Reproductive efficiency of Bali cattle and it’s crosses with Simmental breed in the lowland and highland areas of West Nusa Tenggara Province, Indonesia

L Wira Pribadi^1,2, Sucik Maylinda³, Moch Nasich³ and S Suyadi³

¹ Post Graduate Program, Faculty of Animal Science, Brawijaya University, Jalan Veteran Malang, Indonesia
² Faculty of Animal Science, Mataram University, Jalan Majapahit 62 Mataram, West Nusa Tenggara, Indonesia
³ Faculty of Animal Science, Brawijaya University, Jalan Veteran, Malang, Indonesia.
suyadi2008@yahoo.com

Abstract

The reproductive efficiency of Bali cattle and its crosses with Simmental breed in lowland (0-100 m) and in highland (700-1.000 m above sea level) area of West Nusa Tenggara province, Indonesia, were evaluated by measuring the days open (DO), pregnancy rate (PR), calving interval (CI), calving rate, and pre-weaning mortality (PM) of Bali breed (B), Bali x Simmental crossbred (SB), SB x Simmental back crossed (SBS), and SB x Bali back crossed (SBB) in the number of 52, 48, 41, and 39 cows in lowland, and 57, 40, 44, and 35 cows in highland areas.

The daily thermal environment such as air temperature, relative humidity, and THI (Temperature Humidity Index) were 31.3 ^oC, 63.4%, and 78.1 for lowland, and 24.5 ^oC, 87.6%, and 69.4 for highland areas, respectively. Both lowland and highland animals were fed local forages with similar botanical and nutritional composition. Genotype of cows and altitude of farms areas significantly affected (P<0.05) the reproductive efficiency of the cows. Reproductive efficiency of Bali cows was higher than its crosses with Simmental (84.5 d, 93%, 367 d, 89.3%, and 7.4% vs 120 d, 82.6%, 405 d, 78.1%, and 9.8%, for DO, PR, CI, calving rate, and PR respectively). The crossbred cows showed higher reproductive efficiency in highland than those in lowland environment (106 d, 88%, 388 d, 84.2%, and 4.1% vs 135 d, 80.3%, 421 d, 73.9%, and 14.2%, for DO, PR, CI, calving rate, and PR respectively), and genotype with larger proportion of Simmental have lowest reproductive efficiency in lowland but it was highest in highland environment. Crossing Bali cattle with Simmental breed took place in lowland may leads to reduce reproductive efficiency than those in highland environment.

Key words: altitude, calving rate, days open, preweaning mortality, pregnancy rate

Introduction

Bali cattle are an indigenous cattle breed in Indonesia, originated from Banteng (Bibosbanteng) which is better known as Bos sondaicus. Bali cattle are one of the important beef cattle breeds contributing to the development of livestock industries in Indonesia, and are the most predominant genotype within the eastern island, e.g. in West Nusa Tenggara province. The majority of these cattle are maintained traditionally, therefore, the growth performance is considered to be low. However, comparing to other breeds, Bali cattle have better adaptation abilities especially in marginal environment (Zulkharnaim et al 2011), high meat quality and low fat percentage (Bugiwati 2007), high fertility and calf each year over a long time (Entwistle and Lindsay  2003), and have high heterosis effect in crossbred (Noor et al 2011).

The effort to increase productivity of Bali cattle in some areas made use of crossbreeding with exotic breeds, such as Simmental, Limousine, Charolais, Hereford, and Brahman breed, in which Simmental was suggested the best one. However, this effort was apparently not followed by management improvements. Moreover, it may have negative impacts due to genotype-environment interactions. Replacing indigenous with exotic breed in South East Asia might in fact create significant problem, e.g. distocia because of heterosis increasing calf birth weight, low tolerance on harsh environment condition, and increased work to feed each animal because of higher growth and greater size at maturity (McCool  1992).

