7 pp.

Revised; Originally Published: 2000 / 6 pp.

Four studies were conducted to evaluate the potential for post-extraction algal residue (PEAR) to be incorporated as a protein source in the grazing sector of the beef cattle industry. In Experiment 1, blends of PEAR and conventional protein supplements (dried distillers’ grains, DDG; cottonseed meal, CSM) were offered to steers consuming Bermudagrass to evaluate palatability of PEAR. Supplement completion, time required for consumption, and amount of supplement consumed were recorded. In Experiment 2, isonitrogenous amounts of PEAR and CSM (100 mg N/kg BW) were supplemented to steers consuming low-quality forage to compare effects on nutrient utilization. Experiment 3 evaluated the optimal inclusion rate of PEAR to steers consuming low-quality forage. Treatments included no supplemental protein, 3 levels of PEAR (50, 100, and 150 mg N/kg BW) and 1 level of CSM (100 mg N/kg BW). In Experiment 4, the effects of upstream operations on the nutritive value of PEAR were quantified. Observations indicate PEAR may be blended with existing protein sources in the beef industry without negatively affecting palatability, but there may be palatability concerns when PEAR is offered alone. Provision of 100 mg N/kg BW of PEAR or CSM stimulated forage intake (P ≤ 0.05) and increased N retention (P = 0.02) relative to unsupplemented animals. Imbalances in mineral intakes (Ca:P ratio of 8:1) were observed when PEAR was supplemented, but not CSM. Total digestible OM intake (TDOMI) responded quadratically (P = 0.01) to increasing provision of PEAR with maximization occurring when PEAR was provided at 100 mg N/kg BW. There was not a difference in TDOMI (P = 0.13) at isonitrogenous levels of PEAR and CSM, indicating forage utilization was stimulated to a similar extent. Excess mineral levels and imbalances in PEAR were largely a result of cultivation, harvesting, and extraction procedures which could be controlled. Thus, there is potential to alter production streams to optimize oil yield and co-product value. Overall, our results indicate PEAR can be incorporated as a protein source in the beef cattle industry, thus increasing economic viability of biofuel production from algal biomass.

Potential protein supplements to grazing cattle were evaluated in two projects. In the first project, Karanja seedcake samples were prepared and ruminally incubated using the in situ method to measure nutrient disappearance in cattle consuming low-quality forage. Organic matter and CP were fractionated by degradability into A, B, and C fractions. Organic matter fraction A degradability ranged from 59.6 to 89% (P < 0.05) for all the karanja seedcake samples. Fraction A of CP ranged from 61.6 to 96.2% degradability for all the samples (P < 0.05). Karanja seedcake samples were observed to contain highly degradable nutrients and our results indicate karanja seedcake may possibly be utilized in grazing cattle protein supplements, consequently increasing economic sustainability of biofuel production. In the second experiment, four non-protein nitrogen supplements were ruminally infused in steers consuming low-quality forage. Supplements included a 40% CP mineral mix (40MM), 60% CP mineral mix (60MM), 25% CP liquid (25L), or 35% CP liquid (35L). Protein provision stimulated forage OM intake and total OM intake for both liquid supplements. Forage OM intake tended to be greater for the liquid supplements; 25L (P = 0.06) and 35L (P = 0.08), then control. Total OM intake significantly increased (P < 0.01) for both liquid supplements, when compared to the control treatment. Total digestible OM intake was greater (P < 0.01) for 25L (3.4 kg/d) and 35L (3.36 kg/d) than control (2.94 kg/d). Forage and total OM intake were not significantly affected by 40MM or 60MM treatments. Total tract digestions (OM and NDF) were not observed to be significantly different (P ≥ 0.11) between supplements and control. Ruminal ammonia was greater (P < 0.01) for all supplements then control and total ruminal VFA concentrations increased from 84.7 to 98.7 mM for control versus supplemented. Supplementation with liquids had a significant effect on intake. Our results indicate of the four supplements, liquid supplements improved the utilization of low-quality forage by cattle, thus improving nutrient stewardship.

