Characterization of Oestrus Cycles in Namibian Swakara and Damara Sheep through Determination of Circannual Plasma Progesterone Levels

Kandiwa, Erick; Mushonga, Borden; Madzingira, Oscar; Samkange, Alaster; Bishi, Alec S.; Tuaandi, Dolly

doi:10.1155/2019/5320718

Cited by 6 publications

(5 citation statements)

References 19 publications

(27 reference statements)

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“…Studies have often reported that neonatal mortality rates differ between different breeds (Mukasa-Mugerwa et al 2000;Swarnkar et al 2019;Topal et al 2017). The Dorper is a synthetic breed, fashioned through the fusion of two exotic breeds, and the Damara has literally tracked down from North Africa to southern western Africa, over several hundreds of years, from its origins in Asia (Kandiwa et al 2019). According to a number of reports, the Damara has adapted to local disease and production conditions, breeds throughout the year, and has a good mothering ability (Almeida 2011;Kandiwa et al 2019;von Wielligh 2003).…”

Section: Discussionmentioning

confidence: 99%

“…Significantly more winter-born than summer-born Dorper and Swakara lambs weighed below 3 kg than in summer. It is surprising that the majority of Damara lambs were born in winter with weights greater than 3 kg especially when recent reports are pointing out that the breed now breeds equally well throughout the year in the Namibia climate (Kandiwa et al 2019). Earlier reports, however, have conflicting views on the effect of lambing/kidding season on birth weight with some reporting higher birth weights in winter-born lambs (Doaa et al 2009;Fasae et al 2012) and yet others reporting higher birth weights in summer-born lambs (Barzdina and Kairisa 2015;Hagan et al 2014).…”

Section: Discussionmentioning

confidence: 99%

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Production performance of sheep and goat breeds at a farm in a semi-arid region of Namibia

Kandiwa

Nguarambuka

Chitate

et al. 2020

Trop Anim Health Prod

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This study retrospectively investigated the effect of breed and season on the lambing/kidding dynamics, growth performance, neonatal viability, and weaning dynamics of sheep (Damara, Dorper, and Swakara) and goats (Boer goat and Kalahari Red) at a farm in the Khomas Region of Namibia between 2004 and 2015. Litter size was dependent on breed (X 2 (12, N = 3388) = 796, p < 0.001), with twinning more frequent in Dorper sheep and Kalahari Red and Boer goats than in the Damara and Swakara sheep (p < 0.05), while triplets were more prevalent in the Dorper sheep and Kalahari Red goats (2.8% and 1.0%, respectively; p < 0.05). Distribution of birth weight categories was dependent on breed. There was a significant difference in the proportions of birth weight categories between breeds (X 2 (12, N = 3388) = 467, p < 0.001) whereby Dorper lambs were mostly born weighing below 3 kg (2.6%, p < 0.05); Boer goat kids, Kalahari Red kids, and Damara lambs were mostly born weighing 3 to < 4 kg (4.3%, 6.3% and 19.9%, respectively; p < 0.05); Swakara lambs were mostly born weighing 4 to < 5 kg (12.2%, p < 0.05), and Swakara lambs were mostly born weighing ≥ 5 kg (3.3% and 2.3%, respectively, p < 0.05). Weaning age categories were dependent on breed (X 2 (12, N = 3388) = 241, p < 0.001) whereby Dorper lambs were mostly weaned at below 3 months of age (2.8%, p < 0.05); Damara lambs were mostly weaned at 3 to < 5 months of age (12%, p < 0.05), and Boer goat kids were mostly weaned at ≥ 5 months of age (0.9%, p < 0.05). Neonatal viability was dependent on breed (X 2 (8, N = 3388) = 49.2, p < 0.001) whereby Dorper lambs were more susceptible to abortions and neonatal deaths (0.6% and 1.5%, respectively; p < 0.05) than the rest of the breeds. Breed and lambing season interacted to produce effects on the birth weight of offspring although lambing season alone did not have a significant effect on Boer goat and Kalahari Red kids' birth weights.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Production performance of sheep and goat breeds at a farm in a semi-arid region of Namibia

Kandiwa

Nguarambuka

Chitate

et al. 2020

Trop Anim Health Prod

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“…The country’s central highlands receive an annual rainfall of between 300 mm and 400 mm and have an altitude of up to 1900 m (Kandiwa et al 2017 ). The vegetation is predominantly shrub-veld and ambient temperatures range from 7 °C in winter to 33 °C in summer (Kandiwa et al 2019 ). The Khomas region has about 556 farming establishments, with approximately 44 000 primarily commercial beef cattle (Directorate of Veterinary Services 2018 ).…”

Section: Methodsmentioning

confidence: 99%

Seroprevalence and associated risk factors of bovine neosporosis in the Khomas region of Namibia

Samkange

Chitanga

Tjipura-Zaire³

et al. 2023

Onderstepoort j. vet. res.

