Call number: LD2668 .T4 1978 F59 / Master of Science

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Sixty Bonsmara heifers (328 ± 3.9 kg) on planted pastures were used to evaluate the effect of two energy sources and three growth promoters on body weight gain. Two supplementary feeds with dried apple pulp (A) or maize (M) as main energy source were formulated on an iso-nutrient base. One of three different growth promoters was included in each energy supplement: placebo (no growth promoter, designated as Treatments Ap and Mp), ionofore (monensin, designated as Treatments Am and Mm) and essential oil extract (from oregano, designated as Treatments Ao and Mo). A fixed amount of the supplements was offered to the six treatment groups in a growth/finishing study on cultivated grass-legume pastures. Animals were stratified according to initial weight in ten blocks and treatments were assigned randomly to animals in each block. The 66 day growth study was conducted during spring (Sepember to November, 2014) in the Western Cape Province of South Africa near Greyton. The cultivated pastures consisted of a perennial grass-legume mixture. A rotation grazing system was applied and animals were moved to new paddocks once a week. Based on falling plate meter readings, the heifers consumed a calculated mean amount of 4.48 ± 0.08 (SEM) kg DM/day over the entire experimental period. A fixed amount of 4 kg (“as is” basis) of the respective supplements were offered daily during the first 42 days, followed by 5 kg/day from 43 days until the end of the study (66 days). Animals were weighed bi-weekly and average daily gain (ADG) was calculated. The mean ADG of the six treatment groups was 1.44 kg/day. No interactions occurred between the energy sources and growth promoters used in the concentrates and main effects were thus interpreted. The supplements that contained apple pulp as energy source resulted in a higher (P < 0.02) ADG (1.54 kg/day) than the maize containing supplements (1.33 kg/day). There were no differences between any of the growth promoters, with the placebo resulting in similar growth rates than monensin and oregano oil extract. Mean ADG values (kg/day) of the different growth promoter treatments were 1.44 (placebo), 1.49 (monensin) and 1.38 (oregano). All the heifers were slaughtered at the end of the trial. Carcass weight and dressing percentage did not differ between energy sources or growth promoters. The mean dressing percentage was 52.5%. The mean income over feeding cost for the 66 day period of the three maize energy source treatments was R254.20/heifer, while that of the apple pulp treatments was R524.75/heifer. According to this study, concentrate supplements containing apple pulp as main energy source were economically more desirable than those containing maize as primary energy source. / AFRIKAANSE OPSOMMING: Sestig Bonsmaraverse (328 ± 3.9 kg) op aangeplante weiding is gebruik om die invloed van twee energiebronne en drie groeibevorderaars op massatoename te ondersoek. Twee supplemente met gedroogde appelpulp (A) of mielies (M) as hoofenergiebron is op ‘n isonutriëntbasis geformuleer. Een van drie groeibevorderaars is in elk van die energiesupplemente ingesluit: placebo (geen groeibevorderaar, aangedui as Behandelings Ap en Mp), ‘n ionofoor (monensin, aangedui as Behandelings Am en Mm) en ‘n essensiële olie-ekstrak (van