east Halmahera regency

Based on the research results conducted in East Halmahera, the average weight of Balinese cattle is 264.77 kg, with an average chest circumference of 154.38 cm, an average body length of 122.35 cm, and a gumba height of 113.53 cm. Compared to the body morphology of cattle in other areas, especially on Java island of Java, the cattle in this area is smaller. In addition to reproductive problems, many other factors also cause low performance, including feeding problems, inbreeding and disease management. The desired birth weight standard in the selection program is important to prevent the occurrence of dystocia (Said et al., 2020).

The results of previous research showed that the highest estimated weight of adult males and females in Jatiguwi village is 340.40 kg and 352.31 kg, respectively (Prafitri et al., 2022) Among the cattle slaughtered, the highest weight is in the 300-400 kg weight category. Based on the research, external traces were found on 2 cattle (1%) of 200 cattle observed at the Denpasar city slaughterhouse (Yuliantika et al., 2016). The birth weight and calving interval are productivity traits that can be improved by selection programs. However, the desired birth weight standard in the selection program is important to prevent the occurrence of dystocia There is no significant difference in reproductive performance between working and non-working cattle (Suteky, 2009). Furthermore, the average body size of female cattle in East Halmahera Regency, North Maluku is presented in Table 4.

 

Table 4: Average, standard deviation and coefficient of variation in body length, gumba height and chest circumference of Female Balinese Cattle in East Halmahera Regency, North Maluku.

Variable	Amount of cattle	Average	Standard deviation	Coefficient of diversity
Body weight (Kg)	N	264.77	3.27	1.24
Chect circumference (cm)	N	154.38	2.06	1.33
Body length (cm)	N	122.35	1.60	1.31
Gumba height (cm)	N	113.53	2.01	1.77

 

Description: Amount of sample N=320.

 

Selection is an effort to improve the genetic quality of a livestock population. The selection response that occurs depends on the intensity of selection, heritability and standard deviation of the selected traits. The standard deviation of the characteristics or performance of the selected cattle will show the diversity in the population, which is known as the coefficient of diversity. The most effective selection to improve the genetic quality of Balinese cattle is based on the chest circumference compared to others (DA et al., 2017). Morpho Metrics are studies related to variations and changes in livestock body size and are useful for identifying and describing livestock potential quantitatively (Sumaryadi et al., 2021).

Data on the weight of Bali cattle in this area is important to use as a reference or have implications in other places. The importance of this data is so that we can find out and select cows that perform well in terms of body weight for further breeding and try to overcome the weight problems experienced by mother cows.

Low body weight can also be affected by diseases other than feed and management. Previous research generally found enzootic pneumonia in calves and young cattle (Poonsuk et al., 2023). Diseases can also reduce production, one of which is bovine interdigital phlegmon (IP), an infective bacterial disease due to lesions in the interdigital skin (Celani et al., 2023).

Conclusions and Recommendations

Based on the research results, it can be concluded that all variables studied in mother cows such as age at first calving, post partum estrus, post partum mating, calving interval and body weight of Bali cow mothers at this research location are relatively poor when compared to mother cows in other areas in Indonesia, especially on the island of Java. This research is very useful and can be applied in other places regarding reproductive performance as a basis for selecting and improving the reproductive performance of Bali cattle among breeders with traditional rearing systems in the area.

Acknowledgment

This study was financially supported by the Community Service Research Institute (LPPM) and the Faculty of Agriculture, Universitas Khairun. The author would like to thank Prof. Dr. M. Irfan Koda, SPi, MSi, Head of the Institute for Research and Community Service for relevant suggestions, Dr. Sri Utami and Gunawan SPt., MSi for their contribution in material and moral support to this research project from the beginning until the preparation of this paper.

Novelty Statement

In this case, the novelty raised is that this study produces comprehensive data in East Halmahera Regency concerning the reproductive performance of Balinese cows breed traditionally.

Author’s Contribution

SF: Conceptualization, data curation, formal analysis, investigation, methodology, writing original draft. SU: Conceptualization, data curation, formal analysis, investigation, methodology, project administration, writing original draft, writing review and editing. Gunawan: Conceptualization, funding acquisition, investigation, methodology, project administration.

Conflict of interest

The authors declare that they are not aware of any competing financial interests or personal relationships that may exist influence the work described in this paper.