Crossbreeding systems are used in beef cattle production to take advantage of heterosis (non-additive effects) and to exploit breed differences for specific characteristics (additive effects) to improve performance and value of the progeny (Tang et al 2011). But, the system was often followed by disadvantages in genetics called genetic barrier (Ashari et al 2012), as has been found in case of crossbreeding between Bali breed (Bos sondaicus) and Simmental breed (Bos Taurus) that has a problem such as sterility in male crossbred, however it’s female offspring would be mild decrease in reproductive performance.

In cattle, the decrease in reproductive performance (fertility) will act as a barrier to economic exploitation (Vandeplassche1982; Suyadi et al 2014; Suyadi and Nugroho 2014). Indeed, it is necessary to measure various parameters of fertility in order to evaluate reproductive efficiency.

Reproductive traits are lowly heritable (Goyacheand and Guiterrez 2001; Cammack et al 2009; Hansen 2009), indicating that a large proportion of the variation is environmental. Therefore, it is important to evaluate factors influencing economically important traits in a diversity of environments to understand the production environment while making management decisions in a crossbreeding system, since interactions may influence productive efficiency.

Thermal elements of the environment such as air temperature and humidity were the most importance aspects of cattle production environment, because of their direct effects on productivities (Soeharsono 1998). In the tropical countries, the thermal environment is varied by altitude (Lakitan 2002). Indeed, low altitude (lowland) existing as hot environment, while the high altitude (highland) as cold environment.

Performances of a breed or crossbred cattle are not expected to be the same under all environments. Therefore, the breed and crossbred together should be evaluated under a variety of environmental conditions.

The objective of this study was to investigate reproductive efficiency of Bali cattle and its crosses with Simmental cattle in lowland and highland environment of West Nusa Tenggara,  Indonesia.

Materials and Methods

This study was carried out in the small-holder farms of cattle production which spread at two different altitude areas i.e. lowland (0-100 m) and highland (700-1000 m above sea level) area of West Nusa Tenggara province, eastern of Indonesia. These two different altitude areas showed average daily temperature, relative humidity, and temperature-humidity index (THI) of 31.3 ^oC, 63.4%, and 78.1 for lowland, and 24.5 ^oC, 87.6%, and 69.4 for highland, respectively.

A total of 356 cows were used in this study, consisting of Bali breed (B), Bali x Simmental crossbred (SB), SB x Simmental back crossed (SBS), and SB x Bali back crossed (SBB) in the number of 52, 48, 41, and 39 cows in lowland, and 57, 40, 44, and 35 cows in highland areas. All of the cows were taken purposively based on some criteria such as 4 to 8 years of age, within the range of body condition score (BCS) 3 to 5, should be healthy, and last artificially mated within 2012 using Simmental. Both lowland and highland animals were fed local forages with similar botanical and nutritional composition.

Reproductive efficiency data as measured by days open (DO), pregnancy rate (PR), calving rate (CR), calving interval (CI), and pre-weaning mortality (PM) were observed directly. The term of response variables are as follows:

Days open is the interval (days) from calving to conception. Cows showing long DO have low reproductive efficiency (Suyadi et al 2014).

Calving interval is the period of time between two successive calvings. It is the sum of the gestation period and days open period (Vandeplassche1982; Suyadi et al 2014).

Calving rate is the percentage of cows served, which calve at term and have optimal chances of producing a living calf. This value might be lower than the conception rate determined during early pregnancy period because an average of 3 percent of abortions has to be occurred during pregnancy period (Vandeplassche1982).

Pre-weaning mortality is the percentage of animals dead between birth and weaning (Lush 1993; Gunawan et al 2011).

Data were arranged in accordance to the genotype of cows and location (altitude area). Analysis of variance and mean comparisons with least significance difference test were performed using SPSS program considering genotype, location, and genotype x location effects.  

Results

Days Open (DO)

The means DO of Bali cows and its crosses with Simmental breed are provided in Table 1. Days open was affected by both genotype of cows and altitude of location.

However, Bali (B) cows raised in lowland showed not different DO with those raised in highland environment. In contrast, the crossbred cows (SB, SBS, and SBB) showed longer DO in lowland than those in highland environment. Furthermore, among the genotypes, B cows showed shorter DO than crossbred, and, genotype with higher proportion of Simmental tend to have longer DO, both in lowland and highland environments.

