Milk production performance of Ankole crossbreds and Holstein Friesian cattle in different production environments of Rwanda.

The aim of the study was to assess the productive performance of dairy cattle in three different agro-ecological zones of Rwanda: Congo-Nile/Western (WAZ), Central plateau/Central (CAZ), and Eastern plateau/East Agro-ecological Zones (EAZ). A single-visit multi-subject survey was conducted to obtain information on the dairy cattle performance from 51 farms. The breed groups were classified as Ankole x Holstein Friesian (AF), other Ankole crossbreds (AX), and pure Holstein Friesian (F). The F had higher (p < 0.001) milk yield than AF in all zones except EAZ and AF had higher (p < 0.0001) milk yield than AX in all zones. Across all zones, F produced 9 L more than AX and 6 L more than AF per day. Cows from EAZ had the highest average milk yield; however, it was not significantly different from CAZ. The difference that was observed between AF in EAZ and AF in the other two zones indicates that agro-ecological zones should not only be the target in livestock development activities rather additional factors such as feed availability at farm level, social economic, and market infrastructure should be considered in Rwanda.

Challenges and opportunities of smallholder pig production systems in Rwanda.

To decipher the dynamics, challenges, and opportunities of smallholder pig farming in Rwanda, a household survey was conducted in ten districts of the country. A total of 900 households selected randomly across four provinces and one city, 12 districts, 28 sectors, and villages were interviewed using a pretested printed questionnaire. Most of the respondents were heads of household: 70.9% for western, 63.5% in eastern, 54.1% in northern, and 52.5% in southern province, and their mean age was 46.7 years and had widely varying education levels. Crossbred pig genotypes were the most preferred due to their high growth rate and produce large litters compared to local pigs, as well as their high resistance to disease, and can better utilize low-quality feeds compared to pure exotic pigs. Piglets and sows were the biggest populations on most farms. Production of piglets for sale was the main purpose of rearing pigs in 63.7% of the farms. Natural mating was almost (99.1%) exclusive on all farms, implying that artificial insemination is yet to take root in Rwanda. Weeds were reported to be the main feed resource used particularly in wet season, while cereal grain mashes and concentrates were used by very few farmers due to high costs. Dominant challenges related to limited pig and pork markets, high taxation, limited extension services, and disease outbreak were highlighted. The most common diseases affecting pigs were swine erysipelas and internal parasites. Access to veterinary services by the households was limited especially in northern province (20%) leading to wrong diagnosis. Capacity building and provision of access to quality animal health services as well as setting up of markets were proposed as strategies to improve pig production by smallholders in Rwanda and grab a share of the lucrative pork market in the region.

The effect of high temperature and humidity on milk yield in Ankole and crossbred cows.

Tropical regions are characterized by high temperature and humidity across the year. At high values of temperature humidity index (THI), there is a risk of heat stress leading to lower milk yield. The objective of this study was to describe the effect of season and the effect of maximum daily THI on milk yield of that day in purebred Ankole and Ankole-Friesian, Ankole-Jersey and Ankole-Sahiwal crosses in a tropical climate. In total, 53,730 records of daily milk yield from 183 cows in Rwanda were analyzed. The results showed that THI had a negative effect on daily milk yield above a threshold, but the effect was small (- 0.11 kg milk/THI unit at most). Purebred Ankole cows had the lowest daily milk yield and the lowest threshold (THI mean 66), as compared to the crossbreds (THI mean 68-69). Ankole-Friesian had a steeper decline in daily milk yield above the threshold than Ankole. The crossbreds, especially Ankole-Friesian, had higher daily milk yield than purebred Ankole also at very high THI. The results indicate some differences between breed groups in the way of coping with a hot and humid climate and raise questions about dairy cows' adaptation to such a climate.

Genome-Wide Association Study of Growth Performance and Immune Response to Newcastle Disease Virus of Indigenous Chicken in Rwanda.

