Orientador: Carlos Antonio Gamero / Banca: Silvio José Bicudo / Banca: Ciniro Costa / Banca: Kleber Pereira Lanças / Banca: Wagner dos Reis / Resumo: O sorgo forrageiro pode ser cultivado em áreas e situações ambientais secas e quentes, onde a produtividade de outras forrageiras pode ser normalmente antieconômica. O revolvimento do solo pode ser efetuado somente nas linhas de semeadura (semeadura direta) ou totalmente na área destinada à semeadura (preparo convencional), com arações, gradagens, subsolagem e escarificação (cultivo reduzido). A velocidade de deslocamento ideal para a semeadura é aquela em que o sulco é aberto e fechado sem remover exageradamente o solo, permitindo a distribuição das sementes em espaçamentos e profundidades constantes. O experimento foi instalado e conduzido em condições de campo, em solo classificado como Nitossolo Vermelho Distroférrico, na Fazenda Experimental Lageado da Faculdade de Ciências Agronômicas da UNESP, Campus de Botucatu. A presente pesquisa teve como objetivo avaliar a resposta da cultura do sorgo em quatro velocidades de deslocamento (3, 5 ,6 e 9 km h-1) e quatro sistemas de manejo de solo: SD (semeadura direta); GP (gradagem pesada + semeadura); GPL (gradagem pesada + duas gradagens leves + semeadura) e CR (escarificação + semeadura). Os dados obtidos foram submetidos a análise de variância em esquema fatorial 4 x 4 e um delineamento em blocos ao acaso com parcelas subdivididas. Foram determinados os seguintes parâmetros: massa seca da cobertura vegetal, porcentagem de cobertura do solo, resistência do solo à penetração, profundidade de deposição de sementes, área de solo mobilizada e profundidade de sulco de semeadura, velocidade média, patinagem do trator em operação, força média de tração na barra, potência média na barra de tração, capacidade de campo teórica do conjunto trator-equipamento, consumos horário e operacional... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract : Sorghum silage can be cultivated in dry and hot areas and environmental situations, in which productivity of some other forage is anti economic. Soil mobilization can be used only in seeding lines (no-tillage), or totally in the area for the seeding (conventional tillage), with plowing and drainage and sub soiling and chiseling (reduced crop). The ideal speed displacement for seeding is the one in which the rill is open and closed without exaggeratedly removing the soil, allowing seed distribution at constant spacing and depths. The experiment was installed and conducted in field conditions, in dystrophic Red Nitossol, at Fazenda Experimental Lageado, in Forest Sciences, College of Agronomic Sciences, São Paulo State University-FCA/UNESP-Botucatu (SP). The present research aimed at evaluating the response of sorghum crop in function of 4 displacement speeds (3, 5, 6 e 9 km h-1) and 4 soil management systems: SD (No-tillage), GP (Heavy disk harrow + sowing), GPL (heavy disk harrow + two leveling harrows + sowing) and CR (chiseling + sowing). The obtained parameters were analyzed statistically through analysis of the median values in a 4 x 4 factorial scheme and a completely randomized block design with split-plots. The following parameters were determined: dry mass of cover crop, percentage of soil cover, soil resistance to penetration, seed deposition depths, area of displaced soil, sowing depths, mean flow velocity, tractor slip in operation, median power of traction in the bar, median drawbar pull, theoretical field capacity of the group tractor-equipment, hourly and operational fuel consumption, early and final plant population, plant heights, stem diameter, fresh and dry mass of the aerial part, thousand grain mass, fresh and dry mass productivity. Speed variation in the operation... (Complete abstract click electronic access below) / Doutor

