Experiments were conducted to investigate the effects of formulating rations using different ingredients and of manipulating the cation-anion balance of the rations on production, acid-base status, metabolism of macrominerals and renal function of dairy cows. The effects of dietary cation-anion balance were studied during early, mid and late lactation as well as during the dry period. Feeding an alfalfa-haylage based diet vs a corn silage based diet, both having the same cation-anion balance did not affect the voluntary consumption, milk yield or milk composition of cows in early lactation. The acid-base status of the animals was not affected by dietary treatment. The lower urinary bicarbonate concentration observed with the alfalfa haylage-based diet was not associated with a lower total urinary bicarbonate excretion since urine volume was significantly higher than when cows were fed the corn silage-based diet. Manipulating dietary cation-anion balance, however, resulted in changes in acid-base status at all stages of lactation studied. Urinary bicarbonate concentration and total daily excretion were increased by a higher dietary cation-anion balance at all stages of lactation. Similar effects of dietary cation-anion balance on urinary bicarbonate did not, however, translate into similar changes in production or intake by cows at differing stages of lactation. Cows in early and mid lactation seemed to have benefited more from a highly positive dietary cation-anion balance than cows in late lactation or dry period.

The economic feasibility of lupins in a cropping system as a protein supplement for a representative dairy cattle herd in Southwest Quebec (SWQ) to substitute for soybeans was investigated using a single period linear programming (LP) model. At current prices, lupins were not a profitable base case scenario. The gross margin of the dairy farm was $147,918. This resulted in a total soil loss of 3,504 tonnes (t), 50 percent higher than soil tolerance, T (acceptable level of soil loss) of 14 t ha$ sp-1,$ and produced 541 kg of Nitrogen (N). Sale of corn grain (CG) was 442.3 t, constituting about 39 percent of the gross margin but had a negative effect on the soil. The farm purchased 59 t of straw for animal bedding. / When the environmental constraint of soil erosion, 14 t ha$ sp{-1},$ was imposed, the gross margin was estimated to be $131,148 while total N and soil loss were 2,454 kg and 1,708 t, respectively. Lupins were produced on 18.3 ha with this soil loss level constraint. The tradeoff between soil loss and gross margin and lupins was observed. The N fixation constraint reduced the gross margin while it increased soil loss. CG sales were reduced from 442 to 244.5 t but milk production increased by 163 hectolitres (HL). Sensitivity analysis on labour supply and farm size indicated that lupins became an alternative to soybeans when farm size and labour supply were larger and fewer respectively. / Lupins would substitute for soybeans if yield is increased by 5 percent; cost of production is reduced by 10 percent and home grown clean lupin seed is used for 2 or 3 more years or government provides a subsidy of $328 ha$ sp-1.$ This is approximately equal to the CG subsidy.

Lupin seed has the potential to be used as a protein supplement in ruminant rations, but its usage is restricted by the presence of alkaloids. Experiments were conducted with the aim of determining whether the removal of specific toxic alkaloids, lupanine and 13-hydroxylupanine, from crushed lupin seed (CLS) would improve the organic matter intake (OMI) and average daily gains (ADG) in lambs, and also improve the lactation performance in dairy cows. Effects on liver function in lambs were also investigated. An additional study on the effects of the detoxification of CLS on the degradation of protein was conducted. In Experiment 1, 30 growing Corriedale lambs were fed five diets for 105 d according to a randomized complete block design (RCBD) with six blocks. Two diets contained intact CLS at 15% (LUI-15) or 30% (LUI-30) of DM; two other diets contained detoxified CLS at 15% (LUD-15) or 30% (LUD-30) and the control (CON) diet was supplemented with crushed sunflower seed, which was locally prepared, on-farm. All diets were formulated to be isonitrogenous (16% CP). The alkaloid content (lupanine and 13-OH lupanine) of the diets was.31,.70,.21 and.52% for LUI-15, LUI-30, LUD-15 and LUD-30, respectively. Thus, diets containing detoxified CLS