Productive and reproductive performance of Holstein Friesian dairy cows in Ethiopia

M Tadesse, J Thiengtham, A Pinyopummin* and S Prasanpanich

Department of Animal Science, Faculty of Agriculture, Kasetsart University BangKen campus,
POBox, 10903 Chatuchak, Bangkok
Mill_tadesse@yahoo.com   ;   agrjat@ku.ac.th   ;   fvetacp@ku.ac.th   ;   agrskp@ku.ac.th
* Department of Large Animals and Wildlife Clinical Sciences, Faculty of Veterinary Medicine, Kasetsart University,
Kamphaeng Saen, Nakhon Pathom, 73140 Thailand
Mill_tadesse@yahoo.com   ;   agrjat@ku.ac.th   ;   fvetacp@ku.ac.th   ;   agrskp@ku.ac.th

Abstract

Data collected from 1987 to 2007 on reproductive traits (3 herds; n=1750) and milk production (2 herds; n=1230) of Holstein Friesian (HF) dairy cattle in Ethiopia were used to determine reproductive performance and milk yield. These data were from 493 dairy cows/heifers. Data were analyzed using fixed effect analysis of variance.

Period of calving and parity significantly (p < 0.001) influenced lactation milk yield (LMY), calving to first service interval (CFSI), days open (DO) and calving interval (CI). The effect of herd of cows was significant (p < 0.001) on service per conception (SPC), CFSI, DO and CI. Age at first calving (AFC) was only significantly (p < 0.001) influenced by period of calving. The overall mean LMY, AFC, SPC, CFSI, DO and CI were estimated to be 3710±111 kg/cow, 39.2±7.5 months, 1.80±1, 115±1.7 days, 148±1.72 days and 446±90.8 days respectively.

Except for SPC, the results obtained for AFC, CFSI, DO, CI and LMY were below the standard expected from commercial dairy herd. Poor efficiency of estrus detection,  poor estrus expression by animal or both were the most probable management factors accounted for longer period of CFSI and DO and hence CI. Improving the level of nutrition as well as efficiency of estrus detection system is required for optimal reproduction and lactation performance of HF breed in the study herds.

Key words: calving interval, calving to first service interval, days open, Holstein Frisian

Introduction

Although the indigenous Zebu cattle are more adapted to the local tropical environment, their capacity for milk production is usually low (Vaccaro et al 1977). Selection for high milk production within indigenous cattle would require a long-term genetic improvement program. However, in the highland areas of the tropics with an annual rainfall above 1000 mm, dairying is being carried out with relative success using imported and now adapted Bos taurus breeds, as well as their crosses with the Zebu (Katyega 1988). But there is a concern about reproductive performance of imported breeds and their high grade crosses under tropical condition. The introduction of artificial insemination (AI) into dairy cattle in Ethiopia allowed for genetic improvement of local breed through crossbreeding specially in urban and peri-urban areas. However fertility rate of high grade and pure exotic dairy cattle suffered from poor reproduction performance, poor conception rate, long post partum anestrus and calving interval (Kiwuwa et al 1983; Madalena et al 1990). These lower reproductive perforance could be related to genetic, environmental/management factors or both. Ample information available on the effect of these factors on reproductive performance of crossbreed dairy cattle at research and ranch condition (Kiwuwa et al 1983; Million 2001). However, study on reproductive performance of dairy cattle arificially inseminated under intensive dairy management system in Ethiopia is limited. Moreover, recent changes in the genetics, productivity, and management of dairy cows have led to a decline in reproductive efficiency (Lucy 2001). Reproductive decline in dairy cows become evidence in the mid-1980’s and may be continuing on modern dairy farms (Lucy 2001). Hence, there is a need to periodical evaluation of reproductive performance of dairy cattle and factors affecting their performance.

The purpose of this study is to determine reproductive performance and the factors affecting reproductive and milk production traits of HF cows reared under intensive dairy production system in Ethiopia.

