Effect of Bulls on Birth Rate and Birth Weight by Using Semi-Intensive Bali Cattle Maintenance

This study was to know the effect of the Bull on conception rate and birth weight of Bali cattle raised with semi-intensively. This study uses an entirely randomized design (CRD) with four treatments with unbalance data. The survey conducted during a three months period of December 2012 to February 2013, at the Laboratory of beef cattle Production, Faculty of Animal Science, Hasanuddin University, Makassar. Materials of the study were as four bulls of dams Bali cattle with age from 2.5 to 4 years,12 Bali cows, and 55 calves born from 2005 through 2012. The animals house throughout the year and they were exercise and grazing, approximately 4 hours in the daytime until afternoon. In the house, the animals were fed using elephant grass, additional feed (rice brian), salt, and water adlibitum. The results of this study showed that conception rate and calving rate of Bali cattle raised semi-intensive ware 95.62% and 86.25% respectively. The average birth weight was 13,06 kg. It can be concluded that the conception rate and birth weight is affected by them ales, while the calving rate no significant effect of Bull.

demand, b) the high number of productive female slaughterhouses and community awareness/breeders will minimize prolific female slaughter is still low, c) low birth rate and calf harvest, e).The level of cattle expenditures for inter-island trade purposes is not controlled, especially the broiler inter-island illegal,).Loss of population buffer areas included in the territory of West Sulawesi and 6).No programmed nursery (Sonjaya, 2012).
Bull is a thing to be considered to increase population and productivity in beef/broiler farms.The male will marry the parent resulting in conception and produce a new calf.Birth weight is also inseparable from the influence of bull where only certain males who can deliver high birth weight.These were the basis of research on the impact of bulls on conception rates and keep birth weight in Bali cattle at Hasanuddin University Cut Laboratory livestock.
The decline in livestock productivity is thought to be caused by conception rates and lower birth rate (birth weight).The influence of males is one of the factors that influence marriage so that the occurrence of conception, birth and high birth weight of calf.Therefore, it is necessary to assess how far the influence of males on conception rate and birth weight of Balinese cow-calf

B. Methodology 1. The Material
The material of this research is using Bali cattle which consist of: 4 male tail, 12 head of mother and 55 calves kept at Cattle Laboratory, Faculty of Animal Husbandry, Hasanuddin University, Makassar, Data collected starting from 2005 -2012 from note and observation directly.

Livestock Maintenance
The management of Bali cattle at the Cattle Laboratory is semi-intensive maintenance that combines ranching and shepherding.The marriage system is done naturally (using a stud).Table 1 Showed the distribution of male usage.

Research Procedures
This research used by processing the data obtained from Livestock Breeding Laboratory of Husbandry Faculty, Hasanuddin University, Makassar.Based on the records obtained from parent conception data, birth, and childbirth weight, from each male each year.The bulls used were four from 2006 to 2012 (Table 1).The Conception rate is the number of pregnant cattle in one year.The indicator for measuring conception rates that are often used is the number of broodstocks in 1 year divided by the number of females in productive.

b) Rate of Birth
The birth rate or crude birth rate (CBR) is the average number of livestock born in each year.The birth rate is calculated by the formula CBR = N / R X 100%, N is the number of births in that year and R is the number of pregnant female mothers in the population.

c) Weigh of Birth
Birth weight is the result of weighing of the new calf.Birth weight is obtained by considering calves no later than one day (24 hours) after birth.