O objetivo com este estudo foi avaliar o efeito de teores crescentes de proteína no concentrado de vacas leiteiras no terço inicial da lactação mantidas em pastagens de capim elefante (Pennisetum purpureum), manejadas com altas taxas de lotação durante o período chuvoso, sobre as seguintes variáveis: 1) produção e composição de leite; 2) peso vivo e condição corporal dos animais; 3) consumo de matéria seca; 4) parâmetros sanguíneos; 5) parâmetros ruminais; 6) composição bromatológica e morfológica da pastagem; e 7) comportamento animal. Buscou-se também a caracterização da PB do capim e a adequação proteica da dieta, visando otimizar a eficiência de utilização do nitrogênio. Foram utilizadas 30 vacas (HPB × Jersey) distribuídas em 10 grupos homogêneos, cada um compondo um quadrado latino 3x3, de acordo com a composição racial, dias em lactação e produção de leite e receberam suplemento concentrado com três níveis de PB durante períodos de 21 dias. Os concentrados continham milho moído fino, minerais, vitaminas e os três níveis de proteína (T1: 7,8; T2: 15,4; T3: 20,5% PB) foram obtidos substituindo-se parte do milho por farelo de soja. O capim elefante foi adubado com 50 kg N ha-1 por pastejo e apresentou teor médio de PB de 15,5%. As produções de leite e de leite corrigido para 3,5% de gordura, os teores e produções de gordura, proteína e caseína no leite, o consumo de matéria seca (CMS) não foram influenciados (P>0,05) pelos teores de PB dos concentrados. A concentração de nitrogênio ureico no leite aumentou linearmente (P<0,01) com o aumento dos teores de PB dos concentrados. A excreção de N pela urina foi maior (P<0,01) para os animais recebendo os concentrados contendo farelo de soja (T2 e T3) em relação àqueles consumindo o concentrado contendo apenas milho (T1). Além disso, a concentração de N amoniacal no rúmen foi menor (P<0,05) para estes últimos animais, que apresentaram, ainda, perda de peso durante o período experimental. A excreção total de N no ambiente acompanhou o comportamento do teor de PB dos concentrados. O fornecimento de farelo de soja no concentrado de vacas em terço inicial de lactação, mantidas em pastagens tropicais manejadas intensivamente, não resulta em benefício produtivo, mas favorece a acréscimo do peso corporal dos animais. / The aim of this study was to evaluate the effects of increasing levels of protein in the concentrate for early lactation cows maintained in an elephant grass pasture (Pennisetum purpureum), which was managed under high stocking rate during the raining season. The following variables were evaluated: 1) milk yield and composition; 2) body weight and condition score; 3) dry matter intake; 4) blood parameters; 5) rumen parameters; 6) chemical and morphological composition of the pasture; and 7) animal behavior. Protein fractionation of the pasture, and diet protein balancing were also studied as a way to improve efficiency of nitrogen use. Thirty Holstein × Jersey cows, distributed in 10 homogenous groups according to breed composition, days on lactation, and milk production, were used. In each group a 3×3 Latin square experiment was designed. Treatments consisted of 3 levels of crude protein in the concentrate supplement (T1: 7.8; T2: 15.4; T3: 20.5% CP). Concentrates were composed of finely ground corn, and mineral and vitamin mixture. Protein levels were obtained by adding soybean meal. Elephant grass pasture was fertilized with 50 kg N ha-1 after every grazing period, and presented 15.5% CP in average. Milk yield, fat corrected milk (3.5% fat), milk fat (g day-1 and %), milk protein (g day-1 and %), milk casein (g day-1 and %), and dry matter intake were not affected (P>0.05) by the supplement protein level. Concentration of ureic nitrogen in the milk increased linearly (P<0.01) as protein supplementation was increased. Nitrogen excretion in the urine was higher (P<0.01) for cows receiving the concentrates with soybean meal (T2 and T3), in comparison with those fed supplements containing just corn (T1). Moreover, these later had lower N-NH3 concentration in the rumen (P<0.05), and a negative body weight gain. Total N excretion to the environment follows the increasing in the protein level supplementation. Feeding soybean meal to early lactation cows, maintained in an intensively managed tropical pasture, does not result in productive benefits; however, it promotes an increasing in body weight of the animals.

