Plant extracts are used as possible methane mitigants and to replace antibiotic feed supplements previously used prophylactically to improve the adaptation of lambs in intensive feeding systems. This study investigated the effects of Acacia mearnsii tannin extract used as anti-methanogenic feed additives on carcass and meat quality of lambs. Forty Dohne Merino lambs, with an initial mass between 23.90 kg and 37.40 kg, were first stratified according to their initial body weight and thereafter one of the eight lambs with similar body weight were randomly assigned to four treatment groups (n = 10 lambs/treatment). The lambs were fed ad libitum with a basal total mixed ration. Four experimental diets were formulated: TMR diet (control); TMR diet with Rumensin® at a dosage of 75 mg/kg of DM feed (Monensin; Positive control); TMR diet with raw condensed Acacia tannin at 20 g/kg of DM feed (Crude tannin); TMR with addition of encapsulated condensed Acacia tannin at 20 g/kg of DM feed (Encapsulated condensed tannins). The lambs were slaughtered at a live mass of about 50 kg after a 19 week trial period. Dietary tannin additives did not affect the carcass composition or colour aspects of lamb meat. However, there were minor changes in fatty acid profiles, particularly in the intramuscular adipose tissue. The addition of encapsulated tannin extract resulted in a higher proportion of C18:2n6t (0.15

This study researched the effects of two commercially available zilpaterol hydrochloride (ZH) β-adrenergic agonists, denoted as ZH-A and ZH-B, on the meat quality characteristics of typical South African feedlot bulls (taurine × indicus composites), over extended aging periods of up to 120 days. The effects of ZH were studied to address concerns about the possible adverse effects of ZH on beef quality following extended aging, which typically occurs during the exportation of beef by boat. The completely randomized control study consisted of 3 homogenous experimental groups, with 3 replicates per treatment and 50 bulls per replicate = 450 animals. Treatments were a negative control (CT) with no ZH supplementation added to the basal diet or a basal diet supplemented with either zilpaterol hydrochloride A (ZH-A) or zilpaterol hydrochloride B (ZH-B), both at 105 g ZH/ton, fed from the first day of the finishing period (D0) for 30 days. Subsamples were collected from 38 random carcasses from each treatment for proximate analysis and meat quality analysis using Longissimus dorsi samples. ZH supplementation decreased meat tenderness (Warner–Bratzler shear force values (WBSF)) of bulls fed ZH-A or ZH-B, compared to those fed the CT diet (p < 0.05; η2 = 0.24). The WBSF values of both ZH treatments were about 0.5–0.8 kg higher during the aging periods compared to the CT, but ZH did not affect post-mortem meat aging or meat quality characteristics differently compared to the CT. Post-mortem aging per se influenced all meat quality characteristics investigated (p < 0.001; η2 > 0.30), showing improvements in WBSF, a decrease in meat colour and an increase in drip and cooking losses. L*-values increased from 3 to 56 days of aging and then decreased to day 120 (p < 0.001; η2 = 032). Chroma values decreased from day 3 to day 120 (p < 0.001; η2 = 0.50). Hue° decreased from day 3 to day 7 and stabilized until day 120 (p < 0.001; η2 = 0.40). Moisture and cooking loss (CL) increased to 56 days and then decreased to 120 days.

Background: The welfare of crocodiles on commercial farms in southern Africa requires precise assessment, focusing on stocking densities and pen conditions. However, disputes between animal welfare groups and farm owners persist due to inadequate methodologies for quantifying these factors. Objectives: This study aimed to address these disputes and enhance crocodile welfare assessment by introducing a novel technique using a low-cost consumer uncrewed aerial vehicle (UAV) and open-source photogrammetry software. The objective was to quantify key welfare parameters accurately and efficiently. Method: The study involved applying the UAV-based technique to two large Nile crocodile ( Crocodylus niloticus) ) farms in South Africa. The approach enabled the mapping and surveying of crocodile pens, facilitating the determination of stocking densities, biomass indicators, and other pen-related attributes. Comparisons were made between UAV-derived crocodile counts and farmer estimates. Results:The The UAV-based crocodile counts significantly differed from the estimates provided by farmers, underscoring the need for a more precise assessment method. The technique's cost-effectiveness was evident, with implementation expenses totalling less than R10 000, a fraction of the cost associated with commercial UAV surveys. Conclusions: The introduced UAV-based technique offers a valuable solution to the ongoing debates regarding crocodile welfare on commercial farms. By quantifying key parameters accurately and economically, it empowers farmers and animal welfare groups to make informed decisions. The method's ease of adoption, demonstrated through its use by some Southern African crocodile farmers, signifies its potential for widespread application, ultimately contributing to improved crocodile welfare.