contained approximately 30% less alkaloids than those with intact CLS. Estimates of ADG of lambs fed diets containing detoxified CLS was higher (P $<$.01) (120 g.d$ sp{-1}$) than that of lambs fed intact CLS (76 g.d$ sp{-1}$). The OMI (73 g/Wkg$ sp{0.75}$) was also higher, although not significantly, for lambs fed diets containing detoxified CLS. Feed conversion efficiency was increased (P $<$.05) by the detoxification of CLS. Lambs fed diets containing intact CLS consumed more OMI as time progressed, suggesting that adaptation to CLS might have occurred. Lambs fed diets containing intact CLS demonstrated increased trends in the activity in plasma of the enzymes glutamic oxaloacetic transferase (GOT) and $ gamma$-glutamyl transfer

The effect of untreated roughages on digestibility and rumen fill of the gut was reviewed as physical mechanism influencing the regulation of roughage intake. The review of literature also focused on identifying factors that affect the way in which urea-ammoniation alters the roughage intake, digestibility and performance of ruminant animals. Trials were carried out with fistulated cows to address to what extent concentrate proportion and urea-ammoniation affected microbial colonization and degradation of roughage diets in the rumen. One interest of this study was to develop a model that would help to predict the benefit associated with urea-treatment of roughages. The first trial (Chapter 3) investigated the effect of urea-ammoniation of roughage and concentrate proportion of the diet on degradation of roughages, and the benefit associated with the treatment of roughages. Four rumen-fistulated Jersey cows were fed on a basal diet composed of either urea treated (3 kg of urea per 100 kg of straw) or untreated Eragrostis curvula hay. These basal diets were supplemented with concentrate composed of maize meal (78%) and cotton seed cake (22%). The concentrate contributed 0, 25, 50 and 75% of the total ration and hay the rest. The experiment consisted of 6 periods. Each period lasted 19 days, comprising 12 days of adaptation to the experimental diet followed by 6 days degradability measurements and 1-day rumen fluid collection. During each period the 4 Jersey cows were randomly allocated to 4 of the 8 dietary treatments, ensuring that each diet was fed to 3 animals during the entire experimental period. The experimental roughages used in this trial were wheat (Triticum sativum) straw, barley (Hordeum Vulgare) straw, coastcross (k11) (Cynodon hybrid) hay, veld hay (natural grass), oat (Avena sativa) straw, oat (Avena sativa) hay, maize (Zea mays) stover, kikuyu (Pennisetum clandestinum) grass, weeping love grass (Eragrostsis curvula) and Italian rye (Lolium multiflorum) grass. Each roughage (sample) was subdivided into two equal portions, one of which was then treated with urea. The urea solution was prepared by dissolving 30 g of urea in 0.4 liter of water. The solution was fully distributed over I kg of roughage. Treated roughages were sealed tightly and stored at room temperature for 5 weeks in plastic bags. Immediately after opening, the different roughages, including the untreated ones, were sun dried, chopped fine by hand and ground through a 2-mm screen in a laboratory mill. About 3 g of each sample was weighed into labeled nylon bags. The bags were tied to a stainless steel disc with 10 evenly spaced small holes drilled through the periphery of the disc serving as anchor points. The bags were incubated (in duplicate per time interval) in the rumen for 120, 96, 72, 48, 24, 12, 6 and 3 h, sequentially. The treated samples were incubated in animals fed treated hay, while untreated samples were incubated in animals given untreated hay. Immediately after removal from the rumen, the bags, including the 0 hour ones, which had not been incubated but soaked in warm water for I hour, were washed in 6 cycles (each lasting 4 minutes) in a semi-automatic washing machine. The washed bags were then dried in a forced draught oven at 60 degrees C for 48 hours, cooled in a desicator and weighed. The pH of the rumen fluid ranged between 6.5 and 6.8 for all diets. Rumen ammonia concentration was higher (P<0.002) when the basal diet consisted of urea treated hay. Increasing the concentrate proportion in the diet had the desired effect of increasing rumen ammonia concentration without severely affecting pH. Urea-ammoniation increased (P<O.OOO1) the slowly degradable fraction (B), potential degradability (PD), effective degradability (ED) of dry matter and neutral detergent fiber (NDF), decreased (P>0.05) lag time (LT) but had no effect on the rate of degradation (c) of dry matter. Concentrate proportions affected (P<0.05) the slowly degradable fraction, potential degradability, lag time and effective degradability but had no effect (P>0.05) on the rate of degradation of dry matter (DM). Maximum and minimum values of the slowly degradable fraction, potential degradability and effective degradability of DM and NDF were obtained at the 25 and 75% concentrate levels, respectively. Within urea-ammoniation, roughage type affected (P<O.OO1) the B-fraction, PO and EO of OM and NDF degradation. Rate of degradation of DM of untreated roughages varied from 0.022 h(-1) in wheat straw to 0.087 h(-1) in rye grass, while for urea treated roughages it varied from 0.022 h(-1) in oat straw to 0.082 h(-1) in rye grass. Rye grass degraded almost three to four times faster than urea treated oat or untreated wheat straw. Urea-ammoniation was less effective in increasing DM and cell wall degradation rates (c) of rye grass compared to wheat straw. The results showed that low quality roughages such as wheat straw benefited relatively the most from urea-ammoniation. The effect of urea-ammoniation and dietary manipulation on microbial colonization (Chapter 4) of fiber particles in the rumen of animals was also investigated in two experiments. In Experiment 1, the cows were fed on rations comprising either urea-ammoniated or untreated Eragrostis curvula hay supplemented with concentrate at hay to concentrate ratio of 100:0, 75:25, 50:50, 25:75, resulting in eight different rumen environments. The experiment consisted of two periods. Each period lasted 12 days of adaptation to the experimental diet followed by one-day incubation of urea-ammoniated and untreated barley straw. Experiment 2 consisted of two urea-ammoniated (7.5 kg of urea per 100 kg of hay) hay levels (20 and 40% of the total ration) and concentrate levels (60 and 80%). Fistulated Jersey cows were adapted for 12 days after assigning to the dietary treatment. Feed was given at the rate of 9.0 kg day(-1) per animal portioned into equal meals of 4.50 kg each and offered at 08:00 and 16:00 every day. About 3 g of urea-ammoniated or untreated barley (Hordeum vulgare) straw, ground through a 2-mm screen, was weighed into a labelled nylon bag and incubated for 3, 6 or 12 h in the rumen of the fistulated cows. Microbes adhering to incubated fiber particles were examined under the Environmental Scanning Electron Microscopy (ESEM) and analysed on the image analyser. Depending on morphology , the microbes were divided into three groups: bacilli (rod), cocci (round) and others (spiral, fimbrea and cluster ; not specifically defined or undefined microbes). Urea-ammoniation of dietary roughage decreased (P<O.OO1) bacilli counts and total bacteria count but had no effect on count of the undefined group of microbes on fiber particles in the rumen of cows (Experiment 1). Concentrate proportions had no effect (P>0.05) on bacilli, cocci and total bacterial count on fiber particles. However, the results from electron micrograph observations revealed that the total bacterial count tended to decrease as the concentrate level increased in the diet of cows. Bacilli, cocci, undefined group of microbes and total count of microbes increased (P<0.05) as length of incubation increased. In Experiment 2, incubated feed, concentrate proportion and time of incubation had no effect (P>O.05) on bacilli , others (undefined group of microbes) and total count of fiber-adhering microbes in the rumen of cows. However, increasing concentrate in the diet of cows tended to decrease (P<O.07) the count of fiber-adhering cocci. The total count of microbes on fiber particles was higher in animals fed 80% concentrate as compared to 60% concentrate. The benefit derived from urea treatment in terms of B-fraction, effective degradability and potential degradability of DM and fiber of roughages increased with increasing the NDF content. Therefore, the important conclusions drawn from the results of the present study is that urea-ammoniation of roughages should be done strategically and that high quality roughages may give little return per unit of cost of ammoniation. This means that the benefit associated with urea-ammoniation would be justified for poor quality roughages only. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.