The objetive of this study was to evaluate the association between wheat pasture (WP) and sorghum silage (SS), from a nutritional and production viewpoint, to optimize the use of both resources. Three experiments were performed: I. Consumption, digestibility of DM, N and use of forage fiber; II. Mass of WP, weight and growth performance: average daily gain (ADG) and beef production/ha and, III. Estimation of voluntary intake by an external marker, LIPE. WP nutritional quality, %: June: 25.6, 18.1, 18.0, 88.9, 36.2, 15.6, July: 38.4, 18.2 , 17.1, 88, 8; 36, 3, 15.7, August 8: 45.6, 14.0, 16.6, 78.9, 42.1, 19 7, August 24: 41.7, 16.7, 14.7, 73.2, 52.4, 21.0, September: 25 0, 18.6, 9.7, 71.4, 60.0 and 26.5 for dry matter (DM), crude protein (CP), non-structural carbohydrates (CNES), in vitro DM digestibility (DMD), neutral detergent fiber (NDF) and acid detergent fiber (ADF), respectively. The values for the same quality parameters of SS were 30.4, 51.2, 7.8, 61.3, 35.3, 2.5, 18.9 and 1.9. In Experiment I, 24 lambs of 38+4.4 kg of body weight (BW) were placed in individual metabolism cages. The treatments were: WP ad libitum, SS ad libitum, 800WP (800g WP + SS), 600WP (600g WP + SS), 400WP (400g WP + SS) and 200WP (200g WP + SS). Total diet intake was determined by the difference between offered and rejected feed. Total fecal output (FO), as well as marker technique (LIPE) were used to estimate in vivo DMD. Other determinations included: NDF, ADF, IVDMD, NDF digestibility, ADF digestibility and balance of nitrogen (N). The Experiment II lasted 101 days (from 11/06 to 19/09, 2007). 60 heifers of 8 months of age and 200 +24.7 kg BW were used, which were distributed in six treatments in a factorial arrangement of two alternatives for availability (WP and WP + SS) and three intensities (A, M and B) with two replications. In Experiment III, 24 heifers were used. The treatments evaluated were the same as in Experiment II. SS intake was estimated by the difference between offered and rejected, and total intake of feed by an external marker, LIPE. The DMD was determined in vitro. In experiment I there was effect of diet (p <0.01) on NDF, IVDMD FDA, DIVFDA, N content in the diet, urine and N retained. Increasing WP allowances to SS basal diet showed no differences between them, nor against the pure diets, with the total DM intake in lambs. Animals that consumed WP, could replace up to 75% of this ingredient from SS, without to lower the consumption of MSD. Only in the ad libitum diet of WP N maintenance requirements of the lambs were covered, with negative balance in the other treatments. In experiment II there were differences (p <0.0001) between diets, and interaction D x I (p <0.05) for total C in WP and IVDMD. The total C was higher in WP without the addition of SS (A, M and B) for the three I with a substitution effect with depressed in consumption of WP in SS treatments. In experiment III, there were no significant differences for availability of WP between treatments (p = 0.9391 for D and p= 0.4171 for I), there was differences between dates sampling (DS) and interactions between I x DS and between I x DS x D. The average forage availability for WP was 800 kgDM/ ha. The ADG and AW differ significantly (p <0.0001) between weighing dates. The receptivity of WP increased by 83% (p ≤ 0.01) by the use of SS for AS and 69% for MS, the effect was not significant for BS (31%). There was variation in the relationship PB: CNES between diets with SS respect to the diets based only on WP, however AG of the heifers did not differ between treatments. The use of high grazing intensities of WP would not affect the ADG in heifers, which would increase the stocking rate or extend the grazing period of WP without affecting production. The enclosure for 20 h in SS and grazing WP for 4 h in growing heifers