ORIGINAL PAPER

Factors effecting reproductive performancein Rwandan cattle

Hannah Bishop & Dirk Pfeiffer

Accepted: 8 September 2007 /Published online: 2 October 2007# Springer Science + Business Media B.V. 2007

Abstract The objective of this study was to assessthe reproductive performance of Rwandan cattle anddetermine the effects of husbandry practices on repro-duction. One hundred and fifty Ankole and Crossbreedcattle from 87 farms, were body condition scored (BCS)on a scale of 1(lean) to 5 (fat), and examined rectally forpregnancy and ovary size and structures present.Questionnaires were completed by the farmers to obtaininformation on husbandry and management practices.Themean age of onset of pubertywas 27.7±10.4months,the interval from parturition to first oestrus was 8.7±7.8 months, calving index was 16.8±5.2 months and44% (95% CL 0.36-0.52) of cows examined rectallywere anoestrus. Crossbred cattle reached puberty youn-ger than Ankole cattle, 23.4±10.4 and 28.4±9.6 monthsrespectively (p<0.05; t=1.944; df=121). Cows in poorBCS (< 2.5) are 1.67 times as likely to be in anoestrus asthose with higher BCS (≥ 2.5) (χ2=9.476; df=2; p<0.01). Increased weaning age resulted in increasedcalving index (p<0.001; t=−3.60; df=38). Reproduc-tive performance of Rwandan cattle is poor. Many ofthe problems can be attributed to husbandry practicesand lack of experience and training in raising cattle.

Keywords Anoestrus . BCS . Cattle . Puberty .

Reproduction . Rwanda

It has been anecdotally reported that many of theRwandan Ankole cattle appear to have poor reproduc-tive efficiency due to late onset of puberty and pro-longed anoestrus post calving. Maximum return isdependant on milk yield and calf production and thesedepend on reproductive activity. The aims of this studyare to establish the average age at onset of puberty, asdefined by the first observed oestrus, the average lengthof postpartum anoestrus, as define by the interval fromparturition to first oestrus, and the average calvingindex, as defined by the interval between successivecalving, in Ankole cattle. To identify areas of husbandryand management that are substandard and determinetheir association with poor reproductive efficacy so thatimproved farming methods can be introduced toenhance reproductive efficiency and hence economics.

One hundred and fifty cows from eighty sevenfarms in the Gitarama Province were used for this study,one hundred and twenty three pure bred Ankole andtwenty seven crossbred cows (Ankole x Fresian orAnkole x Jersey). Three out of ten districts were selectedfrom within the Gitarama Province (Gitarama, Ruhangoand Karengera) due to contacts with local veterinariansand convenience of location. Cattle races are set upthroughout the countryside for markets and as centersfor veterinary treatment. Farmers were informed andreminded about the study for 2 months prior to the startof data collection. The cattle races were visited on a date

Trop Anim Health Prod (2008) 40:181–184DOI 10.1007/s11250-007-9078-1

H. Bishop (*) :D. PfeifferRoyal Veterinary College,Hawkshead Lane, North Mymms,Hatfield, Hertfordshire AL9 7TA, UKe-mail: hbishop@rvc.ac.uk

arranged with local farmers and all the cattle at the raceswere examined.

All cows were assigned a body condition score(BCS), ranging from 1 (lean) to 5 (fat), which was basedon visual and tactile evaluation of the tail head andlumbar regions (Wildman et al. 1982) and examined perrectum. The reproductive tract was carefully palpatedto determine the reproductive status of each cow. Thereproductive status was defined as:

– pregnant: palpable enlargement of the uterus i.e.> 30 days since successful service

– cycling and non-pregnant: one or both ovaries werelarge (> 2 cm) with either a Corpus Luteum (CL) orlarge follicle >8 mm (Draincourt et al. 1991)

– non-cycling and non-pregnant: both ovaries weresmall (<1 cm) with no CL or dominant follicle.

All the owners were asked to complete a question-naire, which was translated into Kinyarwanda, thelocal language. None of the farmers kept records ofreproductive performance and so accuracy of data wasreliant on their memories.

All data were entered into SPSS for statisticalanalysis. Reproductive indices were compared inAnkole and cross bred cattle using chi-squared andt-test. BCS were grouped into 3 categories. Cows with aBCS < 2.5 were defined as too thin and BCS > 3.5 weredefined as too fat and between 2.5 and 3.5 were definedas normal (Ferguson 1996). The proportion of cows ineach category of BCS that were not cycling wascompared using the Chi-squared and relative risk.Pearson’s correlation co-efficient was calculated forweaning age and milk yield against calving index andinterval from parturition to first oestrus.

From the questionnaires, 64.9% (95% CL 0.57–0.73) of farmers had received only primary schooleducation, 23% (95% CL 0.16–0.35) had received noeducation whatsoever and only 1.3% (95% CL 0.0052–0.031) of farmers had received specific training inanimal husbandry or agriculture. Farmers had onaverage been raising cattle for 15±12.4 years and 20%(95% CL 0.14–0.54) of farmers have owned cattle< 5 years.

The majority of farms were smallholders owning1–3 cows (20% own one cow; 30% two cows and 13%three cows) and kept other livestock including goats,sheep, chickens and pigs. 55% (95% CL 0.47–0.63) offarmers permanently housed their cattle. Only 6% (95%CL 0.02–0.14) supplement grazing but of these 44.4%

(95% CL 0.36–0.52) use concentrates. 70.3% (95% CL0.63–0.74) of farmers do not receive regular veterinaryinspections of their cattle and 53.5% (95% CL 0.45–0.61) do not use regular parasite control.

