One hundred and twenty lactating Holstein cows in mid-lactation were offered diets varying in protein level and degradability at two locations during hot and moderate weather. Treatments were: (1) High protein (19%), high degradability (65%); (2) High protein (19%), medium degradability (40%); (3) Medium protein (15.5%), high degradability (65%); (4) Medium protein (15.5%), medium degradability (40%). Diets were individually fed during hot weather at the University of Arizona Dairy Farm and contained 38.4% alfalfa hay, 12.4% cottonseed hulls, 9.8% whole cottonseed, and 39.4% concentrate (dry matter). Diets were group fed during moderate weather at the Brigham Young University Dairy Farm, Provo, Ut, and contained 31.3% corn silage, 14% alfalfa haylage, 9.4% whole cottonseed and 45.3% concentrate (dry matter). Average daily ambient temperatures were 35.1°C for hot and 26.8°C for moderate weather locations. Fat-corrected milk (3.5%, 2 x milkings) and milk persistency were lower for treatment 1 than other treatments. For the respective treatments during hot weather means were: 23.4, 26.6, 28.5, 28.4 kg/d; 83.2, 91.2, 90.9, 90.3%; and for moderate weather means were: (3 x milkings): 34.7, 31.8, 32.2, 32.4 kg/d; 97.0, 93.4, 92.1, 90.3%. Dry matter intakes during hot weather were 21.5, 21.9, 23.3, and 23.1 kg/d. Respiration rate and rectal temperature during hot weather were: 90.1, 87.9, 90.9, 94.7 counts/min; 39.0, 39.3, 39.3, 39.5°C and for moderate weather: 61.2, 58.2, 55.5, 67.4 counts/min; 38.8, 38.6, 38.7, 38.8°C. Serum T₃,T₄ and cortisol were generally unaffected by treatment, but were depressed during hot weather. Serum glucose was not significantly affected by treatments at either environmental locations. Animals consumed more water with highly degradable protein diets at each location along with consuming more water during thermal stress. These data show that 3.5% fat-corrected milk and milk persistency are significantly affected (P <.01; P <.025) by rations high in protein of high degradability during heat stress.

An experiment involving three feeding trials was conducted to study the effect of substituting chopped wheat straw for alfalfa in diets for lactating dairy cows. The results of these trials have shown that in complete mixed diets or diets containing long alfalfa hay, replacement of half of the alfalfa in rations containing 45% roughage for lactating dairy cows with chopped wheat straw does not adversely affect DM intake or milk yield and increase milk fat percentage. Replacing half of the long alfalfa with chopped alfalfa also apparently improved lactational performance although not as dramatically as that of chopped straw. Ammoniation of wheat straw did not improve the performance response by lactating cows. Inclusion of chopped straw in the diets seemed to enhance the efficiency of milk production. Higher ruminal acetate:propionate ratios and increased digestibility of ether extract resulted from feeding straw. Digestibility of other nutrients were generally either not affected or were depressed by straw feeding. Increasing the chopped wheat straw level to 75% of the roughage resulted in lower DM intake and milk yield and negative body weight gains but higher milk fat levels. It did not appear that maintenance of constant ADF level in a dairy ration regardless of roughage level was the solution to the maintenance of milk fat levels. Thus it has been indicated that under the conditions of this experiment a combination of chopped alfalfa and wheat straw can be used successfully in complete mixed rations for high producing dairy cows. For the most part all productive parameters measured were improved by the addition of straw and by the feeding of complete mixed diets. This was especially true for milk fat which, from a dairyman's viewpoint, is very important because of its impact on milk pricing. It would also have a direct bearing on management by reducing labor costs through elimination of labor intensive handling of long alfalfa. Mechanical handling of complete mixed rations is relatively easier and cheaper.

