Renata Apocalypse Nogueira Pereira

Resposta de vacas leiteiras à substituição parcial de farelo de soja por ureia encapsulada

Avaliou-se a substituicao parcial de farelo de soja na dieta-controle por ureia encapsulada ou por ureia, ambos acrescidos de polpa citrica. Dezoito vacas foram alocadas a uma sequencia de tres tratamentos, em seis quadrados latinos 3x3, com periodos de 21 dias. O teor de proteina bruta nas dietas foi 15,5%, cerca de 1,5% oriundo de nitrogenio nao proteico (NNP). O uso de NNP reduziu o consumo diario de materia seca em 0,8kg (P=0,04), sem influenciar a producao de leite (31,5kg, P=0,98). A conversao do alimento em leite foi menor na dieta-controle (P<0,09). As fontes de NNP aumentaram o teor de N-ureico no plasma (NUP) duas horas apos a alimentacao da manha (P=0,06). A frequencia de NUP acima de 22,0mg/dL foi maior com ureia (P<0,01), similarmente ao observado para o teor e a secrecao diaria de N-ureico no leite (P<0,01). A substituicao de farelo de soja por NNP e polpa citrica melhorou a eficiencia alimentar, sem afetar o balanco de nitrogenio.

Desempenho e características de carcaça de frangos de corte alimentados com dietas à base de milho e farelo de soja suplementadas com complexos enzimáticos

This study was conducted to evaluate the effect of the supplementation of enzymatic complexes on the performance and carcass characteristics of broiler chickens from both sexes. Five diets were evaluated: positive control diet based on corn and soybean meal with meat and bone meal without enzyme; negative control diet formulated with 3% less of metabolizable energy; negative control + 0.05% of complex A (600 U/g of xylanase, 8000 U/g of amylase and 800 U/g of protease); negative control + 0.04% [...]This study was conducted to evaluate the effect of the supplementation of enzymatic complexes on the performance and carcass characteristics of broiler chickens from both sexes. Five diets were evaluated: positive control diet based on corn and soybean meal with meat and bone meal without enzyme; negative control diet formulated with 3% less of metabolizable energy; negative control + 0.05% of complex A (600 U/g of xylanase, 8000 U/g of amylase and 800 U/g of protease); negative control + 0.04% of complex B (200 kNU/g of α-amylase and 350 FBG/g of β-glucanase); and negative control + 0.04% of complex B + 0.01% of enzyme C (1000 FXU/g of xylanase). No significant differences were found in the performance of birds from 1 to 7 days of age. From 1 to 21 days of life, males consumed more ration than females. Diets four and five resulted into better weight gains only for males. The best results of feed conversion were obtained with the use of the enzymatic complexes. In the total period, males and females that received the positive control consumed less ration than the other diets. Diet four provided the best weight gain result for males. In relation to feed conversion, males presented the best conversion rate from the use of enzymatic complexes. Females that received diet one and diet five presented better feed conversion rates. No significant differences were observed for the effect of diets on the carcass, breast and abdominal fat yields. It could be concluded that the use of the enzymatic complexes was effective in recovering the performance of birds but decreasing 3% of the metabolizable energy.

Response of lactating cows to live yeast supplementation during summer.