Material and methods 

Location of the study and data sources

Data for this study were obtained from three dairy herds (Holetta, Stella and Dinkity) located in urban and peri-urban dairy production system of Addis Ababa milk-shade. Stella and Dinkity are situated within Addis Ababa city, while Holetta dairy farm is located 20 km west of Addis Ababa in Holetta town. The area receives bimodal rainfall with two rainy seasons in a year. The short rainy season occurs between March and May and main rainy season is during June to September while the dry season from October to February. The average temperature is 15.9^oC with variations between 7^oC and 25^oC. The average monthly rainfall is 90.75 mm. The highest average rainfall is 269 mm occurring in August and the lowest rainfall is 9mm occurs during month of November. The average relative humidity is about 60.7% and the lowest average relative humidity is 49% which occurs in February; 82% is the highest average monthly relative humidity which occurs in July (long rainy season).

Herd management

Grass hay constituted the major proportion of the feed supply. Whenever there was a short supply of hay, tef (Erogrostis tef) straw was substituted. In all herd milking cows were supplemented with home made concentrate composed of wheat by-products or maize, (28-30%), Noug seed cake (68-70%) (Guizotia abyssinica) and 1% salt while they were milked. The amount of concentrate offered depended on the volume of milk from each cow. Artificial insemination (AI) with semen produced from locally recruited bulls from Ethiopian National Artificial Insemination Centre (NAIC) was practiced. AI was done based on visual observation of standing heat by herd attendant two times daily during morning and afternoon (office hours). Animals from Dinkity herd was managed in a loose housing system while those at Holetta and Stella farm allowed grazing during day time and housed at night in barn. Cows were hand milked twice a day at all farms. Animals on the farm were regularly vaccinated against common infectious diseases such as rinderpest, contagious bovine pleuropneumonia (CBPP), anthrax, blackleg and foot and mouth disease. Regular preventive treatments were administered against prevalent endo- and ecto- parasites. Abortion, still birth and retained placenta were common on clinical case book records.

Data collection and derivation of study variables

Data collected from 1987 to 2007 on birth dates, calving dates, dates of first and subsequent artificial insemination, and lactation milk yield were used. From the collected information, the following dependent variables of interest were derived; age at first calving (AFC) as the number of months from birth date to first calving, calving to first service interval (CFSI) interval in days from the calving date to the first service date, days open (DO) as the interval in days between calving and conception and calving interval (CI) was the interval in days between two consecutive calving. Lactation milk yield (LMY) was the total lactation milk yield, service per conception (SPC) as the number of services the cow required until she conceived.

A total of 493, 1186, 1175, 1170, 1750 and 1230 records on AFC, CFSI, DO, CI, SPC and LMY were analysed (Table 1). Three seasons were established based on weather and climatic conditions of the area; June to September as long rain season, March to May as short rainy season and October to February as dry season. Further, all parturition numbers were classified into seven parities; 1, 2, 3, 4, 5, 6, 7. All parities above 7 were pooled together in parity 7 because only a few cows that had completed more than 7 lactations. For CFSI, DO, CI, LMY, the year of calving were grouped into the following 4 periods of calving; period one (1987-92), period 2 (1993-1997), period 3 (1998-2002) and period 4 (2003-2007). For AFC additional period was included for cows born before 1987. Data on AFC, CFSI, DO, CI obtained from three herds (Dinkity, Holetta and Stella) while LMY were from only two (Holetta and Stella) herds. Data were initially analysed with all interactions in the model and then reanalysed after removing the non significant interaction effect. For LMY interaction between parity and season of calving and parity and herd were kept in the final analysis as significant effect was evident.

Because of high coefficient of variation (CV), data on CFSI and DO were transformed using log transformation. The General Linear Models procedure was used for data analysis. Three statistical models were used during data analysis; model 1 was used to analysis data on LMY, model 2 for AFC and model 3 for CFSI, SPC, DO and CI.

