MSCAGR (Animal Science) / Department of Animal Science

When plants are exposed to multiple environmental stress factors, one form of stress can affect the response to another stress. This study used seedlings of a new cultivar of wheat(Triticum aestivum L. cv. 1862), grown under factorial combinations of two levels of ultraviolet-B (UV-B)radiation, two salinity regimes and two levels of iron treatment in chelator-buffered nutrient solutions in a growth chamber. A number of morphological and physiological measurements were made. The accumulation of chlorophyll, UVabsorbing compounds and proline in shoots, as well as phytosiderophores (PSs) in root exudates were measured. Feed value measurements included crude protein, water-soluble carbohydrates, acid detergent fibre and Fe in shoots and roots. After 21 days of stress exposure, results showed that Fe deficiency and NaCl stress generally decreased plant growth and function as well as nutritive value, but increased plant biochemical protection traits such as proline accumulation (16.3 fold under salinity stress) and release of PSs (2.4 fold under Fe deficiency). Interestingly, UV-B radiation affected belowground parameters, inducing a 47% reduction in PS release, together with decreasing root DM by 9% and Fe concentration in roots by 7%. When Fe deficiency and NaCl stress were combined, the results showed a decrease in PS release by 3.5 fold compared to unstressed plants. UV-B radiation synergistically increased UV-absorbing compound levels in combination with Fe deficiency, compared to plants grown under optimal Fe levels. This stress combination also resulted in a cumulative effect by decreasing Fe concentration in shoots and roots. However, salt stress did not interact with UV-B radiation for any of the traits measured. In addition, some three-way interactions were noted, with the Fe x NaCl x UV-B stress combination slightly decreasing PS release and resulting in a cumulative effect by decreasing Fe concentration in roots. In conclusion, this study found that aboveground stress factors such as UV-B can affect important aspects of belowground plant function, and that Fe deficiency can interact with UV-B and salinity stress in modifying plant responses to either stress alone.

A series of experiments were conducted to investigate how dietary and ruminal factors regulate urea-N recycling in ruminants. In Experiments 1, 2, and 3, urea-N kinetics were measured using 4-d intra-jugular infusions of [15N15N]-urea. In Experiment 1, the objective was to determine how interactions between dietary ruminally-degradable protein (RDP) level and ruminally-fermentable carbohydrate (RFC) may alter urea-N transfer to the gastrointestinal tract (GIT) and the utilization of this recycled urea-N in rapidly-growing lambs fed high N diets. The dietary factors were: 1) dry-rolled barley (DRB) vs. pelleted barley (PB) as the principal source of RFC; and 2) dietary levels of RDP of 60 vs. 70% (% of CP). Nitrogen intake, fecal and urinary N excretion increased as dietary RDP level increased; however, method of barley processing had no effect on N use. Dietary treatment had no effect on urea-N kinetics; however, endogenous production of urea-N (UER) exceeded N intake. For all diets, 0.669 to 0.742 of UER was recycled to the GIT; however, 0.636 to 0.756 of the GER was returned to the ornithine cycle. In Experiment 2, the objective was to delineate the effects of partial defaunation of the rumen on urea-N kinetics in lambs fed low or high N diets. Treatments were: 1) partial defaunation (PDFAUN) vs. faunation (FAUN); and 2) low (10%, LOW) vs. high (15%, HIGH) dietary CP. Linoleic acid-rich sunflower oil was fed as a partially-defaunating agent. Partial defaunation decreased ruminal NH3-N concentrations. The UER and urinary urea-N excretion (UUE) were lower, and the GER tended to be lower in PDFAUN as compared to FAUN lambs; however, as a proportion of UER, GER was higher and the proportion of recycled urea-N that was utilized for anabolism (i.e., UUA) tended to be higher in PDFAUN lambs. The UER, GER and UUE were higher in lambs fed diet HIGH; however, as a proportion of UER, GER and its anabolic use were higher in lambs fed diet LOW. In Experiment 3, the objective was to delineate how, at similar N intakes, interactions between ruminal partial defaunation and altering dietary RFC may alter urea-N kinetics and N metabolism in lambs. Treatments were: 1) PDFAUN vs. FAUN; and 2) DRB vs. PB. Urinary N excretion was lower and retained N was higher in PDFAUN compared to FAUN lambs. The UER was similar across treatments; however, the GER, expressed as absolute amounts or as a proportion of UER, UUA, and microbial N supply were higher in PDFAUN compared to FAUN lambs. As a proportion of UER, GER was higher, whereas UUE was lower in lambs fed PB compared to those fed DRB. In Experiment 4, the objective was to determine the effects of feeding oscillating dietary CP compared to static dietary CP concentration on N retention and in vitro urea flux across ruminal epithelia. Dietary treatments consisted of a medium CP diet (MEDIUM; 12.8% CP) or diets