The demand to conserve indigenous species through the cryo-gene bank is increasing. Spermatozoa remain sensitive to cryopreservation damages especially that of avian species thus limiting the use of reproductive biotechnologies such as artificial insemination in the conservation programs. Long-chain polyunsaturated fatty acid (LCPUFAs), specifically omega n-3, expanded a research interest to improve animal reproductive efficiency through improving spermatozoa quality. This is driven by the fact that mammals cannot synthesize omega-3 de-novo because they lack delta-12 and delta-15 desaturase enzymes thus supplemented in the diet is mandatory. Delta-12 and delta-15 add a double bond at the 12th and 15th carbon-carbon bond from the methyl end of fatty acids, lengthening the chain to 22 carbon molecules. Fish oil is a pioneer source of omega n-3 and n-6 fatty acids. However, there is a report that numerous fisheries are over-exploited and could collapse. Furthermore, processing techniques used for processing by-products could complement alterations of the amino acid profile and reduce protein retrieval. Alternatively, flaxseed oil contains ±52–58% of total fatty acids and lignans in the form of α-linolenic and linoleic acid. Alpha-linolenic acid (ALA,18:3n-3) is enzymatically broken-down de-novo by delta-6 desaturase and lengthened into a long-chain carbon molecule such as eicosapentaenoic acid (C20:5n-3). Nevertheless, controversial findings following the enrichment of diet with flaxseed oil have been reported. Therefore, this paper is aimed to postulate the role of flaxseed oil as an alternative source of omega n-3 and n-6 fatty acids to improve semen quality and quantity from livestock animals. These include the interaction between docosahexaenoic acid (DHA) and spermatogenesis, the interaction between docosahexaenoic acid (DHA) and testicular cells, and the effect of flaxseed oil on semen quality. It additionally assesses the antioxidants to balance the level of PUFAs in the semen.

South African indigenous breeds’ population is decreasing at a time when their genetic material is mandatory due to the rising climate change and global warming. South African indigenous sheep breeds include Namaqua Afrikaner, Zulu, BaPedi, and Damara sheep. These breeds are the most preferred breeds by rural farmers in South Africa due to their adaptability, low feed, and veterinary requirements. However, since they are characterized by small body sizes, farmers tend to crossbreed them with exotic breeds. An early survey conducted in Kwa-Zulu Natal revealed a 7.5% decline in Zulu sheep between 2008–2011. It has recently been observed that the population left is genotypically mixed with exotic genetic material due to uncontrolled breeding techniques that rural farmers apply. Therefore, the aim of this review is to address the present status, difficulties, and conservation approaches applied to save these breeds. However, this review will be limited to the current extinction status as it appears in the Food and Agriculture Organization (FAO) system, data from recent studies, difficulties limiting the conservation success of these breeds, and the current conservation approaches in use to conserve these breeds.

South Africa recognizes the value of indigenous breeds such as Potchefstroom Koekoek, Boschveld, Ovambo, Venda, Naked Neck, and nondescript village chickens. Indigenous chickens support sustainable food systems, improve nutrition, and enhance livelihoods in rural communities, thereby contributing to the United Nations’ Sustainable Development Goal (SDG) 2 on Zero Hunger. These breeds are not only vital to rural farmers for food production, income generation, and subsistence but also provide rural farmers with cheap nutritious protein such as eggs and meat for household consumption. Moreover, they are preferred by rural farmers because they are relatively affordable to produce, can withstand harsh environmental conditions amid accelerated climate change compared to exotic breeds, and require less/no feed supplementation. However, despite the numerous advantages of keeping these chickens, it has been found that they are mostly in danger of extinction due to evolving production methods that favor exotic breeds. Therefore, understanding their extinction status, different implications for conserving their genetic material, challenges encountered, and future approaches to rescue these breeds remain vital. Hence, the aim of this systematic review was to assess the extinction status, challenges, and conservation approaches for these breeds. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were utilized to search for suitable articles addressing the objective of the current review. Research articles were grouped and evaluated for eligibility, and the data from the Domestic Animal Diversity Information System database were used. Records such as duplicates of studies addressing origins, phenotypic and genetic diversity, the conservation of indigenous chickens, semen cryopreservation of indigenous chickens, climate change effects on indigenous chickens, and the use of extenders with exotic chickens and other chicken types, reports in other languages, and reports that were inaccessible were excluded. Articles addressing origins, phenotypic and genetic diversity, the conservation of indigenous chickens, semen cryopreservation of indigenous chickens, climate change effects on indigenous chickens, and the use of extenders with indigenous chickens were included in this review. The keywords used to search articles online were as follows: South African indigenous chicken; extension status; conservation; genetic resources; genetic markers; effective population size; inbreeding; and characterization. This systematic review found that there is less information in the Domestic Animal Diversity Information System regarding South African indigenous and village chickens, suggesting a lack of reporting in this system. Moreover, our review confirmed that most South African indigenous chickens are threatened and, hence, require interventions such as assisted reproductive technologies and other strategies in order to improve efficiency.