References

Ananda HM, Wurlina W, Hidajati N, Hariadi M, Samik A, Restiadi TI (2020). Hubungan antara umur dengan calving interval, days open, dan service per conseption sapifriesian holstein (Fh). Ovozoa J. Anim. Reprod., 8(2): 94. https://doi.org/10.20473/ovz.v8i2.2019.94-99

Atha NR, Madi H, Sri SSD (2020). Factors affecting calving interval of krui cows in pesisir Selatan District Pesisir barat regency. Atha Nadhila Rosa, Madi Hartono, Sri Suharyati, Siswanto, 4(3): 134–141. https://doi.org/10.23960/jrip.2020.4.3.134-141

Baco S, Malaka R, Zulkharnaim, Hatta M (2020). The body condition and reproduction performances of Bali cattle cows through the improved feeding in the intensive management system. IOP Conf. Ser. Earth Environ. Sci., 492(1): 1–8. https://doi.org/10.1088/1755-1315/492/1/012101

Budiyanto A, Hartanto S, Prasetya ID, Subroto I, Asy’ari ZH, Sihombing EST, Mabel YE, Orintamara AS, Nasir MW (2023). Karakteristik calving interval pada Sapi Jawa-Brebes di Kabupaten Brebes Jawa Tengah Indonesia. J. Sain Vet., 41(1): 130. https://doi.org/10.22146/jsv.77833

Celani G, Stratic P, Albano P, Petrizzi L, Mortellaro CM, Varasano V (2023). Clinical efficacy of a single intravenous regional limb perfusion with marbofloxacin versus ceftiofur sodium to treat acute interdigital phlegmon in dairy cows. May, 1–11. https://doi.org/10.3390/ani13101598

DA, W., Oka IGL, Ardika IN (2017). Efektivitas Seleksi Dimensi Tubuh Sapi Bali Induk. Majalah Ilmiah Peternakan, 20(1): 16. https://doi.org/10.24843/MIP.2017.v20.i01.p04

Fatmona S (2007). Pengembangan peternakan sapi potong yang diintegrasikan dengan perkebunan kelapa di Kabupaten Halmahera Barat Provinsi Maluku Utara. (Institut Pertanian Bogor).

Fatmona S, Gunawan G (2022). Daya tampung (carrying capacity) sapi potong di Kecamatan Gebe, Kabupaten Halmahera Tengah, Provinsi Maluku Utara Indonesia. Cannarium, 20(2). https://doi.org/10.33387/cannarium.v20i2.5179

Fatmona S, Gunawan G (2022). Potential and strategy for development of livestock areas in Ternate City, North Maluku Province. J. Agri. (Agribisnis Perikanan), 15(1): 343-353.

Fatmona S, Putranti OD, Rustanto R (2021). Karakteristik Kuantitatif Induk Sapi Bali (Bos sondaicus) Di Kecamatan Wasile. In: Prosiding Seminar Nasional Agribisnis, 1(1). http://ejournal.unkhair.ac.id/index.php/agri/ax.php/agri/article/viewFile/4077/2619

Galib I., C. Sumantri dan A. Gunawan (2017). Aplikasi ukuran linier tubuh sebagai penduga bobot badan pada kerbau rawa. J. Ilmu Prod. Dan Teknol. Hasil Petern., 5(1): 41–45.

Guti MA, Aponte PM, Garc M (2023). Genomic and phenotypic udder evaluation for dairy cattle selection: A Review. pp. 1–24.

Setiawan H, Suharyati S, Siswanto MH (2021). Factors affecting calving interval of ongole grade (PO) cattle in Wawasan Vilage Tanjungsari District South Lampung Regency. J. Res. Innovat. Anim., 5(3): 133–139. https://doi.org/10.23960/jrip.2021.5.3.133-139

Hamid A (1975). The use of progesterone ria to increase efficiency and quality. Cl, 37–43. https://doi.org/https://inis.iaea.org/collection/NCLCollectionStore/_Public/32/032/32032355.pdf

Hasnudi NG, Hasanah U, Patriani P (2016). Pengelolaan Ternak Sapi Potong Dan Kerbau (ed. N.L. Auliah); Cetakan pe). CV. Anugrah Pangeran Jaya. https://www.researchgate.net/profile/Peni-Patriani/publication/341453327_PENGELOENN-TERNAK-SAPI-POTONG-DAN-KERBAU.pdf

Heryani LGS, Susari NNW, Gunawan IWNF (2018). Variabel Komponen Utama Pada Morfometrik Sapi Putih Taro Berdasarkan Pengukuran Badan. Bull. Vet. Udayana, 10(1): 93. https://doi.org/10.24843/bulvet.2018.v10.i01.p15

Irwansyah, Junaedi, Suparman (2021). Reproductive performance of bali cattle cross breed brahman cattle through improving the genetic quality of local livestock in special effort for cows to be pregnant program. Tarjih Trop. Livest. J., 1(1): 1–7. https://doi.org/10.47030/tropical.v1i1.94