with oscillating CP content (OSC) fed in two different sequences i.e., 2 d of low CP (9.7% CP) followed by 2 d of high CP (16.1% CP; OSC-HIGH) or vice-versa (OSC-LOW). Ruminal epithelial tissues were collected and mounted in Ussing chambers under short-circuit conditions and the serosal-to-mucosal urea flux (Jsm-urea) was measured using 14C-urea. Although N intake was similar, retained N and microbial N supply were greater in lambs fed the OSC diets compared to those fed the MEDIUM diet. The total Jsm-urea was higher in lambs fed the OSC-LOW compared to those fed the OSC-HIGH diet. Across diets, the addition of phloretin (a known specific inhibitor of facilitative urea transporter-B; UT-B) reduced Jsm-urea; however, phloretin-insensitive Jsm-urea was the predominant route for transepithelial urea transfer. In summary, data presented in this thesis provide new insights that the improved N retention typically observed in defaunated ruminants and in ruminants fed oscillating dietary CP concentrations is partly mediated via increased urea-N recycling to the GIT and utilization of recycled urea-N for anabolic purposes.

A series of experiments were conducted to investigate how dietary and ruminal factors regulate urea-N recycling in ruminants. In Experiments 1, 2, and 3, urea-N kinetics were measured using 4-d intra-jugular infusions of [15N15N]-urea. In Experiment 1, the objective was to determine how interactions between dietary ruminally-degradable protein (RDP) level and ruminally-fermentable carbohydrate (RFC) may alter urea-N transfer to the gastrointestinal tract (GIT) and the utilization of this recycled urea-N in rapidly-growing lambs fed high N diets. The dietary factors were: 1) dry-rolled barley (DRB) vs. pelleted barley (PB) as the principal source of RFC; and 2) dietary levels of RDP of 60 vs. 70% (% of CP). Nitrogen intake, fecal and urinary N excretion increased as dietary RDP level increased; however, method of barley processing had no effect on N use. Dietary treatment had no effect on urea-N kinetics; however, endogenous production of urea-N (UER) exceeded N intake. For all diets, 0.669 to 0.742 of UER was recycled to the GIT; however, 0.636 to 0.756 of the GER was returned to the ornithine cycle. In Experiment 2, the objective was to delineate the effects of partial defaunation of the rumen on urea-N kinetics in lambs fed low or high N diets. Treatments were: 1) partial defaunation (PDFAUN) vs. faunation (FAUN); and 2) low (10%, LOW) vs. high (15%, HIGH) dietary CP. Linoleic acid-rich sunflower oil was fed as a partially-defaunating agent. Partial defaunation decreased ruminal NH3-N concentrations. The UER and urinary urea-N excretion (UUE) were lower, and the GER tended to be lower in PDFAUN as compared to FAUN lambs; however, as a proportion of UER, GER was higher and the proportion of recycled urea-N that was utilized for anabolism (i.e., UUA) tended to be higher in PDFAUN lambs. The UER, GER and UUE were higher in lambs fed diet HIGH; however, as a proportion of UER, GER and its anabolic use were higher in lambs fed diet LOW. In Experiment 3, the objective was to delineate how, at similar N intakes, interactions between ruminal partial defaunation and altering dietary RFC may alter urea-N kinetics and N metabolism in lambs. Treatments were: 1) PDFAUN vs. FAUN; and 2) DRB vs. PB. Urinary N excretion was lower and retained N was higher in PDFAUN compared to FAUN lambs. The UER was similar across treatments; however, the GER, expressed as absolute amounts or as a proportion of UER, UUA, and microbial N supply were higher in PDFAUN compared to FAUN lambs. As a proportion of UER, GER was higher, whereas UUE was lower in lambs fed PB compared to those fed DRB. In Experiment 4, the objective was to determine the effects of feeding oscillating dietary CP compared to static dietary CP concentration on N retention and in vitro urea flux across ruminal epithelia. Dietary treatments consisted of a medium CP diet (MEDIUM; 12.8% CP) or diets with oscillating CP content (OSC) fed in two different sequences i.e., 2 d of low CP (9.7% CP) followed by 2 d of high CP (16.1% CP; OSC-HIGH) or vice-versa (OSC-LOW). Ruminal epithelial tissues were collected and mounted in Ussing chambers under short-circuit conditions and the serosal-to-mucosal urea flux (Jsm-urea) was measured using 14C-urea. Although N intake was similar, retained N and microbial N supply were greater in lambs fed the OSC diets compared to those fed the MEDIUM diet. The total Jsm-urea was higher in lambs fed the OSC-LOW compared to those fed the OSC-HIGH diet. Across diets, the addition of phloretin (a known specific inhibitor of facilitative urea transporter-B; UT-B) reduced Jsm-urea; however, phloretin-insensitive Jsm-urea was the predominant route for transepithelial urea transfer. In summary, data presented in this thesis provide new insights that the improved N retention typically observed in defaunated ruminants and in ruminants fed oscillating dietary CP concentrations is partly mediated via increased urea-N recycling to the GIT and utilization of recycled urea-N for anabolic purposes.

