L M J Schwalbach's research while affiliated with University of the Free State and other places

Publications (43)

Article
The cryopreservation process is one of the most crucial factors that affect the post-thaw quality of frozen goat semen. The aim of this study was to compare 4 different semen diluents (Tris-BSA, Tris-yolk, Bioxcell(®), and Ovixcell(®)). A total of 5 indigenous bucks were used as semen donors. Semen was evaluated for macroscopic and microscopic char...
Article
Growth and carcass characteristics of lambs fed diets containing sun-dried and coarsely ground cactus pear (Opuntia ficus-indica 'Algerian') cladodes, supplemented with different nitrogen sources, were evaluated. Forty-five young Dorper wether lambs (weighing ± 22 kg) were randomly allocated to three diets; the 15 lambs per diet were subdivided in...
Article
The effect of anabolic steroid treatment on young Boer goat bucks (12 months of age; mean body weight of 47.0 ± 3.8 kg) was investigated. Bucks were individually housed and randomly allocated to two treatment groups and fed a pelleted maintenance diet (8.5 MJ ME/kg and 13% CP). Bucks in the first group (n = 9) received a weekly i.m. injection of 25...
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Low lifetime rearing success and high perinatal mortality of lambs have been associated with small pelvic areas in ewes. It would therefore make sense to include pelvic area as a criterium for selecting breeding ewes; however, measuring it in vivo poses some challenges. The aim of this study was to determine pelvic height, width and area and to est...
Article
The effects of incremental levels (0, 24 and 36%) of sun-dried and coarsely ground Opuntia cladodes in balanced diets on feed and water intake and excretion of urine and faeces were investigated. Nine Dorper wethers (mean live weight 45.3 ± 1.9 kg) were stratified according to body weight in three treatment groups and a diet randomly allocated to e...
Article
In an attempt to optimize germplasm and reproduction biotechnology IVF laboratory conditions in South Africa, we compared the effects of 2 triple-gas incubation systems, a tri-gas thermo incubator and a modular chamber with premixed gas, on the development of bovine embryos in vitro. After aspirating ovaries collected from a local abattoir, 778 ooc...
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The aim of this trial was to assess post-partum ovarian activity of the does of two South African goat breeds from their serum progesterone concentrations. Between seven and 100 days post-partum, does from the Boer goat breed and an indigenous rural goat type were allocated to two nutritional treatments within breed. One group per breed received a...
Article
The role of the amino acid 3-methylhistidine as an indicator of protein breakdown and weight loss is often suggested. Despite existing information for other animal species, little is known about the actual levels of 3-methyhistidine in the serum of less studied domestic species such as the goat. We have evaluated the 3-methyhistidine serum concentr...
Article
The aim of this study was to evaluate the ovarian response and embryo recovery rates in Boer goat does superovulated with pFSH following a pre-treatment with a GnRH agonist (GnRHa) outside the natural breeding season. Oestrus was synchronised in 22 does with CIDR's for 17 days, and these were superovulated with a total dose of 200 mg pFSH/doe admin...
Article
The aim of the work was to determine the effects of feeding winter veld hay plus a supplement on scrotal, testicular and semen characteristics in young Boer goat bucks. Fifteen Boer goat bucks (6–8 months of age), were allocated to two groups and fed ad libitum for a period of 29 days. The WH group (winter hay or control group; n=8) received a chop...
Article
A total of 32 Horro (Bos indicus) bulls, with an average initial body weight and age of approximately 211 kg and 6 years were evaluated. The bulls were divided into two treatment groups. One group was given a supplementary concentrate at a rate of 1.5 kg/day and the second group served as the control and received no supplementation. The observation...
Article
Fifteen Boer goat bucks, (6–8 months old), were allocated into two groups and fed ad libitum for a period of 29 days. The WH group (winter hay; n = 8) received a chopped diet consisting of grass hay, predominantly Themeda trianda grass (cut during the winter) from a natural pasture (veld). The WH+S group (winter hay plus supplement; n = 7) received...