increases the receptivity of WP, may improve the stability of the productive results and thus increase the benefits of farms. / El objetivo de este trabajo fue evaluar las interacciones entre el verdeo de trigo (VT) y el silaje de sorgo (SS), desde el punto de vista nutricional y productivo, para optimizar el aprovechamiento de ambos recursos. Para esto se realizaron tres experimentos: I. Consumo, digestibilidad de la MS, uso del N y de la fibra del alimento; II. Disponibilidad del verdeo, peso vivo y respuesta productiva: ganancia diaria de peso y peso acumulado por hectárea; y III. Estimación del consumo voluntario por medio de un marcador externo, LIPE. Calidad nutritiva del VT en %: junio: 25,6; 18,1; 18,0; 88,9; 36,2; 15,6; julio: 38,4; 18,2; 17,1; 88,8 36;3; 15,7; 08 de agosto: 45,6; 14,0; 16,6; 78,9; 42,1; 19,7; 24 de agosto: 41,7; 16,7; 14,7; 73,2; 52,4; 21,0; septiembre: 25,0; 18,6; 9,7; 71,4; 60,0 y 26,5 para materia seca (MS), proteína bruta (PB), carbohidratos no estructurales (CNES), digestibilidad de la MS (DIVMS), fibra detergente neutro (FDN) y fibra detergente ácido (FDA), respectivamente. Los valores para los mismos parámetros de calidad del SS fueron: 30,4; 51,2; 7,8; 61,3; 35,3; 2,5; 18,9 y 1.9. En el Experimento I se utilizaron 24 corderos de 38+4.4 kg de peso vivo (PV), que se ubicaron en jaulas de metabolismo individuales. Las dietas evaluadas fueron: VT ad libitum, SS ad libitum, 800VT (800g de VT+SS), 600VT (600g de VT+SS), 400VT (400g de VT+SS) y 200VT (200g de VT+SS). Mediciones: consumo de MS (C) de SS y VT por oferta y rechazo y con el marcador, FDN, FDA, DIVMS, DIVFDN (digestibilidad de la FDN) y DIVFDA (digestibilidad de la FDA); producción de heces (PH) y balance de nitrógeno (N). El Experimento II duró 101 días (del 11/06 a 19/09 de 2007). Se utilizaron 60 vaquillonas de 8 meses de edad y de 200 +24,7 kg PV, que se distribuyeron en 6 tratamientos en un arreglo factorial de dos alternativas de Disponibilidad (VT y VT+SS) y tres Intensidades (A, M y B), con dos repeticiones. En el Experimento III se utilizaron 24 vaquillonas. Los tratamientos fueron los mismos que en el Experimento II. Se estimó el C de SS por oferta y rechazo y C total con un marcador externo, LIPE. La digestibilidad se determinó in vitro. En el Experimento I hubo efectos de dieta (p<0.01) sobre contenido de FDN, FDA DIVMS, DIVFDA, contenido de N en la dieta, en la orina y retenido. Asignaciones crecientes de VT a una dieta basal de SS no mostraron diferencias entre sí, ni tampoco frente a las dietas puras, en el consumo de MS total con corderos. Animales que consumieron VT, pudieron reemplazar hasta un 75% de este ingrediente por SS, sin que decayera el consumo de MSD. Solamente en la dieta de VT ad libitum se cubrieron los requerimientos de mantenimiento de N de los corderos, siendo el balance negativo en los demás tratamientos. En el Experimento II, no hubo diferencias significativas para disponibilidad de VT entre los tratamientos (p= 0,9391 para D y p= 0,4171 para I), sí hubo entre fechas (F) de muestreo y para las interacciones entre I*F y entre I*F*T. La disponibilidad promedio del VT fue de 800 kgMS/ha. La GP y el ADP presentaron diferencias significativas (p<0,0001) entre fechas de pesadas. La receptividad del verdeo aumentó en 83% (p≤ 0,01) por el uso de SS para AS y un 69% para MS, no siendo significativo el efecto para BS (31%). En el Experimento III hubo diferencias (p<0.0001) entre D, y para la interacción D x I (p<0.05) para C total, de VT y para DIVMS. El C total fue mayor en VT sin aporte de SS (A, M y B) para las tres I, con un efecto de sustitución con depresión del consumo del VT en los tratamientos con SS. Hubo variación en la relación PB:CNES entre las dietas a base de SS con VT respecto a las dietas basadas únicamente en VT sin embargo las GP de las vaquillonas no difirieron entre tratamientos. La utilización de altas intensidades de pastoreo de VT no afectarían las GP en vaquillonas, lo cual permitiría aumentar la carga animal o prolongar el período de pastoreo del VT sin afectar la producción. El encierre durante 20 horas en SS y pastoreo de 4 horas en VT en recría de vaquillonas aumenta la receptividad del mismo, pudiendo mejorar la estabilidad de los resultados productivos y aumentar de esta forma los beneficios de la explotación.