Juliantari NKA, Laksmi DNDI, Bebas W (2021). Jarak beranak sapi bali pada kelompok-kelompok ternak di wilayah kerja pusat kesehatan hewan sobangan, mengwi, badung, Bali. Indonesia Med. Vet., 10(5): 748–757. https://doi.org/10.19087/imv.2021.10.5.748

Ketut MI, Endang B, Subur PSB, Nafiatul U, Tri NC, Kustono, Gede SBI, Wattimena J (2016). Calf birth weight and post partum estrus bali cow fed complete feed from palm oil plantation in central borneo indonesia. The 17th Asian- Australasian Association of Animal Production Societies Animal Science Congress. pp. 345–349. https://www.semanticscholar.org/paper/Calf-Birth-Weight-and-Post-Partum-Estrus-Bali-Cow-Mudhita-Baliarti/50d04e2565f9ce117c3dd982c3df75c021e9b1f8

Laksmi DNDI, Trilaksana IGNB, Darmanta RJ, Darwan M, Bebas IW, Agustina KK (2019). Correlation between body condition score and hormone level of Bali cattle with postpartum anestrus. Indian J. Anim. Res. pp. 1599–1603.

Lan L, Kenas S (2022). Effects of low pasture quality on body condition score and reproductive performance of beef cattle. Int. J. Dairy Sci., 17(1): 13–23. https://doi.org/10.3923/ijds.2022.13.23

Luthfi M, Efendy J (2019). The success pregnancy rate with estrous synchronization hormones in Madura cow. J. Ilmu-Ilmu Petern., 29(3): 209–215. https://doi.org/10.21776/ub.jiip.2019.029.03.02

Mastrodonato M, Scillitani G, Trani R, Cardone F, Corriero G, Nonnis MC (2022). Sexual and asexual reproduction in a Mediterranean Tethya (Porifera, Demospongiae) species. BMC Zool., 7(1): 1–8. https://doi.org/10.1186/s40850-022-00142-9

Muslimin MI, Laksmi DNDI, Trilaksana IGNB (2022). Waktu Munculnya Estrus Postpartum pada Berbagai Paritas pada Sapi Bali. Bull. Vet. Udayana, 158: 479. https://doi.org/10.24843/bulvet.2022.v14.i05.p06

Pemayun TGO, MKB, Trilaksana IGNB, Anak, Kendran AS, Dharmayudha AAGO, Fajar IWN, Gunawan (2020). Calf birth weight, onset of estrus and postpartum estrogen levels of bali cows raised in the highlands and lowlands of gianyar regency, Bali. pp. 71. https://doi.org/10.17582/journal.jahp/2020/8.2.71.74

Pernas S, Fernandez-Novo A, Barrajon-Masa C, Mozas P (2023). Bull semen obtained on beef farms by electroejaculation: Extenders and holding temperatures. Animal, MPDI, pp. 1–14.

Poonsuk K, Kordik C, Hille M, Cheng TY, Crosby WB, Woolums AR, Clawson ML, Chitko-McKown C, Brodersen B, Loy JD (2023). Detection of mannheimia haemolytica-Specific IgG, IgM and IgA in Sera and their relationship to respiratory disease in cattle. pp. 1–15. https://doi.org/10.3390/ani13091531

Prafitri R, Febrianto N, Y APA, Huda AN (2022). Database of nutrition status, production and reproduction performance, and social economy of a farmer of a beef cattle farm in Sumberpucung District, Malang Regency. 32(3): 354–362. https://doi.org/10.21776/ub.jiip.2022.032.03.06

Prasetiyo Y, Hartono M, Siswanto (2015). Calving interval sapi perah laktasi di balai besar pembibitan ternak unggul dan hijauan pakan ternak (BBPTU-HPT) Baturraden Purwokerto Jawa Tengah. J. Ilmiah Petern. Terpadu, 3(1): 7–14.

Prasetya MA, Atmoko BA, Ibrahim A, Budisatria IGS, Panjono, Baliarti E (2022). Reproductive performances of bali cows kept by smallholder farmers in Bima and Dompu Regency, West Nusa Tenggara. Proc. Int. Conf. Improv. Trop. Anim. Prod. Food Secur. 20(Itaps 2021): 175–178. https://doi.org/10.2991/absr.k.220309.036

Praxitelous A, Katsoulos PD, Tsaousioti A, Brozos C, Theodosiadou EK, Boscos CM, Tsousis G (2023). Ovarian and energy status in lame dairy cows at puerperium and their responsiveness in protocols for the synchronization of ovulation. Academic Pustaka Utama. Jakarta. pp. 1–15. https://doi.org/10.3390/ani13091537

Ramadhan YF, Warman AT, Maulana H, Baliarti E (2022). The primipara reproductive performance of Bali cows with natural mating compared to artificial insemination. IOP Conf. Ser. Earth Environ. Sci., 1114(1). https://doi.org/10.1088/1755-1315/1114/1/012058