O estudo dos teores protéicos oferecidos aos animais possui crucial importância, pois estes exercem influência determinante no desenvolvimento da infecção parasitária. Investigou-se o efeito da utilização de dois diferentes teores protéicos (18,5% e 8,6% de PB na MS) sobre as alterações fisiopatológicas desenvolvidas por bezerros primo infectados com o nematóide intestinal Cooperia punctata. Objetivando determinar se a suplementação possibilitaria aos animais infectados responderem mais prontamente ao desafio parasitário, realizaram-se estudos de composição corporal, retenção de compostos nitrogenados, acompanhamento clínico completo, avaliação de peso e carcaça, avaliação quantitativa e qualitativa da carga parasitária e exames histopatológicos. Os animais que receberam suplementação apresentaram um quadro clínico menos severo, perderam menos peso, tiveram um maior rendimento de carcaça, apresentaram lesões teciduais mais exuberantes, maiores taxas de excreção urinária de nitrogênio, expulsaram os parasitos para porções distais do trato gastrointestinal e demonstraram uma eficiência de retenção de nitrogênio 3,6 vezes maior que os animais mantidos na dieta basal. Demonstrou-se que a suplementação protéica resultou em efeitos positivos para os animais infectados. / The study of protein levels offered to cattle is very important when one aims at nematode control, since they can effectively affect the development of parasitic infection. The effect of two different levels - 18.5% and 8.6% CP on DM basis on the pathophysiology of Cooperia punctata infection on naive calves was examined. Aiming at determine if protein supplementation allow animals to better withstand parasitic challenge, several parameters were evaluated: body composition, nitrogen retention, clinical evolution, weight gain, carcass yeld, quantitative and qualitative assessment of parasitic burden and histopathology. Supplemented animal presented a milder clinical signs, lost less weight, had higher carcass yeld, greater tecidual lesions, higher urinary nitrogen excretion, expelled parasites to distal parts of gastrointestinal tract and showed a 3.6 greater efficiency for nitrogen retention than animal kept on basal diet. It became clear that protein supplementation resulted in benefits to infected animals.

O presente trabalho teve como objetivo avaliar o desempenho de novilhas da raça Nelore, suplementadas com níveis de proteína bruta em pastagem de capimbraquiarão (Brachiaria brizantha cv. Marandu), no período de transição água-seca. O experimento foi conduzido na Faculdade de Zootecnia e Engenharia de Alimentos - FZEA/USP em Pirassununga-SP. Utilizou-se quatro tratamentos: Controle (CTRL) sendo sal mineral; Suplemento com 20% de proteína bruta (20%); suplemento com 40% de proteína bruta (BC 40%), sendo esses de baixo consumo e suplemento 40% de proteína bruta de alto consumo (AC 40%). O ciclo de pastejo foi de 35 dias, sendo sete dias de ocupação e 28 dias de descanso. O delineamento experimental foi em blocos completos casualizados com 4 repetições.Foram utilizadas 96 novilhas da raça Nelore com peso médio inicial de 316 kg e cerca de 18 meses de idade, num período experimental de 105 dias, tendo início em 09 de abril e término em 27 de agosto de 2008, considerado período de transição água-seca. Para o ganho de peso médio diário, não houve diferença estatística entre os tratamentos AC 40% e BC 20% (p<0,05), sendo o GPD de 0,470 e 0,369 gramas/dia, respectivamente, enquanto que para os tratamentos CTRL, 20% e BC 40%, não houve diferença estatística (P>0,05), sendo osGPD de 0,336, 0,369 e 0,353 gramas/dia, respectivamente. A utilização de suplementos protéicos no desempenho de novilhas teve desempenhos satisfatórios no período de transição água-seca, porém, para a recomendação da utilização, recomenda-se realizar uma análise econômica, pois somente assim, garantirá qual será o melhor tratamento para o período. / The aim of this study was to evaluate the performance of Nelore heifers supplemented with crude protein levels in pasture of Brachiaria grass (Brachiaria brizantha cv. Marandu), during the transition period of wet-dry seasons. The experiment was conducted at the Faculty of Animal Science and Food Engineering - FZEA / USP in Pirassununga-SP. It was used four treatments: Control (CTRL) being mineral salt, supplement with 20% of crude protein (20%) supplement