Masters Degrees (Animal Sciences)

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Browsing Masters Degrees (Animal Sciences) by browse.metadata.advisor "Ciacciariello, M."

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    The effect of different incubation temperatures on chick quality
    (Stellenbosch : University of Stellenbosch, 2007-03) Du Preez, J. H.; Ciacciariello, M.; University of Stellenbosch. Faculty of Agrisciences. Dept. of Animal Sciences.
    ENGLISH ABSTRACT: Over the last few decades various authors have reported the influence of day old chick quality on integrated broiler industries. Although various methods of determining chick quality have been reported, defining a good or a first grade day old chick can be problematic as it involves many subjective measurements. Incubation temperature (embryo temperature) is probably the biggest, most influential factor during incubation on chick quality. High temperatures cause the most damage. It leads to poor growth, stress, black buttons, threads, weak chicks, chicks with poorly erupted down that are bleached in appearance, low hatchability, late embryonic death and early broiler mortality. This trial was designed to test whether 37.2, 37.4 or 37.5ºC was the optimum incubation temperature for hatching Hybro G+ chicks with superior quality. The parameters that were measured were the chick length, bodyweight, and the yolk residue of the day old chicks of the flocks set at different setter temperatures. After hatching, 1 440 chicks (480 chicks per temperature treatment) were placed at a broiler facility where the daily mortalities, weekly bodyweight gain and feed conversion were recorded and calculated. The age of the breeder flock had a significant effect on all three parameters measured in the incubation trial with p values of <0.001, <0.001 and 0.005 respectively. There were no significant differences in chick quality parameters due to different incubation temperatures. The age x temperature interaction could be attributed to the large influence of the age of the breeder on egg size and consequently chick parameters. The results could be related to the fact that bigger eggs from older breeder flocks have higher initial egg mass, which will result in heavier embryos and thus converted to a larger day old chick. The performance trial performed after the incubation trial showed no significant effect of the incubation temperature on 7-day and daily mortalities, weekly bodyweight gain and feed conversion efficiency to 42 days of life. The lack of effects observed in these trials could be attributed to the small range of temperatures used in addition to the difficulties brought about the use of multi-stage incubators.
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    The effects of a multiple-enzyme combination in maize-soya diets for broiler chickens
    (Stellenbosch : University of Stellenbosch, 2007-03) Fourie, Juan-Louis; Ciacciariello, M.; Lambrechts, Helet; University of Stellenbosch. Faculty of Agrisciences. Dept. of Animal Sciences.
    The effect of a multiple-enzyme combination in mash and pelleted vegetarian maize-soya diets for broilers was evaluated in terms of apparent excreta- and ileal nitrogen- and amino acid digestibility and production performance. Two separate digestibility trials and one performance trial were conducted. For Trial 1, the apparent nitrogen (N) - and amino acid (AA) digestibility was determined by the collection of the excreta (total collection method) and in Trial 2 from digesta collected at the terminal ileum (ileal digestibility method). Production performance was also recorded in Trial 1. In Trial 3, the effect of the multipleenzyme combination in potentially improving performance of broilers in commercial conditions was evaluated. Broilers were fed a balanced- and low apparent energy (AME) vegetarian maize-soya diet with the addition of the multiple-enzyme combination. The addition of enzymes improved the apparent excreta- and ileal N digestibility of the mash diets during the period 14-21 d, and the ileal N-digestibility of the pelleted diets at 28 and 35 d of age. Conflicting results with regard to apparent excreta- and ileal AA digestibility were found. By both methods the digestibilities of threonine (Thr), methionine (Met) and phenylalanine (Phe) (14-21 d) and Cys (22-28 d and 29-35 d) were improved by the addition of the enzyme combination to the mash diets. Over the entire experimental period (14-35 d) the ileal digestibilities of histidine (His), Cys and leucine (Leu)of the mash diets were improved by 0.2 %, 0.2 % and 1.9 % respectively, following enzyme addition. By both methods the digestibilities of Thr, arginine (Arg), Met, Cys, Phe and Leu (14-21 d), serine (Ser), Arg, glutamic acid (Glu), Val, His, aspartic acid (Asp), lysine (Lys), proline (Pro), Met, tyrosine (Tyr), Phe and Leu (22-28 d), and Pro (29-35 d) were improved by the combination of enzymes and pelleting. For the entire experimental period (21-35 d), the ileal digestibilities of Ser, His, Lys, Met, Tyr, Cys, Phe and Leu was improved by the combination of enzymes and pelleting, indicating enzymatic activity was not destroyed by cold pelleting at 60 - 80º. The improvements in apparent nitrogen- and AA digestibilities were, in most cases, not reflected in production performance, although the combination of enzymes and pelleting resulted in improved body weight gain (BWG) for the first two weeks of chicks life and significantly improved the feed conversion ratio (FCR) during the second week of the chicks’ life. The effect of the multiple-enzyme combination on the production performance of broilers on a low AME- and commercial diet was mostly non-significant except for a significantly lower feed iii intake of the balanced diet for the fourth and fifth week of chick’s life following enzyme addition. A financial calculation showed, however, that the enzyme combination might increase profitability of a nutritionally balanced vegetarian maize-soya diet for broilers.