In the first of three experiments, four Holstein multiparous dairy cows, equipped with ruminal and duodenal cannulas, were used to determine the impact of different methods of treating soybean meal (SBM) on ruminal degradability and intestinal digestibility of CP and amino acids (AA). Solvent extracted SBM (SE), expeller SBM (EP), lignosulfonate SBM (LS) and heat and soy hulls SBM (HS) were incubated in the rumen, in nylon bags, for various intervals up to 48h. Additional samples incubated for 16 h were pre-treated with pepsin HCI, and then used for determination of intestinal digestibility either in situ (mobile bag technique) or in vitro. Treatment of SBM (EP, LS, HS) increased rumen undegradable protein (RUP), and AA availability in 30%. Estimates of intestinal digestibility of AA and CP were lower when measured in vitro than in situ. Among the treated SBM products, four EAA (Ile, Leu, Phe and Val) showed differences in availability, with values consistently lower for HS than for LS. The second experiment involved a comparative assessment of the availability of lysine in SE and rumen protected SBM products (EP and LS). Lysine availability was assessed either by the increment in plasma flux of 15N lysine, the increment in intestinally digestible lysine (using chromic oxide as a digesta marker) or by the use of a "plasma lysine response curve" designed to predict intestinally available lysine. The plasma Lys flux was not different between the different SBM products. However, SE + 70 g.d-1 omasal infusion of Lys (SE70) increased Lys flux by exactly 70 g.d -1 above the SE treatment. No differences were observed on duodenal Lys flow, post-ruminal digestion and digestible Lys between the SBM diets (SE, EP, LS). Irrespective of the method of assessment, lysine availability was not altered by the method of treating SBM. The third study evaluated the relative impact of supplying rumen-undegraded protein (RUP) versus altering the carbohydrate source on milk yield and efficiency N usage for milk production. Protein supplementation (SE and EP) increased DMI, whereas the inclusion of beet pulp (BP) replacing 50% of high moisture shelled corn decreased DMI. The results of this research suggest that, under normal conditions of feeding, supplying rumen protected SBM to enhance the supply of intestinally available essential AA does not improve lactation performance; providing beet pulp as a source of readily fermentable fibre also failed to affect milk yield or efficiency of N usage for milk production by dairy cattle.

Graduation date: 1971

Includes bibliographical references (leaves 175-196). / xii, 196 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The influence of starch in grain-based diets on fat development in cattle and sheep is investigated. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Sciences, 1995

As vacas leiteiras necessitam logo após o parto ingerir grande quantidade de energia para sustentar a síntese de leite que aumenta linearmente. Com isso o objetivo do trabalho foi avaliar o efeito dos níveis de óleo de palma na forma protegida como suplemento na alimentação de vacas leiteiras, sobre a dinâmica corporal, produção e composição do leite, perfil metabólico e reprodução. O experimento foi conduzido nos meses de julho e agosto de 2013 no município de Chopinzinho –Paraná, foram utilizadas 27 vacas da raça Holandesa com peso médio de 651 ±82,7 Kg, distribuídas conforme delineamento em blocos casualizados (DBC) de acordo com a fase de lactação (0 a 90 dias) e três tratamentos de níveis de inclusão de gordura protegida Magnapac® (Madrid, Espanha). Os blocos foram formados a partir da produção média de leite, devidamente equilibrados por peso, idade, número de crias. Os tratamentos constituíram da inclusão de gordura protegida de óleo