The concentration of trace elements in the liver is used as an indicator of the mineral nutritional status of an animal, as a benchmark of environmental mineral exposure, to follow the metabolism of an element in the body and for various other purposes. Concentrations are expressed on a wet (fresh) liver basis or on a dry liver basis. From a literature search and evidence from an analytical laboratory, large variations (varying from < 20% to > 40%) have been recorded on the percentage of moisture in the livers of ruminants. Such variations potentially compromise the interpretation of results on mineral concentrations in livers, and preclude robust comparisons between studies. Among the factors that can affect the moisture content of livers are: inconsistencies in sampling and preparation of liver samples; exposure to toxic substances; ill-health of the animal; fat content of the liver; and age of the animal. It was estimated that the mean dry matter (DM) content of the livers of healthy ungulates containing less than 1% liver fat is between 27.5% and 28.5%, and on a fat-free basis 25-26% DM. For routine analyses of liver samples it is suggested that to limit variations owing to differences in liver moisture content, liver mineral concentrations should be expressed on a DM basis, and for in-depth scientific studies on mineral metabolism on a dry, fat-free basis. However, if mineral concentrations are expressed on a wet basis, it is advisable to supply the liver DM content as well.

Population surveys of crocodilians using uncrewed aerial vehicles (UAV) or drones may become accurate and cost-effective alternatives to more traditional approaches. However, there are currently no quantitative methods for deriving body condition scores of crocodilians through remote sensing. This study presents seven UAV-based morphometric measures collected from rectified aerial imagery of farmed Nile crocodiles. Two hundred and eighty-eight Nile crocodiles, from two commercial crocodile farms in South Africa were included in this study. One farm housed crocodiles which appeared to have wider abdominal girths than those on the second farm, allowing comparisons for a range of sizes and body condition states. An initial disturbance assessment was conducted, and an appropriate flight altitude selected for image acquisition of farmed Nile crocodiles. Altitudes between 40m and 60m above ground level suited the studies requirements and minimized disturbance. A UAV-based body condition index for Nile crocodiles was then developed, offering a non-invasive alternative to traditional condition scoring methods. The body condition index (BCI) was calculated for each crocodile by measuring the relationship between total length and belly width (with the equation: BCI = BW/TL*10) derived from photogrammetrically processed orthophotos in GIS. The BCI values were then normalized to form a body condition score (BCS) with the equation: BCS = (BCI/1.27)*4 + 1. The BCS ranked crocodile body conditions from 1-5, where a score of 1 identified a crocodile that was comparatively thin or emaciated, while a score of 5 identified a crocodile that was relatively fat or obese in contrast to the other crocodiles assessed. A BCS of 3 was the most frequent across all crocodiles in the study, with few animals scoring a 1 or 5. The farm housing crocodiles with narrower abdominal girths had no BCS 5 occurrences, and the farm housing crocodiles with wider abdominal girths had no BCS 1 occurrences. This UAV-based body condition score could be applied to large wild or captive populations for a fast-paced health and welfare evaluation.

This study aimed to compare the effects of feeding 60 mg of the beta-adrenergic agonist, zilpaterol HCl (Zilmax (R)), per steer per day versus feeding 120 mg of the beta-adrenergic agonist, R-salbutamol (Salbutamate (R) 10%), per steer per day for the last 30 days of the finishing period on the growth, efficiency, and carcass characteristics of 228 typical South African feedlot steers in a completely randomised control study. The steers were slaughtered at the same abattoir after a 3-day withdrawal period. The growth and feedlot parameters included starting mass, slaughter mass, average daily gain, live mass gain, and lean carcass gain. The carcass characteristics included warm (WCW) and cold carcass mass (CCW), carcass length (CL), subcutaneous fat thickness measured over the 13th rib (SCF), dressing percentage, carcass compactness, carcass classification score, age code, and fat code using the South African carcass classification system. The inclusion of zilpaterol HCl as a feed additive resulted in higher growth and efficiency, with an ADG of 1.3 kg/day (P <0.05) in steers fed zilpaterol HCl compared to 1.1 kg/day for steers fed R-salbutamol. Steers in the zilpaterol HCl experimental group had a 12.5 kg higher average slaughter mass, yielding similar to 3 kg higher calculated lean gain than steers fed R-salbutamol. Steers fed zilpaterol HCl yielded better carcass characteristics of 11.4 kg higher CCW and marginally longer carcasses compared to steers fed Rsalbutamol. Therefore, the overall growth, feedlot performance, and carcass characteristics were higher in the zilpaterol HCl-fed steers than in R-salbutamol-fed steers.