Pregnancy rate (PR)

The mean PR of Bali cows and its crosses with Simmental breed at different altitude of farms are provided in Table 2. It was shown that PR in this study is affected by genotype of cows and altitude of farms.

The average PR of 93.1% obtained for B cows was significantly higher than 83.2, 80.8, and 83.9% obtained for SB, SBS, and SBB cows, respectively. The PR was also different among crossbred cows (P<0.05) both in lowland and highland environment, in which the breed group with higher proportion of Simmental showed lowest PR in the lowland but highest in the highland environment. There was an increase in PR from lowland to highland for the crossbred cows. In contrast, B cows in the lowland tend to have higher PR than that in highland, eventhough it was not significantly different.

Calving interval (CI)

The mean CI of Bali cows and its crosses with Simmental breed are provided in Table3. This interval is affected by genotype of cows and altitude of farms.

Calving interval of B cows raised in lowland was not different (P>0.05) with those in highland, but the crossbred cows show longer (P<0.05) CI in lowland than those in highland environment. There was an increase in CI from B to crossbred cows and the genotype with higher proportion of Simmental showed longer CI than other genotypes, both in lowland and highland environments.

Calving rate

Table 4 shows the effect of genotype and altitude environment on the calving rate of Bali cows and their crosses with Simmental breed in the lowland and highland areas. The results indicated that there was no significant difference (P>0.05) in calving rate between B cows raised in lowland and highland environment. Calving rate of B cows was obtained in average of 89.2%.

However, crossbred cows raised in lowland showed lower (P<0.05) calving rate than those in highland. It was also obtained that, calving rate of the crossbred cows were significantly lower than B cows and, the genotype with higher proportion of Simmental showed lower calving rate than the other genotypes, both in lowland and highland environments.

Pre-weaning mortality (PM)

Table 5 shows the effect of genotype and altitude environment on the PM of Bali cows and its crosses with Simmental breed in the lowland and highland environments. The results indicated that PM was significantly affected by both genotype of cows and altitude of farms.

In the hot environment of lowland, the mean PM of 8.7% for B cows was lower than those for SB and SBS cows (17.2 and 19.2% PM) respectively, but it was higher than 6.2% for SBB cows. In contrast to the PM found at the cold environment of highland, the mean PM of 6.1% for B cows was higher than 2.86, 5.11, and 3.12% for SB, SBS, and SBB cows, respectively.

There was a decrease in PM for the same genotypes from lowland to highland environment, in which 30.3, 83.4, 73.4, and 50.1% decreasing index for B, SB, SBS, and SBB cows, respectively. The overall means for PM in this study were in the range of 2.9 to 19.2%. 

Discussion

Presently, a number of crossbred cattle are found in the country. These crossbred cattle, although may be of genetically more superior composition than the indigenous local cattle in order to their productivity, they will be limited by environmental factors such as temperature, humidity, and other components of climate in the tropical farm areas. In this study crosses of Bali x Simmental (SB, SBS, and SBB) farmed in hot environment of lowland showed low reproductive efficiency that indicated by low pregnancy rate, long period of days open, long calving interval, low calving rate, and high pre-weaning mortality.

Crossbred cows farmed in colder environment of highland showed better reproductive efficiency than those of lowland. On the other hand, the indigenous Bali cows showed higher reproductive efficiency compared to those of crossbreds both in lowland and highland environment.

Reproductive efficiency has long been recognized as the most important aspects of cow-calf production. Success in this operation depends to a large extent on the establishment of a year-round calving interval in cows (Shrestha et al 2004; Kamal et al 2012). In order to achieve this interval, an optimum voluntary waiting period of 65 days is recommended followed by conception within 85 to 90 days of the postpartum (Opsomer et al 1998; Noakes  et al 2000; Kamal et al 2012).