162 leaves printed on single pages, preliminary pages i- vii and numbered pages 1-152. Includes bibliography and abbreviations. / Digitized at 600 dpi grayscale to pdf format (OCR), using a Bizhub 250 Konica Minolta Scanner. / Thesis (PhD(Agric))--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: Maize, forage sorghum, lucerne, oats, barley and triticale are the most common silage crops in South Africa, while tropical grasses like Eragrostis curvula and Digitaria eriantha are ensiled to a lesser extent. The aim of this study was to determine the effect of adding a lactic acid bacterial inoculant to E. curvula, D. eriantha, lucerne, forage sorghum, maize and oat silage. The effect of the addition of a lactic acid bacterial inoculant when ensiling E. curvula on the fermentation dynamics during ensiling and the aerobic stability of the silage was determined. The addition of the lactic acid bacterial inoculant to E. curvula at ensiling resulted in a more rapid lowering in pH and improved preservation. Inoculated silage had a higher lactic acid content, less protein breakdown and a lower butyric acid content compared to that of the control silage. Both silages were stable when exposed to air for five days. Digitaria eriantha was ensiled, with or without the addition of a lactic acid bacterial inoculant containing Lactobacillus plantarum. Streptococcus faecium and Pediococcus acidilactici together with the enzymes, cellulase, hemicellulase and amylase. The addition of the inoculant resulted in a more rapid drop in pH, a higher level of lactic acid, an increase in the number of lactic acid bacteria, less protein breakdown and lower numbers of enterobacteria, clostridial spores, yeast and mould compared to the control silage. Digitaria eriantha hay, control and inoculated silage diets were fed to 24 Merino rams (n = 8 per treatment) to determine intake and digestibility. The intake of diets consisting of 90.9% D. eriantha hay, control silage or inoculated silage, differed significantly (p<0.05) at 1395, 1540 and 1848 g DM/day, respectively. The in vivo organic matter digestibility (glkg) of D. eriantha hay, untreated silage and inoculated silage diets was 561, 546, 574, respectively. The addition of the bacterial inoculant when ensiling D.eriantha resulted in better preservation, improved aerobic stability, as well as a higher in vivo organic matter digestibility and intake of D. eriantha silage. The addition of an inoculant or molasses to lucerne (Medicago sativa), ensiled in laboratory silos was investigated. The addition of the additives resulted in an increased preservation rate as indicated by a more rapid lowering of pH, a faster rate of lactic acid production and less protein breakdown compared to control silage. The inoculant was more effective than the molasses in improving the rate of preservation. The aerobic stability of lucerne silage was not affected by inoculation or the addition of molasses. The addition of an inoculant to wilted big bale lucerne silage was studied. The inoculant improved silage quality as indicated by a lower pH, higher lactic acid content, lower ammonia nitrogen content and lower level of butyric acid in inoculated silage compared to the control lucerne silage. The composition of big round bale lucerne silage differed markedly from that of lucerne ensiled in laboratory silos as