Thesis (M.Sc. (Agriculture)) --University of Limpopo, 2010 / Ten experiments were conducted to determine the effect of dietary energy to protein ratio level on growth and productivity of indigenous Venda chickens raised in closed confinement from day-old up to thirteen weeks of age. The ten experiments were based on five different energy levels of 12.2, 13, 13.2, 13.4 and 14 MJ ME/kg DM. Each dietary energy level had five different levels of protein concentrations of 220, 190, 180, 170 and 160 g/kg DM, thus ending up with twenty five different dietary energy to protein ratio levels. Experiments 1 to 5 examined the effect of dietary energy to protein ratio on productivity of unsexed Venda chickens aged one to six weeks. Experiments 1 to 5 each commenced with 160 unsexed day-old indigenous Venda chicks with an initial weight of 25 ± 2 g per bird and each lasted for a period of six weeks. In each experiment, the chicks were randomly assigned to five treatments with four replications, each having eight birds. Thus, 20 floor pens (1.5 m2 /pen) were used in total for each experiment. All the five experiments were carried out around the same time. A complete randomized design was used for each experiment. A quadratic regression model was used to determine the ratios for optimum feed intake, growth rate, feed conversion ratio, live weight, metabolisable energy and nitrogen retention in each experiment while a linear model was used to determine the relationship between optimal responses in the above variables and dietary energy to protein ratio levels. Dietary energy to protein ratio level for optimal response for any variable was relative and depended on the energy to protein ratio values of the diet. Energy to protein ratios of 63, 67, 70, 74 and 78 MJ ME/kg protein promoted optimal live weights of 415, 408, 370, 365 and 344 g at six weeks of age for diet energy levels of 12.2, 13, 13.2, 13.4 and 14 MJ ME/kg DM, respectively. However, optimal response trends for different variables were also influenced by the dietary energy to crude protein ratio. Optimal feed intake increased linearly with increasing dietary energy to protein ratio levels. Similarly, optimal metabolisable energy level increased linearly with increasing dietary energy to protein ratio levels without any increase in live weight. On the other hand, increasing dietary energy to protein ratio level decreased growth rate with a linear deteriorating feed conversion ratio,thus, negatively affecting live weight of the chickens at six weeks of age. However, increasing dietary energy to protein ratio levels improved efficiency of protein utilization with a linear deteriorating metabolisable energy utilization. In experiments 1 to 5, correlation analysis indicated that optimal feed intake, feed conversion ratio and metabolisable energy level were positively and strongly correlated with dietary energy to protein ratio levels while optimal live weight, growth rate and nitrogen retention were negatively and strongly correlated with dietary energy to protein ratio levels. The study indicated that a diet containing a crude protein content level of 178 g/kg DM and an energy level of 14 MJ ME/kg DM allowed for optimal utilization of absorbed protein and energy for growth in unsexed indigenous Venda chickens aged between one and six weeks. Experiments 6 to 10 examined the effect of dietary energy to protein ratio level on productivity of male Indigenous Venda chickens raised in closed confinement from seven up to 13 weeks of age. Each experiment commenced with 100 seven-week old male Venda chickens with an initial weight of 320 ± 2 g per bird. In each experiment, the chickens were randomly assigned to five treatments with four replications, each having five birds. Thus, 20 floor pens (1.5 m2/pen) were used in total for each experiment. All the five experiments were carried out around the same time and for a period of seven weeks. A complete randomized design wasused for each experiment. A quadratic regression model was used to determine energy to protein ratios for optimum feed intake, growth rate, feed conversion ratio,live weight, metabolisable energy, nitrogen retention, carcass yield, breast