This study investigated the effect of ambient temperature and humidity on milk urea nitrogen (MUN) concentration in Holstein cows. Meteorological data corresponding to the dates of milk sampling were collected over six years. A linear mixed-effects model including a random effect term for cow identification was used to assess whether temperature and humidity were predictive of MUN concentration. Age, days in milk, temperature humidity index (THI), ration, milk yield, parity and somatic cell count were also evaluated as main effects in the model. A general linear model including all variables as random effects was then fitted to assess the contribution of each variable towards the variability in MUN concentration. Maximum daily temperature and humidity on the sampling day were positively associated with MUN concentration, but their interaction term was negatively associated, indicating that their effects were not independent and additive. Variables that contributed the most to the variability of MUN concentration were dietary crude protein (21%), temperature (18%) and other factors (24%) that were not assessed in the model (error term). Temperature has a significant influence on urea nitrogen concentration and should therefore always be considered when urea nitrogen concentration data are used to make inferences about the dietary management of dairy cows.

The current study assessed the ambient temperatures, and those selected, by captive adult Nile crocodiles on a commercial farm in South Africa. Non-invasive data capture techniques were developed to ensure the crocodiles natural behaviours were not disrupted or altered. Thermal and climate data, over summer and winter seasons, were collected from local weather stations, an on-site Internet of Things system, and a Mavic 2 Enterprise Dual drone. The method developed in this paper transformed relative thermal maps (produced by a DJI Mavic 2 Enterprise Dual drone) into a predictive model in which temperatures were derived to within 2.6 degrees C per pixel of a processed orthophoto. Crocodile thermal and behavioural data were extracted from the drone imagery and juxtaposed with climate and thermal data from the pen. The greatest number of crocodiles were counted during early morning winter flights and the lowest number during late afternoon summer flights. Material (concrete, water, nest, grass/sand) selection by crocodiles varied with season, time of day and daily climatic conditions. Crocodile back temperature (10.2-49.6 degrees C, mu = 30.4 degrees C) ranges fell within those of their positional/environmental (10.6-66.6 degrees C, mu = 28.7 degrees C) temperature range selections. Strong, positive, significant correlations were found between crocodile back temperatures and positional temperatures for both winter and summer seasons, highlighting ectothermy. Application of this methodology on a commercial crocodile farm facilitated the inspection of potential shortfalls of the pens design from a thermal perspective, as well as suggestions for improvements that would ameliorate crocodile thermal discomfort (relating to hyperthermia).

The most important factor that determines beef tenderness is its proteolytic activity, and the balance between calpain-1 protease activity and calpastatin inhibition is especially important, while contributions can also arise from calpain-2 and, possibly, calpain-3. The meat ageing process itself affects these processes. To determine whether genotypes in the calpain–calpastatin system can enhance tenderness through a 20-day ageing period, South African purebred beef bulls (n = 166) were genotyped using the Illumina BovineHD SNP BeadChip through a gene-based association analysis targeting the cast, capn3, capn2 and capn1 genes. The Warner–Bratzler shear force (WBSF) and myofibril fragment length (MFL) of Longissimus thoracis et lumborum (LTL) steaks were evaluated between d 3 and d 20 of ageing, with protease enzyme activity in the first 20 h post-mortem. Although several of the 134 SNPs are associated with tenderness, only seven SNP in the cast, capn2 and capn1 genes sustained genetic associations, additive to the ageing-associated increases in tenderness for at least three of the four ageing periods. While most genomic associations were relatively stable over time, some genotypes within the SNP responded differently to ageing, resulting in altered genomic effects over time. The level of ageing at which genomic associations are performed is an important factor that determines whether SNPs affect tenderness phenotypes.

