Study on reproductive performance of crossbred dairy cattle under smallholder conditions in and around Zeway, Ethiopia

D Yifat, B Kelay*, M Bekana*, F Lobago*, H Gustafsson** and H Kindahl**

Hawassa University, Faculty of Veterinary Medicine, Hawassa, Ethiopia
*Addis Ababa University, Faculty of Veterinary Medicine, P.O. Box 34, Debre Zeit, Ethiopia
^** Swedish University of Agricultural Sciences, Department of Clinical Sciences, Box 7039, SE-75007, Uppsala, Sweden
fikre_lobago@yahoo.com

Abstract

A study was conducted to assess the reproductive performance of crossbred dairy cows in urban and rural smallholder dairy farms in Zeway Ethiopia and its surrounding. A total of 287 (141 rural and 146 urban) smallholder dairy farms that owned 2-5 crossbred dairy cows were visited and reproductive performance of 503 (244 rural and 259 urban) crossbred dairy cows were studied.

The overall mean values (n=503) for age at first calving (AFC), calving interval (CI), days open (DO), gestation length (GL) and number of services per conception (NSPC) were 32.1 months, 412 days, 135 days, 278 days and 1.67, respectively. The mean values of CI and DO were significantly shorter in the urban than in the rural area. Parity number significantly influenced DO and NSPC. While, season of previous calving had significant effect on CI, DO and NSPC of smallholder crossbred dairy cows.

In general, the smallholder crossbred dairy cows in the urban area had better reproductive performance than in the rural area. The overall observed reproductive performance of smallholder crossbred dairy cattle in this study was good. Thus, the ongoing activities to improve and expand crossbred dairy cattle production at smallholder level in the region should be encouraged.

Key words: Calving interval, gestation, Holstein, urban, Zebu

Introduction

Livestock productivity remains marginal in Ethiopia, despite the large livestock resource in the country, due to various reasons among which is the low genetic potential of indigenous cattle for milk and meat production (Negussie et al 1998; Shiferaw et al 2003). Improvement of the genetic potential of indigenous cattle in the tropics can be achieved most suitably by cross breeding high producing cattle of temperate origin with adapted indigenous cattle at a level where the advantage of heterosis is most exploited (Mason 1974). In Ethiopia, crossbred cattle mainly cross of zebu with Holstein-Friesian cattle have been used for milk production for decades (Alberro 1983; Mukasa-Mugerwa et al 1991; Bekele et al 1991; Negussie et al 1998). Accurate evaluation of the reproductive efficiency of indigenous stocks and their crossbred in different production systems is essential for the development of appropriate breeding strategies (Negussie et al 1998). Low reproductive efficiency hinders genetic improvement efforts and causes direct economic loss (Mukasa-Mugerwa et al 1991). In many cases reproductive efficiency of cattle has been measured mainly by considering parameters such as age at puberty, age at first calving, days open, calving interval and number of services per conception (Alberro 1983; Agyemang and Nkhonjera 1990; Haile-Mariam et al 1993; Bekana 1997; Negussie et al 1998; Shiferaw et al 2003; Masama et al 2003; Lyimo et al 2004). Reproductive efficiency of dairy cows is influenced by different factors including genetic, season, age, production system, nutrition, management, environment and disease (Alberro 1983; Agyemang and Nkhonjera 1990; Mukasa-Mugerwa et al 1991; Bekele et al 1991; Negussie et al 1998; Shiferaw et al 2003).

A number of research works have been conducted on reproductive performance of indigenous and crossbred cows under a relatively controlled condition at research centers, government owned farms and in some urban and peri-urban dairy areas in central highland of Ethiopia (Alberro 1983; Mukasa-Mugerwa et al 1991; Bekele et al 1991; Haile-mariam et al 1993; Negussie et al 1998; Shiferaw et al 2003). However, there are no such works conducted in rural areas especially in the lowland areas. Therefore, the current research was initiated with the objectives of assessing the reproductive performance and factors that influence reproductive performance of crossbred dairy cows owned by urban and rural smallholder dairy producers in and around Zeway, Ethiopia.

Materials and methods 

Study area and study animal management

This study was conducted in Zeway town and its surrounding (Adami-Tulu District), which is part of the mid-Rift Valley that lies 130-180km South of Addis Ababa. The altitude ranges from 500-1800 meters above sea level. The area has an annual rainfall averaging between 500 and 900 mm. The rainfall is bimodal with short rainy season from March to May and long rainy season from June to September followed by the dry season from October to February. The area has an average maximum and minimum temperature of 27.2 ⁰c and 12.7 ⁰c, respectively, and a relative humidity of 60% (Ebro et al 1998).