Four studies were conducted to determine the effect of synchronization of protein and starch degradation on nutrient utilization, microbial protein synthesis and milk production in dairy cows. In Experiment 1, five cereal grains and five protein supplements were compared for extent of solubility and degradability of their starch and nitrogen fractions. Results indicated large differences which permitted their ranking from high to low degradability as follows: grains, oats > wheat > barley > corn > milo protein supplements, soybean meal > cottonseed meal, (CSM) > corn gluten meal > brewers dried grains, (BDG) > blood meal. In Experiment 2, the five grains were incubated for varying times in vitro (with added amylase) or in situ to determine rate and extent of degradation of dry matter, crude protein and starch. Results showed that rate of starch degradation followed a similar, but slightly different trend than in trial 1 (wheat > barley > oats > corn > milo). Rates for DM and CP degradation were similar than those for starch. In Experiment 3, high (barley, HS) and low (milo, LS) degradable starch sources were combined with a high (CSM, HP) and a low (BDG, LP) degradable protein sources to formulate four diets; HSHP, HSLP, LSHP and LSLP. Diets were fed to 32 cows, starting two to four weeks postpartum, for a 60-d milk production and digestibility study. Apparent digestibility was calculated using chromium oxide. Organic matter digestibility was higher (P < .05) was found in nutrient output to the small intestine among diets and microbial CP synthesis was higher (P > .05) for barley diets.

Two production trials were conducted for 84 d each. The first with 22 Holstein cows in late lactation. The second with 46 Holstein cows in early lactation. Treatments were C (control) and AO (A. oryzae 3g/d). Diets were for production trial 1 a 1:1 forage: concentrate ratio; for trial 2 was 2:3. Milk production in trial 1 was higher (P > .05) in AO fed cows during the first weeks of the trial. In trial two AO cows consistently produced more milk (P < .03). Rectal temperatures during hot weather (over 35°C) were consistently lower in AO fed cows, though not significant (P > .10). Two digestibility trials followed the production trials. For all digestion trials, Cr₂O₃ was used as digesta marker. In trial one AO tended to increase digestibility of DM (P > .10). In trial two digestibilities of DM, NDF and ADF were higher in AO fed cows (P < .05). Three other trials were conducted with mature Holstein cows fitted with ruminal and duodenal cannulae. The first trial tested two levels of forage (1:2 vs 2:1; forage to concentrate) and C vs AO in a 4x4 latin square design. AO increased (P < .05) ADF digestibility in the high concentrate died. No change (P > .10) in rumen pH, concentrations and proportions of VFA, and ammonia concentrations resulted from AO treatments. In the second trial C, AO and SC (Saccharomyces cerevesiae 3 g/d) were compared in a repeated 3x3 latin square design. A 1:2 forage to concentrate diet was fed to six lactating cows. Both AO and SC increased (P < .05) rumen NDF digestibility. The third trial compared C vs AO in a swithchback design with four lactating cows fed a 2:3 forage to concentrate diet. AO increased (P < .05) rumen fiber digestion. AO did not affect rates of passage of corn or alfalfa hay; or the potentially digestible DM of milo, alfalfa hay or wheat straw. AO did increase (P < .05) digestion rate of alfalfa DM. In vitro AO increased DM digestibility. That effect can be reproduced by incorporation of the additive at the time of inoculation.

No description available.

This study examines how Bovine Somatotropin (BST) may impact Arizona dairy producers. The results of dairy scientists experimenting with BST are summarized in terms of reported milk yields and possible changes in feeding and herd management. Dairy enterprize budgets representative of Arizona are constructed to examine how income statements may change if BST is approved. The effects of increased milk supply on Arizona milk prices are estimated using the institutional structure of the Central Arizona Order and the United Dairyman of Arizona. Results of experiments with BST in Arizona are used to generate net returns at several rates of adoption under changing milk prices for three dairy farms in Arizona.