Model 1: Y_ijklm = u + B_i + S_j + YR_k + P_l + (B*P)o +(S*P)t + e_ijklot

Where:

Y_ijklotn = LMYof n^th cow in l^th parity, k^th period of calving, j^th season of calving and i^th herd

 u = overall mean

B_i = the effect of i^th herd

S_j = the effect of j^th season of calving

YR_k = the effect of k^th period of calving
P_l = the effect of l^th parity

(B*p)o= the effect of o^th herd and parity interaction

(S*P)t=the effect of t^th season of calving and parity interaction

e_ijklton = random residual error term

Model 2: Y_ijkn = u + B_i + S_j + YR_k + e_ijkn

Where:

Y_ijkn = Age at first calving of n^th cow born in k^th period of birth, j^th season of birth and of i^th herd

u = overall mean

B_i = the effect of i^th herd

S_j = the effect of j^th season of birth

YR_k = the effect of k^th period of birth

e_ijklotn = random residual error term

Model 3: Y_ijklm = u + B_i + S_j + YR_k + P_l + e_ijlkm

Where:

Y_ijklm = the m^th record (CFSI, DO, SPC, and CI) of n^th cow in l^th parity, k^th period of calving, j^th season of calving and i^th herd

 u = overall mean

B_i = the effect of i^th herd

S_j = the effect of j^th season of calving

YR_k = the effect of k^th period of calving
P_l = the effect of l^th parity

e_ijklm = random residual error term

Least square means comparison was performed using significance level at (p < 0.05)

Results and discussion 

Lactation milk yield (LMY)

Period of calving, parity, interaction between parity and season of calving, parity and herd significantly (p <0.001) influenced LMY, while the effect of season of calving and herd of cow were not significant (Table 2). The overall mean LMY was 3710 kg/cow with a coefficient of variation of 29.9%

The mean LMY of 3710 kg/cow obtained in this study is lower compared to 4791 kg LMY of HF breed in Zimbabwe Makuza and McDaniel (1996); 5905 kg/cow in Tunisian HF cow Ajili et al (2007); 5152 kg LMY in HF population in Canada Jairath et al (1995) and 4489 kg/cow in southern Malawi (Wollny et al 1998). These lower LMY of HF cows in the present study compared to literature results indicative of poor adaptation of this exotic breed to climatic and management condition in Ethiopia.

Mean lactation milk yield was significantly (p < 0.05) highest during latter period (2003-2007) and lowest during period 1 (1987-1992). The progressively increased trend in lactation milk yield over the period of calving is an indicative of improved management, adaptation HF breed to the environment through time or both.

Mean lactation milk yield increased from parity one to third parity. The differences among parity three to six were not significant however, after parity six a declined trend was observed. The increased trend in LMY up to third parity and decreased trend then after is similar to the results reported in HF cross Ahmed et al (2007) in Sudan. Mackinnon et al (1996) also reported a decrease in milk yield after the third parity on crosses of Ayrshire, Brown Swiss and Sahiwal in Kenya. However, the Fogera-Friesian crosses at Gonder Breeding Station (Ethiopia), the maximum lactation yield was attained at fourth and fifth parity and declined then after (Goshu and Mekonnen 1997). Martinez et al (1988) reported that age difference (i.e. difference of lactation number) is one of the important non-genetic sources of variation in milk yield.

Age at first calving (AFC)

Period of birth significantly (p < 0.001) influenced AFC, while the effect of herd and season of birth was not significant. The overall mean AFC was estimated to be 39.2±7.5 months with coefficient of variation of 19%.

The mean AFC obtained in this study is higher than 29.3 months that was reported for Tunisian Friesian-Holstein cows Ajili et al (2007); 823 days (27.2 months) in HF cows in Pakistan Niazi  and Aleem (2003) and 988 ± 9.81 days (32.7 months) reported by Sattar et al (2005). The prolonged AFC of HF cows in present study compared to literature results could be attributed to factors such as poor nutrition and management practices including poor heat detection at the time of mating the heifers. With good nutrition it is expected that heifers would exhibit fast growth and attain higher weights at relatively younger ages. A significant reduction in AFC from 44.1 months during the period < 1987 to 34.6 months during 2003-2007 indicated progressive improvement in management and also adaptation of HF breed to the prevailing tropical environment.