with 40% of crude protein (BC 40%), as low consumption and with crude protein of 40% as high consumption (AC 40%). The grazing cycle was 35 days, seven days of occupation and 28 days of interval. A randomized complete block design, with 4 repetitions was utilized. It was used 96 Nelore heifers with an average weight of 316 kg and around 18 months, in a probationary period of 105 days, starting on 09 April and ending in August 27, 2008, considered the transitional period of wet-dry seasons. For the average daily gain, there was no statistical difference between treatments AC 40% and 20% (p<0,05), being GPD of 0.470 and 0.369 grams/day, respectively, while for the treatments CTRL, 20% and BC 40%, there was no statistical difference (P>0,05), being GPD of 0.336, 0.369 and 0.353 grams/day, respectively. The use of crude protein supplements on performance of heifers had performed satisfactorily during the transition period of wet-dry seasons however, to recommend the use, it is suggest to perform an economic analysis, for only thus ensure the best treatment for the period.

Master of Science / Animal Sciences and Industry / John R. Jaeger / Cattle consuming low-protein forage (<7% CP) require additional supplemental protein to maintain BW and BCS. Daily delivery of protein supplements places undue financial burden on cattle producers. Supplementing cows as infrequently as once every 6 d) has resulted in similar changes cow BW and BCS when compared to daily supplementation. As calving season nears, producers may wish to increase supplementation frequency. The responses to a change in supplementation frequency during the third trimester of gestation have not been widely investigated. Therefore, our objective in Study 1 was to evaluate the effect of altering supplementation frequency during late gestation on performance of spring-calving cows grazing low-quality, dormant native range and supplemented with dried distillers grains with solubles (DDG). Angus × cows (n = 238; mean age = 6 ± 2.5 yr; average initial BW = 618 ± 56.2 kg; average initial BCS = 5.7 ± 0.03) were stratified by age, BW, BCS, and assigned randomly to 1 of 4 treatments: 1) DDG daily (D1); 2) DDG once every 6 d (D6); 3) DDG daily from d 1 to d 60 and then every 6 d (D1-D6); 4) DDG every 6 d from d 1 to d 60 and then daily (D6-D1). Treatments were initiated 100 d prior to expected onset of calving. Cow BW and BCS were measured every 28 d. Cows were sorted daily before supplementation at 0830 h. Supplement delivery was calculated to meet dietary CP requirements. Increasing supplementation frequency 28 d prepartum negatively affected final BW and BW change from d 61-88 for the D6-D1 supplementation group (P < 0.05) compared to other supplementation groups. Cow BW change for the study (d 1-88) was also less (P < 0.02) for the D6-D1 group compared to other groups but was also affected (P < 0.01) by year. Under the conditions of our study, increasing supplementation frequency 28 d before calving was not a viable means of increasing prepartum cow performance. The development of replacement heifers is a significant expense for cow-calf producers. Reducing the cost of heifer development programs while achieving high pregnancy rates is an industry-wide goal. Therefore, our objective in Study 2 was to determine if DDGS was a viable replacement for an oilseed meal-based protein supplement when developing heifers on low-quality, dormant native range. Treatments consisted of daily supplementation of either 1.65 kg DM DDG (DDG; 0.57 kg CP) or 1.37 kg DM of a 73.6% soybean meal and 26.4% rolled sorghum grain mixture (SBM-S; 0.56 kg CP). Treatments were administered from 1/15 until 4/8 (84 d). Initial BW and BCS were not different between treatments (P ≥ 0.29). Final BW and BCS also did not differ (P ≥ 0.55) between treatments; moreover, rates of BW and BCS change were not different (P ˃ 0.30) between treatments. Proportions of heifers pubertal before ovulation synchronization, first service conception rates, and final pregnancy rates were not affected (P > 0.40) by treatment. Under the conditions of our study supplemental CP fed at a rate of approximately 0.56 kg daily was sufficient to promote growth and BCS change adequate for optimal reproductive performance; moreover, supplement ruminal degradability of CP did not influence heifer performance over an 84-d development period.