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    Efficiency of broiler production : a case study of two commercial enterprises around Gaborone (Botswana)
    (Stellenbosch : Stellenbosch University, 2005-12) Kelebemang, Gertrude Nurse; Ciacciariello, M.; Stellenbosch University. Faculty of AgriSciences. Dept. of Animal Sciences.
    ENGLISH ABSTRACT: The study investigated the performance of broiler production III two enterprises around Gaborone. The main emphasis was on performance and feed efficiency of four major production parameters, which include feed intake (FI), age at slaughter, body weight (BW) and feed conversion ratio (FeR). The averages for slaughter age, BW (live weight), FI and FeR for the two enterprises combined were 39.6 days, 1.8 kg, 3.41 kglbird and 1.96, respectively. For the entire rearing period the average performance efficiency factor for the two enterprises was 224. The results of the current study showed that age at slaughter, BW, cumulative FI, FeR and mortality in the two farms declined significantly (P
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    The influence of processing of lupins and canola on apparent metabolizable energy and broiler performance.
    (Stellenbosch : University of Stellenbosch, 2005-12) Breytenbach, Liesl ; Ciacciariello, M.; Ekermans, L. G.; University of Stellenbosch. Faculty of Agrisciences. Dept. of Animal Sciences.
    The extrusion and dehulling of sweet blue lupins (Lupinus angustifolius, cultivar Wonga) and the expansion of full-fat canola seed were evaluated in terms of their effect on the nitrogen corrected apparent metabolizable energy (AMEn) value and broiler performance.
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    Investigating the high incidence of bone disorders in a broiler farm : a case study
    (Stellenbosch : University of Stellenbosch, 2006-03) Mkhize, Felicity Nomfuzo; Ciacciariello, M.; University of Stellenbosch. Faculty of Agrisciences. Dept. of Animal Sciences.
    Rickets is described as a disease that affects young growing poultry. Poorly mineralized bones with thickened and irregular growth plates characterize it. The onset of rickets is characterized by a failure of mineralization of cartilage and bone. Other symptoms of rickets include reluctance to movement in affected birds. These birds will sit on their hocks and if startled they use their wings for balance. On necropsy, bones are soft and fragile and they have thickened growth plates. In this study 30% of the chicks aged between 7 and 8 days from a broiler flock, started showing splay leg problems. Affected chicks were unable to support their weight on their legs, some showing paralysis. The bones were soft and rubbery. To try and identify the possible cause, bones from the affected chicks were analyzed for calcium (Ca) and phosphorus (P) to determine the Ca:P ratio. Blood serum was also analyzed for the mineral content. Ca and P were the main focus of the tests as the problem was suspected to be rickets. The feed was analyzed for protein, Ca and P. The bone analysis showed a Ca:P ratio of less than 2:1, while results of the blood serum showed an inverse Ca: P ratio. The analysis results of the feed as well as the bones showed an imbalance in the Ca:P ratio which according to literature and research done is a possible cause for rickets. These findings combined with the symptoms displayed by the affected birds, lead to the suggestion that the problem in this study was rickets.