There is an increased interest in the use of medicinal plants as alternatives to antibiotic growth promoters and as agents for methane production mitigation. This study investigated the effects of Azadirachta indica and Moringa oleifera feed additives on the carcass and meat quality of lambs. Forty South African Mutton Merino lambs, weighing between 29 and 43 kg, were randomly assigned to four treatment groups (n = 10 lambs/treatment) and fed a basal total mixed ration (TMR) containing soybean meal (17%), yellow maize (28%), Alfalfa hay (20%), Eragrostis curvula hay (22.2%), molasses (6.0%), wheat offal (5%), urea (0.8%) and vitamin premix (0.5%) on a DM basis. The dietary treatments: TMR diet (control); TMR diet with A. indica leaf extract (A. indica leaf extract at a dosage of 50 mg per kg of feed: neem); TMR diet with M. oleifera leaf extract (M. oleifera leaf extract at a dosage of 50 mg per kg DM of feed: moringa); TMR diet with monensin (at a dosage of 50 mg monensin sodium per kg of feed: positive control). After an adaptation period of 10 days to the experimental conditions, the lambs from all treatment groups were fed ad libitum with the experimental diets. The lambs were slaughtered at a live weight of 60–65 kg after a 23 week trial period. The plant extract dietary additives had no significant effects on the carcass characteristics of the lambs. In comparison to monensin, supplementing with moringa leaf extracts resulted in a higher proportion of C18:1n9c (45.0% ± 0.57 vs. 40.5% ± 0.80; p < 0.05), total MUFAs (47.3% ± 0.66 vs. 42.6% ± 0.87; p < 0.05), and UFA:SFA ratio (1.01 ± 0.03 vs. 0.85 ± 0.03; p < 0.05), which may be beneficial for human health. Our results suggest that natural feed additives, such as A. indica and M. oleifera leaf extracts, can be included in lamb diets without compromising meat fatty acid composition. The negative economic impacts of such technologies on animal production and farm profitability should not be expected.

This study compared the inherent meat tenderness of South African breed-types under typical South African commercial abattoir practices (Phase 1). Phase 2 evaluated meat tenderness and calpain system differences of A-age (feedlot and pasture) animals, AB-age (feedlot and pasture) animals, and B-age (pasture) animals under the determined ideal slaughter conditions for South African crossbred beef breeds. Feed was withdrawn for either three hours or 24 hours pre-slaughter. Within each feed withdrawal group, three electrical stimulation (ES) treatments were applied, viz. ES for 15 seconds, 120 seconds or no stimulation. The carcasses were placed in chillers at 4 ºC within 1 hour after slaughter. In Phase 2, the effect of animal age and feeding regime were investigated using animals of A-age (feedlot and pasture), AB-age (feedlot and pasture) and B-age (pasture). All carcasses were electrically stimulated for 15 seconds. pH and temperature measurements were recorded early post mortem and at 24 hours post mortem. The effect of ageing on meat characteristics was tested on 1 day, 7 days and 14 days post mortem from samples removed from the m. longissimus lumborum (LL) muscle. The ideal post-slaughter procedure was identified as ES-15 electrical stimulation where pH decline was controlled (not too rapidly) by applying electrical stimulation for a short period. Longer feed withdrawal period increased dark-firm-dry (DFD) meat occurrence (pHu >6) in the Nguni and Simmentaler-cross. Brahman-cross longissimus (LL) tended to be more tender with paler colour and higher drip loss when 120 ES was applied. Electrical stimulation of 15 seconds during Phase 2 showed that none of the carcasses were exposed to heat or cold shortening. Longer feed withdrawal recorded higher Warner Bratzler shear force (WBSF) than three hour feed withdrawal. However, ES neutralized the effect of stress on tenderness. On average, the AB-age feedlot animals produced the most tender LL followed by the B-age pasture and A-age feedlot which was similar to the AB-age pasture. A-age pasture animals produced the least tender LL steaks. The calpain proteolytic system played a pivotal role in determining the ultimate meat tenderness and although connective tissue becomes less soluble in older animals it did not play the determinant role in tenderness in this study. The intramuscular fat (< 3%) played an important role in the tenderness outcome of Nguni LL which marbled well at AB-age. Judging eating quality on the grounds of age alone is not reliable, because carcasses from older animals were not necessarily tougher than those of younger animals. The South African classification system and resultant remuneration should be revisited and consumers should be educated accordingly. Production systems should be optimised by using ideal pre- and post-slaughter conditions and adapted to accommodate different breed-types.