The subtropics are affected by severe climate change, which may induce heat stress in animals. Moreover, the region is significantly seasonal; hence, mitigating climate risks and implementing climate adaptation measures are necessary. Sustainable Development Goals 1, 2, and 13 call for no poverty, zero hunger, and climate action. These are the most severe problems affecting food security in the modern world. Food security refers to a situation in which all people have physical, social, and economic access to sufficient, proper, and healthy food that satisfies their dietary requirements. Nevertheless, the projected increase in the human population implies a greater demand for employment opportunities; hence, developing countries are building more industrial areas. The burning of fossil fuels in various industries potentiates climate change and environmental pollution. It is predicted that the ecological temperature will increase by almost 2.3–4.8 °C by 2100 due to climate change. Agriculture and animal products remain vital in Africa as drivers of the economy and transformation for sustainable livelihood and development. Sheep production has long been used as a source of income and livelihood and provides jobs for people who live in rural areas. It is also sometimes used for ritual ceremonies and to pay penalties to local authorities. Nevertheless, sheep have been identified to be sensitive to heat stress, characterized by low reproductive performance, low microbiota quantities, and poor general health. There are different strategies for mitigating heat stress; however, many smallholder farmers have limited access to education and lack the financial support required to incorporate artificial shade and plant trees for shade to limit heat stress. In this review, we aim to understand the effects of environmental heat stress on sheep production and reproductive performance. Based on this review, it can be concluded that heat stress can threaten food security if not addressed, especially for farmers who depend on sheep rearing. As a result, future studies are recommended to understand different adaptation methods that can be used to mitigate the heat stress effect on sheep productivity, reproductivity, and general health.

The current study aimed to evaluate the effects of the dietary inclusion of flaxseed oil and ascorbic acid on the reproductive performance of South African indigenous sheep (Ovis aries). Twenty-two matured South African indigenous rams (eight BaPedi, nine Zulu, and five Namaqua Afrikaner; age of 6 years and body weight of 64.4 ± 1.6 kg) were randomly assigned into five treatment groups (NC (standard diet), PC (basal diet), FO (5% flaxseed oil), AA (4% ascorbic acid), and FO + AA (5% flaxseed oil + 4% ascorbic acid)). Semen samples were collected during the natural breeding season using an artificial vagina. Semen samples were evaluated for macroscopic (semen volume, pH, and sperm concentration) and microscopic (morphology, malondialdehyde, membrane permeability, and sperm cell motility parameters) characteristics. Eighty-one South African indigenous ewes were synchronized using controlled intravaginal drug devices impregnated with 0.3 g progesterone for 10 days and then injected with 300 IU of Pregnant Mare Serum Gonadotropin. These ewes were then hand-mated. The data were subjected to the General Linear Model (GLM) in Minitub^® 2017. A cross-tabulated Chi-Squared (χ²) test was used to track the frequencies of the conception rate. Treatment means were separated using Student’s Least Significant Difference (LSD) and considered significantly different when the p-value was less than 0.05. No considerable breed effect was observed for semen volume, semen pH, sperm concentration, intact membrane, and non-intact membrane. FO + AA led to higher semen volume (1.05 ± 0.06 mL), intact sperm membranes (88.83 ± 1.27%), and low malondialdehyde levels (0.37 ± 0.04 nmol/mL) in comparison to other treatment groups. Total sperm motility was higher in FO + AA (95.81 ± 0.80%) compared to FO, AA, PC, and NC. The conception rate was higher in FO (94%), AA (94%), and FO + AA (100%) when compared to NC (71%) and PC (79%). The testosterone concentration did not differ among PC, FO, AA, and FO + AA. It was concluded that the inclusion of 5% flaxseed oil (FO and FO + AA) improves both the semen quality and the conception rate of South African indigenous sheep.

South Africa is home to numerous indigenous and locally developed sheep (Nguni Pedi, Zulu, and Namaqua Afrikaner, Afrino, Africander, Bezuidenhout Africander, Damara, Dorper, Döhne Merino, Meat Master, South African Merino, South African Mutton Merino, Van Rooy, and Dorper), goat (SA veld, Tankwa, Imbuzi, Bantu, Boer, and Savanna) and cattle (Afrigus, Afrikaner, Bolowana, Bonsmara, Bovelder, Drakensberger, South African Angus, South African Dairy Swiss, South African Friesland, South African Red, and Veld Master) animals. These breeds require less veterinary service, feed, management efforts, provide income to rural and or poor owners. However, most of them are under extinction risks and some with unknown status hence, require immediate conservation intervention. To allow faster genetic progress on the endangered animals, it is important to generate productive animals while reducing wastages and this can be achieved through sex-sorted semen. Therefore, this systematic review is aimed to evaluate the prospects of X and Y-sexed semen in ruminant livestock and some solutions that can be used to address poor sex-sorted semen and its fertility. This review was incorporated through gathering and assessing relevant articles and through the data from the DAD-IS database. The keywords that were used to search articles online were pre-gender selection, indigenous ecotypes, fertility, flow cytometry, artificial insemination, conservation, and improving sexed semen. Following a careful review of all articles, PRISMA guidelines were used to find the articles that are suitable to address the aim of this review. Sex-sorted semen is a recently introduced technology gaining more attention from researchers particularly, in the conservation programs. Preselection of semen based on the sex chromosomes (X- and or Y-bearing chromosomes) is of paramount importance to obtain desired sex of the offspring and avoid animal wastage as much as possible. However, diverse factors can affect quality of semen of different animal species especially after sex-sorting. Flow cytometry is a common method used to select male and female sperm cells and discard dead and abnormal sperm cells during the process. Thus, sperm sexing is a good advanced reproductive technology (ART) however, it is associated with the production of oxidative stress (OS) and DNA fragmentation (SDF). These findings, therefore, necessitates more innovation studies to come up with a sexing technology that will protect sperm cell injuries during sorting in frozen-thawed.