oreganum, aangedui as Behandelings Ao en Mo). ‘n Vasgestelde hoeveelheid van die supplemente is aan elk van die ses groepe in ‘n groei/afrondingsproef op aangeplante weidings aangebied. Diere is volgens aanvangsmassa in tien bloke gestratifiseer en behandelings is ewekansig aan diere in elke blok toegeken. Die 66-dae groeistudie is gedurende die lente (September tot November) in die Wes-Kaapprovinsie van Suid-Afrika naby Greyton uitgevoer. Die weidings het uit ‘n meerjarige gras-klawermengsel bestaan. ‘n Rotasiebeweidingstelsel is gevolg en diere is weekliks na nuwe kampies verskuif. Volgens die lesings van ‘n valplaatmeter het die verse ‘n gemiddelde weidingsinname van 4.48 ± 0.08 (SEM) kg DM/dag getoon. ‘n Vasgestelde hoeveelheid van 4 kg (lugdroë basis) van die onderskeie supplemente is daagliks gedurende die eerste 42 dae van die proef aangebied, gevolg deur 5 kg/dag vanaf 43 dae tot aan die einde van die proef (66 dae). Diere is tweeweekliks geweeg en die gemiddelde daaglikse toename is (GDT) bereken. Die gemiddelde GDT van die ses behandelingsgroepe was 1.44 kg/dag. Geen interaksies tussen die energiebronne en groeibevorderaars is waargeneem nie en hoofeffekte is gevolglik geïnterpreteer. Die supplemente wat appelpulp as energiebron bevat het, het tot ‘n hoër (P < 0.02) GDT (1.54 kg/day) gelei as die mieliebevattende supplemente (1.33 kg/dag). Daar was geen verskille tussen enige van die groeibevorderaars nie met die placebo wat soortgelyke resultate as monensin en oreganum olie-ekstrak gelewer het. Gemiddelde GDT waardes (kg/dag) van die onderskeie groeibevorderaars was 1.44 (placebo), 1.49 (monensin) en 1.38 (oreganum). Al die verse is teen die einde van die proef geslag. Karkasmassa en uitslagpersentasie het nie tussen energiebronne of groeibevorderaars verskil nie. Die gemiddelde uitslagpersentasie was 52.5%. Die gemiddelde wins bo voerkoste van die drie energiebronsupplemente was R254.20/vers, terwyl dié van appelpulpbehandelings R524.75/vers was. Volgens hierdie studie was die supplemente wat appelpulp as hoofenergiebron bevat het, meer winsgewend as dié wat mielies as hoofenergiebron bevat het.

The objective of this study was to evaluate the variability of growth curves of dairy heifers and estimate genetic parameters. 15066 records taken from birth until 26 months (808 days) on 2754 heifers of Quebec were considered. The pedigree file comprised 10123 animals. The Mixed procedure of SAS with ordinary polynomials was used for simple phenotypic analyses, fitting fixed linear, quadratic and cubic regressions of body weight (in kilograms) on age (in months) as well as random intercept, and random linear and quadratic regressions for each animal. The Wombat program (Meyer, 2007), with Legendre polynomials was used to estimate the genetic parameters by fitting fixed herd-year-season of birth and quartic regression of body weight on age in days, as well as random regressions for quadratic additive genetic and cubic permanent environmental effects. Heritability estimates of body weight ranged from 0.22 at around 70 days to 0.45 at around 210 days. Heritabilities of body weight at birth and 808 days were 0.35 and 0.32, respectively. The additive genetic correlations between body weights at different ages ranged from -0.37 to 1.00. In general, the genetic correlations were higher than the permanent environmental and phenotypic correlations.