the former had a higher pH, ammonia nitrogen, butyric acid and acetic acid content and a lower lactic content. Whole crop forage sorghum cultivar FS2 was harvested at the late bloom (20.7% DM) and soft dough (28.9% DM) stages of maturity and ensiled in laboratory silos with the addition of commercial silage inoculants. At both stages of maturity the inoculants caused a more rapid rate of pH decline and a higher amount of lactic acid production. All the silages were well preserved. Silages of the sorghum ensiled at the late bloom stage with all treatments were stable after 5 days of aerobic exposure, whereas sorghum ensiled at the soft dough stage with the addition of the inoculants deteriorated upon aerobic exposure. It is concluded that addition of lactic acid bacterial inoculants to mature sorghum at ensiling might impair the aerobic stability of the silage. The yield, nutritional value and production potential of silage made from twenty one maize hybrids was compared. It was concluded that maize hybrids did differ in metabolizable energy content, rate of digestion, predicted intake and predicted milk production potential. The content of NDF and ADF did not differ between the maize hybrids used in this study and could therefore not be used to predict nutritional value or production potential. Maize was harvested at the hard dough stage and ensiled with or without the addition of a lactic acid bacterial inoculant in laboratory silos and in 210 litre drums. The adding of the inoculant to maize at ensiling did not result in a more rapid drop in pH and higher levels of lactic acid. The intake and growth of South African Mutton Merino lambs fed inoculated and untreated maize silage diets was determined. The average daily gain of lambs fed a diet consisting of either 60% control or inoculated maize silage over a growth period of 60 days was 239 ± 26 and 255 ± 44 g/day, respectively. Although the laboratory study showed very little effect of adding a lactic acid bacterial inoculant to maize at ensiling, lambs tended to consume more of the inoculated silage. In the second study the effect of the addition of a lactic acid bacterial inoculant with an enzyme to maize at ensiling on the fermentation dynamics during ensiling, aerobic stability of the silage, the intake, milk production and milk composition of Jersey cows fed maize silage diets was determined. The inoculant did not result in a more rapid lowering of the pH or a more rapid lactic acid production compared to untreated maize silage made in laboratory silos. Both the control and inoculated maize silages were well preserved. The addition of the inoculant to maize at ensiling improved the palatability, intake and the aerobic stability of maize silage compared to the untreated control maize silage. Milk production, milk composition, live weight and condition score of Jersey cows was not significantly affected by the addition of the inoculant to maize silage. The effect of the addition of an enzyme containing lactic acid bacterial inoculant to big bale oat (Avena sativa, cv Cederberg) silage on silage composition, silage intake, milk production and milk composition of Jersey cows was determined. The crop was cut at the bloom stage, wilted and ensiled in big round bales. The inoculant, Sil-All, was applied during the baling process on half of the bales. Silages were fed to Jersey cows in an intake and milk production study. Both the control and inoculated oat silages were well preserved. The inoculated oat silage had a lower level of butyric acid than the control oat silage. Cows fed the inoculated oat silage produced more (P=O.05) milk (17.7 kg/day) than cows fed the control oat silage (16.7 kg/day). The addition of a lactic acid bacterial inoculant to big bale oat silage improved silage composition and animal performance. This study