Data Analysis
The data obtained were analyzed using Randomized Complete Randomized Design (RAL) with four different treatments and replications.If the treatment has a significant effect, then further test is done to distinguish the effect of treatment.The data analysis by using the following formula (Gasperz, 1991): Explanation: Y ijk : The observations for the i-th bull factor and the j th replication.μ : Common middle value.Α i : Influence of i th bull factor (i =1, 2, 3, 4).Ε ij : Random effects (experimental error) at the i-th stage (bull factor) and on j-th repeat (j =1,2, 3, … n).
In this analysis the data on conception rate, birth and death were analyzed based on descriptive and Chi-square analysis.The data analysis by using the following formula (Gasperz, 1991): The formula of Chi-Square:  Explanation: Different superscripts on the same column show very significant differences (P <.01), P1= First bull, P2=Second bull, P3= Third bull, and P4 = fourth bull.
Based on Table 2, it shows that the percentage of conception rates of mothers from different males.At P1 is the highest parent conception rate reaching 100%, this is because all parent mated with P1 is pregnant.Although all pregnant women but the lowest average birth rate of 66.66%, this is caused by the abortus parent (miscarriage).While for the lowest conception rate is P4 is 92% and birth rate 91.66%, this is caused by some parent mated with P4, not all conception and pregnant parent occurs abortus (miscarriage), so that design and birth rate does not reach 100 %.Although The conception rate of P2 is higher than conception rate of P4, the birth rate is lower.While at P3, conception rate 96.43% but birth rate reach 100% because all concept cows give birth Based on the percentage of conception rates in Table 2, known that there are three groups of males whose conception percentage is less than 100%.The low conception rate of mothers coupled with P2 and P4 compared to other mothers was due to a non-pregnant parent that year, and the newborn was pregnant the following year due to repeated mating.The average conception rate obtained in the study is 95.55%.
Repeat breeding is a female cow that has regular cycles and periods of marriage that have been rated 2 or more times with a fertile male or inseminated with fertilized fertile cement but still not pregnant.Factors of failure of fertilization are the main factors causing repeated cow mating.Although the failure of fertilization occurs in female animals, the causal factors also occur in male animals or can be caused due to management factors that are less good.
Based on the results of Chi-square analysis (X2count <X2α = .05= .96<9.49), showed that the bulls had a significant effect on the conception rate.The point means that cows are related to conception rates.The end is because the males are in a genetic factor that intimately affects the marriage to produce offspring as well as male fertility, marital management, feed availability, and maintenance management that have more influence on conception rates.It is by the opinion of Jakob (1994) which states that the conception rate on the control of beef cattle population depends on the fertility of male and female beef cattle as well as the quality of marital management.It is corroborated by Salisbury & Vandenmark (1985) that the influence of males on the fertility of female cows and bulls is difficult to know because the factors are so complex and numerous.Environmental factors such as seasons each year, factor management and dietary factors affect more cows than males.Susilawati, Srianto, Hermanto, & Yuliani (2003) stated that males aged 2 to 7 years could produce the best cement with high conception rates in females who are married compared to males aged beyond that interval.

Rate of Birth
Based on Table 2. it can be seen that birth rates from mains mated to P1, P2, and P4 do not reach 100%.The point is due to P1 and P4 there are several parent abortus (miscarriage) due to male genetic differences.Based on the results of Chi-square analysis (X2count> X2α = 0.05 = 12.63> 9.49), indicates that the influence of the male has no significant effect on the birth rate.The point means that research on birth rates is more influenced by environmental and genetic factors, although male influences are few but still play a role in birth.Early embryonic mortality in female cows is often due to inbreeding marriage or marriage of a bitch or a thousand so that the ugly traits of both male and female parent will appear more frequently in its derivatives (Hardjopranjoto, 1995).Embryonic mortality indicates mortality from ovum and fertile embryos to the end of implantation (Hafez, 1993).
The mean birth rate obtained in this study was 86.25%.This birth rate includes a high birth rate when compared to previous Bali cattle-birth studies.Wahyuni (2000) stated that Bali cattle birth rate reached 83.4%.Darmaja (1980) study, which obtains an average birth rate of 81.87% of Bali cattle for first, second and third births in areas with paddy-rice, paddy-rice, and crops planted.

Birth Weight of Bali's calf
Birth weight is an essential factor in the growth of cow-calf.Cows with massive birth weight and normal birth will be better able to maintain their life.Based on the analysis of variance, showed that the males had a very significant effect on calf birth weight (P <0.01).As stated by Karnaen & Arifin (2010), which indicates that the birth period shows the impact on calf birth weight (calf) in other words the birth weight between one birth period with another is significantly different.
From Table 2, we can see the mean birth weight of different males namely P1, P2, P3, and P4 are respectively 12.5, 11.92, 14.37, and 14.23 kg.The point shows that an excellent stud or superior will produce good offspring as well.While the average birth weight obtained is 13.06 kg.This figure is higher than the study of Sumbung, Batosama, Ronda, & Garantjang (1978), the results of research conducted from 1975 -1977 on the campus of Ujung Pandang Hasanuddin University, the average birth weight of cows Bali 12.6 ± 2.6 kg.Sutan (1988) said that some things have a relationship and affect birth weight, among others, the mother nation (female/male), gender of the child, duration of a pregnant mother, age or parity of mother and mother food during conception.Also, the high average birth weight obtained due to improved management and feed.