Tropical grass silages with spineless cactus in diets of Holstein × Zebu heifers in the semiarid region of Brazil.

One of the factors that limit ruminant production in the semiarid region is the lack of roughage in the dry season. The management of forage plants adapted to edaphoclimatic conditions is a strategy to improve animal production. This study was conducted to examine the effects of biomass sorghum silage (BSS; Sorghum bicolor (L.) Moench) and BRS capiaçu grass silage (CGS; Pennisetum purpureum Schum) with or without spineless cactus (Opuntia spp.) in crossbred Holstein × Zebu heifers' diets on the intake, apparent digestibility of the nutrients and animal performance (e.g., final weight, daily weight gain) (experiment 1). Also, to evaluate the ruminal kinetics of dry matter (DM) and neutral detergent fiber (NDF) of roughages used in diets using two animals cannulated in the rumen (experiment 2). In experiment 1, ten heifers with an initial body weight of 200 ± 2.74 kg (mean ± standard deviation) and a mean age of 10 months were used. The animals were distributed in an experimental design in two simultaneous 5 × 5 Latin squares. Five experimental diets were used: diet 1, Volumax sorghum silage (VSS); diet 2, biomass sorghum silage (BSS); diet 3, BRS capiaçu silage (CGS); diet 4, biomass sorghum silage (60%) with spineless cactus (40%) (BSS + SC); and diet 5, BRS capiaçu grass silage (60%) with spineless cactus (40%) (CGS + SC). The diets were formulated with sorghum silage or BRS capiaçu grass silage with or without spineless cactus (roughage) and a maize- and soybean-based concentrate (75:25 roughage-to-concentrate ratio) on DM basis. The experiment lasted 105 days, divided into five periods of 21 days (17 days for the adaptation of the animals to the diets and management and 4 for data collection and samples). The diets containing CGS and CGS + SC resulted in lower dry matter intake (DMI; 5.61 kg day-1; P < 0.01), which was 19.4% lower than the diets with VSS, BSS, and BSS + SC (7.00 kg day-1). The BSS + SC and CGS + SC diets showed higher crude protein digestibility (P < 0.01) at 21.9% than the other treatments (Volumax, BSS, CGS). The different diets did not change the final weight or the daily weight gain of the heifers. The BRS 716 biomass sorghum silage and BRS capiaçu grass combined with spineless cactus increased (P < 0.05) the intake of nonfibrous carbohydrates and did not interfere (P > 0.05) with the final weight or average daily gain of the crossbred Holstein × Zebu heifers. The standardized potentially degradable fraction (Bp) of the NDF was 13.91% higher (P < 0.01) for BSS and BSS + SC (61.6%) compared to the others (53.0%). A diet based on BSS + SC is recommended for feeding crossbred heifers in the growing phase.

Effects of different banana crop wastes on nutrient intake and digestibility, microbial protein synthesis, feeding behavior, and animal performance of ¾ Holstein × Zebu heifers in a semiarid rangeland.

The objective of this study was to evaluate the use of banana crop wastes in diets of ¾ Holstein × » Zebu heifers on the intake and digestibility of nutrients, microbial protein synthesis, feeding behavior, and animal performance. Eight ¾ Holstein × » Zebu heifers were utilized with an average age of 18 ± 1.0 months and an average body weight (BW) of 298 ± 3.06 kg. The experiment was distributed in two simultaneous 4 × 4 Latin squares. The treatments were as follows: Diet 1 (SS)-sorghum silage as exclusive dietary roughage; diet 2 (SSL)-sorghum silage (50%) associated with 50% leaf hay of banana trees (on a DM basis); diet 3 (SSBP)-sorghum silage (50%) associated with 50% banana peel hay; and diet 4 (SSPS)-sorghum silage (50%) associated with 50% pseudostem hay of banana trees. The roughage:concentrate ratio was 75:25. The greatest dry matter intake (DMI; p < 0.01) was found in heifers that received the SS and SSBP diet, mean of 10.19 kg/day. The SS diet showed greatest dry matter digestibility (DMD; p < 0.01) and crude protein digestibility (CPD; p < 0.01). The concentration of total purines (p < 0.01) and absorbed purines (p < 0.01), microbial protein synthesis (p < 0.01), and microbial efficiency (p < 0.01) was higher in the SSBP diet in comparison with SS and SSL diets. The longest eating time was observed in animals that received the SSL diet, being 17.79% higher (p = 0.01) than the SSBP diet. The final BW (p = 0.39) and BW gain (p = 0.39) were similar, with averages of 319.84 kg and 1.08 kg/day, respectively. Biometric measurements were not altered as a function of bedtime (p > 0.05). Banana wastes can be used to feed ¾ Holstein × » Zebu heifers in partial replacement for sorghum silage as they do not alter the animals' weight gain and body development.