Service per conception (SPC)

Service per conception (SPC) was significantly (p<0.001) influenced by parity and herd of animal while period and season of calving had no significant effect. The overall mean SPC was estimated to be 1.8.

The overall mean SPC obtained in this study was lower than SPC of 2.0 reported in HF dairy cattle in Nigeria Ngodigha et al (2009) and 2.11 for HF in Pakistan (Niazi and Aleem 2003).

Mean SPC was significantly highest for cows in Holetta herd and lowest at Stella herd. Similar significance difference between herds in SPC was reported Ben Salem et al (2006) for HF breed in Tunisia. The relatively higher SPC for cows in latter parities (6 and above) is in agreement with SPC of 2.19 reported for parity 6 (Ray et al 1992). Older cows may be more susceptible to possible effects of higher milk production on involution of the cervix and uterus in addition to delayed first postpartum ovulation (Fonseca et al 1983). Successful service or insemination depends on many factors such as quality of semen, skill of the inseminator, proper time of insemination and cows related factors. Management, nutrition and climate conditions may also affect the success of insemination. The findings of the present study on SPC suggested comparatively better insemination services at the herds under the study during the period of the study.

Calving to first service interval (CFSI), days open (DO) and calving interval (CI)

Of the total 1175 records of DO about 19.0% were bred too early in lactation (< 85 days), and 14.4% bred at optimal time (85-115 days), about 7.05 and 6.13% require 130 days indicating slight to moderate problem, while the majority 53.40% required greater than 145 days (Table 4). The proportion of cows with greater than 145 days of DO was estimated to be 63.9, 52.4 and 52.1% of the total DO in Dinkity, Stella and Holetta herd respectively.

Of the total CI (1170) records, only 15.4% had short CI (11.7 months) and about 18.40% had optimal CI which met the standard set for commercial dairy farms. The majority 51.9% had longer CI more than 14 months or 420 days (Table 5). The proportion of cows with greater than 420 days (14months) of CI is 63.2, 50.9 and 50.5 of total CI at Dinkity, Holetta and Stella herd respectively.

Year of calving, herd and parity had significant (p<0.001) effect on CFSI, DO and CI, while season of calving had no significant effect on CFSI and DO and significantly (p<0.05) influenced CI. Mean CFSI, DO and CI was 115±1.7, 148±1.72 and 446 ±91 days with a coefficient of variation of 11% and 11% and 20% respectively. Mean CFSI was significantly (p< 0.05) highest for cows at Dinkity herd followed by cows at Stella herd, and significantly (p<0.05) lowest days at Holetta herd, while DO and CI was significantly (p<0.05) highest at Dinkity farm and lowest at Holetta herd (Table 6).

Mean CFSI, DO and CI was significantly (P< 0.05) longest for cows that calved during the period 1 (1987-92). Mean CFSI, DO and CI were significantly (p < 0.05) declined from period 1 to period 2 and remain constant from period 2  to period 3. However, after period 3, DO and CI slightly declined, while CFSI slightly increased (Table 6). Mean CFSI, DO and CI significantly (p < 0.05) declined from 1^st to 3^rd parity. Cows in the first parity had significantly (P <0.05) longest CFSI, DO and CI (Table 6).

Calving to first service interval (CFSI)

The average CFSI of 115±1.7 days obtained in this study is similar to the value of 111 days reported in HF breed in Turkey Cilek (2009) and lower than 170 days reported in Tanzania Asimwe and Kifaro (2007) and 142 days in Ethiopia (Shiferaw et al 2003). However, longer than the ideal interval of 60-90 days Berry et al (2003) which could be attributed to different factors. Most investigators suggest that the reason for the delay in interval to first service is greater negative energy balance in modern dairy cows. Negative energy balance delays the resumption of ovarian activity (Butler and Smith 1989). Ovulation and estrus after calving are delayed when the positive feedback effects of estradiol on release of LH from the pituitary, and circulating concentrations of metabolic hormones such as insulin and insulin-like growth factor-I, are reduced by a variety of environmental factors (Rhodes et al 2003). The main factors are limited energy intake, lower body reserves, increased partitioning of energy to milk production.