Ensiling high moisture grain often increases starch and protein digestibilities due proteolysis during storage. However, the length of storage is fundamental to allow great protein matrix break down. The central objective of this work was to evaluate the effect of length of storage of reconstituted sorghum grain silage (RSGS) on dairy cows performance. Simultaneously it was evaluated the effect of sodium benzoate on silage nutritive value and its impact on animal performance. The hypothesis was that sodium benzoate reduces proteolitic activity due its antimicrobial properties. Two sequential experiments with mid-lactation Holstein dairy cows were set. The first experiment evaluated the effect of different length of storages on RSGS treated or not with sodium benzoate (0.2% as fed). Silages treated with additive (Benzoate) and non-treated (Control) were stored for 30 or 90 days prior feeding. Twenty mid-lactation dairy cows with 168 &#177; 87 days in milk (DIM) were used in 5 replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement. Dry ground sorghum grain was reconstituted to 35% moisture and ensiled in 200-L plastic drums. Treatments were: RSGS stored for 30 days without additive (30 CON), RSGS stored for 30 days with sodium benzoate (30 BEN), RSGS stored for 90 days without additive (90 CON) and RSGS stored for 90 days with sodium benzoate (90 BEN). Lengthening silage storage increased 1,2-propanediol concentration and protein solubility of silages. Milk yield was greater in favor of cows fed silage stored for 90 days compared to 30 days (31.2 vs. 30.0 kg/d). Starch (89.3 vs. 86.9%) and protein (57.1 vs. 54.0%) digestibility was also greater for silages stored for 90 days compared to 30 days. Sodium benzoate reduced silage ethanol concentration (0.20 vs. 0.08% of DM), but did not altered statistically protein solubility (CON = 18.9 vs. BEN = 15.6% of CP) or ammonium-N (CON = 4.38 vs. BEN = 3.94 % of N). The second trial were conducted with 12 mid-lactation dairy cows (170 &#177; 47 DIM) to evaluated the effect of sodium benzoate on nutritive value and dairy cows performance fed RSGS stored for 150 days, treated (Benzoate) or not (Control) with sodium benzoate. Cows received a standard diet containing dry ground sorghum for 14 days. At the end of adaptation period, cows were paired blocked and randomly assigned to one of two treatments (Control or Benzoate) for 28 experimental days. During experimental period cows received the same diet with the exception of dry ground sorghum, which was totally replaced with RSGS. Silages treated with sodium benzoate had low ethanol (0.84 vs. 0.18 % of DM) and ethyl-lactate (388 vs. 157 mg/kg of DM) concentration as a consequence of low yeast population (4.73 vs. 2.52 log cfu/g). Soluble protein was reduced on treated silages (26.2 vs. 20.6 % of CP). Aerobic stability was higher for treated silages (51 vs. 146 h). Dairy cow performance was not altered by treating silages with sodium benzoate. In conclusion, extending the length of storage of RSGS increased dairy cows use feed efficient and nitrogen use efficiency due higher starch and protein digestibility. Sodium benzoate promoted typical response on silage fermentation and did not alter animal performance. / A ensilagem de grãos úmidos geralmente aumenta a digestão do amido e da proteína devido a proteólise durante o