The mean DO of B cows found in this study was 81 and 88 days for lowland and highland environment respectively. Bali cows raised in lowland tend to have 7.8 days shorter days open than those raised in highland areas, which is statistically not different. The average DO period of 84.5 days for the B cows was slightly lower than the period average 95.6 days reported for the breed in the same province (Ashari 2013). It was also similar to that of 85 to 90 days recommended for the establishment of a year-round calving interval in cows (Opsomer et al 1998; Noakes  et al 2000; Kamal et al 2012).

However, crossbred cows in which their mean DO of 115, 157, and 122 days in lowland, and 103, 107, and 107 days in highland environment for SB, SBS, and SBB cows respectively (Table 1), were found to have an average of 25.9 days longer DO in lowland than those in highland environment. This longer DO of the crosses in lowland environment might be due to thermal stress experienced by the animal because of high daily temperature (31.3 ^oC) and THI (78.1) of the environment. High environmental temperatures may suppress estrus resulting in period of anoestrus which interfere with ovulation (Habeeb et al 1992). Heat stress lengthens estrous cycle and shortens estrus period (Fuquay 1981), also causes loss of ovarian activity and conception, then, interval from parturition to conception (days open) and number of service per conception may increase (Od’Ompanich 2010).

The recorded average DO of 119 days for the crossbred cows was shorter than 163 days reported for the genotypes in the same province (Ashari 2013). However, it was highly significantly longer than that obtained for Bali cows. Among the genotypes observed, the longest DO was recorded for SBS cows (157 days), which means that crossing Bali cattle with the Simmental indicated larger proportion of Simmental may lead to increase in days open of offspring by an average of 73 days. In relevance to this result, a previous study (Diwyanto and Inounu 2009) has reported that crossbreeding between Indonesian local cattle (PO) and Simmental breed  that took place in Java island lengthens days open by 31, 47, and 78 days for F-1 (50% Simmental), backcross-1 (75% Simmental), and backcross-2 (87,5% Simmental), respectively.

The recorded average CI of 365.6 days for B cows were slightly longer than 360.9 days reported for the breed in Breeding Centre of Bali Cattle in Bali province (Gunawan et al 2011). While the recorded average Cl of 403.4 days for the crosses was shorter than 450.6 days reported considering the genotypes in the same province (Ashari 2013). The average CI among the indigenous and crossbred cattle in the tropical country was reported within range of 365-536 days (Kamal 2010).

There was a decrease in CI from lowland (421 days) to highland (388 days) of crossbred cows observed, indeed the genotype with higher proportion of Simmental showed greater decreasing index. This may be due to the more comfortable environment of the highland for the genotypes, where the animals have higher feed intake (Vermorel 1987; LeDividich et al 1992) and of course higher energy intake (Lymo et al 2004), and using less energy for maintenance (Davis et al 2003). However, another study in PO x Limousin crossbreds that took place in East Java (Suyadi et al 2014) reported no significant effects of altitude environment on calving interval. Some other factors including the animal itself, farm management, nutrition, and other climatological aspects might be involved and could explain that different result.

Pregnancy rate (PR) was also found higher for B cows than the crosses, both in lowland and highland environment (Table 2). The obtained average PR of 93.1% for B cows was higher than 88.4% reported for the breed in Breeding Centre of Bali Cattle in Bali province, Indonesia (Gunawan et al 2011). While the obtained average PR of 82.6% for the crossbred cows was within the range of 71.3 to 88.2% (Dradjat 2002), but it was lower than 87.6% reported for the genotypes in the same province (Ashari 2013). Pregnancy rate varied from 75 to 95% between herds and from 65 to 100% between sires, with an overall pregnancy rate of 93% (Bormann et al 2006).

The average calving rate found for Bali cows in this study was 90.1%, which was not influenced by the altitude of farms. It was, however, slightly higher than 87% reported for the breed in the similar farm management of lowland environment (Dahlanuddin et al 2011). While calving rate for the crossbred cows was found on average to be 74.9% dependingon genotype and location (altitude). This value was, however, 15.2% lower than that of Bali cows.