clearly showed that the composition of silages made in bunker silos under commercial farm conditions differ largely from that of silages made in small scale laboratory silos. When the effect of silage additives on aerobic stability of silage is determined the evaluation should include studies on large scale bunker silages. Evaluation of silage additives should include intake and animal production studies. / AFRIKAANSE OPSOMMING: Mielies, voersorghum, lusem, hawer, gars en korog word algemeen as kuilvoer gewasse benut terwyl tropiese grasse soos Eragrostis curvula en Digitaria eriantha tot 'n mindere mate ingekuil word. Die doel van hierdie studie was om die invloed van 'n melksuurbakterieseinokulant op E. curvula-, D. eriantha-, lusem-, voersorghum-, mielie- en hawerkuilvoer te bepaal. Die invloed van 'n melksuurbakteriese-inokulant op die fermentasiedinamika en die aerobiese stabiliteit van E. curvula-kuilvoer is bepaal. Die toediening van die melksuurbakterieseinokulant tot E. curvula tydens inkuiling het 'n vinniger tempo van pH daling en beter preservering tot gevolg gehad in vergelyking met kontrole kuilvoer. Inokulant behandelde kuilvoer het 'n hoer melksuurinhoud, minder protei'en afbraak en 'n laer bottersuurinhoud as kontrole kuilvoer gehad. Beide kuilvoere was stabiel tydens blootstelling aan lug vir vyf dae. Digitaria eriantha is ingekuil met ofsonder die toediening van 'n melksuurbakteriese-inokulant wat Lactobacillus plantarum. Streptococcus faecium en Pediococcus acidilactici sowel as die ensieme, sellulase, hemisellulase and amilase bevat het. Die inokulant het 'n vinniger tempo van pH-daling, hoer vlakke van melksuur en melksuurbakterie, minder protei'en afbraak en laer getalle van enterobakterie, klostridiale spore, giste and swamme in vergelyking met die kontrole tot gevolg gehad. Digitaria eriantha hooi, kontrole kuilvoer en gei'nokuleerde kuilvoer diete is aan 24 Merino ramme (n = 8 per behandeling) gevoer vir bepaling van inname en verteerbaarheid. Die inname van diete wat uit 90.9% D. eriantha hooi, kontrole kuilvoer of gei'nokuleerde kuilvoer bestaan het, het betekenisvol (p<0.05) verskil en was 1395, 1540 en 1848 gDM/dag, respektiewelik. Die in vivo organiesemateriaal verteerbaarheid (gIkg) vanD. eriantha hooi, kontrole kuilvoer en geYnokuleerde kuilvoer was 561, 546, 574, respektiewelik. Die toediening van die bakteriese-inokulant tydens inkuiling vanD. eriantha het beter preservering, verbeterde aerobiese stabiliteit asook 'n hoer in vivo organiesemateriaal verteerbaarheid van D. eriantha kuilvoer tot gevolg gehad. Die effek van toediening van 'n melksuurbakteriese-inokulant en van molasse tot lusem (Medicago sativa) ingekuil in laboratoriumsilos is ondersoek. Die inokulant toediening en molasse toediening het die tempo van preservering versnel, die pH het vinniger gedaal, melksuur is teen 'n hoer tempo geproduseer en minder proteYen afbraak het plaasgevind in vergelyking met die kontrole kuilvoer. Die tempo van preservering is meer effektief deur toediening van die inokulant verhoog as deur die toediening van molasse. Die aerobiese stabiliteit van lusernkuilvoer is nie beYnvloed deur die toediening van inokulant ofmolasse nie. Die effek van die toediening van 'n melksuurbakteriese-inokulant tot groot rondebaal lusernkuilvoer is ondersoek. Die inokulant het die kwaliteit van die kuilvoer verbeter en het 'n laer pH, hoer melksuur, laer ammoniak stikstofen laer bottersuurinhoud in rondebaallusernkuilvoer tot gevolg gehad in vergelyking met kontrole kuilvoer. Groot rondebaallusernkuilvoer het grootliks verskil van lusernkuilvoer wat in laboratoriumsilos ingekuil is. Die rondebaal kuilvoer het 'n hoer pH, hoer ammoniak-stikstof-, bottersuur- en asynsuurinhoud en 'n laer melksuurinhoud gehad as laboratorium lusernkuilvoer. Voersorghum kultivar FS2 is op die