Dairy cows experiencing heat stress have reduced intake and increased reliance on glucose, making feeding strategies capable of improving diet digestibility plausible for improving postrumen nutrient flow and performance. The effect of yeast on digestion and performance of lactating cows during the warm summer months of southeastern Brazil was evaluated. Cows were individually fed in tie stalls and temperature-humidity index was above 68 during 75.6% of the experiment. Twenty-eight Holstein cows (207±87 d in milk) received a standard diet for 14 d and then a treatment for 70 d, in a covariate-adjusted, randomized block design with repeated measures over time. Treatments were yeast (Saccharomyces cerevisiae) or control. Yeast was top dressed to the diet in the morning, equivalent to 25×10(10) cfu of live cells and 5×10(10) cfu of dead cells. The diet contained corn silage (37.7%), Tifton silage (7.1%), raw soybeans (4.1%), soybean meal (16.5%), finely ground corn (20.7%), and citrus pulp (11.9%). Yeast increased milk (26.7 vs. 25.4 kg/d) and solids yield (3.06 vs. 2.92 kg/d), especially lactose. Response in milk yield was consistent over time and started at d 5. The daily intake of digestible OM, total-tract digestibility of nutrients, urinary allantoin excretion, chewing pattern throughout the day, and dry matter intake did not respond to yeast. A trend was observed for increased plasma glucose with yeast (62.9 vs. 57.3mg/dL), lowered respiratory frequency (48 vs. 56 breaths/min), and increased plasma niacin content (1.31 vs. 1.22 µg/mL), though cows had similar rectal temperature. Ruminal lactate and butyrate as proportions of ruminal organic acids were reduced by yeast, but no effects on other organic acids, ruminal pH, or protozoa content were detected. Plasma urea N over 24h was increased by yeast. On d 72 to 74, citrus pulp was abruptly replaced with finely ground corn to induce acidosis. The increased load of starch increased dry matter intake between 0700 and 1300 h, jugular blood partial pressure of CO2, HCO3-, and base excess, and decreased blood pH for both treatments. The yeast treatment had a higher blood pH compared with the control, 7.34, and 7.31, respectively. Yeast supplementation improved lactation performance of dairy cows under heat stress. Improvement in lactation performance apparently involved the regulation of body homeothermia, rather than improved digestibility.

Supplementation of prepartum dairy cows with β-carotene

The prepartum supplementation of dairy cows with β-carotene was evaluated. Cows were blocked by parity and expected calving date and assigned to a treatment: β-carotene (1.2 g/cow per d) or control (no supplementation). The same total mixed ration batch was offered to all cows, and β-carotene was top dressed to individual cows once per day. The data set contained 283 Holsteins that received a treatment for >14 d (29.1±6.9 d). Frequency distributions were analyzed with the GENMOD procedure of SAS using logistic regression for binomial data. Continuous variables were analyzed with the MIXED procedure of SAS. Within parity, nonparametric estimates of the survivor function for reproductive variables were computed using the product-limit method of the Kaplan-Meier method with the LIFETEST procedure of SAS. Plasma β-carotene concentration before supplementation was similar between supplemented and nonsupplemented cows (2.99µg/mL) and peaked at 3.26±0.175µg/mL on d -15±2.4 precalving for supplemented cows (2.62±0.168µg/mL for control). Colostrum density, milk yield, and milk composition were similar between treatments. β-Carotene tended to increase milk protein content from 2.90 to 2.96% and to decrease the proportion of primiparous cows with a milk fat to protein ratio >1.5 from 22.6 to 6.4%. The proportion of primiparous and multiparous cows with difficult calving, metritis, progesterone >1 ng/mL at 21 d and at 42 d in lactation, % conception at first service, and % pregnancy at 90 and 150 d in lactation were similar between treatments. A trend for decreased incidence of somatic cell count >200,000 cells/mL was present in multiparous cows supplemented with β-carotene (38.9% vs. 28.1%). β-Carotene was associated with a reduction in the proportion of multiparous cows with retained placenta 12 h postpartum from 29.9 to 21.7%; time of placenta release was 392 min (340 to 440) for β-carotene and 490 min (395 to 540) for control (median and 95% confidence interval). For primiparous cows, placenta release was not affected by β-carotene (incidence was 15.4%). The intervals from calving to first estrus, to first service, and to conception were not affected by β-carotene supplementation in either parity. However, independent of treatment, cows with improved reproductive efficiency had increased postpartum β-carotene concentration in plasma. The prepartum supplementation of β-carotene increased plasma concentration around calving. No response in milk yield or reproductive performance was detected. Beta-carotene supplementation was associated with a lower incidence of retained placenta in multiparous cows.