All farmers in the study relied on behavioral changesfor the detection of oestrus. The signs of oestrus werepoorly expressed with 86% (95% CL 0.80–0.92) offarmers relying on a thick, clear, vulval discharge andonly 8.7% (0.04<p<0.13; 95% confidence limit) ofcows standing to be mounted. Some farmers wereunsure on the signs of oestrus , 4 farmers reported abloody vulval discharge as a sign of oestrus and 6.5%(95% CL 0.02–0.11) of farmers reporting that they ‘tiedthe cow down’ because she would not stand for the bullto mount her. Natural service is used by 82.3% (95%CL0.76–0.88) of farmers and 87.2% (95% CL 0.80–0.95)are breed on first oestrus. 91.3% (95%CL 0.85–0.98) offarmers opting for artificial insemination (AI) chosetimed AI of which 91.3% (95% CL 0.85–0.98) is by atechnician rather than a veterinarian.

The mean age of onset of puberty was 27.7±10.4 months in this sample of Rwandan cattle, com-parable to 22–36 months in South American Zebucattle (Nogueira 2004). The average interval fromparturition to first oestrus was 8.7±7.8 months com-pared to >150 days, which is characteristic of Bosindicus/Bos Taurus cattle, resulting in a prolongedcalving index. The average calving index was 16.8±5.2 months in Rwandan cattle. Late onset of puberty,

Table 1 Effect of breed on reproductive performance

Breed Ankole Crossbred

Mean age at 1st puberty (months) 28.42±8.78 23.42±9.59Mean interval from parturitionto 1st oestrus (months)

8.78+7.66 8.12±8.89

Mean calving index (months) 16.61±4.65 17.83±7.91% not cycling on rectal palpation 43.9 44.4Total Number of Cattle 123 27

Table 2 Effect of BCS on reproductive performance

BCS % not cycling on rectal palpation*

<2.5 64.52.5–3.5 44.6>3.5 28.9

* Total of 150 cattle examined

182 Trop Anim Health Prod (2008) 40:181–184

prolonged anoestrus and calving index were the causeof poor reproductive performance in Rwandan cattle,which is in agreement with similar studies on Bosindicus, Bos Taurus and B.indicus/B.taurus crosses(Baruselli et al. 2004; Azage et al. 1993; Lyimo et al.2004 respectively). The poor reproductive performancecaused a reduction in the number of calves produced inthe cow’s life time, the number of lactations and there-fore milk production. This results in economic losses.(Butler et al. 1981; Savio et al. 1990a,b; McDougallet al. 1995; Opsomer et al. 1996)

Table 1, shows the effects of breed on reproductiveperformance. Crossbred cows are younger at firstoestrus compared to Ankole cows (t=1.94; df=121;p<0.05). Ankole cattle had a later onset of pubertycompared to Crossbred cattle, 28.4 and 23.4 monthsrespectively. However, there was no difference in thelength of postpartum anoestrus and calving index inAnkole and Crossbred cattle in this study, suggestingthat the poor reproductive indices are more likely to bedue to environmental conditions and husbandry prac-tices rather than genetics.

On the whole, cattle were in good condition andhad an average BCS of 3.2±1.1 because the study tookplace at the end of the rainy season when grass had beenwidely available. Further studies would benefit frommonitoring changes in BCS throughout the year todetermine the effect of seasonal variation in quantity ofgrass. The effect of BCS on proportion cycling ispresented in Table 2. Thin cows are 1.45 times morelikely to be in anoestrus as normal cows and 2.23 timesmore likely than fat cows (χ2=9.476; df=2; p<0.01).The low BCS reflects a poor availability of nutrientsand periods of negative energy balance. This is inagreement with other studies reporting that undernutrition due to dependency on poor quality naturalforages and high parasite burdens is the main hinderingfactor in cattle reproduction in tropical regions (Lyimoet al. 2004; Montiel and Ahuja 2005; Shiferaw et al.2005).

Pearson’s correlation co-efficient showed no sig-nificant correlation between milk yield and intervalfrom parturition to first oestrus (Coefficient=−0.038;p<0.185) and calving index (Coefficient=−0.002; p<0.246). However, there was a positive correlation bet-ween the weaning age and interval from parturition(Coefficient=0.26; p<0.05) and calving index (Coeffi-cient=0.54; p<0.01). This is in agreement with otherstudies of tropical cattle demonstrating that, late wean-

ing of calves is a common occurrence due to financialconstraints and to aid milk let-down in the cow, and is amajor cause of prolonged anoestrus (Lyimo et al. 2004;Msanga and Bryant 2004).

In conclusion, to make farming more profitable inRwanda it is vital that the reproductive performance ofcattle improves. There are many challenges facingRwandan farmers if they are to succeed. The majorconstraints, according to this study, are the age ofweaning, poor oestrus detection and poor nutrition. Toimprove these factors, many farmers would benefit fromincreased training and experience in cattle rearing.

Acknowledgements The author thanks Stan Lee for his helpin translating the questionnaire, acting as a translator andhelping in all matters practical, special thanks to Marlene Leefor her hospitality during my stay with them in Rwanda.

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