laat blom (20.7% DM) en op die sagte deeg (28.9% DM) stadium met die byvoeging van melksuurbakteriese-inokulante ingekuil in laboratoriumsilos. Toediening van beide inokulante tot sorghum hetop beide die inkuilstadiums gelei tot 'n vinniger tempo van pHdaling en meer melksuurproduksie. Aile kuilvoere insluitend die kontrole kuilvoer was goed gepreserveer. Kontrole sowel geYnokuleerde sorghumkuilvoer ingekuil op die laat blomstadium was stabiel tydens aerobiese blootstelling vir 5 dae. Sorghumkuilvoer ingekuil op die sagtedeegstadium met die byvoeging van inokulante was onstabiel tydens aerobiese blootstelling. Die toediening van melksuurbakteriese-inokulante tot sorghum wat op die sagtedeegstadium ingekuil word kan aerobiese stabiliteit van die kuilvoer grootliks benadeel. Die opbrengs, voedingswaarde en produksiepotensiaal van kuilvoer gemaak van 21 mielie hibriede is vergelyk. Verskille in metaboliseerbare energie inhoud, tempo van vertering, voorspelde inname en voorspelde melkproduksie het tussen mielie hibriede voorgekom. Die neutraalbestandevesel- en suurbestandeveselinhoud het nie verskil tussen hibriede nie en derhalwe kon dit nie gebruik word om voedingswaarde ofproduksiepotensiaal te beraam rue. Mielies is op die hardedeegstadium met of sonder die toediening van 'n melksuurbakterieseinokulant in laboratoriumsilos en 210 liter dromme ingekui!. Die toediening van die inokulant het geen invloed op tempo van pH-daling ofproduksie van melksuur gehad nie. Die inname en groei van SA Vleismerino lammers wat 'n dieet bestaande uit 60% kontrole of inokulant behandelde mieliekuilvoer ontvang het, is bepaa!. Die gemiddelde daaglikse toename van lammers was 239 ± 26 and 255 ± 44 g/dag vir die kontrole en inokulant mieliekuilvoer dieet respektiewelik. Alhoewel die laboratoriumstudie weinig verskille tussen die kontrole en die geYnokuleerde mieliekuilvoer getoon het, het lammers geneig om meer van die geYnokuleerde mieliekuilvoer in te neem. In die tweede studie met mieliekuilvoer is die effek van toediening van 'n melksuurbakteriese-inokulant met ensieme, op die ferrnentasiedinamika tydens inkuiling, die aerobiese stabiliteit van mieliekuilvoer asook die inname, melkproduksie en melksamestelling van Jersey koeie bepaa!. Die inokulant het nie die tempo van pH daling en produksie van melksuurverhoog nie en beide kontrole en geYnokuleerde mieliekuilvoerwas goed gepreserveer. Die toediening van die inokulant tot mieliekuilvoer het die smaaklikheid, inname en die aerobiese stabiliteit van mieliekuilvoer verhoog in vergeiyking met kontrole mieliekuilvoer. Melkproduksie, melksamestelling, liggaamsmassa en kondisiepunt van Jersey koeie is nie betekenisvol beYnvloed deur die toediening van die inokulant tot mieliekuilvoer nie. Die effek van die toediening van 'n ensiem bevattende melksuurbakteriese-inokulant tot groot rondebaal hawer (Avena sativa, cv Cederberg) kuilvoer op die samestelling van kuilvoer, kuilvoerinname, melkproduksie en melksamestelling van Jersey koeie is bepaa!. Die gewas is gesny op die blomstadium, verwelk en as rondebaalkuilvoer gepreserveer. Die inokulant, Sil-All, is tydens die baalproses toegedien op die helfte van die bale. Kuilvoere is aan Jersey koeie gevoer in 'n inname en melkproduksiestudie. Beide die kontrole en geYnokuleerde hawerkuilvoer was goed gepreserveer. Die bottersuurinhoud van geYnokuleerde hawerkuilvoer was laer as die van die kontrole hawerkuilvoer. Koeie wat geYnokuleerde hawerkuilvoer gevoer is het meer (P=0.05) melk (17.7 kg/dag) geproduseer as koeie wat kontrole hawerkuilvoer ontvang het (16.7 kg/dag). Die toediening van 'n melksuurbakteriese-inokulant het kuilvoer kwaliteit en diereproduksie verbeter. Hierdie studie wys duidelike verskille uit tussen kuilvoer wat in bunkersilos onder kommersiele toestande ingekuil is, en kuilvoer wat in laboratoriumsilos gemaak is. Wanneer die effek van kuilvoerbymiddels op die aerobiese stabiliteit van kuilvoer bepaal word behoort finale evaluasie gedoen te word op kuilvoer gemaak in bunkersilos soos onder plaastoestande plaasvind. Evaluasie van kuilvoerbymiddels behoort inname en diereproduksiestudies in te sluit.