de palma na proporção de 0, 250 e 500 g/animal/dia. As pesagens de leite e coleta para análise da composição centesimal, bem com as coletas de sangue foram realizadas nos dias 07, 14 e 30 após início da suplementação. Os diagnósticos reprodutivos foram realizados nos dias 0 e 30.Os resultados da produção total de leite não apresentaram efeito significativo (P>0,05) em relação aos diferentes níveis de gordura protegida. Quanto à composição centesimal do leite os parâmetros, gordura, proteína, lactose, extrato seco total, extrato seco desengordurado, ureia e contagem de células somáticas não tiveram efeito significativo (P>0,05). No perfil metabólico as variáveis que apresentaram aumento linear (P<0,05) foram Colesterol Total e Colesterol-LDL as demais variáveis, aspartato amino transferase, gama glutamil transferase, albumina, proteínas totais, uréia, fosfatase alcalina, colesterol hdl e triglicerídeos não foram influenciadas (P>0,05). Em relação a parte reprodutiva a suplementação com gordura promoveu aumento na taxa de prenhez e retorno ao cio nos grupos 250 e 500 gramas, bem como diminui a quantidade de vacas em anestro. A suplementação de gordura protegida de óleo de palma na dieta de vacas leiteiras se mostrou eficiente no aumento dos níveis plasmáticos de colesterol total e colesterol – LDL, promovendo melhorias na reprodução, porém não altera significativamente a produção de leite bem como sua composição. / Dairy cows need to eat right after childbirth lot of energy to support milk synthesis increases linearly. With the objective of this study was to evaluate the effect of levels of palm oil in protected form as a supplement in the diet of dairy cows on body dynamics, production and milk composition, metabolic profile and reproduction. The experiment was conducted in the months of July and August 2013 in the city of Paraná, Chopinzinho, 27 Holstein cows were used with an average weight of 651 ± 82.7 kg, distributed according to a randomized block design (RBD) according to lactation (0-90 days) and three treatments inclusion levels of protected fat Magnapac ® (Madrid, Spain). The blocks were formed from the average milk production, properly balanced for weight, age, number of offspring. The treatments included the Protected fat of palm oil in the proportion of 0, 250 and 500 g / animal / day. The weight of milk and collection for analysis of chemical composition, as well as blood samples were taken on days 07, 14 and 30 after starting supplementation. Reproductive diagnoses were made on days 0 and 30.Os results of total milk production showed no significant effect (P> 0.05) in relation to different levels of protected fat. On proximate composition of milk parameters, fat, protein, lactose, total solids, nonfat dry extract, urea and somatic cell count had no significant effect (P> 0.05). The metabolic profile variables that showed a linear increase (P <0.05) Total Cholesterol and LDL-Cholesterol other variables, aspartate aminotransferase, gamma-glutamyl transferase, albumin, total protein, urea, alkaline phosphatase, HDL cholesterol and triglycerides did not were affected (P> 0.05). Regarding reproductive part supplementation with fat promoted an increase in pregnancy rate and return to estrus in groups 250 and 500 grams, as well as decreases the amount of cows in anestrus. The supplementation of protected fat of palm oil in the diet of dairy cows proved effective in increasing plasma levels of total cholesterol and LDL - cholesterol, promoting improvements in reproduction, but does not significantly alter milk production and its composition. / 5000