Effect of different roughage sources associated banana pseudostem hay on the nutritional and behavioral parameters and performance of F1 Holstein/Zebu lactation cows.

The objective of this study was to evaluate the association of pseudostem hay of banana trees of different roughages in the diet of F1 Holstein/Zebu cows on their nutrient intake and digestibility, nitrogen balance, microbial synthesis, ingestive behavior, and milk production. The experiment was distributed in two simultaneous 4 × 4 Latin squares. The treatments were as follows: diet 1-sorghum silage as exclusive dietary roughage; diet 2-sorghum silage (70%) associated with 30% pseudostem hay of banana trees (dry matter basis); diet 3-70% elephant grass with 30% pseudostem hay of banana trees (dry matter basis); and diet 4-70% sugarcane with 30% banana pseudostem hay (dry matter basis). The roughage/concentrate ratio was 75:25. The animals fed with sorghum silage presented 14.45% higher intake (p = 0.01) to that of animals fed hay and elephant grass. The diets containing silage and silage with hay showed digestibility of neutral detergent fiber corrected for ash and protein that was 57.75% higher (p < 0.01) than that of other diets. Cows fed elephant grass spent more time intake (p = 0.01). Diets did not influence milk yield (p = 0.47), and the milk yield corrected for 3.5 fat (p = 0.22), final weight (p = 0.06), and intake efficiency (p = 0.57), presenting a mean of 14.16 kg/day, 15.94 kg/day, 590 kg, and 0.9 kg of milk/kg of ingested dry matter, respectively. The utilization of pseudostem hay associated with other roughage can be an alternative to milk yield in F1 Holstein/Zebu cows.

Mineral content of longissimus lumborum from growing lambs fed crude glycerin.

The objective of the study was to evaluate whether crude glycerin (CG), which was supplied as a dietary ingredient for growing lambs, affected the macro- and micromineral contents of the longissimus lumborum (LL). Twenty-four lambs were placed in two treatments: animals that received no CG and animals that received CG as part of their diet. The experiment lasted for 56 days. The phosphorus, potassium, magnesium, calcium and chromium contents in the LLs of the lambs were not significantly different between the groups. Cadmium, nickel and lead were not detected in the LLs of lambs fed CG. The zinc, iron and copper contents decreased in the LLs of lambs fed CG (approximately 10%, 14%, and 30%, respectively) (P ≤ .03). The sodium content in the LLs increased with the inclusion of CG in the diet (11%) (P = .029). We concluded that the zinc, iron and copper contents decreased in the LLs of the lambs fed CG and sodium content increased.

Combinations of cactus pear with different roughage sources on the production, chemical composition, and milk fatty acid profile of F1 Holstein/Zebu cows.

