Effect of heterologous seminal plasma and semen extenders on motility of frozen-thawed ram sperm

Frozen-thawed ram semen crosses the cervix poorly, necessitating laparoscopic insemination. Acceptable fertility can be achieved with frozenthawed ram semen deposited at the external cervical opening if ram seminal plasma is added. Homologous seminal plasma improves the fertility of frozen-thawed sperm of boars and dogs. Heterologous seminal plasma may have effects as well; the addition of bovine seminal plasma increases the ability of buffalo sperm (Syncerus caffer) to fertilize bovine oocytes in vitro. The aim of the current study was to compare the effects of seminal plasma of rams and bulls, dog prostatic fluid, protein-free TALP, TrilEq (Triladyl with 0.5 ml of Equex STM paste added to each 100 ml) and skim milk upon longevity and percentages of progressively and aberrantly motile frozenthawed ram sperm. Three ejaculates from each of 6 rams (2 Dorpers, 2 Döhne merinos, and 2 merinos), aged 2 to 4 years, were extended in TrilEq, pooled and frozen as a single batch per ram at 200 × 106/ml in 0.25 ml straws. Seminal plasma of rams was obtained from the same rams, while seminal plasma of five bulls were obtained by centrifugation of their ejaculates and dog prostatic fluid consisted of the post-sperm fractions of the ejaculates of 5 dogs. Within a 10 species, the seminal plasma or prostatic fluid from different donors was pooled and frozen in aliquots at −18 °C. The 108 straws (6 rams, 6 diluents, 3 replicates) were thawed in random order. Once thawed, a straw was emptied into a tube with 0.85 ml of the appropriate medium at 37 °C and kept at that temperature for 6 h. The percentage of progressively motile sperm was estimated at ×200 magnification immediately (time zero) and 2, 4 and 6 h after thawing. One person thawed the semen and prepared motility specimens, while another performed all motility evaluations. Data were evaluated by means of repeated-measures ANOVA, with rams as subjects and time and medium as fixed effects. Non-significant interactions were removed from the model. Pairwise comparison of means was done by means of Bonferroni's test (P < 0.05). The model included Ram, Time, Medium, and Ram × Medium, and Time × Medium interactions, which were all significant (P < 0.01). Mean progressive motility decreased from each time to the next and were 39.0% (0 h), 26.0% (2 h), 19.6% (4 h) and 12.6% (6 h); SEM 1.38%, n = 108. Mean motility was higher for skim milk (39.9%) than for all other media except TrilEq (27.7%), which was better than bull seminal plasma (13.0%), whereas TALP (20.5%) and ram seminal plasma (21.9%) were similar to TrilEq and bull seminal plasma (SEM 2.85%, n = 72). The interactions (Ram × Medium or Time × Medium) were mainly due to dog prostatic fluid, ram seminal plasma, TrilEq, and TALP, while milk resulted in the best and bull seminal plasma in the lowest motility. This study shows that heat-treated skim milk maintains progressive motility of frozen-thawed ram sperm better than dog prostatic fluid and seminal plasma of bulls and rams, TrilEq and protein-free TALP. In contrast to ram seminal plasma, skim milk is known to result in poor fertility of frozenthawed ram semen after cervical insemination. It would thus appear that maintenance of progressive motility in vitro may be a poor indicator of fertility after cervical insemination.Dissertation (MSc (Veterinary Science))--University of Pretoria, 2006.Production Animal StudiesMScunrestricte

Smallholder Goat Production in Southern Africa: A Review

Goats play a crucial role in improved livelihoods and food security in Africa. Indigenous and locally developed types exhibit a wide range of phenotypic diversity, but are commonly well adapted to the harsh environment in which they need to survive and produce. They have various functions in communities in developing countries, from providing food security to being a liquid form of cash and playing a role in ceremonial occasions. The Southern African goat population exceeds 35 million animals, most of which are kept in small-scale traditional production systems in communal areas. These traditional production systems are characterised by informal, lowly-skilled labour, small numbers of animals and limited resources. Most goats are part of mixed crop-livestock systems, where different livestock species and crop farming compliment one another. The productivity and offtake from these animals are relatively low. Some goats form part of agropastoral production systems, with marginally higher management and resource inputs. Both of these systems are dependent on a high degree of variability where the keepers/farmers can exploit various resources as and when necessary. Goats possess a range of adaptive mechanisms that enable them to deal with harsh and challenging environments, making them the ideal species for use in these production systems. This chapter aims to provide background information on the current smallholder management practices of goat keepers in Southern Africa

The use of moringa oleifera and leucaena leucocephala tree leaves to improve smallholder goat production in Mozambique

This study investigated the potential benefit of introducing Moringa oleifera (MO) and Leucaena leucocephala (LL) leaves as supplementary feed resource for indigenous goats feeding systems in southern Mozambique. The study started with a description of smallholder goat production systems in three resource-poor districts of Mozambique and subsequently investigated the variation and seasonal fluctuations of natural fodder quality in the Changalane district throughout a year period. Thereafter, the effect of tree forage supplementation on growth and reproductive performance of Landim goats were evaluated by simulating a typical feeding system used in the study area. In study one, a survey was conducted in three villages to collect data on indigenous goats and in smallholder husbandry practices in terms of feeding, health and reproduction management. Information from 45-smallholder goat keepers were recorded using a survey, which was complemented by interviews. Results showed that goats were raised under extensive systems, under free grazing. Tethering was a common management practice, with limited supplementation during the dry season. In general, during the dry season the natural pasture were scarcity and poor in quality and consequently does not sustained the energy and protein requirements of ruminants for maintenance and other functions. In study two, the eight key species that were consumed by the goats (namely Sclerocarya birrea, Spirostachys africana, Dichrostachys cinerea, Flueggea virosa, Acacia nigrescens, Acacia nilotica, Panicum maximum and Morus alba) were collected and analysed. Daily energy intake (4.27 ± 0.17 MJ/kg DM vs 3.71 ± 0.41 MJ/kg DM) and crude protein (CP) intake (92.83 ± 16.05 g DM/head/day vs. 59.38 ± 13.12 g DM/head/day) were higher in the rainy season than in the dry season. Daily intake of calcium and phosphorus did not show significant seasonal variations and were below the requirements levels for maintenance of a 20 kg bodyweight goat during the dry season and for the pregnant goat during both seasons. These results showed a need to supplement goats with energy, protein and phosphorus for maintenance, growth and reproduction during the dry season. In study three, the impact of supplementation with LL and MO on the growth and reproduction performance of indigenous goats were evaluated. Fifty-six goats were randomly divided into seven groups, with four castrated males and four females in each group. One group was used as the control group (animals grazing on natural veld without any supplementation), while first three groups were fed with LL and the other three groups with MO tree leaves, respectively. Compared to the control group, both treatments had a significant effect, irrespective of the level of supplementation in terms of overall body weight gain and the final body weight of the bucks. All female reproduction parameters measured for the supplemented groups were superior when compared to the control group. Findings of this study suggest the benefit of using LL and MO tree leaves as supplement for Mozambican goats to overcome the adverse effects of seasonal fluctuations in feed quality on their growth and reproductive performance.Thesis (PhD)--University of Pretoria, 2019.Animal and Wildlife SciencesPhDUnrestricte