meatyield and fat pad deposition in each experiment while a linear model was used to determine the relationship between optimal responses of the above variables and dietary energy to protein ratio levels. Energy to protein ratios of 60, 71, 66, 72 and 71 MJ ME/kg protein promoted optimal live weights of 1167, 950, 983, 1235 and 1172 g at thirteen weeks of age for diet energy levels of 12.2, 13, 13.2, 13.4 and 14 MJ ME/kg DM, respectively. Optimal response trends in feed intake, growth rate, feed conversion ratio, nitrogen retention, and metabolisable energy intakes in male Venda chickens tended to increase with increase in dietary energy to protein ratio level. In contrast, optimal carcass and breast meat yield tended to decrease with increasing dietary energy to protein ratio level. However, optimal live weight and fat pad remained unchanged with increase in dietary energy to protein ratio value. Additionally, increasing dietary energy to protein ratio level improved efficiency of protein utilization with deteriorating metabolisable energy utilization.On the other hand, experiments 6 to 10 showed that optimal feed intake, growth rate, feed conversion ratio, live weight, metabolisable energy level, nitrogen retention and fat pad were positively and poorly correlated with dietary energy to protein ratio levels while optimal carcass weight and breast meat yield were negatively and poorly correlated with dietary energy to protein ratio levels This study indicated that a diet containing 193 g CP/kg DM and an energy level of 14 MJ ME/kg DM allowed for optimal utilization of absorbed protein and energy for growth in male indigenous Venda chickens aged between seven and thirteen weeks.It is, therefore, concluded that optimal response trends for different variables in growing unsexed Venda chickens offered diets differing in optimal dietary energy to protein ratio levels are influenced by the diet crude protein content rather than the feed energy level per se. Diets containing decreased dietary energy to protein ratio levels may promote improved growth rate and efficient feed conversion ratio while naturally restricting feed intake. Diets containing increased dietary energy to protein ratio levels favoured efficient utilization of consumed dietary protein. However, with such diets, protein became limiting and birds increased their feed intake attempting thereby to obtain more of the limiting protein in order to meet their protein requirement regardless of the energy value of the diet.It is, also, concluded that growing male Venda chickens increased their feed intake with increase in dietary energy to protein ratio. This is contrary to what has been observed in broiler chickens which decrease their intake with increase in diet energy value. It is suggested that this might reflect the differences between indigenous and broiler chickens in terms of their genetic and physiological abilities to regulate their feed intakes according to dietary energy levels. / National Research Foundation (NRF)

Worldwide, millets are regarded as significant grains; however, they are the least exploited. Millet grain is abundant in nutrients and health-beneficial phenolic compounds, making it suitable as food and feed. The diverse contents of nutrients and phenolic compounds present in finger and pearl millet are good indicators that the variety of millet available is important when selecting it for use as food or feed. The phenolic properties found in millets comprise of phenolic acids, flavonoids, and tannins, which are beneficial to human health. Research has shown that millet phenolic properties have high antioxidant activity. Phytochemicals present in millet grains have positive effects on human health by lowering the cholesterol and phytates in the body. The frantic demands on maize and its uses in multiple industries have merit the search for alternative grains, to ease the pressure. Substitution of maize with pearl and finger millets in the diets of different animals resulted in positive impact on the performance. Of late, millet grain has been incorporated in other foods and used to make traditional beverages. In Chapter 1, the topic of the research was introduced, stating