Nitrogen balance and microbial protein synthesis in dairy cows fed with peanut meal to replace soybean meal.

This research was carried out to evaluate the effect of replacing dietary soybean meal with peanut meal, on intake and digestibility, microbial protein synthesis, and nitrogen balance in lactating cows. Twelve crossbred Holstein × Gyr cows at 84 days in milk (DIM) were distributed in a triple 4 × 4 Latin square. The treatments consisted of increasing peanut meal levels (0, 330, 670, and 1000 g/kg dry matter basis) in replacement of soybean meal in the diet. Replacing soybean meal with peanut meal had no effect on the intake and digestibility of dry matter and nutrients. Nitrogen balance and percentage of retained were similar among treatments. Microbial nitrogen synthesis and microbial protein synthesis efficiency were similar among treatments. Thus, in regions where its cost is lower, peanut meal can totally replace soybean meal in dairy cow diets without affecting nitrogen balance and microbial protein synthesis.

Effect of replacing soybean meal with peanut meal on milk production and fat composition in lactating dairy cows.

The objective of this study was to evaluate the effects of replacing soybean meal with peanut meal on milk production, chemical and fatty acid composition, nutritional quality indicators of the lipid fraction, and the economic viability of the diets. Twelve crossbred cows in the initial lactation third, with a bodyweight of 545 ± 37 kg and average milk production of 28 kg/day of milk were distributed in a 4 × 4, triple Latin square design. The treatments consisted of diets with substitution levels of soybean meal for peanut meal (0; 330; 670; and 1000 g/kg in DM). The peanut meal inclusion to replace soybean meal in the diets provided a decreasing linear effect for the protein (P = 0.02) and casein (P = 0.01) concentration in milk. Milk production, total solids concentration, feed efficiency, fatty acid composition, and nutritional quality indicators of the milk lipid fraction were not influenced by the substitution levels. The diet cost per kg DM decreased due to the peanut meal inclusion as a protein source. The partial or total substitution of soybean meal for peanut meal in the feedlot cows diet reduces the cost of feed, without affecting milk production and total solids yield.

Metabolic status of lactating cows given a hepatoprotectant and different feed energy sources.

The present study aimed to evaluate the effects of hepatoprotective agents added to diets containing different energy sources on the metabolic status of lactating dairy cows in confinement. Sixteen Holstein × Gir crossbred midlactation cows with a body weight of 553 ± 85 kg were included in this feeding trial. These animals were arranged in a 4 × 4 Latin square experimental design. A 2 × 2 factorial arrangement was employed in this feeding experiment. Experimental treatments consisted of the administration of diets supplemented with a hepatoprotectant and diets without hepatoprotectant. These diets contained varying amounts of ground corn or citrus pulp as energy sources. Serum markers for energy metabolism and proteins were evaluated and liver enzymes were measured. Blood samples were collected in the morning before (0 h) and 4 h after the animals were fed these diets. There was no interaction between the hepatoprotective agent and the dietary energy sources for the metabolic status variables. Ground corn as an energy source yielded higher serum concentrations of glucose, HDL (high-density lipoprotein) cholesterol, and globulins, whereas b-hydroxybutyrate (BHB), non-esterified fatty acids (NEFA), total cholesterol, albumin, and aspartate aminotransferase (AST) yielded the highest concentrations in diets containing citrus pulp. There was interaction between time and hepatoprotective agent in serum LDL (low-density lipoprotein) cholesterol concentration. The present study shows that ground corn diets increased the synthesis of glucogenic nutrients, whereas citrus pulp used as an energy source altered the lipid status of lactating cows. The hepatoprotective agent increased postprandial serum LDL cholesterol levels.

Dynamics of degradation of high-quality tropical forage according to levels of nitrogen supplementation.