Suplementação de vacas leiteiras com Saccharomyces cerevisiae cepa KA500

Performance and digestive efficiency of dairy cows supplemented with live yeast strain KA500 were evaluated. Twenty Holstein cows formed ten blocks of two animals based on daily milk production and were randomly assigned to a sequence of two treatments, in a cross-over design, with 28-day periods, and measurements on the fourth week. Treatments were: 10g of yeast (2x1010/cfu/g) or control. The composition of the diets were (% of DM): corn silage (45.0), tifton hay (4.1), and a corn, citrus pulp, soybean meal-based concentrate (50.9). The dry matter intake was 21.3kg with yeast and 21.8kg for the control (P=0.01), and milk yield was 29.6 and 29.3kg, respectively (P=0.45). Milk yield per unit of intake was 1.37 with yeast and 1.32 for the control (P=0.05). The supplementation of yeast reduced (P=0.02) the somatic cell count in milk. There was no effect of the supplementation upon variables related to the rumen function or the total tract digestibility of nutrients. Yeast supplementation increased feed efficiency and reduced milk somatic cell count.

Despalha da cana-de-açúcar e desempenho de novilhas e vacas leiteiras

Two experiments evaluated the responses in weight gain of heifers and milk yield of cows to the removal of the apical and lateral leaves of sugarcane. In both the animals were individually fed in total confinement. In Experiment 1, 32 Holstein x Gir heifers (295±45kg of body weight) were paired, blocked and allocated to a treatment for 42 days, following a 14-day standardization period. Treatments were whole or deleafed sugarcane. Body weight and intake were measured over time. The content of ingredients and nutrients in diets dry matter (DM) were 77.1% sugarcane, 19.2% soybean meal, 1% urea, 14.1% crude protein (CP), and 38.8% neutral detergent fiber (NDF) for deleafed sugarcane, and 78.6%, 17.9%, 0.9%, 13.7%, and 45.3% for whole sugarcane, respectively. Daily weight gain was 1.395kg for deleafed and 1.125kg for whole sugarcane (P=0.05). There was no treatment effect on DM intake (P=0.78). Leaf removal increased the rate of feed intake (P=0.04) and the daily intake of digestible non-NDF organic matter (P=0.03). In Experiment 2, 14 Holsteins (256±124 days of lactation) were paired blocked and allocated to a sequence of two treatments in a cross - over design, with 21 - day periods, and measurement of the response on the third week. The deleafed sugarcane diet had 18.4% sugarcane in DM, 37.6% corn silage, 44% corn, citrus pulp, soybean meal based concentrate, 17.3% CP, and 32.9% NDF, while the whole sugarcane diet had 18.2%, 37.7%, 44.1%, 16.6%, and 34.7%, respectivel y. Deleafing tended to increase DM digestibility (P=0.06) and the daily intake of digestible organic matter (P=0.10), without affecting milk yield (18.4kg, P=0.65). Deleafing s ugarcane increased the weight gain of heifers consuming a high proportion of sug arcane in the diet, but this practice did not induce a positive performance response in late lactating cows consuming 18% sugarcane in the diet.

Substituição parcial de farelo de soja por ureia de liberação lenta em rebanhos leiteiros comerciais

Two experiments evaluated the partial replacement of soybean meal by encapsulated urea (Optigen®II, Alltech do Brasil, Curitiba, PR, Brasil). From a Control diet, 1kg of soybean meal was replaced by an isonitrogenous mixture containing 160g of Optigen®II + 2.5kg of corn silage in Exp.1, or 150g of Optigen®II + 850g of finely ground corn in Exp.2. In Exp.1, 61 Holstein cows were blocked and allocated to a treatment for 21 days, and measures of the same variable at the end of the standardization period were used as covariate. In Exp.2, 97 cows were allocated to a sequence of two treatments for 21 days, in a simple reversal (crossover) design. Response to treatments was evaluated from day 17 to 21. In both experiments, the nutrient composition of the offered diet and orts, orts as a % of the offered, body weight, and body condition score of the animals did not differ across treatments. Daily milk yield was 38.4kg/d for Control and 38.9 for Optigen®II in Exp.1 (P=0.62), and 27.0kg/d and 27.2 in Exp.2 (P=0.64), respectively. Encapsulated urea decreased milk fat content in Exp.2 (P=0.04). Optigen®II increased milk urea nitrogen from 16.3 to 17.3mg/dL in Exp.1 (P<0.01) and the ratios of milk produced to feed consumed (P=0.08) and allantoin to creatinine in urine (P=0.03) in Exp.2. Replacing soybean meal with Optigen®II did not induce lower performance.