the importance of the study and to motivate on the significance of millet grains. Aims and objectives were also listed. Chapter 2 presented extensive literature review on millet and their uses in human and livestock nutrition. In addition, the use of tannin as alternative feed was also reviewed. Different studies have been conducted to investigate the suitability of millet grain as an energy source, in the animal industry. However, studies on the Southern African types of millet are limited; this might be due to lack of information on their nutritional composition and their suitability as animal feed. Overall, the aim of this study was to profile the nutritional characteristics of selected millet grains in South Africa and Zimbabwe, their suitability as energy source for human and livestock and to study the effect of pearl millet type on the performance indices of Ross 308 broiler chickens. In Chapter 3, the general materials and methods used to reach the scientific conclusion for this study was summarised. In Chapter 4, physical and chemical analysis were conducted on millet grains obtained from South Africa and Zimbabwe, the results revealed that the physiochemical characteristics of the millet grain qualify it as a suitable candidate in replacing maize as an energy source. To further understand the characteristics of the millet grain, Chapter 5 analysed the phenolic compounds available in the millet grain obtained from South Africa and Zimbabwe. The results showed that the grain is endued with valuable phenolic compounds beneficial in the nutrition of both human and animals and aid as health benefit. Chapter 6 investigated the various inclusion levels of pearl millet in a bid to establish the most suitable combination for the poultry sector. Pearl millet grain used in this experiment went through different breeding improvements and selections conducted at the Grain Crop Institute in Potchefstroom, South Africa. Pearl millet grain was used as the main source of energy for Ross 308 broiler chicks for a period of 42 days with performance indices investigated. The results revealed that pearl millet can be incorporated in the diets of broiler chickens, in replacement of maize, without adversely affecting the performance. In addition, the economic justification of replacing maize with pearl millet was studied. The cost of the grains was determined and the cost per weight gain was determined. The results showed that indeed it is economically sound to replace maize with pearl millet in the diet of poultry. The quadratic function best fitting optimum treatment combination in relation to performance parameters such as body weight, body weight gain, feed conversion ratio and internal organs was also examined. In Chapter 7, the research was generally discussed to tie up the conclusions of the experiments conducted. General recommendations were also given on the compounds of millet varieties and their health benefits to both humans and animals. / Kuwo wonke umhlaba, amabele athathwa njengezinhlamvu ezibalulekile, kodwa awasetshenziswa kakhulu. Uhlamvu lwebele lunemisoco eminingi kanye nenzuzo yempilo ngama-phenolic compound, okwenza ukuthi afaneleke kakhulu njengokudla kwabantu kanye nemfuyo. Imisoco eminingi equkethwe kanye nama-phenolic compound atholakala eminweni kanye nezinhlamvu zebele ayizinkomba ezinhle zokuthi izinhlobo zamabele ezitholakalayo zibaluleke kakhulu ekukhethweni njengokudla kanye nokudla kwabantu noma imfuyo. Amaphenolic properties atholakala kumabele aqukethe ama-phenolic acids, ama-flavonids, kanye nama-tannins, ayinzuzo kakhulu empilweni yabantu. Ucwaningo luthole ukuthi ama-phenolic properties amabele anomsebenzi wezinga eliphezulu lama-antioxidant. Ama-phytochemicals atholakala kwizinhlamvu zamabele anenzuzu enhle kakhulu kwimpilo yabantu ngokwehlisa izinga le-cholesterol kanye nama-phytate emzimbeni. Ukudingeka kakhulu kombila kanye nokusetshenziswa kwawo kwizimboni eziningi, kubangele ukuthi kwenziwe ucwaningo ngezinye izinhlamvu ukwehlisa ingcindezi. Ukuthatha isikhundla sombila, sithathwa amabele kwidayethi yezilwane ezehlukene kwaba nomphumela omuhle kakhulu ngokusebenza. Kamuva nje, izinhlamvu zamabele