Apart from nutritional effect poor estrus detection by herdsman, poor estrus expression of HF could be the other factors for long CFSI in this study. Under intensive modern dairy production system where animals are housed in the dairy barn (concrete floor) it is very difficult for the animal to show mounting activity. Research showed that mounting activity was reduced by almost the half when cows were left on concrete as opposite to softer floors while the duration of oestrus activity was reduced by 25% (Britt et al 1986). Lack of planed and focused estrus detection system in herds under present study worsens the situation. People involved in heat detection are only present at regular working hours when they should be present at very specific hours because the pattern of heat onset is variable, with the greatest activity occurring early morning and late evening (Plasse et al 1970). Many specific reproductive health problems, such as, ovarian cysts, retained placenta and metritis are quite common in dairy herds. They require a good reproductive health program, which is essential for efficient reproduction management. Unfortunately, this type of program is lacking in many herds in Ethiopia where veterinarians are usually called on an emergency basis.

The significance difference in CFSI between herds could be due to variation in herd management and difference in heat detection efficiency between herds. Since all herds were kept under similar environment with in 20 km from Addis Ababa town difference among herds is not related to environmental effect. The inconsistent trend in CFSI across period of calving could be related to different factors such as management related factors or availability of feed across years. Year effect on reproduction in the tropics has been reported to be indirect due to dynamic climatic changes which are frequently associated with disease pattern and changes in management by farmers (Mulangila 1997).

The present result of parity effect on CFSI was in agreement with Elhag (2003) who suggested that the shortest time taken for occurrence of first oestrus was reported to be at the 3^rd to the 4^th calving, the moderate period was at the 5^th to the 6^th calving and the longest time taken was at 9^th to the 10^th calving. The significantly longer CFSI obtained in parity one probably reflect the greater nutritional stress being imposed on younger cows due to requirements for growth as well as lactation.

Days open (DO)

The estimated mean DO of 148±1.72 days in this study is similar with DO of 150 days in HF dairy breed in Turkey Cilek  (2009) and lower than the results reported by Asimwe and Kifaro (2007) of 205+2.6 days for HF in Tanzania; and Estévez et al (1995) of 198 days and Shiferaw et al (2003) of 185 days in Ethiopia. Such differences could have been caused by difference in environmental factors under which animals kept or management factors such as ability of farmers to detect heat signs after calving, and interval from CFSI was prolonged, and eventually influencing the number of DO.

The significance difference in days open between herds was related to difference in management such as nutrition, health and heat detection by farmers which affect CFSI and hence days open. The significant effects of period (P<0.001) of calving on DO was also reported by Asimwe and Kifaro (2007) and Mangurkar et al (1985). The longer DO during period one (1987-92) is the results of longer CFSI since there was no effect of repeated breeding as evident from the result of SPC during this period (Table 3). The longer DO for cows calved in parity one followed by those in second, third and fourth parities are in agreement with findings reported by Asimwe and Kifaro (2007); Lozano et al (1992) who had reported similar trend of DO tending to decrease with advancement in age. This could be due to physiological stress experienced by the first calvers in early lactation and delayed CFSI and hence DO.

Calving interval (CI)

The overall mean CI of 445±90.8 days obtained in this study is similar to CI of imported (449 days) and local born Friesian cows (436 days) in Pakistan Niazi and Aleem (2003) and comparable to 459 days obtained by Kiwuwa et al (1983) and 459+2.4 days by Million (2001) for HF crosses in central highland of Ethiopia. However, longer than the results reported by Pedron et al (1989) of 392-407 from different herds; and 421 days obtained by Moges Dereje and Baars (1998) in Holstein Frisian breed in Ethiopia under research station. However the CI in the present study is above the normal interval of 365 days expected on a commercial dairy farm. This longer CI is mainly attributed to the result of longer CFSI and DO obtained which could be related to environmental factors, mismanagement practices like poor housing (Britt et al 1986), poor nutrition or failure to detect heat by the farmer (Msanga et al 1999). Vaccaro (1979) concluded that the performance of temperate dairy cattle in the tropical areas of Latin America was disastrous. Purebred temperate cows suffered unacceptably high losses, which indicated that the animals of temperate zone did not adapt well to the harsh environments of the tropics.