Grünland mit hoher Produktivität und Futterqualität bildet die Grundlage der Wiederkäuerernährung. In Grünlandbeständen mit ausbleibender oder geringer Stickstoffdüngung sind Leguminosen unerlässlich für Produktivität und Futterqualität, was auf die Fähigkeit von Leguminosen Luftstickstoff zu binden zurückzuführen ist. Gegenwärtig ist Trifolium repens L. eine der wichtigsten Futterleguminosen im Grünland der gemäßigten Zonen Europas. Es ist allerdings bekannt, dass T. repens eine gute Wasserversorgung benötigt, um einen hohen Ertrag zu erzielen. Verringerte Niederschlagsmengen in der Vegetationsperiode, die unter Klimawandelbedingungen vorausgesagt werden, könnten somit die Ertragsleistung von T. repens verringern. In Zukunft steigt dadurch möglicherweise auch die Bedeutung anderer Futterleguminosen, die besser an trockenere Bedingungen angepasst sind und somit als Alternative für T. repens dienen könnten. Da die Kenntnisse über das agronomische Potenzial solcher möglichen alternativen Leguminosen begrenzt sind, haben wir in dieser Studie fünf vielversprechende und wahrscheinlich besser an Trockenheit angepasste Leguminosen untersucht. Für unsere Versuche haben wir Lotus corniculatus L., L. uliginosus Schkuhr, Medicago lupulina L., M. falcate L. und Onobrychis viciifolia Scop. ausgewählt. In einem ersten Schritt wurde das agronomische Potenzial der Leguminosen im Hinblick auf Etablierung und frühe Ertragsentwicklung mit nicht limitierter Wasserversorgung getestet. Weiterhin wurden der Ertrag und die Ertragsstabilität sowie die Wassernutzung der alternativen Leguminosen bei temporärer Trockenheit untersucht und mit der von T. repens verglichen. Der Einfluss von Trockenstress auf wichtige Futterwert bestimmende Inhaltsstoffe der Leguminosen (Rohprotein, neutrale Detergenzienfasern, saure Detergenzienfasen und wasserlösliche Kohlenhydrate) war überdies Gegenstand der Betrachtungen. Um die oben genannten Parameter zu untersuchen, wurde von 2009 (Einsaatjahr) bis 2011 ein Experiment in Großgefäßen in einer Vegetationshalle durchgeführt. In diesem Versuch wurden alle Leguminosen sowohl in Monokultur als auch in einer praxisüblichen Mischung mit Lolium perenne L. angesät. Im Versuchszeitraum folgten die klimatischen Bedingungen in der Vegetationshalle einem normalen jahreszeitlichen Verlauf, der Frost im Winter und höhere Temperaturen im Sommer umfasste. Der für den Versuch notwendige Trockenstress wurde in drei Aufwüchsen innerhalb von zwei Jahren durch temporären Bewässerungsstopp erzeugt. Dabei wurde im Frühjahr 2010 (April/Mai) ein moderater und im Sommer 2010 (Juli/August) sowie im Frühjahr 2011 (April/Mai) je ein starker Trockenstress induziert. Mit Ausnahme von M. falcata, welches eine verzögerte Anfangsentwicklung zeigte, waren die Keimung und die Etablierung von allen alternativen Leguminosen vergleichbar mit der von T. repens. Die Ertragsleistung von M. lupulina und L. corniculatus in Monokultur war ähnlich hoch wie die von T. repens. In Mischung zeigten beide alternativen Leguminosen zwar Potenzial, aber die Ertragsleistungen waren dennoch geringer als die der T. repens/L. perenne Mischung. In unserem Versuch führte Trockenstress zu verringertem Ertrag und er beeinflusste auch die agronomische Wassernutzungseffizienz (Verhältnis von Ertrag zu Wasserverbrauch). Ausschlaggebend waren dabei die