zifakelwe kwezinye izidlo ezisetshenziswa ukwenza iziphuzo zomdabu. Kwisahluko 1, isihloko socwaningo sethulwa khona, ukuchaza ukubaluleka kocwaningo kanye nokuqikelela ngokubaluleka kwezinhlamvu zamabele. Izinhloso nezinjongo nazo zifakelwe kuhla. Isahluko 2, sethula ukubuyekezwa kwemibhalo ngamabele kanye nokusetshenziswa kwawo kubantu kanye nokudla kwemfuyo. Nangaphezu kwalokho, ukusetshenziswa kwe-tannin njengokunye ukudla kwemfuyo kuye kwabuyekezwa. Kwenziwe ucwaningo olwehlukene ukuphenyisisa ngokufaneleka kwezinhlamvu zamabele njengomthombo wamandla (we-eneji) kwimboni yezilwane. Kodwa, ucwaningo ngezinhlobo zamabele eNingizimu ne-Afrika alukenziwa ngokwanele; lokhu kungenzeka kungenxa yokuswelakala kolwazi ngemisoco equkethwe kanye nokufaneleka njengokudla kwezilwane. Kanti ngokwengamele, inhloso yalolu cwaningo bekuwukwenza iprofayili yemisoco ngezinhlamvu zamabele athile eNingizimu Afrika kanye naseZimbabwe, ukufaneleka kwawo njengomthombo wamandla (we-eneji) kubantu kanye nemfuyo, kanye nokwenza ucwaningo ngemiphumela yenhlobo yamabele ngama-performance indices wamachwane e-ROss 308. Kwisahluko 3, kusetshenziswe imetheriyali kanye namamethodi asetshenzisiwe ukufinyelela isiphetho sezesayense kulolu cwaningo, kwafinyezwa. Kwisahluko 4 kwenziwe uhlaziyo lokubambekayo kanye namakhemikhali ngezinhlamvu zamabele ngokutholakale eNingizimu Afrika kanye naseZimbabwe, imiphumela ikhombise ukugqama kwe-physiochemical kwezinhlamvu zamabele ukufaneleka kwazo njengekhandideti ekuthatheni isikhundla sombila njengomthombo wamandla. Ukuqhubeka nokuqondisisa ukuphawuleka kwezinhlamvu zamabele, iSahluko 5 sihlaziye ama-phenolic compound kwizinhlamvu zamabele aseNingizimu Afrika neZimbabwe. Imiphumela ikhombisa ukuthi uhlamvu lwamabele lunama-phenolic compound ayinzuzo ekudleni okunomsoco kubantu kanye nezilwane, kanye nokuba wusizo lwenzuzo kwimpilo. Isahluko 6 siphenyisise ngamazinga okubandakanywa kwamabele ukwenzela ukuthola ukufaneleka kwawo kumkhakha wezinkukhu. Izinhlamvu zamabele e-pearl zisetshenziswe kule ekspirimenti, eyenziwa ezigabeni ezehlukene zokuthuthukisa ukuzalisa kanye nokhetho olwenziwe ngabe-Grain Crop Institute ePotchefstroom, eNingizimu Afrika. Amabele e-pearl asetshenziswe njengomthombo omkhulu we-eneji kumachwane eRoss 308 isikhathi sezinsuku ezingu 42 kanti kwaphenyisiswa ngokusebenza kwama-indices. Imiphumela iveze ukuthi amabele epearl angafakelwa kwidayethi yamachwane, ukuthatha isikhundla sombila, ngaphandle kokuphazamisa ukusebenza. Nangaphezu kwalokho, ukufaneleka kwezomnotho ngokuthatha isikhundla zombila sithathwa ngamabele e-pearl kuye kwacwaningwa. Izindleko zezinhlamvu ziye zabekwa kanti futhi nesisindo ngezinhlamvu kuye kwabekwa. Imiphumela ikhombisa ukuthi kuyinto enhle kwezomnotho ukuthatha isikhundla sombila sithathwa ngamabele e-pearl kwidayethi yezinkukhu. Ukusebenza kwe-quadratic function kufaneleke kakhulu kwi-optimum treatment combination mayelana nama-parameter okusebenza afana nokwenyuka kwesisindo somzimba, ukuguqula i-feed conversion ratio kanye nezitho zangaphakathi nazo ziye zahlolwa. KwiSahluko 7, ucwaningo kuye kwaxoxwa ngalo ukuhlanganisa iziphetho zama-ekspirimenti enziwe. Izincomo ezinabile, ziye zanikezwa ngama-compound ezinhlobo zamabele kanye nezinzuzo zawo kwezempilo kubantu kanye nezilwane / Lefaseng ka bophara, leotša le bonwa bjalo ka mabele a bohlokwa kudu; le ge go le bjale, ke dibjalo tšeo di sa bjalwego kudu. Dithoro tša leotša di tletše ka phepo ye ntši le ditswaki tša fenoliki tšeo di nago le mohola maphelong, gomme se sa dira gore di be maleba bjalo ka dijo le phepo. Dikagare tša lona tšeo di fapafapanego le ditswaki tša fenoliki tšeo di whetšagalago ka gare ga leotša la finger le la pearl ke dilaetši tše kaone tša gore mehutahuta ya leotša yeo e hwetšagalago e bohlokwa ge e kgethwa bjalo ka sejo le phepo. Diteng tša fenoliki tšeo di hwetšwago ka agre ga leotša di na le diesiti tša fenoliki, difolabanoite, le dithaninse, tšeo di lego mohola go maphelo a batho. Dinyakišišo di laeditše gore diteng tša fenoliki tša leotša di na le mošomo wa godimo wa dihlwekišammele tšeo di bitšwago dianthioksitente. Difaethokhemikhale tšeo di lego gona ka gare ga dithoro tša leotša di na le diabe tše