The significant effect of herd on CI obtained in this study is in agreement with Ben Salem et al (2006) who reported similar significant effect of herd on CI in HF breed in Tunisia. The significant longer CI for cows at Dinikity herd was related to longer CFSI and DO.

The significantly (p < 0.05) longer CI for cows calved during period one and declined trends then after related to management factors. Kifaro (1984) and Lozano et al (1992) have been demonstrated similar findings. Wilson and Willis (1974) also found year to year difference in CI on Brahman and Santa Gertrudis cattle in hot climate. Year effect on CI in the tropics has been reported to be indirect due to dynamic climatic changes which are frequently associated with disease pattern and changes in management by farmers (Mulangila 1997). The progressive reduction in CI from 485 days for cows calving during the period 1987-92 to 436 days for cows calving from 2003-07 could be a sign of improvement in the ability of farmers to manage their dairy cattle, and to the adaptation of the breed to the prevailing environment through time.

Unlike CFSI and DO, the significant effect of season of calving on CI is not expected. However the result is inline with Wilson and Willis (1974) who reported significance effect of season of calving on CI

The decrease in CI between the first and subsequent parities is in agreement with earlier studies by Kifaro (1984), Agyemang and Nkhonjera (1986) and Balikowa (1997). In an analysis of data collected over 20 years on zebu cattle in Venezuela, Montoni et al (1981) found that CI was longest between the first and second calving, and shortest between the fifth and sixth calving which is in agreement with present study. This could be associated with improvement in reproductive management and it also indicates that physiological maturity is attained with advanced age of cows. The prolonged CI for first calvers has been reported to be physiologically necessary to allow animals to replenish their fat reserves depleted during lactation and this allows them to put on weight prior to the next calving (Mahadevan 1951).

Conclusions

• Results obtained indicate that parity of cows had significant (p < 0.001) effect on all traits. Except for SPC, period of calving showed significant effect on all other traits.

  
  

• The effect of herd was significant (P< 0.001) on SPC, CFSI, DO and CI but not significant for LMY and AFC while season of calving had no significant influence on most of the traits studied.

  
  

• The results obtained for AFC, CFSI, DO, CI and LMY were below the standard expected from commercial dairy herd.

  
  

• The major problem associated to poor reproduction performance observed in this study is related to delay on postpartum resumption of ovarian activity as indicated by longer CFSI. Since the number of service per conception is within the normal that expected for modern dairy farm, poor expression of estrus by the cow, failure to detect estrus by herd attendant or both were the major causes for poor reproduction performance of HF in present study.

  
  

• The slightly declined DO and CI and increased in LMY across period of calving indicating improvement in management and adaptation of HF breed to the climate of the study area through time. Since many of the reproductive traits studied are characterized by wide ranges of values and high coefficients of variation such as CFSI and DO (before transformation), CI and LMY. Such large coefficients of variation are indicative of opportunities for improvement in these traits. Since most reproductive traits have a low heritability, it is apparent that most progress can be achieved by paying attention to management factors, especially improving the level of nutrition and estrus detection efficiency. Furthermore, better reproductive health management is also required.

Acknowledgments 

The authors are grateful for the financial support provided by the Rural Capacity Building Project (RCBP) under Ministry of Agricultural and Rural Development, Ethiopia. They would also like to thank the management of Stella, Dinikity and Holetta dairy farm for allowing us access to their farm records. The authors wish to thank also staff of animal science and dairy research at Debre Zeit Agricultural Research Centre for assistance with data collection and staffs of department of animal science, at Kasetsart University for their valuable comments and suggestion during seminar presentation.

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Received 23 November 2009; Accepted 13 January 2010; Published 7 February 2010

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