Browsing by Author "Bonato, M."

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Foster parenting, human imprinting and conventional handling affects survival and early weight of ostrich chicks
    (South African Society for Animal Science, 2012) Wang, M. D.; Cloete, S. W. P. (Schalk Willem Petrus van der Merwe); Bonato, M.; Dzama, K.; Malecki, I. A.
    The effects of human imprinting and foster parenting by adult ostriches on the survival and growth performance of ostrich chicks were compared to conventional chick-rearing practices in two separate experiments. In the first experiment, the growth rate and survival of chicks imprinted onto humans were compared with those of chicks reared by adult foster parents (n = 100 for both groups). Survival is expressed as proportions, while weights were measured in kg. Treatment did not affect chick survival to 3 weeks (0.90 for imprinted chicks vs. 0.89 for foster chicks), or from 4 to 12 weeks (0.86 vs. 0.83, respectively). Chick weight was not significantly different between groups at 4 weeks, but at older ages, those chicks reared by foster parents consistently outperformed imprinted chicks (means ± SEs being 12.8 ± 0.4 vs. 8.2 ± 0.4 kg at 9 weeks, 37.1 ± 0.8 vs. 19.9 ± 0.80 kg at 18 weeks and 46.2 ± 1.1 vs. 28.6 ± 1.2 kg at 22 weeks). In the second experiment, the treatments consisted of a human-imprinted group of chicks and a group subjected to conventional rearing methods (as customary on the research farm). Chick survival to four weeks was significantly higher for imprinted chicks than for conventionally reared chicks (0.97 vs. 0.84), although chick weight was independent of treatment at 4 weeks (6.27 ± 0.16 kg for the imprinted group vs. 6.18 ± 0.17 kg for the conventional group) and at 15 weeks (respectively 16.5 ± 0.68 vs. 15.2 ± 0.70 kg). Overall, chicks reared by foster parents were heavier than human-imprinted chicks, while early survival of imprinted chicks was better than that of chicks reared by conventional handling. Imprinting thus affected survival of ostrich chicks relative to conventional rearing practices. Because most ostrich chicks are reared with conventional methods, the present study indicates that improvements can be made by adopting alternative approaches. Further studies are needed to ascertain how foster parenting and imprinting may be utilized to optimize chick performance, including the long-term consequences of these practices.
  • Thumbnail Image
    Item
    Meat quality, skin damage and reproductive performance of ostriches exposed to extensive human presence and interactions at an early age
    (Springer, 2020) Muvhali, P. T.; Bonato, M.; Engelbrecht, A.; Malecki, I. A.; Mapiye, Cletos; Cloete, S. W. P. (Schalk Willem Petrus van der Merwe)
    The effect human presence and interactions performed after hatch to 3 months of age has on ostrich meat quality, skin damage and reproductive performance at a later age was investigated in 416-day-old ostrich chicks. The chicks were allocated to one of the three treatments, which varied with regard to exposure to human presence and care for 3 months post-hatch: HP1—extensive human presence with physical contact (touch, stroking), gentle human voice and visual contact; HP2—extensive human presence with gentle human voice and visual contact without physical contact; S—standard control treatment, where human presence and visual contact were limited to routine management, feed and water supply only. Carcass attributes (carcass weight, dressing percentage and drumstick weight), meat quality traits (pH, colour and tenderness) and skin traits (skin size, skin grading and number of lesions) were evaluated on twenty-four 1-year-old South African Black (SAB) ostriches. Reproductive performance (egg production, average egg weight, number of clutches, clutch size, chick production, average chick weight, fertility and hatchability percentage) were recorded for the first three breeding seasons of 23 SAB pair-bred females from this study. No differences in carcass attributes, meat quality, skin traits and reproductive performance were found between treatments (P > 0.05). It was evident that exposure of day-old ostriches to extensive human presence and interaction as chicks did not influence carcass attributes, meat quality or skin traits at slaughter age, but more importantly, it did not compromise their reproductive performance.
  • Thumbnail Image
    Item
    Ostrich ejaculate characteristics and male libido around equinox and solstice dates
    (Springer, 2020) Muvhali, P. T.; Bonato, M.; Malecki, I. A.; Du Plessis, L.; Soley, J. T.; Cloete, S. W. P. (Schalk Willem Petrus van der Merwe)
    The study evaluated the effect of time of the year in which changes in photoperiod occurs on ostrich semen characteristics and male libido. Semen was collected for 5 days before, on and 5 days after winter solstice (21 June 2016), spring equinox (22 September 2016), summer solstice (21 December 2016) and autumn equinox (20 March 2017) in the southern hemisphere. Semen was collected from 10 South African Black ostrich males (average age ± standard deviation; 4.5 ± 2.27 years) using the dummy female. Semen volume, sperm concentration, total sperm per ejaculate, sperm motility traits, percentage of normal sperm, head and tail abnormalities and percentage of affected sperm in the hypo-osmotic swelling test (HOS) were evaluated. Male libido defined as the willingness of males to mount the dummy female was also recorded. Semen samples collected around summer solstice, spring and autumn equinox were higher in sperm concentration and sperm output compared with winter solstice (P < 0.05). Study periods did not influence semen volume, sperm motility traits, the percentage of normal sperm, head abnormalities and HOS. Tail abnormalities were higher around winter solstice than around spring equinox (P < 0.05). Male libido and the success of semen collection were significantly higher around spring equinox (P < 0.05). Changes in photoperiod in the southern hemisphere do not affect semen production in ostriches. However, high sperm output and male libido around spring equinox and summer solstice dates suggest that these periods may be preferred for semen collection for artificial insemination and storage purposes.