Mixed crop-livestock farming is the predominant production system in the rural area. The main livestock types kept in the area include cattle, sheep, goat, equines, camels and poultry. The indigenous cattle are Arsi (zebu) type and crossbred cattle represent only 3% of the total cattle population in the area. The average number of cattle owned per household in Adami-Tulu woreda is 22.2. Cattle are used as a source of draft power, manure, milk and meat. The main livestock feed resource in the area is natural pasture and supplemental feeds include hay and crop residues like maize stover and teff straw. The development of small-scale irrigated agriculture using Zeway Lake have significant impact in increasing livestock feed resource during the dry season through agricultural by-products especially horticulture by-products. The major livestock diseases prevalent in the area include anthrax, blackleg, brucellosis, dermatophilosis, mastitis and parasitic problems (Ebro et al 1998).

The rural smallholder dairy farms keep animals’ free stall and seldom practiced supplementation of feed with concentrates. The urban smallholder dairy farms keep only crossbred dairy cattle and regularly provide supplementation feeds like concentrates and keep cows tie stall (Ebro et al 1998). Breeding of crossbred cows both in the rural and urban farms were mostly done by AI using either Friesian or Jersey sires semen. In some cases, natural mating is used with Friesian sires. Heat detection is commonly done visually by farmers and reported to AI technician. In the rural area, smallholder dairy producers need to travel 5 to 10 km distance to get the inseminator for AI service.

Study protocol

A total of 287 (141 rural and 146 urban) smallholder dairy farms were selected randomly from Adami-Tulu District (Ziway Town and the surrounding). Each farm owned 2-5 crossbred dairy cows. The selected farms were visited and reproductive performance of 503 (244 rural and 259 urban) crossbred dairy cows were studied. A structured questionnaire and follow up formats were used to record data on general farm conditions, cow attributes (age, parity, and breed) and individual cow/heifer reproductive performance parameters like age at first calving (AFC), calving interval (CI), gestation length (GL), days open (DO), number of services per conception (NSPC) and other related information. The data were obtained either from records or farm owner interviews or personal observations.

Data analyses

The effects of the production systems on reproductive performance parameters were analyzed using Independent t-test analysis method. The effects of factors influencing reproductive performance parameters were analyzed using the General Linear Model Procedure. In all cases, the SPSS statistical package (2002) was used.

Results 

Reproductive performance

The overall mean value for AFC was 32.1 months (2.67 years). Cows in the study area were giving calves on average every 418 days (13.7 months) and conceive on average 135 days (4.49 months) after calving. The average number of services required for each conception was 1.67. Cows in the study areas had an average gestation length of  278 days (9.3 months) (Table 1).

The mean values for CI and DO were significantly (P < 0.001) lower in the urban area (406 and 130 days, respectively; n=259) than in the rural area (418 & 140 days, respectively; n=244). Although the observed values in the urban areas for the other reproductive parameters were higher, the differences were not statistically significant (P > 0.05).

Factors influencing reproductive performance

The results of multivariate analysis of variance to determine the effect of factors on the parameters of reproductive performance of smallholder dairy cows are presented in Table 2. The results revealed that parity number significantly affected DO (P < 0.01) and NSPC

 (P < 0.001). Lower values of DO (134 days) and NSC (1.45) were found in cattle with 3 or more calving. In addition, season of previous calving significantly influenced CI (P < 0.001), DO (P < 0.01) and NSPC (P < 0.01).Higher values of CI (419 days) and DO (141) were found in cows, which had their previous calving during the dry season, whereas higher number of services per conception (1.75) was required during the dry season. Breed of cows had no significant (P > 0.05) effect on any of the parameters considered. None of the factors had significant (P > 0.05) influence on the length of gestation period of the cows (Table 2).