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In general ram semen does not cryopreserve acceptably in terms of post-thawed survival and fertilization. In South Africa it is common to feed high energy diets to breeding rams in performance testing schemes and in preparation for shows and sales, as conditioned (fat) rams often realize better prices. Anecdotal evidence suggests that high energy d...
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The aim of the study was to monitor the physiological changes in plasma free amino acid profiles in Boer goats under nutritional restriction. Fifteen Boer goat bucks were allocated to two experimental groups: CG (control), fed Themeda trianda hay, supplemented with maize, molasses and urea ad libitum; and RG (restricted feeding) fed the same hay (8...
Article
A trial was conducted to evaluate the effect of pre-treatment with a GnRH agonist (GnRHa) on the superovulatory response in Boer goats during the natural breeding season. Twenty-one does were synchronised with CIDR's for 17 days and superovulated with a total dose of 200 mg FSH/doe, administered i.m. in seven dosages, at 12 h intervals, starting 48...
Article
The reproductive performance following oestrous synchronisation and artificial insemination (AI) was evaluated during the natural breeding season (autumn) in 90 indigenous (Boer and Nguni) South African goats. All does were synchronised for 16 days with medroxyprogesterone acetate (MAP) followed by an IM injection of 300 IU PMSG at progestagen with...
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In this study the serum testosterone levels of 177 Dorper rams participating in the Free State ram performance testing scheme were determined and correlated to certain phenotypic traits, body measurements and growth performance. All rams were managed extensively on natural pastures. Serum testosterone levels showed a positive correlation (P < 0.05)...
Article
An oestrous synchronization study was conducted on 202 Dorper ewes kept under extensive veld conditions of South Africa, during the transition period from the natural breeding to the anoestrus season. Two types of intravaginal progestagen sponges, namely MAP (60mg) (n=102) and FGA (40mg) (n=100), three times of PMSG administration relative to spong...
Article
The aim of the work was to determine serum free amino acid and myofibrillar protein profiles in Boer goats following undernutrition in order to study the physiological consequences of undernutrition in this goat breed. Fifteen Boer goat bucks were allocated to two experimental groups: CG (control group), fed ad libitum Themeda trianda hay, suppleme...
Article
The aim of the study was to investigate the milk potential of Boer goat and South African local Indigenous goat does, under intensive and extensive nutritional regimes. Thirty-six Multiparous does (18 Boer and 18 Indigenous) were allocated to intensive (complete diet) and extensive (natural pastures) environmental groups, following kidding. Does we...
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In this study, the influence of two feeding regimes on certain reproductive characteristics of young Dorper rams was investigated. Thirty-two Dorper rams were divided into two homogeneous groups. Rams in the first group (n=16), 472.5±8.0 days old were fed ad libitum intensively on a diet (9.5MJME/kgDM and 12.5% protein) for 7 weeks, while the secon...
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Se realizó un estudio para establecer los coeficientes de correlación entre 5 proteínas miofibrilares: Miosina de cadenas largas (MHC), Actina, Proteína C, ??Actinina y Tropomyosina + Troponina T. Quince cabritos Boer se dividieron en dos grupos, uno subalimentado (RG; n= 8) que consumió heno de invierno de Themeda trianda y grupo control (C; n= 7)...
Article
A study with the aim of developing a protocol for the successful cryopreservation and thawing of African lion (Panthera leo) sperm was conducted. Semen from six chemically immobilized adult lion males was collected by electro-ejaculation and frozen using Biladyl and glycerol or dimethyl sulfoxide (DMSO) cryoprotectants at 4 and 8%. Five months afte...
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A study with the aim of evaluating the reversibility of the nutritionally induced changes in the scrotal and testicular characteristics of young rams was conducted. Thirty-six Dorper rams, 11 to 12 months of age were randomly divided into three groups of 12 rams each and fed at different energy levels for 127 days. At the end of this period, half o...
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A study with the aim to evaluate the effects of different dietary energy concentration (8.23, 9.77 and 11.32 MJ ME/kg DM) on scrotal, testicular and semen characteristics of young Dorper rams was conducted during the breeding season. Thirty-six 11-12 month old Dorper rams were randomly allocated to three groups of 12 rams each and fed at different...
