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Conception rates and calving intervals of different beef breeds at a farm in the semi-arid region of Namibia. Trop Anim Health Prod 2019; 51:1829-1837. [PMID: 30963402 DOI: 10.1007/s11250-019-01876-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 03/22/2019] [Indexed: 10/27/2022]
Abstract
A retrospective study from 2004 to 2017 investigated the effect of bull age, cow age and breed on conception rates, and calving intervals of beef cattle at Neudamm farm, Khomas region, Namibia. Bulls ranging from 4 to 14 years of age were used to breed cows up to 17 years of age. A total of 1804 pregnancies were diagnosed in Afrikaner (81.8%), Nguni (14.1%), and Simmental (4.1%) cows. The overall conception rate of beef cattle during the study period was 71.7 ± 9.5%. The overall conception rate of the Nguni cows (78.3%) was significantly higher than that of the Afrikaner (70.9%) and the Simmental cows (64.9%) (p < 0.05). The age of sires had no effect on overall conception rate in all three breeds (p > 0.05). Afrikaner dams more than 10 years old had the least rate of conception (60.4%, p < 0.05) within that breed category. Nguni dams between four to 10 years had the greatest conception rate (86.5%, p < 0.05). Age of dams had no effect on conception rates in Simmental cattle (p > 0.05). The overall mean length of all calving intervals in the Nguni cows (366 ± 35 days) was significantly shorter than those of the Afrikaner cows (487 ± 62 days) and the Simmental cows (484 ± 110 days) (p < 0.05). The 2013 breeding season produced the highest overall conception rates (~ 85%), and the 2007 breeding season produced the lowest overall conception rate (~ 51%). From a fertility point of view, the Nguni breed seemed best suited for the semi-arid conditions which are prevalent in most of Namibia.
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Mushonga B, Habumugisha D, Kandiwa E, Madzingira O, Samkange A, Segwagwe BE, Jaja IF. Prevalence of Haemonchus contortus Infections in Sheep and Goats in Nyagatare District, Rwanda. J Vet Med 2018; 2018:3602081. [PMID: 30271791 PMCID: PMC6146870 DOI: 10.1155/2018/3602081] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 08/27/2018] [Indexed: 11/18/2022] Open
Abstract
This study investigated the overall prevalence of Haemonchus contortus infection in sheep and goats from five purposively selected subdivisions (sectors) of Nyagatare district from January to December 2014, after a high prevalence of gastrointestinal parasites and generalized poor productivity was reported in small ruminants in some districts of Rwanda. Faecal egg counts (FEC) were performed using the Modified Wisconsin Sugar Floatation method and the Fluorescent-labeled peanut-lectin agglutination test while enumerations, as log (FEC), were done using the modified McMaster method. The overall prevalence of H. contortus infection in sheep and goats was 75.7% (n=949). The overall prevalence of H. contortus infection in sheep (83.4%, n=314) was higher than in goats (71.8%, n=635) (Odds Ratio [OR] 1.98, 95% Confidence Interval [CI]: 1.40-2.79, and p≤0.001). The prevalence of H. contortus infection in female goats (74.2%) was higher than in male goats (64.3%) (OR 1.60, 95% CI: 1.09-2.36, and p=0.01). The prevalence of H. contortus infection in goats from Nyagatare was higher than in goats from Matimba (OR 3.25, 95% CI: 1.76-5.99, and p≤0.001) and from Katabagemu (OR 3.67, 95% CI: 2.04-6.59, and p≤0.001). The prevalence of H. contortus infection in goats from Karangazi was higher than in goats from Matimba (OR 4.72, 95% CI: 2.40-9.28, and p≤0.001). The overall mean monthly log (FEC) for H. contortus in sheep and goats were highest in April (18.9±0.2 and 14.05±0.1, respectively) and October (19.25± 0.2 and 13.75±0.1, respectively). Though, overall, sheep in Nyagatare district were at greater risk of H. contortus infection and goats from Nyagatare and Karangazi sectors were paradoxically at greater risk of H. contortus infection. It was also apparent that young female goats were at greater risk of H. contortus infection than young male goats. H. contortus infection is endemic in small ruminants in Nyagatare district and possibly other districts in Rwanda. Targeted selective treatment (TST) using FAMACHA with emphasis on low-lying swampy pastures and appropriate anthelmintic drugs may be the most economically viable solution in the short term. In the long term breeding of H. contortus resistant small ruminants and strategic grazing using the concept of refugia may bring about considerable relief from H. contortus infection in Nyagatare district, in particular, and Rwanda at large.
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Affiliation(s)
- Borden Mushonga
- School of Veterinary Medicine, Faculty of Agriculture and Natural Resources, University of Namibia, P. Bag 13301, Pioneerspark, Windhoek, Namibia
| | - Dismas Habumugisha
- School of Animal Sciences and Veterinary Medicine, College of Agriculture, Environment and Veterinary Medicine, University of Rwanda, P.O. Box 57 Nyagatare, Rwanda
| | - Erick Kandiwa
- School of Veterinary Medicine, Faculty of Agriculture and Natural Resources, University of Namibia, P. Bag 13301, Pioneerspark, Windhoek, Namibia
| | - Oscar Madzingira
- School of Veterinary Medicine, Faculty of Agriculture and Natural Resources, University of Namibia, P. Bag 13301, Pioneerspark, Windhoek, Namibia
| | - Alaster Samkange
- School of Veterinary Medicine, Faculty of Agriculture and Natural Resources, University of Namibia, P. Bag 13301, Pioneerspark, Windhoek, Namibia
| | - Basiamisi Ernest Segwagwe
- Department of Biomedical Sciences, Faculty of Medicine, University of Botswana, P. Bag UB0074, Gaborone, Botswana
| | - Ishmael Festus Jaja
- Department of Livestock and Pasture Science, University of Fort Hare, P. Bag X1314, Alice, South Africa
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