Made available in DSpace on 2015-03-26T13:55:20Z (GMT). No. of bitstreams: 1 texto completo.pdf: 562262 bytes, checksum: 3877ee62b4d2fbbf059feb8b198e8118 (MD5) Previous issue date: 2013-07-24 / This study aimed to evaluate the effects of different forages on intake, digestibility and performance of dairy heifers. Sixteen dairy heifers were used, and they had initial body weight of 150 ± 19 kg and 8 mo. The animals were divided into a randomized block design with four replications, where each animal was used as experimental unit and blocks formed in accordance with the initial body weight of the animals. They were fed for 70 days. Four sources of roughage were used: corn silage (CS), sorghum silage (SS), sugar cane in nature (SC) sugar cane silage (SCS). The amounts of concentrate were fixed at 0.5% of body weight (BW) for CS and SS, 0.7% BW for SC, and 1.0% BW for SSC. The animals fed diets based on CS and SS had higher average daily gain than those fed with diets containing SC and SCS. Intake and digestibility of dry matter (DM), organic matter (OM) and metabolizable energy (ME) were higher for heifers fed CS and SS. There were differences in intake and digestibility of crude protein (CP) and neutral detergent fiber (NDF) for heifers fed SS. For non-fiber carbohydrates (NFC), there were greater intake and digestibility in heifers fed on CS. There were no diet effect for withers height and body length. There was an effect of CS and SS for chest girth. It is concluded that diets based on corn silage and sorghum silage offer higher performance than diets based on sugar cane in nature or sugar cane silage for dairy heifers. / Objetivou-se avaliar os efeitos de diferentes volumosos sobre o consumo, digestibilidade e desempenho de novilhas leiteiras. Foram utilizadas dezesseis novilhas leiteiras da raça Holandesa, com peso médio inicial 150 ± 19 kg e idade media 8 meses, distribuídas em delineamento em blocos casualizados, com quatro repetições, sendo cada animal considerado uma unidade experimental e os blocos formados com base ao peso inicial dos animais, durante 70 dias. Os tratamentos constituíram de quatro volumosos: silagem de milho (SM), silagem de sorgo (SS), cana-de-açúcar in natura (CN) e silagem de cana-de-açúcar (SC). As dietas foram formuladas fixando a quantidade de concentrado em 0,5% do peso corporal para silagens de milho e sorgo, 0,7% para cana-de-açúcar in natura e 1,0% para silagem de cana-de-açúcar. Os animais alimentados com dietas à base de silagens de milho e sorgo apresentaram maior ganho médio diário em relação aos alimentados com dietas contendo cana-de-açúcar in natura e silagem de cana-de-açúcar. O consumo e a digestibilidade de matéria seca (MS), matéria orgânica (MO) e energia digestível (ED) foram maiores para as novilhas alimentadas com dietas à base de silagens de milho e de sorgo. Houve maior consumo e digestibilidade de proteína bruta (PB) e fibra em detergente neutro (FDN) para as novilhas alimentadas à base de silagem de sorgo. Para carboidratos não-fibrosos (CNF), verificou-se maior consumo e digestibilidade nas novilhas alimentadas à base de silagem de milho. Não foi observado efeito sobre os parâmetros de altura de cernelha e comprimento corporal. Houve maior ganho de perímetro torácico para as novilhas alimentadas com dietas a base de silagens de milho e de sorgo. Conclui-se que dietas à base de silagens de milho ou sorgo proporcionam maiores desempenhos do que dietas à base de cana-de-açúcar in natura ou ensilada para as novilhas leiteiras.