This study investigated the effects of palm oil and fibrolytic enzyme supplementation in high forage diets on growth, carcass characteristics and fatty acid composition of lambs. Forty South African Mutton Merino ram lambs were randomly assigned to four treatment groups (n = 10 lambs/ treatment) and fed a basal total mixed ration (TMR). The treatments were: TMR diet with Megalac as bypass oil (control); TMR diet supplemented with 3% palm oil; TMR diet with cellulase and xylanase enzymes and TMR diet supplemented with 3% palm oil and cellulase and xylanase enzymes. The lambs were slaughtered at a target weight of about 42 kg. Palm oil supplementation resulted in a longer feeding period (P < 0.05) and lower dressing percentage (P < 0.01), but the carcasses had higher meat yield (P < 0.01) and lower fat content (P < 0.05) compared to the other treatment groups. Additionally, palm oil supplementation increased the proportion of C18:0 (P < 0.05) while decreasing (P < 0.05) the proportion of C14:0 (P < 0.05) and C16:0 (P < 0.05) in fat depots, which may be beneficial for human health. The fibrolytic enzyme treatment had minimal effects on growth, carcass characteristics, meat quality and fatty acid composition of lambs. The interaction effect of palm oil and fibrolytic enzymes had positive effects on the UFA: SFA ratio due to an increase (P < 0.05) in C20:3n6 and C20:4n6 and a reduction (P < 0.05) in saturated fatty acids. The results suggest that methane mitigation strategies through palm oil and enzyme supplementation can be used in lamb diets without adverse effects on product quality.

Oocyte recovery is a reproductive technology that can be done by using two techniques, aspiration and slicing. Invitro maturation (IVM) is an additional reproductive technology used to advance an oocyte to a maturation stage; thereafter, it may be used during IVF. The objectives of the present study were (1) to compare two different oocyte retrieval methods (aspiration and slicing) from pig ovaries on oocyte quality and quantity, and (2) to compare three different IVM media [NCSU 37, TCM-199, and modified porcine follicular fluid (mpFF=porcine follicular fluid+FSH+LH] on oocytes’ polar body extrusion. During aspiration, an 18G needle was attached to a 10-mL syringe and all visible follicles were aspirated. During slicing, a surgical blade was used to slice the ovaries held in mDPBS. Follicular fluid collected from both methods was assessed for the presence of oocytes with the aid of a microscope. The collected oocytes were then categorized as Grade A, B, or C: Grade A=oocytes with compacted, multilayered cumulus cells and a homogeneous ooplasm; Grade B=oocytes with a compact cumulus cell layer with homogeneous ooplasm; Grade C=oocytes with a less compact cumulus cell layer with irregular ooplasm containing dark granules. The IVM media were placed in a four-well multidish; thereafter Grades A and B oocytes were allocated per treatment groups and matured for 44h. The treatment means were compared using the Fisher’s protected t-test least significant difference. The results showed significant differences between the grades of oocytes (P<0.05) with Grade A and B oocytes accounting for 50.8% of total oocytes (193.8) for aspiration and 58.7% of total oocytes (488.6) for slicing. The oocytes polar body extrusion was recorded as 25.3, 84.2, and 73.8% for NCSU 37 (P<0.05) and TCM-199 and mpFF respectively (P>0.05). In conclusion, the slicing method proved to be better than aspiration with regards to the retrieval of Grades A and B oocytes as well as the total number of oocytes retrieved. The TCM-199 and mpFF media had a higher percentage of oocytes with polar body extrusion than NCSU 37.