Stärke und die Dauer des Trockenstresses. Besonders starker, aber auch bereits moderater Trockenstress führten bei T. repens zu erheblichen Ertragsverlusten von bis zu 56%. Demgegenüber zeigten vor allem M. lupulina, aber auch L. corniculatus und M. falcata lediglich marginale Ertragsverluste bei moderatem Trockenstress und meist geringere Ertragsverluste als T. repens bei starkem Stress. Die agronomische Wassernutzungseffizienz war bei moderatem Stress verhältnismäßig stabil, wohingegen starker Stress im Vergleich zur Kontrolle meist zu einer geringeren agronomischen Wassernutzungseffizienz führte. Sowohl unter Kontroll- als auch unter Stressbedingungen zeigte speziell M. lupulina in Monokultur eine ähnliche oder sogar eine höhere agronomische Wassernutzugseffizienz als T. repens. Zudem war die agronomische Wassernutzungseffizienz der Mischungen mit M. lupulina, L. corniculatus und M. falcata weniger negativ von starkem Trockenstress betroffen als die Mischung mit T. repens. Dies bestätigte zum einen die Trockenheitsempfindlichkeit von T. repens und zum anderen die bessere Anpassung der alternativen Leguminosen an trockenere Bedingungen. Wir beobachteten, dass eine Änderung in der Stickstofffixierungsleistung der Leguminosen eine gute Erklärungsgröße für Änderungen des Ertrags und der agronomischen Wassernutzungseffizienz darstellt. Hohe Stickstofffixierungsleistung geht dabei meist mit höherem Ertrag und höherer agronomischer Wassernutzungseffizienz einher. Die intrinsische Wassernutzungseffizienz (Verhältnis von assimiliertem CO2 und stomatärer Leitfähigkeit), gemessen als 13C, war ein schlechterer Indikator für die agronomische Wassernutzungseffizienz: Obwohl die intrinsische Wassernutzungseffizienz unter starkem Trockenstress zunahm, sank die agronomische Wassernutzungseffizienz meist ab. Dennoch besitzt die Erhöhung der intrinsischen Wassernutzungseffizienz ein gewisses Potenzial als Anpassung an trockenere Bedingungen Der Trockenstresseffekt auf die Futterqualität war in unserer Studie generell deutlich geringer als der Effekt auf den Ertrag. Besonders moderater Stress hatte wenig Einfluss auf die Futterqualität, während sich die Effekte bei starkem Stress verstärkten. Starker Trockenstress führte meist zu einer Verringerung des Rohprotein- und Fasergehalts (neutrale und saure Detergenzienfasern), wohingegen sich der Gehalt an wasserlöslichen Kohlenhydraten erhöhte. Dies könnte ein Hinweis darauf sein, dass sich die Futterqualität bei Trockenstress sogar verbessert. Nichtsdestotrotz hatten in unserem Versuch die Leguminosenart und die Einsaat als Monokultur oder Mischung einen größeren Einfluss auf die Futterqualität als der Trockenstress. Der Einfluss von Trockenstress auf die Futterqualität ist deshalb bei der Wahl einer geeigneten Futterleguminose weniger von Bedeutung als andere agronomische Eigenschaften. Zusammenfassend ist zu sagen, dass besonders M. lupulina und in geringerem Maße auch L. corniculatus und M. falcata Potenzial als Alternative für T. repens bei Trockenstress zeigen. Nach ausreichender Etablierungszeit entwickeln sich besonders M. lupulina aber auch L. corniculatus und M. falcata stabiler und können sogar höhere Erträge als T. repens bei Trockenstress produzieren. Bezüglich der Futterqualität sind oben genannte alternative Leguminosen ebenfalls vergleichbar mit T. repens.