A chicken genome has several regions with quantitative trait loci (QTLs). However, replication and confirmation of QTL effects are required particularly in African chicken populations. This study identified single nucleotide polymorphisms (SNPs) and putative genes responsible for body weight (BW) and antibody response (AbR) to Newcastle disease (ND) in Rwanda indigenous chicken (IC) using genome-wide association studies (GWAS). Multiple testing was corrected using chromosomal false detection rates of 5 and 10% for significant and suggestive thresholds, respectively. BioMart data mining and variant effect predictor tools were used to annotate SNPs and candidate genes, respectively. A total of four significant SNPs (rs74098018, rs13792572, rs314702374, and rs14123335) significantly (p ≤ 7.6E-5) associated with BW were identified on chromosomes (CHRs) 8, 11, and 19. In the vicinity of these SNPs, four genes such as pre-B-cell leukaemia homeobox 1 (PBX1), GPATCH1, MPHOSPH6, and MRM1 were identified. Four other significant SNPs (rs314787954, rs13623466, rs13910430, and rs737507850) all located on chromosome 1 were strongly (p ≤ 7.6E-5) associated with chicken antibody response to ND. The closest genes to these four SNPs were cell division cycle 16 (CDC16), zinc finger, BED-type containing 1 (ZBED1), myxovirus (influenza virus) resistance 1 (MX1), and growth factor receptor bound protein 2 (GRB2) related adaptor protein 2 (GRAP2). Besides, other SNPs and genes suggestively (p ≤ 1.5E-5) associated with BW and antibody response to ND were reported. This work offers a useful entry point for the discovery of causative genes accountable for essential QTLs regulating BW and antibody response to ND traits. Results provide auspicious genes and SNP-based markers that can be used in the improvement of growth performance and ND resistance in IC populations based on gene-based and/or marker-assisted breeding selection.

Influence of endometritis on milk yield of zero-grazed dairy cows on smallholder farms in Rwanda.

Endometritis being a post-partum uterine infection in dairy cows is likely with substantial production loss through reduction in milk yield (MY), discarded milk during treatment and withdrawal period, and increased cost of veterinary treatment. This study quantified the influence of endometritis on MY of zero-grazed dairy cows managed on smallholder farms in Rwanda. The study enrolled a total of 461 cows within their 21 to 60 days in milk to examine for clinical endometritis (CLE) and subclinical endometritis (SCLE). A cow was considered having endometritis if it was positive for at least one test (CLE or SCLE), otherwise was negative. The MY data were collected prospectively from endometritis positive and negative cows for 30-day post-endometritis diagnosis. Compared to cows negative for endometritis, the positive endometritis cows were 2.4 times more (29.7 vs. 70.3%) with daily MY 15.3% lower (7.5 ± 0.2 vs. 8.9 ± 0.3 litres; p<0.05), representing a reduction of 1.4 ± 0.2 litres of milk/cow/day. Of the CLE positive cows, 33.4% (104/311) were treated using different veterinary drugs, which resulted in 23.5% more discarded milk compared (p<0.05) to untreated positive cows. Discarded milk was higher (p<0.05) among cows treated with oxytetracycline (65.9 ± 4.4 litres) compared to cows treated with procaine penicillin G and dihydrostreptomycin (35.5 ± 2.7 litres). The percentage of total milk loss was much higher (45.6%) among CLE positive cows that received treatment compared to the untreated cows (16.3%). These results demonstrate a strong association between MY loss and endometritis. A timely diagnosis and treatment of the disease is recommended using conventional veterinary drugs that have zero withholding time for milk to reduce the MY loss and associated economic loss, estimated at 154 US$ in a lactation.

Effects of endometritis on reproductive performance of zero-grazed dairy cows on smallholder farms in Rwanda.

Endometritis is a prevalent post-partum uterine infection in dairy cows resulting in suboptimal reproductive performance. The hypothesis was that endometritis status is associated with suboptimal reproductive performance of postpartum dairy cows managed under zero-grazing feeding practice on smallholder farms. In this study, there was evaluation of effects of endometritis diagnosed at 38.5 ±â€¯14.7 days postpartum (dpp) on subsequent reproductive performance. Reproductive performance of 436 cows from 345 farms was recorded for 210 dpp. Values for reproductive performance indicators were less (P < 0.05) in cows determined to be positive compared to negative for endometritis. Cows that tested positive, as compared to negative, for endometritis had longer periods after parturition until initiation of oestrous cycles (median, interquartile range; 85.0, 57.5-127.0 and 62.6, 49.0-90.0 days, respectively), longer durations before being detected pregnant (95.5, 61.8-145.5 and 63.0, 50.0-83.0 days, respectively), lesser pregnancy rates as a result of the first breeding postpartum (16.5% and 32.7%, respectively), more natural-mating or artificial inseminations per pregnancy (1.3 ± 0.1 and 1.1 ± 0.0, respectively) and more occurrences of anoestrus postpartum (48.4% and 11.7%, respectively). These results provide evidence of a strong association between endometritis and suboptimal fertility performance in zero-grazed cows on smallholder farms in Rwanda. Considering there were 70.2% of cows in the present study were diagnosed with endometritis, this is indicative of a widespread herd health issue, warranting that field veterinary practitioners prioritise endometritis in their herd health service delivery to smallholder dairy farmers for effective disease management and herd sustainability.