The study describes the relationship between visual and instrumental measurements for colour and tenderness between 5 South African beef breeds; Bos indicus (Brahman), Sanga type (Nguni), British Bos taurus (Angus), European Bos taurus (Charolais) and the composite (Bonsmara), 10 animals per genotype were used, n=50. The animals were finished off on a feedlot diet for a period of between 90-110 days at the ARC-AP feedlot and were slaughtered at the ARC-AP abattoir when they reached a live weight which would produce a carcass of Class A (no permanent incisors), and fat class 2 to 3 (1-5 mm) (South African Beef Classification System). After exsanguination, the carcasses were split and the right sides were electrically stimulated (ES) and the left sides were not stimulated (NS), but delay chilled. Steaks from both ES and NS treatments were aged until 3 days (d) post mortem (pm) on polystyrene plates at 6°C in a display cabinet and until 9, 14 and 20 d pm in vacuum bags at 1-4°C in a cold room. The steaks were then evaluated by visual analysis for colour, marbling, fibre separation, surface texture and structure integrity using a 10 member trained panel. Instrumental colour was measured using Minolta meter (CIE L*, a*, b*). Instrumental tenderness was measured by shear force using Instron. Results of the study showed that Nguni breed produced the most tender and darker meat whereas, the Bonsmara breed produced the least tender and lightest meat. Good correlations were observed between the visual colour and L* (r=0.809; P<0.0001), b* (r=0.698; P<0.0001) and hue (r=0.797; P=0.797). There were also correlations between shear force and structure integrity (r=-0.410; P<0.0001) and fibre separation (r=- 0.401; P<0.0001). Very low correlations were observed between visual colour and shear force. Therefore, although a trained eye could judge meat colour by visual analysis, it seems not possible to predict tenderness by colour judgement. Visual texture did not show any potential as a reliable visual tenderness attribute, therefore cannot be used to predict meat tenderness. However, there is potential for an experienced eye in predicting tenderness by observing visual structural properties such as fibre separation and structural integrity.

This study investigated the effects of MUN and climatological factors on the inter calving period (ICP), reproductive performance (RP%), and reproductive index (RI) in Holstein Friesian (n = 1177) and Jersey cows (n = 3305) in different seasons in the subtropics. Threshold values for MUN on the reproduction of dairy cows in the subtropics remain controversial due to complex environmental interactions, especially with high environmental temperatures. A retrospective analysis was conducted of data obtained from the National Milk Recording scheme of the Agricultural Research Council (ARC) in South Africa. The results confirm that MUN influences the reproduction of dairy cows in the subtropics. MUN concentrations exceeding 18.1 ± 4.28 mg/dL in Holstein Friesian cows and 13.0 ± 4.70 mg/dL in Jersey cows extended the inter calving period (ICP), and decreased RP% and RI. Jersey cows have a lower threshold MUN concentration compared to Holstein Friesian cows, but they are not adversely affected by high humidity or temperatures, while Holstein Friesian cows are.

In South Africa, supplemental feeding is provided to improve the condition of breeding livestock before the animals are sold by the stud breeders to commercial farmers. This study aimed to evaluate the effects of different ram rearing systems on growth, fat accumulation and semen quality of Döhne Merino (DM), Merino (M) and South African Mutton Merino (SAMM) rams intended for breeding. The ram lambs were stratified according to weight and randomly allocated to one of three treatments, namely an extensive feeding treatment (ET), an extensive-intensive feeding treatment (EIT), and an intensive feeding treatment (IT). Rams in ET grazed for 200 days. Rams in EIT grazed for 73 days, followed by a concentrate diet for an additional 60 days. Rams in IT were fed the concentrate diet for 70 days. Scrotal neck fat was significantly less in IT rams compared with ET and EIT rams. Döhne Merino and M rams in EIT deposited significantly more scrotal fat than DM and M rams in ET. No adverse testicular pathology or differences in semen quality were observed. Regression analyses of pooled data showed extreme functional values for subcutaneous fat and total scrotal fat weight, which, when exceeded, may result in decreased semen volume, percentage normal spermatozoa and mass motility of spermatozoa. Sheep breeders should be cautious when feeding ram lambs in extensive-intensive systems for extended periods since this may affect semen quality adversely.

Intensive Nile crocodile (Crocodylus niloticus) farming operates with considerable variation in housing and stocking density. In this study, current commercial stocking densities for crocodilians were investigated using 261 grower-phase crocodiles (15 months old, average total body length 94.5 cm, and average weight 2.7 kg). Low (2.60 m(2) per crocodile), medium (1.24 m(2) per crocodile), and high (0.41 m(2) per crocodile) stocking densities were tested. Growth, morphometric measures, Fulton's condition scores and skin qualities were assessed over a six-month (May - November 2017) period. High stocking density had no adverse effects on the growth of grower Nile crocodiles. Crocodiles stocked at medium and high densities outperformed those that were stocked at low density in Fulton's body condition scores, change in body condition from the start to the end of the trial, and feed conversion efficiencies. However, the high and, to a lesser extent, the medium stocking densities resulted in lower skin quality scores compared with those in the low-density treatment because of teeth marks from more aggressive behaviour. The results indicated that the medium pen density treatment is closer to the ideal than either the high or low stocking density groups. Stocking densities that provide 0.41 m(2) per crocodile or less should be avoided because of lower skin quality scores, which weigh more heavily than growth and feed efficiency responses in the financial viability of commercial crocodile farming in typical South African production systems.