armazenamento. Porém, o tempo de armazenamento é fundamental para permitir que a matriz proteica seja degradada. O objetivo central desse trabalho foi avaliar o efeito do tempo de estocagem em silagens de sorgo grão reconstituído (SSGR) no desempenho de vacas leiteiras. De forma simultânea foi avaliado o efeito do benzoato de sódio no valor nutritivo de silagens de sorgo grão reconstituído. A hipótese foi que o uso de benzoato de sódio em SSGR reduz a atividade proteolítica devido suas propriedades antimicrobianas impactando no desempenho animal. Uma sequência de dois experimentos com vacas leiteiras da raça Holandesa foram formatados. O primeiro experimento avaliou o efeito de diferentes tempos de estocagem em SSGR tratadas ou não com benzoato de sódio (0.2 % base na matéria natural). Silagens não tratadas (Controle) e tratadas com aditivo (Benzoato) foram armazenadas por 30 ou 90 dias antes do fornecimento. Vinte vacas leiteiras (168 &#177; 87 dias em lactação) foram usadas em cinco quadrados latinos replicados 4 × 4 em arranjo fatorial 2 × 2. Sorgo grão foi reconstituído para 35 % de umidade em ambos os experimentos e ensilados em tambores plásticos com capacidade de 200-L. Os tratamentos foram: SSGR armazenados por 30 dias sem aditivo (30 CON), SSGR armazenados por 30 dias com benzoato de sódio (30 BEN), SSGR armazenados por 90 dias sem aditivo (90 BEN) ou SSGR armazenados por 90 dias com benzoato de sódio (90 BEN). Prolongando o tempo de armazenamento a concentração de 1,2-propanodiol e proteína solúvel aumentaram. A produção de leite foi maior em favor das vacas alimentadas com silagens armazenadas por 90 dias comparadas à 30 dias (31.2 vs. 30.0 kg/d). A digestibilidade do amido (89.3 vs. 86.9%) e da proteína (57.1 vs. 54.0%) foi maior para silagens armazenadas por 90 dias. O benzoato de sódio reduziu a concentração de etanol (0.20 vs. 0.08% of DM), porém não alterou ao nível de significância estatística adotada nesse trabalho a proteína solúvel (CON = 18.9 vs. BEN = 15.6% of PB) e o N-amoniacal (CON = 4.38 vs. BEN = 3.94 % of N). O segundo experimento foi conduzido com 12 vacas leiteiras (170 &#177; 47 DEL) para avaliar o efeito do benzoato de sódio no valor nutritivo e desempenho de vacas leiteiras alimentadas com SSGR estocadas por 150 dias, tratadas (Benzoato) ou não (Controle) com benzoato de sódio. Uma dieta padrão contendo sorgo grão seco moído foi fornecida por 14 dias. No final do período de adaptação, os animais foram pareados dois a dois e distribuídos aleatoriamente a um de dois tratamentos (Controle ou Benzoato) fornecidos por 28 dias. Durante o período experimental as vacas receberam a mesma dieta sendo o sorgo seco totalmente substituído por SSGR. Silagens tradadas com benzoato de sódio tiveram menor concentração de etanol (0.84 vs. 0.18 % de MS) e etil lactato (388 vs. 157 mg/kg de MS) como consequência de uma menor população de leveduras (4.73 vs. 2.52 log ufc/g). A proteína solúvel foi reduzida nas silagens tratadas (26.2 vs. 20.6 % da PB). A estabilidade aeróbia foi mais alta nas silagens tratadas (51 vs. 146 h). Em conclusão, estender o tempo de estocagem em SSGR aumentou a eficiência alimentar e do uso do nitrogênio devido ao aumento na digestibilidade do amido e da proteína. O benzoato de sódio promoveu respostas típicas na fermentação de silagens, e não alterou o desempenho animal.