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Neospora caninum is a coccidian parasite that occurs worldwide and is one of the most important causes of abortion, especially in cattle. However, no studies have been performed in Namibia to determine the N. caninum status in livestock. Therefore, this study aimed to determine the seroprevalence of N. caninum in cattle and the associated risk factors in the Khomas region of Namibia. A total of 736 sera were collected from cows in 32 farming establishments. These comprised 698 beef and 38 dairy cattle sera and were tested using a commercial enzyme-linked immunosorbent assay (ELISA) kit. Questionnaires were concurrently administered to determine possible risk factors associated with N. caninum seropositivity. A total of 42 sera were positive (all beef), giving an animal-level seroprevalence rate of 5.7%. Eight of the 32 establishments had at least one positive animal, giving a herd-level seroprevalence of 25%. There was no significant association between seropositivity and the presence of dogs, jackals, history of abortions, farm size, number of cattle or average annual rainfall. The establishments with moderate to high numbers of Feliformia were 9.8 times more likely to be seropositive to N. caninum than those with none to low levels of the former (p = 0.0245). The authors concluded that the seroprevalence level of N. caninum in the Khomas region was relatively low compared with other parts of the world and that the role of Feliformia in the epidemiology of bovine neosporosis needed to be further investigated.Contribution: Serological evidence of bovine neosporosis and the associated risk factors are reported in Namibia for the first time. This study contributes to the scientific body of knowledge on N. caninum in Africa, which is currently limited.

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“…The country's central highlands receive an annual rainfall of between 300mm and 400mm and have an altitude of up to 1900 metres (Kandiwa et al, 2017). The vegetation is predominantly shrub-veld, and ambient temperatures range from 7 o C in winter and up to 33 o C in summer (Kandiwa et al, 2019). The Khomas region has approximately 560 livestock farming units, mainly commercial and some resettlement farms and communal settlements (Directorate of Veterinary Services, 2018).…”

Section: Study Areamentioning

confidence: 99%

Seroprevalence and associated risk factors for Toxoplasma gondii infection of goats and sheep in the Khomas region of Namibia

Samkange,

Chitanga,

Tjipura-Zaire

et al. 2023

Journal of the South African Veterinary Association

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This study aimed to determine the seroprevalence levels of T. gondii in small ruminants (goats and sheep) and the associated risk factors in the Khomas region of Namibia. A total of 299 and 345 sheep and goat sera, respectively, were collected from 22 farming establishments. An IDEXX Toxotest Ab®, a commercial ELISA kit, was used to test for IgG antibodies to T.gondii. Overall, 3.68% (11/299) of the sheep sera were positive, and 61.54% (8/13) of the sheep ocks tested had at least one positive animal. Only 0.29% (1/345) of the goat sera were positive, and only one of the 19 goat ocks had at least one positive animal giving a herd-level prevalence of 5.26%. Sheep ocks had signi cantly greater animallevel and ock-level prevalences than goats (p < 0.05) and were 13.14 times more likely to be seropositive (OR = 13.14; CI 95%: 1.686-102.382) than goat ocks. A questionnaire was also administered to identify any putative risk factors associated with seropositive cases. Eight risk factors were evaluated, including the total number of goats, total number of sheep, farm size, average rainfall, level of Feliformia, history of abortions and the presence of domesticated cats and strays. Seropositivity to T. gondii was positively associated with the total number of sheep at the farming establishment, history of abortions and farm size (p < 0.05), but not goats. The study concluded that sheep were probably more susceptible to toxoplasmosis than goats and that the T. gondii seroprevalence level in the Khomas region was very low compared to other countries.

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Characterization of Oestrus Cycles in Namibian Swakara and Damara Sheep through Determination of Circannual Plasma Progesterone Levels

Cited by 6 publications

References 19 publications

Production performance of sheep and goat breeds at a farm in a semi-arid region of Namibia

Production performance of sheep and goat breeds at a farm in a semi-arid region of Namibia

Seroprevalence and associated risk factors of bovine neosporosis in the Khomas region of Namibia

Seroprevalence and associated risk factors for Toxoplasma gondii infection of goats and sheep in the Khomas region of Namibia

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