O objetivo com este estudo foi avaliar o efeito de teores crescentes de proteína no concentrado de vacas leiteiras no terço inicial da lactação mantidas em pastagens de capim elefante (Pennisetum purpureum), manejadas com altas taxas de lotação durante o período chuvoso, sobre as seguintes variáveis: 1) produção e composição de leite; 2) peso vivo e condição corporal dos animais; 3) consumo de matéria seca; 4) parâmetros sanguíneos; 5) parâmetros ruminais; 6) composição bromatológica e morfológica da pastagem; e 7) comportamento animal. Buscou-se também a caracterização da PB do capim e a adequação proteica da dieta, visando otimizar a eficiência de utilização do nitrogênio. Foram utilizadas 30 vacas (HPB × Jersey) distribuídas em 10 grupos homogêneos, cada um compondo um quadrado latino 3x3, de acordo com a composição racial, dias em lactação e produção de leite e receberam suplemento concentrado com três níveis de PB durante períodos de 21 dias. Os concentrados continham milho moído fino, minerais, vitaminas e os três níveis de proteína (T1: 7,8; T2: 15,4; T3: 20,5% PB) foram obtidos substituindo-se parte do milho por farelo de soja. O capim elefante foi adubado com 50 kg N ha-1 por pastejo e apresentou teor médio de PB de 15,5%. As produções de leite e de leite corrigido para 3,5% de gordura, os teores e produções de gordura, proteína e caseína no leite, o consumo de matéria seca (CMS) não foram influenciados (P>0,05) pelos teores de PB dos concentrados. A concentração de nitrogênio ureico no leite aumentou linearmente (P<0,01) com o aumento dos teores de PB dos concentrados. A excreção de N pela urina foi maior (P<0,01) para os animais recebendo os concentrados contendo farelo de soja (T2 e T3) em relação àqueles consumindo o concentrado contendo apenas milho (T1). Além disso, a concentração de N amoniacal no rúmen foi menor (P<0,05) para estes últimos animais, que apresentaram, ainda, perda de peso durante o período experimental. A excreção total de N no ambiente acompanhou o comportamento do teor de PB dos concentrados. O fornecimento de farelo de soja no concentrado de vacas em terço inicial de lactação, mantidas em pastagens tropicais manejadas intensivamente, não resulta em benefício produtivo, mas favorece a acréscimo do peso corporal dos animais. / The aim of this study was to evaluate the effects of increasing levels of protein in the concentrate for early lactation cows maintained in an elephant grass pasture (Pennisetum purpureum), which was managed under high stocking rate during the raining season. The following variables were evaluated: 1) milk yield and composition; 2) body weight and condition score; 3) dry matter intake; 4) blood parameters; 5) rumen parameters; 6) chemical and morphological composition of the pasture; and 7) animal behavior. Protein fractionation of the pasture, and diet protein balancing were also studied as a way to improve efficiency of nitrogen use. Thirty Holstein × Jersey cows, distributed in 10 homogenous groups according to breed composition, days on lactation, and milk production, were used. In each group a 3×3 Latin square experiment was designed. Treatments consisted of 3 levels of crude protein in the concentrate supplement (T1: 7.8; T2: 15.4; T3: 20.5% CP). Concentrates were composed of finely ground corn, and mineral and vitamin mixture. Protein levels were obtained by adding soybean meal. Elephant grass pasture was fertilized with 50 kg N ha-1 after every grazing period, and presented 15.5% CP in average. Milk yield, fat corrected milk (3.5% fat), milk fat (g day-1 and %), milk protein (g day-1 and %), milk casein (g day-1 and %), and dry matter intake were not affected (P>0.05) by the supplement protein level. Concentration of ureic nitrogen in the milk increased linearly (P<0.01) as protein supplementation was increased. Nitrogen excretion in the urine was higher (P<0.01) for cows receiving the concentrates with soybean meal (T2 and T3), in comparison with those fed supplements containing just corn (T1). Moreover, these later had lower N-NH3 concentration in the rumen (P<0.05), and a negative body weight gain. Total N excretion to the environment follows the increasing in the protein level supplementation. Feeding soybean meal to early lactation cows, maintained in an intensively managed tropical pasture, does not result in productive benefits; however, it promotes an increasing in body weight of the animals.