Made available in DSpace on 2015-12-10T14:23:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-08-13. Added 1 bitstream(s) on 2015-12-10T14:30:02Z : No. of bitstreams: 1 000853088.pdf: 364929 bytes, checksum: 2b04105cefb597c55d2cf56272e18e71 (MD5) / Objetivou-se com esse estudo avaliar o método de suplementação de 20 bovinos [(Nelore; 10 + 1 mês de idade e 220 + 33kg de peso vivo (PV) iniciais] e 20 bubalinos [Murrah; 10 + 1 mês de idade e 206 + 29kg (PV) iniciais] recriados em pasto de Urochloa brizantha cv. Xaraés, suplementados (0,6% PV) ou não (controle). Foram realizadas pesagens dos animais no início do estudo (0d) e nos dias 28, 56 e 84, para o cálculo do ganho de peso (GP), ganho médio diário (GMD), e coletas de amostras de sangue para determinação da glicose plasmática. Medidas da altura de garupa (AG), escore de condição corporal (ECC), área de olho de lombo (AOL), espessura de gordura subcutânea (EGS; 12a costela) e espessura de gordura da garupa (EGG) foram determinadas no início (0d) e no final (84d) do estudo. Foi realizada avaliação do comportamento ingestivo (tempo no cocho, ruminação, ócio e ingestão de água) considerando o tempo dispendido com cada evento. Custos dos diferentes tratamentos foram calculados. Não houve interação entre espécie e tratamento. Os bovinos apresentaram valores superiores (P < 0,01) de PV0d, PV28d, PV56d, PV84d, GPtotal, GMD28d, GMD56d, GMD84d, GMDtotal, AG0d, AG84d, AOL84d (P = 0,04), custo total/cabeça (P = 0,03) e lucro/cabeça/ha, quando comparados aos bubalinos. Enquanto que maiores valores (P < 0,01) de ECC0d, ECC84d, EGS0d, EGS84d, EGG0d, EGG84d, tempo de permanência no cocho, quantidade de água ingerida (P < 0,01), e consumo percentual de suplemento foram atribuídos aos bubalinos. Foi detectado efeito do tratamento (P < 0,01) para as características de PV0d, PV28d, PV56d, PV84d, GPtotal, GMD28d, GMD56d, GMD84d, GMDtotal, ECC84d, AOL84d, custo total/cabeça, ganho/@, receita/cabeça, para as quais os animais suplementados apresentaram maiores valores quando comparados aos animais controle. Conclui-se que o grupo genético bovino se destacou quanto aos ganhos de ... / The objective of this study was evaluate the supplementation method of 20 beef cattle [Nelore; 10 + 1 month of age and 220 + 33kg body weight (BW)] and 20 buffaloes [Murrah water buffalo, 10 + 1 month of age and 206 + 29kg body weight (BW)] growing in (Urochloa brizantha cv. Xaraés) receiving supplementation (0.6% BW), or not (control). Animals were divided in two treatment groups (n = 10 animals of each genetic group for each treatment). Body weight were conducted at the beginning of the experiment (0d) and 28, 56 and 84 day, to determining weight gain (WG), average daily gain (ADG), and blood samples for determination of glucose. Hip height measurements (HH), body condition score (BCS), rib eye area (REA), backfat thickness - 12th rib (BF), rump fat thickness (RFT) were determined at the beginning (0d) and the end (84d) of the study. The evaluation of feeding behavior was conducted (trough time, rumination, idleness and water intake) considering the time spent on each event. Cost of different treatments was calculated. There was no interaction between species and treatment.The beef cattle had higher values (P <0.01) of BW0d, BW28d, BW56d, BW84d, WGtotal, ADG28d, ADG56d, ADG84d, ADGtotal, HH0d, HH84d, REA84d (P = 0.04), total cost/head (P = 0.03) and income/head/ha when compared to buffaloes. Buffaloes had higher values (P < 0.01) of BCS0d, BCS84d, BF0d, BF84d, RFT0d, RFT84d, length of stay in the trough, water intake, and percentage supplement intake compared to beef cattle. Effect of treatment was detected (P < 0.01) for BW0d, BW28d, BW56d, BW84d, WGtotal, ADG28d, ADG56d, ADG84d, ADGtotal, BCS84d, REA84d, total cost/head, gain/@, income/head where supplemented animals showed higher values when compared to control animals. In conclusion, bovine genetic group excelled for weight gains while consuming a smaller proportion of ...