Suplementação de vacas leiteiras com homeopatia: desempenho e digestibilidade

The effect of supplementing a homeopathic combination on dairy cow performance and nutrient digestibility was evaluated. Thirty-two Holstein cows were paired blocked and randomly assigned to one of two treatments for 63 days, following a 14-day standardization period. Variables measured at the end of the standardization period adjusted weekly measurements of the same variable in the statistical analysis model. Treatments were: Daily supplementation of 150 grams of a homeopathic combination (Hypothalamus, 10-30; Colibacilinum, 10-30; Streptococcus Beta Hemolyticum, 10-60, Streptococcus Uberis, 10-60; Phytolacca, 10-60; Calcium Phosphoricum, 10-30; Natrum Muriaticum, 10-60; Urtica Urens, 10-30, Silicea Terra, 10-400) in mineral vehicle, or 150 grams of the same mineral vehicle (Control). Supplementation with homeopathy increased milk protein content from 3.09 to 3.19% (P=0.01) and tended to increase the daily secretion of protein from 0.737 to 0.776kg (P=0.10). The trend for decreased fiber and organic matter digestibilities (P=0.10), and the similar allantoin to creatinine ratio in urine (P=0.32), suggests that there was an increase in the efficiency of microbial protein synthesis in the rumen. Although the mechanism could not be elucidated, the homeopathic combination increased milk protein content.

Effect of exogenous amylase on lactation performance of dairy cows fed a high-starch diet

Exogenous amylase supplementation can increase starch and fiber digestibility in lactating dairy cows. We evaluated the effect of exogenous amylase supplementation on diets with high starch concentration (32% of dry matter). Twenty-eight Holstein cows (171 ± 80 d in milk, 4 primiparous) received a standard diet for 14 d and then a treatment for 63 d, in a covariate-adjusted randomized block design with repeated measures over time. Treatments were amylase [0.5 g of Ronozyme RumiStar (DSM Nutritional Products, Basel, Switzerland) per kg of total mixed ration dry matter] or control. The diets contained (% of dry matter): 39.4% corn silage, 11.2% rehydrated and ensiled mature corn grain, and 11.7% finely ground mature corn. Amylase increased milk yield (32.3 vs. 33.0 kg/d) and reduced dry matter intake (20.7 vs. 19.7 kg/d), increasing feed efficiency (1.52 vs. 1.63). Amylase also increased milk lactose synthesis (1.49 vs. 1.56 kg/d) and plasma glucose concentration (59.3 vs. 68.6 mg/dL). Secretions of milk fat and protein did not differ. Although milk urea N did not differ, amylase reduced the concentration of urea N in blood, suggesting an increase in ruminal starch degradation. However, the total-tract apparent digestibility of starch (96.3% of intake) and neutral detergent fiber (44.4% of intake), ruminal fermentation profile, and microbial yield estimated by urinary allantoin excretion did not differ. Cows fed amylase sorted in favor of long feed particles and against short particles, had shorter chewing activity (780 vs. 699 min/d), and had fewer meals per day (11.5 vs. 9.7). Amylase improved the feed efficiency of lactating cows fed a high-starch diet; the enzyme increased milk yield and reduced intake.

Silagem de grãos úmidos de milho de textura dura ou macia em dietas com polpa cítrica para vacas em lactação

Lactating cow performance on diets containing citrus pulp and two levels of high moisture corn silage was evaluated. Treatments were: hard texture corn or soft texture corn ensiled at the black layer, with a 9% or 18% factorial corn in the diet. Dietary citrus pulp content was 16.2% or 25.6%, for high and low corn, respectively. Twelve cows received the treatments in 4x4 Latin Squares. Daily milk yield was 27.9kg for hard corn and 28.8 for soft (P=0.19). High corn decreased milk fat content from 3.38 to 3.26% (P=0.04), and increased protein content from 2.99 to 3.03% (P=0.05) and feed efficiency from 1.50 to 1.57kg of milk/kg of intake (P=0.03). The increase of corn content generated a greater decrease in ruminal pH in the soft corn diet than in the hard corn diet (P=0.05 for the interaction of texture versus corn content). Soft corn increased the daily intake of digestible organic matter from 11.7 to 12.3kg (P=0.05). Digestive parameters suggest that ensilaging did not totally eliminate the endosperm texture effect on corn digestibility.