Rasby RJ, Stalker A, Funston RN (2014). Body condition scoring beef cows: A tool form managing the nutrition program for beef herds. The Board of Regents of the University of Nebraska–Lincoln. All Rights Reserved., June, 1–7. http://extensionpublications.unl.edu/assets/pdf/ec281.pdf

Riyanto J, Lutojo L, Barcelona DM (2017). Kinerja reproduksi induk sapi potong pada usaha peternakan rakyat di kecamatan mojogedang. Sains Peternakan, 14(1): 73. https://doi.org/10.20961/sainspet.v13i2.11478

Rohyan J, Sutopo, Kurnianto E (2016). Population dynamics on Ongole grade cattle in Kebumen Regency - Central Java. J. Indones. Trop. Anim. Agric., 41(4): 224–232. https://doi.org/10.14710/jitaa.41.4.224-232

Rusdi B, Hartono M, Suharyati S (2016). Calving interval pada sapi bali di Kabupaten Pringsewu. Jurnal Ilmiah Peternakan Terpadu, 4(4): 277–283.

Said S, Putra WPB, Muzawar M, Kantong SA (2020). Selection of Bali cattle based on birth weight and calving interval records at West Nusa Tenggara Province of Indonesia. J. Indones. Trop. Anim. Agric., 45(1): 15–27. https://doi.org/10.14710/jitaa.45.1.15-27

Setiaji R, Rohadi M, Widyas N, Prastowo S (2022). The effect of non-genetic factors on Bali cattle (Bos javanicus) growth traits. IOP Conf. Ser. Earth Environ. Sci., 1020(1). https://doi.org/10.1088/1755-1315/1020/1/012001

Sonjaya H, Rahim L, Sari DK, Abdullah A, Gustina S, Hasbi H (2020). Estrous and pregnancy rate responses of postpartum Bali cattle to concentrate supplementation with different protein levels of rice-straw as basal ration. IOP Conf. Ser. Earth Environ. Sci., 492(1). https://doi.org/10.1088/1755-1315/492/1/012075

Steel RGD, Torrie JH (1991). Prinsip dan Prosedur Statistika. Gramedia

Strapáková E, Candrák J, Strapák P (2023). Analysis of calving ease and stillbirth and their impact on the length of functional productive life in slovak holstein cattle. pp. 1–10. https://doi.org/10.3390/ani13091496

Strydom T, Lavan RP, Torres S, Heaney K (2023). The economic impact of parasitism from nematodes, trematodes and ticks on beef cattle production. Anim. MDPI, pp. 1–25. https://doi.org/10.3390/ani13101599

Sumaryadi MY, Setiawati EN, Triyanto A, Armelia V (2021). Morphometric characteristics and reproductive performance of pasundan cattle in the North Prianganese and Southern South coast region. J. Zool. Res., 3(2): 9–17. https://doi.org/10.30564/jzr.v3i2.3087

Suteky T (2009). The effect of work on reproductive performance of bali cattle under the oil palm plantation in Bengkulu. pp. 61–65.

Temesgen MY, Assen AA, Gizaw TT, Minalu BA, Mersha AY (2022). Factors affecting calving to conception interval (days open) in dairy cows located at Dessie and Kombolcha towns, Ethiopia. PLoS One, 17(2): 1–15. https://doi.org/10.1371/journal.pone.0264029

Wimbavitrati KA, Sampurna IP, Suatha IK (2020). Penampilan reproduksi induk sapi bali pada simantri di kabupaten badung. Bull. Vet. Udayana, pp. 21-24. https://doi.org/10.24843/bulvet.2020.v12.i01.p05

Yakobus M, Datur M, Thopianong TC, Federika ND, Foeh K, Gaina CD (2023). Time estimation for mating peak and calving of Bali cattle in semi-arid area in Netemnanu village Kupang district. 000(1).

Yuliantika IMY, Adnyana IBW, Sukada IM (2016). Profil Umur, Jenis Kelamin, Berat Badan dan Jejas Eksternal pada Kulit Sapi Bali yang Disembelih di Rumah Potong Hewan Kota Denpasar Periode Mei-Juni 2015. Indonesia Med. Vet., 5(4): 376–387. https://pksb.unud.ac.id/img/admin/post_attc/9f3197886c004f5b7e67f9e3adee290a.pdf

Zafitra A, Gushairiyanto HEDD (2020). Karakterisasi morfometrik dan bobot badan pada sapi bali dan simbal di kecamatan bangko kabupaten merangin. Majalah Ilmiah Peternakan, 23(2): 66. https://doi.org/10.24843/MIP.2020.v23.i02.p04