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Made available in DSpace on 2014-06-11T19:27:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-02-16Bitstream added on 2014-06-13T19:35:45Z : No. of bitstreams: 1 rodrigues_e_me_botfmvz.pdf: 164174 bytes, checksum: 6f150d388d6d03c51572ae0d22cf79f5 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / O objetivo deste trabalho foi avaliar o crescimento de femeas bovinas de diferentes grupos geneticos no sistema intensivo de producao de carne superprecoce, analisando caracteristicas de desempenho como peso vivo (PV), ganho de peso medio diario (GPMD) e crescimento dos tecido muscular e adiposo atraves de avaliacao da area de olho de lombo (AOL) e espessura de gordura subcutanea (EGS) do musculo Longissimus dorsi e espessura de gordura subcutanea da garupa (EGG) do musculo Biceps femoris com imagens coletadas por ultra-som em tempo real nos animais vivos no inicio e fim do experimento. Foram utilizadas 42 femeas de 4 grupos geneticos sendo: 12 . Canchim x . Nelore (. CN), 12 . Canchim x . Nelore (. CN), 10 Simbrasil . Simental X . Nelore ( SIMB) e 10 Three-cross . Simental x . Nelore x . Angus (TC) desmamadas aos 210 dias de idade e peso vivo medio de 247,4 }16,5kg provenientes de creep-feeding durante a fase de cria, e confinadas por aproximadamente 132 }14 dias. Os animais foram abatidos, sendo o criterio de abate peso final de 350kg/PV e 5mm de gordura subcutanea. Os animais do grupo Three-cross apresentaram area de olho de lombo final e final ajustada para 100kg/PV inferiores aos demais grupos, porem apresentaram pesos finais superiores aos demais grupos com um tempo intermediario de confinamento e este grupo tambem apresentou os melhores ganhos de peso medio diario (GPMD) 1,07kg/dia (P<0,05). Nao houve diferenca significativa para area de olho de lombo inicial, espessura de gordura subcutanea (EGS) e para espessura de gordura subcutanea da garupa (EGG). Ajustando-se os valores de (EGG) e (AOL) para o menor numero de dias de confinamento onde os animais Three-cross e Simbrasil foram superiores (P<0,05) para (EGG F 114), e Simbrasil superior (P<0,05) para (AOL F 114). / The objective of this study was to evaluate the growth of young heifers of different genetic groups in an intensive meat production system. It was used 42 animals of 4 different genetics groups: 12 . Canchim x . Nellore (. CN), 12 . Canchim x . Nellore (. CN), 10 Simbrasil . Simental X . Nellore (SIMB) and 10 Three way cross . Simmental x . Nellore x . Angus (TC). The animals received creep feeding supplementation and were weaned at 210 days of age with 247,4 }16,48kg. It was analyzed the characteristics of body weight (BWG), average daily gain (ADG), muscular and fat tissues growth. Real time ultrasound evaluation was used to measure ribeye area (RBA, Longissimus dorsi muscle), back fat thickness and P8 (Top rump, Biceps femoris) fat thickness. The feeding period was 132 (}14) days in feedlot system while daily gain was measured every 28 days. The animals were slaughtered with the final weight of 350 kg and 5mm of back fat thickness. The Three way cross heifers had smaller final and adjusted at 100 kg/PV ribeye area compared with the others groups. This group also had a greater final body weight, better average daily gain (GPMD), 1,07 kg/day (P<0,05) and an intermediate days of feeding. There was no significant differences for initial ribeye area (AOL), back fat thickness (EGS) and P8 (EGG), but when the values were adjusted for days of feeding, greater values (P<0,05) (EGG F 114) and (P<0,05) (AOL F 114), respectively.

Thesis (MPhil (Animal Sciences))--University of Stellenbosch, 2006. / South Africa produces only 0,50 % of the world’s milk. Although the number of milk producers is decreasing in South Africa, the milk production per se is increasing. The total number of small producers is decreasing while the number of big producers is increasing. The cost to raise replacement heifers is very high. Replacement heifers are the cows of tomorrow and should be seen as a valuable investment for the longterm survival and profitability of the dairy farm. A successful heifer rearing program is one in which: • Heifers are economically raised to be of adequate size and body condition to calve at a reasonable age. • Heifers produce high levels of milk during the first lactation. In the current study, the effect of Flavomycin and Mamalvite supplementation to young calves was investigated. According to manufacturer’s claims, Flavomycin would result in improved gains, improved conception rates, shorter calving intervals, increased milk production and improved weaning weights. Mamalvite, according to the manufacturer, should reduce risk of infections, increase feed utilization, increase feed intake and production, and also increase rumen microbial efficiency. Thirty two Holstein calves, four days of age, were randomly divided into four groups of eight. All calves received 4 kg whole milk daily and had free access to calf starter pellets. Treatments were: 30 ml Mamalvite daily supplemented in the milk and 5 g Flavomycin daily per os (Treatment 1), 30 ml Mamalvite daily supplemented in the milk (Treatment 2), 5 g Flavomycin daily per os (Treatment 3) and a control group that received milk only (Treatment 4). All the calves were weighed weekly. According to the results obtained in the current study, neither Flavomycin, nor Mamalvite, nor a combination of the two resulted in an improvement in calf weight gains. It was concluded that it does not appear to be an economically viable option to supplement Mamalvite or Flavomycin to calves that are reared in a well managed environment.