Discussion 

The means AFC found for crossbred heifers in the urban (31.9 months) and rural (32.4 months) areas in this study, are closer to the 31.5 months reported for F₁ crosses of Boran and Friesian cattle and 32.7 months reported for 3/4 Friesian and 1/4 Boran crosses (Haile-mariam et al 1993). However, the current finding is slightly higher than 28.5 months and the 29.2 months reported for crosses of Jersey and Arsi and Friesian and Arsi, respectively, at Assela, Ethiopia (Negussie et al 1998). On the other hand, the finding of AFC in the present study was lower than 36.7 and 40.1 months estimated for crossbred dairy heifers in smallholder dairy farms in Malawi (Agyemang and Nkhonjera 1990), and 58.3 and 36.8 months reported for smallholder crossbred dairy heifers at two locations in Zimbabwe (Masama et al 2003) and 40.6 months for crossbred dairy heifers in different dairy production systems in central highlands of Ethiopia (Shiferaw et al 2003). A number of previous works indicated that management factor especially nutrition determines pre-pubertal growth rates and reproductive development (Negussie et al 1998; Masama et al 2003). The better-managed and well-fed heifers grew faster, served earlier and resulted in more economic benefit in terms of sales of pregnant heifers and/or more milk and calves produced during the lifetime of the animal.

The mean values for CI found for crossbred dairy cows of urban (408 day) and rural (418 days) smallholder dairy farms, respectively in the present study are lower than the 488 and 482 days reported for smallholder crossbred dairy cows in two locations in Malawi (Agyemang and Nkhonjera 1990), 475 days in the central highland of Ethiopia (Bekele et al 1991), 487 and 525 days at Abernossa Ranch  (Haile-mariam et al 1993) and 552 days in the central highlands of Ethiopia  (Shiferaw et al 2003) .On the other hand, CI found in the present study is higher than 351 to 398 days reported by Negussie et al (1998).

The mean value for DO (130 days) found in the urban smallholder dairy farms in this study is similar to 130 days found for smallholder crossbred dairy cows in sub humid costal Tanzania (Lyimo et al 2004). However, the values for both urban (130 days) and rural (140 days) areas in the present study were higher than the 104 and 86 days reported for the smallholder crossbred dairy cows in Zimbabwe (Masama et al 2003) and 121 days reported for Friesian Zebu crossbred cows at Assela livestock farm (Negussie et al 1998). On the other hand, the DO observed in this study was much lower than the 197 days reported for Friesian and Zebu crosses at Abernossa Ranch (Bekele et al 1991), 185 days for crossbred dairy cows in central highlands of Ethiopia (Shiferaw et al 2003), 211 and 216 days reported for F₁ Friesian and Zebu and 3/4 Friesian and 1/4 Zebu crossbred dairy cows of smallholder dairy farms in Malawi (Agyemang and Nkhonjera 1990) and the 152 days recorded for Sanga cows of smallholder dairy farms in Accra plains of Ghana (Obese et al 1999). The differences in the reproductive performance of crossbred cows reported by the different researchers might be attributed to the existing differences in nutritional and reproductive managements among the smallholder dairy producers in different parts of the tropics. Several scholars suggested that differences in management might have accounted for the observed differences on DO (Masama et al 2003; Shiferaw et al 2003; Lyimo et al 2004).

The mean values for NSPC for crossbred cows in the urban (1.67) and rural (1.66) smallholder dairy farms found in the present study agree well with the 1.62 reported in central highlands of Ethiopia (Bekele et al 1991 and Shiferaw et al 2003). Our finding is also in line with 1.61 services per conception reported by Haile-mariam et al (1993) in Abernossa Ranch. It is, however, slightly lower than 2.0 services per conception reported for cows at Asella (Negussie et al 1998). This is probably due to the better experiences that farmers gained through extension services and demonstration trial on the management of crossbred dairy cows and the benefit of AI from the near by Agricultural Research Station, Abernossa Ranch.

The overall mean GL of 278 days for crossbred cows in the urban and rural smallholder dairy farms found in the present study is similar with 277 days reported by Negussie et al (1998) but lower than 286 days reported by Albero (1983) for F₁ Friesian and Zebu crosses in the central highland of Ethiopia. The significant effect of breed on AFC in the rural area is inline with the reports of Agyemang and Nkhonjera (1990). These authors found that heifers with 75% exotic inheritance had higher AFC than heifers with 50% exotic inheritance. Higher AFC in cows with higher exotic blood would appear from inadequacy in meeting the nutrient requirement of high grade crossbred heifers as their body size increases.