kaone go maphelo a batho ka go fokotša kholesterole le difaetheite mmeleng. Dinyakwa tša ka pela go lefela le mešomo ya lona ka diintastering tše ntši di dirile gore go be le nyakego ye kgolo ya dithoro tše dingwe tšeo di ka emelago lefela legato, go nolofatša kgatelelo yeo e beilwego go lefela. Go tšeela lefela legato ka leotša la pearl le la finger ka dijong tša diphoofolo tšeo di fapafapanego go feleleditše ka seabe se sekaone ka ga go šoma ga lona. Go fihla mo lebakeng le, dithoro tša leotša di tsentšwe ka dijong tše dingwe gomme tša šomišwa go dira dino tša setšo. Ka go Kgaolo ya 1, hlogotaba ya dinyakišišo e tsebagaditšwe, ya fa bohlokwa bja dinyakišišo tše le lebaka mabapi le bohlokwa bja dithoro tša leotša. Maike mišetšo le dinepo le tšona di filwe. Kgaolo ya 2 e hlagišitše tekodišišo ya dingwalwa ye e tseneletšego ka ga leotša le mešomo ya lona go phepo ya batho le ya diphoofolo. Godimo ga fao, tšhomišo ya tannin bjalo ka phepo ya boikgethelo le yona e lekodišišitšwe. Dinyakišišo tše di fapafapanego di dirilwe go nyakišiša go ba maleba ga thoro ya leotša bjalo ka methopo wa enetši, ka intastering ya diphoofolo. Le ge go le bjale, dinyakišišo tš0e di dirilwego mabapi le mehuta ya leotša ka Borwa bja Afrika ke tše nnyane; se se ka ba se bakwa ke tlhoklego ya Tshedimošo mabapi le sebiopego sa phepo ka hare ha leotša le go ba maleba ga lona bjalo ka phepo ya diphoofolo. Ka kakaretšo, maikemišetšo a dinyakišišo tše e bile go lebeledišiša dikokwane tša phepo tša dithoro tša leotša tšeo di kgethilwego ka Afrika Borwa le ka Zimbabwe, go ba maleba ga lona bjalo ka methopo wa enetši go batho le go diruiwa le go nyakišiša ka ga seabe ka ga mohuta wa leotša wa pearl go go šoma ga dipalopalo go dikgogo tša nama tša Ross 308. Ka go Kgaolo ya 3, ditlabelo le mekgwa ka kakaretšo yeo e šomišitšwego go fihlelela sephetho sa tša mahlale sa dinyakišišo tše di filwe kakaretšo. Ka go Kgaolo ya 4, tshekatsheko ya naga le ya dikhemikhale e dirilwe mabapi le dithoro tša leotša tšeo di hweditšwego ka Afrika Borwa le ka Zimbabwe, dipoelo di utollotše gore dikagare tša dikhemikhale tša thoro ya leotša di le dira le be lebele leo le loketšego go tšeela legato lefela bjalo ka methopo wa enetši. Go kwešiša go tšwela pele dikagare tša thoro ya leotša, Kgaoilo ya 5 e sekasekile diteng tša fenoliki tšeo di hwetšagalago ka gare ga thoro ya leotša leo le hwetšago ka Afrika Borwa le ka Zimbabwe. Dipoelo di laeditše gore thro ya leotša le tletše ka dikagare tša fenoliki tšeo di lego mohola go phepo ya bobedi batho le diphoofolo le gore le thuša bjalo ka kholego ya tša phepo. Kgaolo ya 6 e nyakišišitše maemo a mehutahuta a kakaretšo a leotša la pearl ka nepo ya go hwetša motswako wa maleba kudu ka lekaleng la dikgogo. Dithoro tša leotša la pearl tšeo di šomišitšwego ka mo tekodišišong ye di sepedišitšwe ka go dikaonafatšo tše di fapanego tša monontšha gomme dikgetho di dirilwe ka go Sehlongwa sa Dibjalo tša Dithoro ka Potchefstroom, ka Afrika Borwa. Dithoro tša leotša la pearl di šomišitšwe bjalo ka mothopo wa enetši go matswiana a nama a Ross 308 mo matšatšing a 42 fao go dirilwego dinyakišišo ka ga dipalopalo tša go gola ga dikgogo. Dipoelo di laeditše gore leotša la pearl le ka tsenywa ka dijong tša dikgogo tša nama, go tšeela legato lefela, ka ntle le go ama gampe go gola ga dikgogo. Godimo ga fao, lebaka la tša ekonomi la go tšeela lefela legato ka leotša la pearl le nyakišišitšwe. Theko ya dithoro e hweditšwe gomme theko ka boima bjo itšego le yona e hweditšwe. Dipoelo di laeditše gore ka nnete go tloga go kwagalago kudu go tša ekonomi go tšeela lefela legato ka leotša la pearl. Mošomo wa tekanelo wa wo o loketšego bokaone motswako wa tlhokomelo ya godimo mabapi le mahlakore a kgodišo ya dikgogo a go swana le boima bja mmele, go nona, rešio ya go fetošetša dijo le ditho tša ka gare le ona o lekodišišitšwe. Ka go Kgaolo ya 7, dinyakišišo di hlalošitšwe ka kakaretšo gore go fihlelelwe sephetho ka ga ditekodišišo tšeo di dirilwego. Ditšhišinyo ka kakaretšo le tšona di filwe mabapi le dikagare tša mehutahuta tša leotša le dikholego tša ona go tša maphelo go bobedi batho le diphoofolo / College of Agriculture and Environmental Sciences / D. Phil. Agr. (Animal Science)