Red meats are often criticized as unhealthy based on their perceived high-fat content and saturated fatty acid composition. Uncertainties about the fatty acid composition and trans-fatty acid contents may discourage consumers to eat red meat, especially those living with non-communicable diseases such as cardiovascular diseases, hypertension and obesity (e.g. the metabolic syndrome). Previous studies have investigated the factors that influence the fat content and fatty acid composition of red meats, including the effects of species, age, nutrition, sex, production systems and growth promotants in animals, but the trans-fatty acid content of red meat has not been well studied to date. The purpose of this chapter is to review the fat content and fatty acid composition of red meats, with specific reference to its cis/trans-fatty acid content. Representative samples of beef sirloin steaks (n = 60) and lamb loin chops (n = 80) (the lumbar part of the longissimus dorsi muscle) were collected from carcasses from several randomly selected abattoirs in the Gauteng region of South Africa for proximate and fatty acid analyses. Results from this study confirm that the intramuscular fat content of red meats is low compared to most fat-containing processed foods. The lean component of beef and lamb contain a trivial proportion of TFA’s, consisting of vaccenic acid, rumenic acid and conjugated linoleic acid (CLA) isomers. The CLA’s in red meat are beneficial due to their antioxidant and anti-carcinogenic properties, so they should not strictly be considered in the TFA definition. This means that the TFA’s in red meats are negligible and pose no harm to human health. Labelling of red meats should be improved to convey this information to consumers.

The objectives of the study were to: Compare oocyte retrieval methods (aspiration and slicing) from pig ovaries on oocyte quality and quantity; compare in vitro maturation (IVM) media (North Carolina State University -NCSU 37; Tissue Culture Medium-TCM 199; and porcine follicular fluid-mpFF) on oocytes polar body extrusion; compare the effect of Electrical Stimulation (ES) and frozen-thawed semen on cleavage rates and compare the effect of culture media, cNCSU 37 and cpFF, on cleavage rates. Follicular fluid collected from the retrieval methods were assessed for the presence of oocytes and categorized as either Grades A, B or C. Grades A and B oocytes were randomly allocated per treatment groups, matured for 44 h and checked for polar body extrusion. Matured oocytes were randomly allocated to either ES or traditional in vitro fertilization (IVF-frozen-thawed semen). The ES and IVF took place in conjuncture with in vitro Culture (IVC) media. Zygotes were checked for cleavage and recorded. The treatment means were compared using the Fisher’s protected t-test least significant difference. Slicing had significantly higher amounts of Grade A (58.7%) and B (50.8%) oocytes than the aspiration method. Oocytes polar body extrusion were 25.3, 84.2 and 73.8% for NCSU 37, TCM 199 and mpFF, respectively. Zygotes cleavage was 48.1% for traditional IVF and 56.8% for ES; 66.6% for cNCSU 37 and 45.7% for cpFF. Slicing proved to be better than aspiration method for the total amount of Grades A and B oocytes retrieved. The TCM 199 and mpFF media had a higher percentage of oocytes with polar body extrusion than NCSU 37. Cleavage rate of zygotes were higher on ES and cNCSU 37.

AbstractPelvis size plays an important role to prevent dystocia in cattle caused by the foeto‐maternal disproportion in commonly primiparous females. The reproducibility and repeatability are two important aspects for the reliability of the measurements to use in the selection of cattle for culling. Pelvic measures were taken with a Rice pelvimeter from 224 young cattle (180 females and 44 males) of four beef breeds in South Africa. One experienced and two inexperienced observers each measured pelvic height and width twice. The proportion measurements with a maximum difference of 0.5 cm within animal compared with the first measurement by the experienced observer are around 80% and by the inexperienced observers around 50% for pelvic height and around 60% for pelvic width. Breed and sex do not affect the reliability of pelvimetry by an experienced observer. Under‐ and overestimation of pelvis size were observed in inexperienced observers, which seems to be unrelated to breed and sex.