Propolis as natural dietary additive can be used to manipulate rumen fermentation towards less methane (CH4) and it may affect animal reproductive and productive performance. To study the application of propolis, three studies were conducted. The first study aimed to evaluate the in vitro nutritive value of two types of propolis (Brazilian red propolis (BRP) and Egyptian brown propolis (EBP) for their anti-methanogenic activity, ruminal fermentation and degradability. Propolis extracts were prepared using 70% ethanol and added to a 50:50 Tifton hay to concentrate diet at three levels [0 (negative control, CTL), 25, 50 and 100 micrograma / 0.5 g substrate]. Each propolis were compared with monensin as positive control. Both BRP50 micrograma and EBP25 micrograma showed similar significant effects on CH4 production as monensin; on average 14.2 ml/TDOM g compared with CTL (19.3 ml/TDOM). Monensin supplementation increased (P<0.001) the propionate concentration and decreased the acetate/propionate ratio, while BRP and EBP enhanced (P<0.001) the individual and total volatile fatty acids concentrations and reduced (P<0.002) protozoa count compared to CTL. The objective of the second study was to evaluate the oral administration of BRP extract to Santa Inês ewes during and after flushing period on the reproductive performance and animal health (hormonal profiles, hematological, biochemical and parasites responses). Thirty adult grazing ewes (40±2.0 kg BW) were divided into two dietary treatments, control (basal diet) and BRP (basal diet plus 3.0g of BRP/ewe/day) for 21 days. Blood and fecal samples were collected weekly for eight weeks. Oral administration of BRP did not affect (P>0.05) any of the observed reproduction traits, but there was promising improvement on the number of services per conceptions and hormones levels: increased (P<0.01) progesterone, decreased cortisol (P<0.05) and thyroxin (T4) (P<0.01) without significant changes in triiodothyronine (T3). Propolis resulted in increasing (P<0.01) of total leukocyte while there were no significant differences observed for other hematological parameters. Propolis increased (P<0.01) total protein and globulin but reduced (P<0.01) triglycerides, glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT) and fecal egg counts (P<0.05) compared with control. The third study was conducted to evaluate the oral administration of BRP extract to Santa Inês ewes from 25±3 day pre-partum through 48 d post-partum on milk yield, milk composition and lamb performance. Twenty Santa Inês ewes (60 ± 2.0 kg BW) were divided into two groups: control (basal diet) and BRP (basal diet plus 3.0g of BRP/ewe/day for 21 days). Milk samples were collected weekly for seven weeks. Propolis fed group showed increasing (P<0.05) milk yield, fat content, fat yield, protein yield, lactose yield and energy corrected milk while somatic cell counts was decreased (P<0.05). Propolis increased (P<0.05) ewes body condition score. Lambs average daily gain and milk conversion ratio were improved (P<0.05) by propolis treatment. The studies highlight the potential of propolis to handle the ruminal fermentation in order to reduce the production of CH4, as well as improved the health of ewes during the breeding season, besides increasing milk production and performance of lambs / Própolis, aditivo natural, pode ser usada para manipular a fermentação ruminal e diminuir a produção de metano (CH4), podendo afetar o desempenho dos animais. Foram conduzidos estudos visando avaliar a aplicação da própolis em ovinos. O primeiro experimento foi realizado com o objetivo de avaliar o valor nutritivo in vitro de dois tipos da própolis (Vermelho Brasileiro (PVB) e Marrom Egípcio (PME)), através da atividade antimetanogênica, fermentação ruminal e degradabilidade. Os extratos da própolis foram preparados usando etanol e adicionados a um substrato base (50:50 feno Tifton x concentrado) em quatro concentrações [0 (controle, CTL), 25, 50 e 100 micrograma / 0,5 g de substrato]; sendo comparadas com a monensina como controle positivo. As própolis PVB50 micrograma e PME25 micrograma apresentaram redução na produção de CH4 similar à monensina, sendo menores que o CTL. A monensina aumentou (P < 0,001) a concentração de proprionato e diminuiu (P < 0,001) a proporção de acetate / propionate, enquanto as própolis aumentaram (P < 0,002) as concentrações dos ácidos graxos voláteis e reduziram (P < 0,001) os protozoários. O segundo estudo objetivou avaliar a administração de extrato de PVB em ovelhas durante o período de \"flushing nutricional\" sobre o desempenho e a saúde dos animais durante a estação de reprodução. Trinta ovelhas (40 ± 2,0 kg PV) foram divididas em dois grupos, controle (dieta basal) e PVB (dieta basal com suplementação de 3,0 g de PVB / ovelha / dia) e suplementadas durante 21 dias. Amostras de sangue e fezes foram coletadas semanalmente durante oito semanas. Administração do PVB não afetou nenhuma característica reprodutiva, mas houve melhora (P < 0.01) no número de serviços por concepção, e aumento (P < 0,01) no teor de progesterona, diminuição (P < 0,01) nas concentrações de cortisol e tiroxina (T4), sem efeito na concentração de tri-iodotironina (T3). Própolis resultou apenas em aumento (P < 0,01) no número de leucócitos dentre os parâmetros hematológicos. A própolis aumentou (P < 0,01) a concentração de proteina total e de globulina, e reduziou (P < 0,05) os teores de triglicerídeos, transaminase oxalacética (TGO), transaminase glutamato piruvato (TGP) e contagem de ovos nas fezes quando comparado com o controle. O terceiro estudo foi conduzido para avaliar a administração do extrato de PVB para as ovelhas desde 25 ± 3 dias pré-parto até 48 dias pós-parto sobre a produção e composição do leite e desempenho dos cordeiros. Vinte ovelhas (56 ± 2,0 kg PV) foram divididas em dois grupos e suplementadas conforme descrito no segundo estudo: controle e PVB durante 21 dias. Amostras de leite foram coletadas semanalmente durante sete semanas. Própolis aumentou (P < 0,05) a produção de leite, conteúdo de gordura, rendimentos de gordura, proteína e lactose e leite corrigido para energia, enquanto diminuiu (P < 0,05) a contagem de células somáticas, mas aumentou (P < 0,05) a condição corporal. O ganho em peso médio diário dos cordeiros e taxa de conversão de leite foram melhoradas (P < 0,05) pelo tratamento com própolis. Os estudos destacam o potencial da própolis para manipular a fermentação ruminal visando redução na produção de CH4, assim como melhorar a saúde de ovelhas durante a estação de reprodução, além de aumentar a produção de leite e desempenho dos cordeiros

No description available.

No description available.