The significant difference of CI between urban and rural areas obtained in the present study is in accordance with the previous reports (Shiferaw et al 2003; Obese et al 1999) but disagree with the report of Agyemang and Nkhonjera (1990) who have reported no significant difference on the length of CI between smallholder crossbred dairy cows at different locations in Malawi, which may be due to management differences. The absence of significant difference between breeds with respect to CI in this study is in contrast to earlier reports (Negussie et al 1998), where Friesian Zebu crosses had significantly higher CI than Jersey-Zebu (Arsi) crosses at Assela livestock farm. The finding in this study that cows which had their previous calving during long and short rainy seasons had a significantly lower CI than those calved during the dry season agrees with the reports of Haile-mariam et al (1993) and Mukasa-Mugerawa et al (1991). This is probably cows calving during the short rainy and early period of the long rainy season take the advantage of improved pasture and recoup in body weight and increase their conception probability during the early post-partum period, which in tern results in reduction of CI (Mukasa-Mugerawa et al 1991 and Haile-mariam et al 1993). The current result indicated that parity had no significant effect on the length of CI, which is in agreement with the report of Agyemang and Nkhonjera (1990) and Haile-mariam et al (1991) for F₁ crosses. However, Negussei et al (1998) and Bekele et al (1991) reported longer CI values for cows in the first and second parity.

In the present study DO was significantly shorter in cows kept in urban areas than in the rural area. Similar finding was reported by Bekele et al (1991) and Shiferaw et al (2003). This difference may be attributed to lack of feed supplementation in the rural areas. Parity number significantly influenced DO in this study, which is in agreement with earlier reports (Bekele et al 1991; Mukasa-Mugerawa et al 1991; Negussie et al 1998) in that cows in the first and second parity have been found to have longer DO than cows in the later parities. On the other hand, Agyemang and Nkhonjera (1990) and Obese et al (1990) reported otherwise in smallholder dairy farms. Moreover, in this study season of calving had a significant influence on the duration of calving to conception interval in contrast to the previous reports (Mukasa- Mugerawa et al 1991; Negussie et al 1998 and Obese et al 1999). This could be probably explained because of the fact that feed availability in the lowland parts of the country is very much influenced by season.

The absence of significant difference between cows' of the urban and rural farms in the number of services per conception was in agreement with the previous report of Shiferaw et al (2003). The significant effect of parity number on the NSPC found in the present study is in accordance with the findings of Negussie et al (1998) and Bekele et al (1991) who reported a decreasing NSPC in the subsequent parities. The absence of significant effect of breed and parity on the length of gestation obtained in the present study is in agreement with the reports of  (Negussie et al 1998). This is may be due to the fact that GL is more or less a constant feature within a given species (Agyemang and Nkhonjera 1990).

Conclusions

• The reproductive performance of crossbred dairy cows owned by smallholder dairy producers in Zeway and its surrounding is good considering the management situation and limited supplemental feed utilized in the area.

  
  

• Both parity and season of previous calving had significant influence on days open and number of services per conception, while only season of the previous calving had significant influence on calving interval.

  
  

• Accordingly, the ongoing activities to improve and expand crossbred dairy cattle production at smallholder level in the study areas should be encouraged.

  
  

• Moreover, in line with this, a sustainable extension service to improve animal feed resources management and animal health care deserve due attention.

References 

Agyemang K, and Nkhonjera L P 1990 Productivity of Crossbred Cattle on Smallholder Farms in Southern Malawi. Tropical Animal Health and Production 22: 9-16

Alberro M 1983 Comparative Performance of F₁ Friesian x Zebu Heifers in Ethiopia. Animal Production 37: 247-252

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Ebro A, Eticha G and Hussen A 1998 Thirty Years of Research Experience of Adami Tulu Agricultural  Research Center. Agricultural Research Coordination Service of Oromia Agricultural Development Bureau. Bulletin No 1: 1-46

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Mukasa-Mugerwa E, Tegegne A, Mesfin T and Teklu Y 1991 Reproductive efficiency of Bos- indices (zebu) cows under AI management in Ethiopia Animal Reproduction Science 24: 63-72

Negussie E, Brannang,E, Banjaw K and Rottmann O U 1998 Reproductive performance of dairy cattle at Assella livestock farm. Arsi. Ethiopia. I: Indigenous cows versus their F1 crosses. Journal of Animal Breeding and Genetics 115: 267-280

Obese F Y, Okantah S A, Oddoye E O K and Gyawu P 1999 Post-partum reproductive performance of Sanga cattle in smallholder peri-urban Dairy Herds in the Accra Plains of Ghana. Tropical Animal Health and Production 31: 181-190

Shiferaw Y, Tenhagn BA, Bekana M and  Kassa T 2003 Reproductive performance of crossbred Dairy cows in different production systems in the central Highlands of Ethiopia. Tropical Animal Health and Production 25: 551-561

Received 27 October 2008; Accepted 13 April 2009; Published 1 June 2009

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