Made available in DSpace on 2014-06-11T19:28:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-28Bitstream added on 2014-06-13T19:57:43Z : No. of bitstreams: 1 moretti_mh_me_jabo.pdf: 820927 bytes, checksum: 9e02dc45b7bc9474b5acb3d859d4d028 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Objetivou-se verificar o efeito da suplementação de baixo consumo, sobre o desempenho de novilhos Nelore mantidos em pastagem de Brachiaria brizantha cv. Marandu. O período experimental foi de julho de 2008 a março de 2009 e foi divido em duas fases, secas e águas. Os tratamentos durante o período da seca constituíramse de um controle, sal com uréia, e suplemento mineral enriquecido, este que era acrescido de proteína verdadeira e aditivos. Já no período das águas avaliou-se um tratamento controle, sal mineral e suplemento mineral enriquecido. O delineamento experimental utilizado foi inteiramente casualizado, em esquema de parcela subdividida. No caso da avaliação conjunta das duas fases o delineamento utilizado foi inteiramente casualizado, em esquema fatorial 2 x 2, sendo os fatores os tipos de suplementação em cada uma das fases. Realizaram-se avaliações de pasto e pesagem dos animais a cada ciclo de avaliação dentro dos períodos estudados. No período da seca foi observada diferença estatística em função dos tratamentos avaliados somente no terceiro ciclo. Os animais que receberam suplementação mineral enriquecida (proteína mais aditivos) ganharam 0,600 kg/dia, contra 0,517 kg/dia daqueles receberam sal com uréia. No primeiro e segundo ciclo os tratamentos não apresentaram diferença significativa em relação ao ganho, 0,307 e 0,113 kg/dia. No período das águas os animais que receberam suplementação mineral enriquecida ganharam mais peso do que os animais que receberam suplementação mineral, 0,800 e 0,696 kg/ dia. Concluiu-se que a suplementação mineral acrescida de proteína e aditivos, permite incrementos no ganho de peso dos animais mantidos em regime de pastejo na ordem de 15% / The objective was to test the effect of low intake supplementation on performance of Nelore steers grazing Brachiaria brizantha cv. Marandu. The experiment was from July 2008 to March 2009 divided into two phases, wet and dry seasons. The treatments during the dry season consisted of a control, a salt urea, and mineral supplement, that it was increased with true protein and additives. In the wet season we evaluate a control treatment, mineral salt and a supplement mineral enriched. The lineation experiment was completely randomized in parcel scheme subdivided. In the case of joint evaluation of the two phases, the lineation was completely randomized in scheme factorial 2X 2, the factors being the type of supplementation in each phase. Evaluations were performed on grazing and animals weighed each evaluation cycle within the periods studied. During the dry season was a statistical difference in the treatments evaluated only in the third cycle. The animals that received mineral supplementation enriched (protein more additive) gained 0.600 kg/day, against 0.517 kg/day those who received salt with urea. In the first and second cycle the treatments showed no significant difference in relation to gain, 0.307 e 0,113 kg/day. In wet season the animals receiving mineral supplementation enriched gained more weight than animals receiving just mineral supplementation, 0.800 e 0.696 kg/day. Concludes the mineral supplementation enriched with protein and additive, allows greater weight gains than animals kept in grazing to order 15%