The present study aimed to evaluate the degradation dynamics of high-quality tropical forage according to the levels of nitrogen supplementation. In this study, 4 rumen-fistulated cows with a body weight of 653 ± 47 kg were used. These animals were distributed in a 4 × 4 Latin square experimental design. Cows were kept under a grazing regime in an area formed by Panicum maximum Jacq. cv. Tanzania. These animals received 4 levels of crude protein (CP) in the supplements (122, 142, 162, and 180 g/kg of CP in DM). The degradability of dry matter (DM), crude protein (CP), and neutral detergent fiber (NDF) was determined by in situ incubation of forage samples at 0, 6, 12, 24, 48, 72, 96, and 120 h. Both the concentration of ammonia nitrogen (NH3-N) and the microbial protein synthesis were affected by CP levels of the supplements (P < 0.05). There was a significant difference (P < 0.05) for fraction b, potential degradability, and effective degradability of DM and NDF, and for the c degradation rate of CP of Tanzania grass which had the highest values at 122 g/kg of CP. Overall, the greatest degradation of nutrients from Tanzania grass occurred in the diet with 122 g/kg of CP and 604 g/kg of NFC in dairy cattle supplements that resulted in the highest rates of nitrogen utilization by rumen microbes.

Comportamento ingestivo de vacas leiteiras alimentadas com silagem de milheto ou milho / Ingestive behavior of dairy cattle fed millet and corn silage

Objetivou-se com este estudo avaliar o comportamento ingestivo de vacas leiteiras alimentadas com dietas contendo como volumoso silagem de milho ou silagem de milheto com 5 ou 20 mm de tamanho de partículas, com ou sem inoculante bacteriano. Foram utilizadas cinco vacas mestiças Holandês × Gir, com aproximadamente 100 dias de lactação ao início do experimento e peso corporal aproximado de 550 kg, produzindo, em média, 15,2 ± 2,3 kg de leite por dia. Os animais foram arranjados num delineamento em quadrado latino 5×5. O tempo total de alimentação, ruminação e ócio, não foi alterado pelo tipo de silagem na dieta. As variáveis que compõem o comportamento ingestivo não foram afetadas quando as vacas receberam as diferentes silagens de milheto comparadas com silagem de milho. O tamanho de partículas entre 5 e 20 mm, a presença ou não de inoculante e o tipo de silagem com teores de MS em 28%, não afeta o tempo total de alimentação, ruminação e ócio em vacas mestiças Holandês Gir com média de produção de 15,2 kg por dia. Silagem de milho ou milheto, tamanho de partículas 5 ou 20 mm, e o uso ou não de inoculante em silagem de milheto, não altera o tempo total despendido com alimentação, ruminação e ócio em dietas para vacas leiteiras mestiças Holandês × Gir com média de produção de 15,2 kg por dia.

The objective of this study was to evaluate the ingestive behavior of dairy cows fed corn and millet silage with a 5 mm particle size without inoculant, millet silage with a 5 mm particle size with inoculant, millet silage with a 20 mm particle size without inoculant, millet silage with a 20 mm particle size with inoculant. Five cows Holstein x Gir, with approximately 100 days of lactation at the beginning of the experiment and a mean body weight of 550 kg, producing an average of 15 kg of milk per day were used. The animals were arranged in a randomized 5 × 5 Latin square. The total feeding time, rumination time, chewing time, number of alimentary bolus, rumination time for bolus and number of chews was determined. The variables that make up the feeding behavior were not affected when the cows were fed different millet silages compared with corn silage. Cows fed corn silage and millet silage of 5 mm particle size had a higher intake of dry matter and neutral detergent fiber. A particle size between 5 and 20 mm, the presence or absence of inoculum and the type of silage with DM at 28%, does not affect the total feeding time , ruminating and resting of cows with an average production of 15.2 kg per day. The presence of the inoculant does not affect the intake of dry matter and neutral detergent fiber. Cows fed diets containing corn silage or pearl millet silage with a 5 mm particle size fed more DM.