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A trial was conducted to determine the effect of egg-weight on the hatchability and growth performance of chickens. Large and medium eggs of New Hampshire (NH) and Rhode Island Red (RIR) hens were grouped in four categories, according to their weight and breed. Twenty-seven eggs from each group namely, New Hampshire-Large (NH-L), New Hampshire-Medi...
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The effects of weaning calves at 180 days (early weaning – EW) or at 240 (control – CW) days following restricted suckling (RS) or unrestricted suckling (US) on the post-partum reproductive performance of cows and calf growth rates were investigated using 40 cow-calf pairs of Ngaoundere Gudali zebu cattle in Cameroon. Uterine involution, oestrous a...
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The objective of this study was to test the efficacy of Gardner’s Sequential Medium on in vitro embryo production in lions. Three young (3–4 yr) nulliparous lionesses were treated with a total of 50 IU purified porcine FSH (Sioux Biochemical, Sioux Center, IA) in a decreasing regimen over 4 days. At 80 h, they were chemically immobilized with a com...
Article
The aim of this study was the determination of muscle and plasma profiles of free fatty acids and of triacylglycerols incorporated fatty acids in fed and underfed Boer goat bucks. This trial with 15 Boer goat bucks weighting 28 Kg had a duration of 30 days during which the 2 distinctive groups of animals were organised (control group—C—fed ad libit...
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The aim of this experiment was to evaluate the efficacy of Neem seed extract (10% water solution) for tick control in goats in the Kilimanjaro area of Tanzania. Eighteen Small East African (SEA) and Toggenburg (TB) female goat kids between 2.5 and 4 months of age were used in the trial. Goats were divided into two similar groups according to age, b...
Article
Quince machos cabríos de raza Boer se distribuyeron en dos lotes: WH (n=8) que consumió heno picado de Themeda trianda y WH+S que consumió lo mismo suplementado con maíz, melaza y urea. El lote WH+S alcanzó mayor peso vivo y mayor ingesta acumulada que el lote WH. La composición de la canal fue similar. Las canales del lote WH presentaron mayor por...
Article
The efficiency of medroxyprogesterone acetate (MAP), fluorogestone acetate (FGA) sponges and controlled internal drug release (CIDR) devices for synchronising oestrus in goats was evaluated during the natural breeding season. Ninety does (42 boer goat and 48 indigenous goats) were assigned to Group A (n=30) 60 mg MAP, Group B (n=30) 40 mg FGA and G...
Article
With the international interest in South African Boer goats and the possible utilization of superior genetic material, 56 Indigenous feral and 25 Boer goat does were used either as recipients or donor animals in a superovulation and embryo transfer program. Donor animals (Boer, n=8; Indigenous, n=16) were superovulated using 20mg follicle stimulati...
Article
A questionnaire-based survey was conducted among a purposive sample of 60 small-scale cattle farmers in the Mopeane Rustenburg district, all of whom owned five or more head of cattle. Results showed that small-scale cattle farming is a part-time activity for most farmers in this district, and a way of investing or saving money in a form that is eas...
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The efficacy of ivermectin, fenbendazole, pyrantel pamoate and doramectin was evaluated under field conditions at 2 sites in the Free State Province of South Africa. The study involved 25 horses at each site, divided into 5 groups of equal size. Ivermectin, fenbendazole and pyrantel pamoate were administered orally at doses of 0.2, 10 and 19 mg/kg...
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Fifteen Boer goat bucks were allocated to two groups: WH (n=8) fed Themeda trianda grass hay; and WH+S (n=7) fed the same hay, plus maize, molasses and urea. Body weights measured and feed consumption were recorded. After slaughter, carcass characteristics and chemical were determined. WH+S animals recorded a higher live weight and feed intake. Car...
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Peso vivo. Minerales en tejidos. ADDITIONAL KEYWORDS Live weight. Minerals in tissues. SUMMARY Minerals of the carcass were evaluated in Boer goat bucks under two feeding regimens: winter grass veld hay with or without supplementation. Non-supplemented animals had a significant decrease in live weight and lower whole quantities for each mineral ana...