Made available in DSpace on 2014-06-11T19:32:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-12-16Bitstream added on 2014-06-13T18:44:44Z : No. of bitstreams: 1 barducci_rs_dr_botfmvz.pdf: 1266267 bytes, checksum: e1878e2a411c880df9e2a0200ef4bf96 (MD5) / O objetivo deste estudo foi avaliar os efeitos da duração de protocolos de adaptação às dietas com alta inclusão de concentrados sobre o desempenho, características de carcaça (CC), comportamento ingestivo (CI) e variação diária na ingestão de matéria seca (VDIMS) de bovinos Nelore terminados em confinamento. O delineamento experimental foi em blocos inteiramente casualizados, em arranjo fatorial 2 × 2, sendo os fatores protocolos de adaptação (escadas e restrição) e tempo de durações dos mesmos (9 e 14 dias), totalizando 24 baias, com 6 repetições (baia) por tratamento (5 animais/baia), com 120 Nelores machos não castrados (361,3 ± 30,2 kg), distribuídos em 6 blocos. Foi observado para os animais do protocolo de restrição menor ingestão de matéria seca (IMS) em quilogramas no período de 0 a 28 dias (P=0,01) e 0 a 56 dias (P=0,10) (9,01 vs. 9,67 e 10,18 vs. 10,66), menor IMS em porcentagem de peso vivo (PV) no período de 0 a 28 dias (P=0,01) e 0 a 56 dias (P=0,03) (2,36 vs. 2,52 e 2,47 vs. 2,58). Para conversão alimentar, eficiência alimentar e custo para ganhar um quilo de PV, os animais do protocolo de restrição tiveram melhores valores no período de 0 a 56 dias (P=0,06) e 0 a 84 dias (P=0,04) (0 a 56 dias: 5,61 vs. 5,97; 0,179 vs. 0,169 e 3,32 vs. 3,53 - 0 a 84 dias: 6,08 vs. 6,38; 0,165 vs. 0,157 e 3,59 vs. 3,77). Foi observado (P=0,0056) efeito principal de protocolo na VDIMS, com maiores valores para os animais adaptados pelo protocolo em escadas na fase de adaptação (0,524 vs. 0,438). No CI, animais do protocolo de restrição apresentaram menor tempo de ruminação (TR) (P<0,01) (304,00 min/d vs. 398,59 min/d), idas ao bebedouro (IB) (P=0,03) (7,40 vs. 8,32), tempo de alimentação por refeição (P<0,01) (5,47 min vs. 7,41 min) e eficiência de ruminação da MS (ERUMS) (P<0,01) (41,93 min/kg vs. 47,76 min/kg)... / One hundred and twenty, 24-mo-old Nellore bulls (361.3±30.2 kg) were fed in 24 pens for 84-d to determine effects of adaptation protocol and length period on feedlot performance, carcass traits, feeding behavior and dry matter intake fluctuations (DMIF) of Nellore cattle. A completely randomized block design with a 2×2 factorial arrangement and 6 replications was used (5 bulls/pen). Factors include adaptation protocols, restricted finishing diet intake (REST) as a means of dietary adaptation compared with diets increasing in concentrate (STEP) over periods of either 9 or 14 d. Low dry matter intake (DMI) in kilograms for the REST animals in the period from 0 to 28 days (P=0.01) and 0 to 56 days (P=0.10) (9.01 vs 9.67 and 10.18 vs. 10.66) as well as low DMI in percentage of body weight (BW) in the period from 0 to 28 days (P=0.01) and 0 to 56 days (P=0.03) (2.36 vs 2.52; 2.47 vs. 2.58) were observed. REST animals showed better values in the period from 0 to 56 days (P=0.06) and 0 to 84 days (P=0.04) in feed conversion, feed efficiency and cost to gain one kilogram of BW (0 to 56 days: 5.61 vs 5.97, 0.179 vs 0.169 and 3.32 vs 3.53 - 0 to 84 days: 6.08 vs 6.38, 0.165 vs 0.157 and 3.59 vs 3.77). STEP animals presented (P=0.0056) higher DMIF at adaptation phase (0.524 vs 0.438). Regarding feeding behavior, REST animals presented lower chewing time (P<0.01) (304.00 min/d vs 398.59 min/d), lower number of visits to drink water (P=0.03) (7.40 vs 8.32), less meal time (P<0.01) (5.47 min vs 7.41 min) and lower chewing dry matter efficiency (P<0.01) (41.93 min/kg vs 47.76 min/kg). Moreover, interaction between protocol and days (P<.0001) to daily feed time, total chewing time, inactivity time, DMI and daily feed efficiency of dry matter was observed, in which REST animal provided the best values along the observation days... (Complete abstract click electronic access below)