There was an increase in calving rate from lowland (68.3%) to highland (81.4%) of the crossbred cows observed (Table 4), in which the genotype with higher proportion of Simmental showed higher increasing index. This was because of the presence of genotype and environment interaction effects on the trait. In relation to these results, it has been stated that calving rate is a reproductive trait that can be influenced by genotype and environment interaction (Maricle 2008).

Furthermore, pre-weaning mortality (PM) was higher in the lowland than those in highland environment (Table 5). The B, SB, SBS, and SBB cows raised in lowland had respectively 30.3, 83.4, 73.4, and 50.1% PM, they were higher than those raised in highland environment. This suggested that the wide variation in thermal environment between those two different altitudes have significant effects on the calves and their dams during pre-weaning period. Thermal environment can have a strong influence on pre-weaning performance of animals (Hahn 1999; Gauhan et al 2002; Beatty et al 2006). The recorded average daily temperature of 31.6 ^oC for lowland environment exeeded the comfort zone temperature range of 10 to 27^oC for tropical cattle breeds (Soeharsono 1998), while the 24.5 ^oC for highland were within normal range; the recorded average daily THI of 79.2 for lowland was indication of thermal stress environment for beef cattle breeds, while the 69.4 for highland was considered to be a safety zone (Dahlen et al 2012). In relevance to this result, aprevious study (Riley et al 2004) reported that the variability in thermal climate especially between different years had significant effect on pre-weaning mortality in Brahman calves. However, it was in contrast with other study (Gunawan et al 2011), who reported that the year did not show significant effect on that trait.

The mean PM in the present study were in the range of 2.9 to 19.2%, with overall mean of 8.6±0.%. It was, however, slightly higher than 7.8±1.5% PM reported for Bali cattle in Breeding Centre of Bali Cattle in Bali province (Gunawan et al 2011), but it was slightly lower than 27.5% PM reported for crossbred cattle’s in smallholder farms of Thailand (Rukkwamsuk 2011). It has been suggested that pre-weaning mortality rates of at least 30% is normal for cattle in the tropics (Holroyd et al 1993; Od’Ompanich 2010).

The highest levels of calf mortality recorded in this study occurred in newborn crossbred calves (SB and SBS) under hot temperature of lowland environment. Noteworthy, the majority of calf mortality in smallholder farms is presumed to be caused in the dry season when feed resources are low in quality and quantity (Fordyce et al 2002), leading to milk production of dams as low as 1.5 liter per day (Belli 2012). Moreover, poor suckling ability do to thermal stress may result in inadequate colostrum intake, thus, the most frequent causes for calf losses were poor immune-competence that may cause pre-weaning mortality (Rea et al 1996).

Although pre-weaning mortality has been pointed out as a problem inherent to Bos sondaicus such as Bali cattle (Gunawan et al 2011; Ashari et al 2012), the pre-weaning mortality has also been reported as a problem in Bos taurus such as Angus, Hereford, Jersey, Holstein, Limousine, and Brown Swiss (Landaeta et al 1997) and Bos indicus such as Brahman (Rea et al 1996) and Ongole (Suyadi et al 2014). Recently, peri-natal calf mortality in F1 Red and Grey Brahman x Hereford was reported to occur without a relationship to dystocia or any pathology (Riley et al 2004).

Based on these results could be considered that reproductive efficiency as measured by days open, pregnancy rate, calving interval, calving rate, and pre-weaning mortality, was higher in Bali cows than its crosses with Simmental breed, and was not different between Bali cows raised in hot environment of lowland and colder environment of highland The crossbred cows had higher reproductive efficiency in highland than in lowland environment and genotypes with larger proportion of Simmental had lowest reproductive efficiency in lowland but it was highest in highland environment. 

Conclusion

• Bali cows have a high chance to produce a calf a year, more than its crosses with Simmental breed which have on average 56 days longer.
  
  
• Cross breeding Bali cattle with Simmental breed under hot environment of lowland may lead to reduced reproductive efficiency of the offspring compared to those in cool environment of highland.

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Received 15 December 2014; Accepted 8 January 2015; Published 4 February 2015

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