Estimating prevalence of endometritis in smallholder zero-grazed dairy cows in Rwanda.

Endometritis is a postpartum uterine disease of cows that interrupts reproductive cycles resulting in suboptimal fertility, reduced performance and profitability of the dairy herd. The objective of the study was to estimate the perceived and observed prevalence of endometritis among zero-grazed dairy cows in smallholder farms in Rwanda. A snowball sampling method was applied in cross-sectional survey to obtain data from 370 farms on 466 cows within their 21-60 days postpartum (dpp). The survey, conducted from September 2018 to March 2019, simultaneously examined cows using the Metricheck Device (MED) to determine the presence and type of vaginal mucus (VMC) based on a score scale of 0 to 3. Cows scoring VMC ≥ 1 were recorded as clinical endometritis (CLE)-positive. Cytotape (CYT) was used to determine the percentages of polymorphonuclear cells (PMN) in endometrial cytology sample. Cows with ≥ 5% PMN were recorded subclinical endometritis (SCLE)-positive, whereas cows with VMC-0 and < 5% PMN were considered healthy cows. At cow-level, endometritis prevalence was 70.2% with 67.2% CLE and 31.8% SCLE while at the herd-level, prevalence was 71.1% with 68.1% CLE and 34.4% SCLE. The differences between the diagnostic performance of the MED and CYT were significant (p < 0.001). Perceived prevalence by farmers was much lower (3.2%) and without agreement with the observed prevalence (kappa = - 0.02, p > 0.05). The highly observed prevalence and farmer underestimation of endometritis prevalence indicate knowledge gaps about endometritis. The extension service therefore needs to increase awareness and education among smallholder farmers about detection and management of endometritis.

Perception of farmers about endometritis prevention and control measures for zero-grazed dairy cows on smallholder farms in Rwanda.

BACKGROUND: Endometritis is a prevalent uterine disease in postpartum cows. The disease reduces fertility performance and milk yield, and subsequently, productivity and profitability of dairy farms. The reduction in performance is associated with considerable economic losses on dairy farms. Smallholder farmers are likely to incur considerable economic losses from the disease where they lack knowledge of effective prevention and control measures for the disease. This study used farmer's perspectives to determine the effectiveness of different management interventions (MIs) for endometritis prevention and control on smallholder farms in Rwanda practicing dairy zero-grazing. The best-worst scaling (BWS) choice method was applied that relied on past 1 year recall data obtained from 154 farmers. These farmers were identified through snowball sampling in a cross-sectional study. RESULTS: Of the 20 MIs evaluated, 12 scored highly for effectiveness. The top four most effective are: avoiding sharing equipment with neighbouring farms (45.5%), consulting animal health service provider about disease treatment (31.8%), keeping cows in a clean and dry shed (26.7%), and selecting sires based on calving ease (26.6%). The MIs considered least effective were: maintaining clean transition cow housing (35.1%), removal of fetal membrane immediately after passing (33.1%), disinfecting the equipment used in calving assistance before and after use (32.5%), and selecting sires with low percent stillbirths (29.2%). CONCLUSION: This study has demonstrated the application of BWS object case method in understanding the MIs that farmers consider are most effective in the prevention and control of endometritis disease in the dairy herds. The MIs are on-farm biosecurity and hygiene, seeking veterinary services for disease treatment and selecting sires for ease of calving. These MIs should be considered for prioritization in extension services and research to continuously improve and enhance their practical application on smallholder dairy farms.