Two trials using 32 heifers each evaluated response to undegraded intake protein (UIP) (30 or SO% CP), energy (supporting .S9 or .91 kg ADG), and source of UIP (blood meal or combination protein supplement). Trial one was a 2x2 factorial, with two levels of energy and UIP. High UIP was achieved with blood meal supplementation. From 6-13 mo of age (phase I), high energy increased ADG and DMI, and high UIP decreased DMI. DM efficiencies (kg DMIlkg BW gain) improved with high energy and high UIP, and roN efficiencies (kg IDN/kg BW gain) improved with high UIP. From 13 mo until calving (phase n), heifers were housed together and fed a common diet. Low energy, high UIP treatment had the highest ADG (1.01 kg/day) for phase I, but the lowest for phase n (.33 kg/day), and low energy, low UIP treatment had the lowest ADG (.62 kg/day) for phase I, but the highest for phase n (.S3 kg/day). Overall ADG from 6 mo until calving averaged .S9 kg/day, and was not affected by energy or UIP. In trial 2, two levels of energy and two sources ofUIP were compared, resulting in four treatments: low energy, high UIP with combination protein supplement; low energy, high UIP with blood meal; low energy, low VIP with soybean meal; and high energy, low UIP with soybean meal. Combination protein supplement contained blood meal, com gluten meal, and fish meal. Trial was 300 days long, and began at 6.5 mo. of age. Dry matter intake and ADO were increased with high energy, but not affected by VIP. Overall DM efficiency was not affected by VIP or energy level. Results of both trials indicate VIP may improve feed efficiency of growing Holstein heifers. / Master of Science

Growth and body composition of 121 Holstein heifers (4.6 to 18 mo and 129 to 407 kg) reared on pasture, drylot and pasture-drylot systems were evaluated in 6 experiments. Heifers were switched from drylot to pasture or the reverse to study carry-over effects from previous treatments; both systems were satisfactory. Alternate 28-day periods of supplement feeding to grazing heifers did not affect final body weight nor wither height, but ADF and heart girth varied during 2 yr. When switching drylot heifers previously fed low and high TDN, to pasture, gains were best for heifers fed the lower TDN diet; also, gains on pasture were best for light heifers. Gains by all heifers grazing mainly orchardgrass-clover pasture were acceptable, but supplementing with a 19% CP concentrate or lasalocid, usually improved gains. Heifers with lowest BW during grazing made compensatory gains in drylot. Urea space estimation technique showed that compensatory gains were mainly fat. Lasalocid feeding increased daily gain and subcutaneous fat deposition but reduced feed intake and ribeye area. When moving grazing heifers to drylot a total mixed ration with fishmeal or soybean meal as protein sources gave similar responses. DM intake of grazing heifers ranged from 8.1 to 10.1 kg/d, vs 7.5 kg/d for arylot. Supplementing grazing heifers with degradable or undegradable protein gave similar responses in growth and body composition. Based on growth and body composition, seasonal grazing of Holstein heifers may reduce costs for rearing replacement heifers. A corn silage-alfalfa silage-orchardgrass hay mixed ration without concentrates when fed ad libitum to heifers in drylot resulted in gain of 934 g/d. Pasture alone heifers gained from 368 to 755 g/d depending on drought and heifer age. Calculations of costs of rearing Holstein replacement heifers were prepared accounting for observations of response to grazing, supplements to grazing and drylot diets. Well managed grazing reduces costs of rearing. / Ph. D.