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Made available in DSpace on 2016-08-15T20:31:24Z (GMT). No. of bitstreams: 1 MonikKOC_DISSERT.pdf: 637237 bytes, checksum: c04ae9e9367303da2f965ee75d79bfdd (MD5) Previous issue date: 2015-02-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective was to evaluate the influence of the addition of propolis extract in diets with different levels of crude protein on growth performance and quality of laying eggs Isa Label created in high temperature environment. For this, we used 104 birds distributed in a completely randomized design in a 2x2 factorial design (CP level and propolis extract) being four diets, one control and another with 5% reduction of crude protein, each with and without the addition of 0.70% of propolis extract with 13 repetitions and two birds each. Were evaluated: egg production rate, feed conversion, absolute and relative weight of yolk, albumen and shell, height and width of the egg, specific gravity, yolk color, eggshell thickness, Haugh unit, albumen and yolk index. Propolis extract (0.70%) provided increase of egg production rate and improves feed conversion, to the crude protein level of 17.70%, and promote coloring sharper yolk. Therefore, the level of 0.70% hydroalcoholic extract of propolis can be used in diets for laying hens Isa label as it improves desirable characteristics such as egg production rate, feed conversion and yolk color when the feed has protein level of 17 7%. And the protein level of 16.82% can be used for laying Isa Label without prejudice to on broiler performance / Objetivou-se avaliar a influência da adição de extrato hidroalcoólico de própolis em rações com dois níveis de proteína bruta, no desempenho produtivo e qualidade de ovos de poedeiras Isa Label criadas em ambiente de alta temperatura. Foram utilizadas 104 aves, distribuídas em delineamento inteiramente casualizado, esquema fatorial 2x2 (proteína bruta e extrato hidroalcoólico de própolis), sendo uma ração controle e outra com redução de 5% da proteína bruta, cada uma com e sem a adição de 0,70% de extrato hidroalcoólico de própolis, com 13 repetições e 2 aves por unidade experimental. Foram avaliados: taxa de postura, conversão alimentar, peso absoluto e relativo de gema, albúmen e casca, altura e largura do ovo, gravidade específica, coloração da gema, espessura de casca, unidade Haugh, índice de albúmen e de gema. O extrato hidroalcoólico (0,70%) proporcionou aumento da taxa de postura e melhora da conversão alimentar, ao nível de proteína de 17,70%, além de promover coloração mais acentuada da gema. Portanto, o nível de 0,70% de extrato hidroalcoólico de própolis pode ser usado em rações para poedeiras Isa Label, já que melhora características desejáveis como taxa de postura, conversão alimentar e coloração da gema, quando as rações têm nível de proteína de 17,7%. E o nível de proteína de 16,82% pode ser usado para poedeiras Isa Label, sem prejuízo no desempenho

Woody plant encroachment is one of the major problems worldwide because it affects negatively the herbaceous layer, which provide forage for livestock production. However, the role of ruminants particularly browsers in the dispersal of woody plant seeds still remains a concern for farmers interested in grass production. Seedpods of various woody plant species constitute a crucial part of the diet of herbivores during the dry season because of their high nutritional quality compared to herbaceous material. The interaction of associated diet quality, seed characteristics and animal species among other factors play a pivotal part in the success of livestock faecal seeds dispersion. Furthermore, dispersed seeds that successfully grow into mature woody plants become an important source of protein for herbivores. The use of woody plants as a source forage is known to be limited by plant secondary metabolites (PSMs) such as condensed tannins. The objectives of this study were to determine 1) the effects of condensed tannins and crude protein of Vachellia tortilis and Dichrostachys cinerea pods in seed recovery and germination fed to goats, and 2) the effects of diet mixing on the feed intake of plant species by goats. In the first experiment, a total of 12 female indigenous goats and 12 female Pedi sheep were utilised in this study, with the average body weights of 29.50 kg ± 1.60 (S.E) and 28.70 kg ± 1.60, respectively. Twelve goats were grouped into two groups of six goats