Citations

... Scrotal circumference (SC) was recorded by the spermatic cord grasping in the first week until the end of experiment in cm to find out the correlation with semen volume. The rams were trained for semen collection by the artificial vagina (AV) method (Matthews et al., 2003). During the trial period, semen collection was performed several times to assess sperm quality (physical and microscopic test) following the procedure described by Santolaria et al. (2015) and Hossain et al. (2018). ...
... However, De Waal et al. (2013) stated that even when animals are fed with dried cactus, feces remain wet due to the presence of mucilage. Sun-dried and coarsely ground cladodes can replace a large proportion of lucerne hay in young lambs' diet (Einkamerer, 2008), considering the importance of cactus-based diets with high-quality N sources for lambs (De Waal et al., 2013). The feeding behavior of milking cows that consumed machine-sliced cacti is recommended to maximize the DM intake and avoid alterations in milk composition compared to the knife-chopped one. ...
... The effects of SWL on several physiological parameters in ruminants, particularly the lipid [17] and Nitrogen [18][19] metabolisms concerning productive [2] and reproductive [3] traits have been studied at length. Recent trends focus on the effects of SWL on protein expression profiles; of note is the comparison of different breeds of domestic animals and their differing levels of adaptation to nutritional stress. ...
... Harapan untuk mendapat kualitas oosit yang baik, perlu diketahui status reproduksi dari sapi donor. MenurutSchwalbach (2000), penilaian dapat dilakukan dengan metode direct (langsung) dan indirect (tidak langsung). Metode direct dilakukan dengan menilai involusi uterus dan atau aktivitas ovarium. ...
... Furthermore, milk lactose, protein, and SNF were higher in MP than in LP goats, whereas milk fat content did not differ between MP and LP goats. Simos et al. [31] reported that milk fat, protein, and SNF were negatively correlated with increased milk yield in goats, and Mmbengwa et al. [32] found a negative correlation between SNF and milk yield. This is contrary to our finding where medium milk yield did not depress milk components in mixed-breed goats. ...
... for morphology analysis. The spermatozoa morphology was recorded as abnormal mid-piece, loose head and tail, cytoplasmic droplets, bent and coiled tail (Bester et al., 2004). In each smeared slide, at least 200 cells were counted and percentage of mentioned defects was calculated and recorded on the Microsoft® Excel sheet. ...
... Duman and Şekeroğlu (2017) and Abiola et al. (2008) reported that the highest hatchability was in medium-weight eggs of broiler hatching eggs. While Çağlayan et al. (2009) and De Witt and Schwalbach (2004) reported that they obtained the highest hatchability from the heaviest eggs in partridges and chickens (New Hampshire and Rhode Island Red), and the lowest hatchability was obtained in the lightest eggs from indigenous chicken genotype (Abudabos et al., 2017). Elibol and Brake (2008) and Iqbal et al. (2016) reported that lighter eggs were better in terms of hatchability in broiler hatching eggs. ...
... However, 45% of the thawed cells rejected the dye propidium iodide, a marker for dead cells, and 49% of sperm had still active mitochondria after thawing [13]. Improved post-thaw motility results (20.5 AE 6.3% and 30.4 AE 18.0%) were achieved with electroejaculated semen of higher original motility (85%-95% and >40%) by Stander-Breedt et al. [14] and Patil [15], respectively. ...
... Seasonal weight loss (SWL) is one of the most pressing issues in animal production in the tropics and the Mediterranean. Indeed, in these regions long dry seasons lead to poor pasture availability, both from a quantitative and qualitative perspectives, ultimately leading to SWL, that in turn has negative significant effects on animal productivity and health, as we have demonstrated for instance in Southern Africa [94] and the Canary Islands (Spain) [95]. To counter SWL, farmers may either supplement their animals, which is something difficult to conduct in remote regions, or they may choose to use breeds that are naturally adapted to such constraint. ...
... The number of ovulations recorded in Groups 2 and 3 did not differ much and was lower, than in previous exper-iments following a superovulatory protocol and similar to the one used for Group 3 of this trial (Lehloenya et al., 2006b). These differences may be attributed to the age of the donor does used in the different trials. ...