per group, one group was fed D. cinerea pods and the other group was fed V. tortilis pods. The group of 12 sheep were divided similarly, the one group was fed D. cinerea pods and the other group was fed V. tortilis pods. Each animal was given V. tortilis and D. cinerea pods at 2.50% of their body weight. All animals were allowed to consume D. cinerea or V. tortilis pods within 24 h, after which the remaining pods were collected and weighed. Faecal collection commenced immediately after the 24 h pods feeding and was carried on until no seeds were discovered in faeces. All faeces extracted from sheep and goats were collected daily in the morning from the faecal bags. In the second experiment, a total of 24 indigenous goats with average body weight of 26.6 kg ± 0.51 were utilised. Goats were arbitrarily selected and grouped into four groups of six goats per group (goats were placed individually in 2 m2 pens). Each group was fed one of the following diets: diet one - Searsia lancea, diet two - S. pyroides, diet three - Euclea crispa and diet four - was a combination of the three plant species (Searsia lancea, S. pyroides and Euclea crispa). Searsia lancea, S. pyroides and E. crispa branches were collected every morning prior to feeding, and were weighed before offering the animals. Refusals were gathered and weighed, and intake was calculated as distinction between weight in and refusals. Plant species foliage were analysed for crude protein, condensed tannin, acid detergent lignin, acid detergent fibre and neutral detergent fibre. During the first experiment, the cumulative percentage seed recovery of V. tortilis from goats (46.00 % ± 1.90) and sheep (52.00 % ± 2.93) was significantly higher than D. cinerea from goats (13 % ± 1.47) and sheep (24.00 % ± 1.16). Germination percentage of D. cinerea seeds that passed through the gastro-intestinal tract of goats (33.12 % ± 2.94) and sheep (36.00 % ± 2.68) was significantly higher than V. tortilis seeds that passed through the gastro-intestinal tract of goats (28.98 % ± 2.68) and sheep (23.04 % ± 2.81). Average D. cinerea (34.56 % ± 1.99) and V. tortilis (26.02 %± 2.10) seeds that went through the gastro-intestinal of goats and sheep had a significantly higher germination rate than the control (i.e. no passage through the gut; D. cinerea = 2.31 % ± 1.55, V. tortilis = 5.07 % ± 2.68). The high mean cumulative percentage seed recovery of V. tortilis (18.80 %) may be attributed to the relatively higher crude protein than D. cinerea (12.20 %). This may encourage animal seed dispersal and germination of woody plant species with relatively high crude protein content. In the second experiment, Searsia lancea contained 8.50 % CP, 21.46 % acid detergent fibre (ADF), 12.50 % ADL and 39.37 % NDF. Searsia pyroides had 9.03 % CP, 27.07 % ADF, 10.89 % ADL and 40.30 % NDF. Euclea crispa had 6.19 % CP, 26.20 % ADF, 16.63 % ADL and 30.02 % NDF. Mixed diet (combination of the three plant species) had 8.96 % CP, 23.72 % ADF, 11.13 % ADL and 38.28 % NDF. Searsia lancea had 2.70 % of CTs while S. pyroides had 5.20 % CT, E. crispa had 6.44 % CT and mixed diet had 7.20 % CT. The mean dry matter intake varied significantly among dietary groups (P < 0.001). Similarly, goats offered a mixed diet consumed more CTs (P < 0.01) than those offered individual forage species. The high mean cumulative percentage seed recovery of V. tortilis may be attributed to the higher crude protein of V. tortilis (18.80 %) than D. cinerea (12.20 %). Higher passage rate may encourage animal seed dispersal and germination of plant species. The results from experiment two support the postulation that animals foraging in mixed diet systems consume more PSMs and achieve higher dry matter intake than animals confined to monocultures or single species feeding systems. Given that woody plant encroachment is already reducing farm-grazing capacities in African savannas and this problem is predicted to double by 2050, strategies that improve herbivore ability to consume woody plants will increase forage availability and inform bush control programmes and policies. Moreover, the concomitant increase in CTs by goats exposed to diets with diverse species also has positive implications for animal / Agriculture, Animal Health and Human Ecology / M. Sc. (Agriculture)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this research was to evaluate of three grazing systems (GS) with Elephant grass (EG) + Italian ryegrass (IR) + spontaneous growing species (SGS); EG + IR + SGS + Forage peanut (FP); and EG + IR + SGS + Red clover (RC), in order to use the area in rotational grazing during all agricultural year. EG was planted in rows with a distance of 4 m each one of them. In the cool-season, IR was sowed between rows of EG; RC was sowed and the FP who has found established since 2006 was preserved on respectively GS. Experimental design was completely randomized with three treatments (GS), two replicates (paddocks) and independent evaluations (grazing cycles). For evaluation, were used lactating Holstein cows receiving 1% of BW day-1 feed supplement concentrate. The pre and post forage mass parameters, botanical and structural composition, forage production and stocking rate were evaluated. Samples were collected by the handplucking method to analyze the organic matter, mineral matter, crude protein (CP), neutral detergent fiber (NDF), in situ organic matter digestibility (ISOMD), in situ dry matter digestibility (ISDMD) of forage. Eight grazing cycle were performed during the experimental period (357 days). The values of forage production and stocking rate were 15.03, 16.33, 17.03 t ha-1 and 3.57, 3.52 and 3.65 animal unit ha-1, respectively grazing systems. Grazing systems involving grasses and forage legumes in different cycles provide use of the area during the agricultural year in rotational grazing with dairy cattle. SGS increased significantly (P≤0.05) over in GS without forage legume. Higher value of CP, ISOMD and lower of NDF for GS mixed with forage legumes. Considering the herbage mass, stocking rate and nutritive value, the pastures mixed to forage legumes showed better performance. / O objetivo desta pesquisa foi avaliar três sistemas forrageiros (SF) com capim elefante (CE) + azevém (AZ) + espécies de crescimento espontâneo (ECE); CE + AZ + ECE + amendoim forrageiro (AM); e CE + AZ + ECE + trevo vermelho (TV), com o intuito de utilização da área em pastejo rotativo durante todo o ano agrícola. O CE foi estabelecido em linhas afastadas a cada 4 m. No período hibernal fez-se o estabelecimento do AZ entre as linhas do CE; o TV foi semeado e o AM que já se encontrava estabelecido desde 2006, foi preservado, considerando os respectivos tratamentos. O delineamento experimental foi o inteiramente casualizado, com três tratamentos (SF), duas repetições (piquetes) e avaliações independentes (ciclos de pastejo). Para avaliação foram utilizadas vacas da raça Holandesa em lactação, que receberam suplementação alimentar com concentrado à razão de 1% do peso corporal dia-1. Foram avaliados parâmetros de massa de forragem pré e pós pastejo, composições botânica e estrutural, produção de forragem e taxa de lotação. Para analisar a matéria orgânica, matéria mineral, a fibra em detergente neutro (FDN), a proteína bruta (PB), a digestibilidade in situ da matéria seca (DISMS) e a digestibilidade in situ da matéria orgânica (DISMO) da forragem, foram coletadas amostras de pastejo simulado. Durante o período experimental (357 dias) foram efetuados oito ciclos de pastejo. Os valores de produção de forragem e de taxa de lotação foram de 15,03; 16,33; 17,03 t ha-1 e 3,57; 3,52 e 3,65 UA ha-1, respectivamente para os sistemas forrageiros. Sistemas forrageiros, envolvendo gramíneas e leguminosas de diferentes ciclos, proporcionam a utilização da área durante todo o ano agrícola em pastejo rotativo com bovinos leiteiros. Houve aumento significativo (P≤0,05) para ECE na pastagem sem leguminosa. Foram observados maiores valores de PB, DISMO e menores de FDN para os SF consorciados com leguminosas. Considerando a massa de forragem, a taxa de lotação e o valor nutritivo, as pastagens consorciadas com leguminosas forrageiras apresentaram melhor desempenho.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2016-08-18T12:29:37Z No. of bitstreams: 2 Dissertação - Vanderli Luciano da Silva - 2016.pdf: 2379182 bytes, checksum: 7f2d6cde360630b08c84abb051eeaf57 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-08-18T12:31:09Z (GMT) No. of bitstreams: 2 Dissertação - Vanderli Luciano da Silva - 2016.pdf: 2379182 bytes, checksum: 7f2d6cde360630b08c84abb051eeaf57 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-08-18T12:31:09Z (GMT). No. of bitstreams: 2 Dissertação - Vanderli Luciano da Silva - 2016.pdf: 2379182 bytes, checksum: 7f2d6cde360630b08c84abb051eeaf57 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-02-19 / This study aimed to evaluate the chemical composition and fermentation characteristics of silage millet farming ADR500 under the inclusion of different levels of corn disintegrated with straw and cob (CEC): 0%, 5%, 10% and 15%, after 78 days of vegetative growth and observe his capacity as moisture scavenger in silage. The experimental design was completely randomized with 4 treatments and 4 replications, totaling 16 experimental units. Data were submitted to analysis of variance, means were compared by 5% Tukey test and regression analysis for the inclusion levels. dry matter content (DM) determined in silage differ (P <0.05) as a function of the MDPS inclusion levels, ranging from 26.53% to 38.69% control treatment and for treatment with higher level inclusion. For values of organic matter found a significant difference only from the IV treatment with 15% inclusion of CEC (P <0.05) compared to other treatments. Regarding crude protein (CP) observed a linear increase (P <0.05) due to the increase of CEC levels, ranging between 9.46% and 14.92%. NDF and the FDA determined in silages ranged from 58.50% to 66.25% and 31.25% for FDA to 38.50 for the FDA so there significant differences between treatments. For certain ether extract in silages millet forage with inclusion of MDPS ranged from 3.13 to 3.95%. The content of mineral matter (MM) showed a significant difference (P <0.05) according to the MDPS inclusion levels, ranging from 5.26 to 7.55%. The inclusion of MDPS reduced (P <0.05) losses gases and effluents in all the treatments, ranging from 6.10 to 3.48 for gas losses and 9.05 to 17.28 for losses effluent and contributed significantly in the dry matter recovery process (MS). The buffer power values (PT), pH and ammonia-N were influenced (P <0.05) by the inclusion of different levels of ground ear corn silage. The levels of acetic, propionic, butyric and lactic, so influenced by the addition of ground ear corn silage. The soluble carbohydrate values have an increasing depending on the MDPS inclusion levels, proving to be efficient in their use to improve the fermentation profile of silages. / Objetivou-se avaliar a composição químico-bromatológica e as características fermentativas da silagem de milheto forrageiro, cultivar ADR500 sob a inclusão de diferentes níveis de milho desintegrado com palha e sabugo (MDPS): 0%, 5%, 10% e 15%, aos 78 dias de crescimento vegetativo e observar sua capacidade como sequestrante de umidade na silagem. O delineamento experimental utilizado foi inteiramente casualizado com 4 tratamentos e 4 repetições, totalizando 16 unidades experimentais. Os dados foram submetidos à análise de variância, as médias comparadas pelo teste de Tukey a 5% e análise de regressão para os níveis de inclusão. Os teores de matéria seca (MS) determinados na silagem diferiram (P<0,05) em função dos níveis de inclusão do MDPS, com variação de 26,53% para o tratamento controle e 38,69% para o tratamento com maior nível de inclusão. Para os valores de matéria orgânica encontrados houve diferença significativa apenas do tratamento IV com 15% de inclusão de MDPS (P<0,05) comparando aos demais tratamentos. Em relação à proteína bruta (PB) observou-se aumento linear (P<0,05) em função da elevação dos níveis de MDPS, variando entre 9,46% e 14,92%. Os teores de FDN e FDA determinados nas silagens variaram entre 58,50% até 66,25% para FDA e 31,25% até 38,50 para o FDA havendo assim diferenças significativas entre os tratamentos. Para o extrato etéreo determinado nas silagens de milheto forrageiro com inclusão de MDPS variaram entre 3,13 a 3,95%. O conteúdo de matéria mineral (MM) apresentou diferença significativa (P<0,05) em função dos níveis de inclusão de MDPS, com variação de 5,26 a 7,55%. A inclusão de MDPS reduziu (P<0,05) as perdas por gases e efluentes em todos os tratamentos avaliados, variando de 6,10 a 3,48 para as perdas por gases e 9,05 a 17,28 para as perdas por efluentes, e contribuiu significativamente no processo de recuperação da matéria seca (MS). Os valores de poder tampão (PT), pH e N-amoniacal foram influenciados (P<0,05) pela inclusão dos diferentes níveis de MDPS à silagem. Os teores dos ácidos acético, propiônico, butírico e lático, forma influenciados pela adição de MDPS na silagem. Os valores de carboidratos solúveis tiveram um aumento crescente em função dos níveis de inclusão do MDPS, demonstrando ser eficiente em seu uso para melhorar o perfil fermentativo da silagem.