The qualities of food, mainly of animal origin, have always been of concern to consumers. It is known that the composition of animals' diets can influence the composition of the foods produced, such as milk. Thus, the objective of this study was to evaluate diets with cactus pear in combination with different forages for F1 Holstein/Zebu cows on the chemical composition and fatty acid profile of milk. Two simultaneous 4 × 4 Latin squares were used in the experimental design. Four experimental diets were used: Diet 1, sorghum silage as the only roughage; Diet 2, sorghum silage combined with cactus pear in a proportion of 50% of the roughage (dry matter basis); Diet 3, elephant grass (Pennisetum purpureum cv. Roxo) as the only roughage; and Diet 4, elephant grass combined with cactus pear in a proportion of 50% of the roughage. The roughage:concentrate ratio was 75:25. The milk urea nitrogen was higher (16.08 mg/dL) in the milk of cows fed the diet with only elephant grass than that of milk from the other diet groups. The other analyzed variables of the chemical composition of milk were not influenced by the diets. However, there was a change in the sum of the saturated and monounsaturated fatty acids. The content of C16:0 fatty acid was higher and that of C18:0 was lower in the milk of cows fed the cactus pear diets than in that of cows fed the other diets. Higher levels of oleic acid were observed in the milk of cows fed with diets containing elephant grass than those in the milk of the cows in the sorghum forage groups. Conjugated linoleic acid (CLA) was higher in the milk of cows fed cactus pear than in that of the other cows. The combination of cactus pear with elephant grass or sorghum silage in the diet did not alter the chemical composition of milk. However, it influenced the fatty acid profile.

Nutritional efficiency of feed-restricted F1 Holstein/Zebu cows in early lactation.

The quantitative feed restriction of lactating cows has been used in intensive production systems as a strategy to reduce production costs. However, the effects of this restriction in F1 Holstein/Zebu cows are unclear. The objective of this work was to evaluate the effect of quantitative feed restriction on nutrient intake and digestibility, nitrogen balance, feed efficiency, feed behavior, and productive performance in F1 Holstein/Zebu cows during early lactation. Sixty F1 Holstein × Zebu cows were used at the stage of initial lactation (50 ± 13 days of lactation), and they had an initial body weight (BW) of 482 ± 43 kg. The experimental arrangement adopted was a completely randomized design, with five feed restriction levels (3.39, 2.75, 2.50, 2.25, and 2.00% of BW) and 12 cows in each treatment group. In the short term (63 days), there were reductions of 45.9% and 47.2% in dry matter intake (P < 0.01) and crude protein (P < 0.01), respectively, when the diet supply was limited from 3.39% BW to 2.00% of BW. There were declines in intake of ether extract (P < 0.01) and nonfibrous carbohydrates (P < 0.01), but there was no change in daily milk production (P = 0.44) nor the daily milk production corrected to 3.5% fat (P = 0.12); the averages were 14.01 kg/day and 13.25 kg/day, respectively. Considering the lower body weight loss, feed restriction is recommended up to 2.5% of the BW.

Productivity and nutritional value of BRS capiaçu grass (Pennisetum purpureum) managed at four regrowth ages in a semiarid region.

The objective of this study was to evaluate the productivity, productive efficiency, and nutritional value of the elephant grass cultivar BRS capiaçu (Pennisetum purpureum Schum.), managed at four regrowth ages during winter in the semiarid region of northern Minas Gerais, Brazil. A completely randomized design with the elephant grass cultivar BRS capiaçu was submitted to four cut intervals (30, 60, 90, and 120 days) in the winter with ten replications, for a total of 40 plots, each with a useful area of 6 × 5 m. There was a linear increase of 76.25% (P < 0.01) in the height of BRS capiaçu grass when cut from 30 to 120 days. Green matter production (P < 0.01) and dry matter production (P < 0.01) increased daily by 1081 kg/ha and 237 kg/ha, respectively. The annual dry matter production was 72 t/ha. Efficiency in water use changed (P < 0.01) from 7.91 kg of dry matter (DM)/mm at 30 days to 57.59 kg of DM/mm at 120 days of regrowth. There was a reduction in the ash content (P < 0.01), crude protein (P < 0.01), and the total digestible nutrient content (P < 0.01) with the increase in the age of the cut. The readily soluble fraction of DM (fraction A, P < 0.01), degradation rate "c" of insoluble fraction "B" (P = 0.01), potential degradability (PD; P < 0.01), and degradability (ED; P < 0.01) decreased linearly as the regrowth age increased. Harvesting is recommended at 90 days of regrowth during the winter season in this semiarid region.

Nutritional and productive parameters of Holstein/Zebu cows fed diets containing cactus pear

Objective: This study ascertained effects of cactus pear in association with different roughage in the diet of F1 Holstein/Zebu cows on intake, nutrient digestibility, nitrogen balance, ingestive behavior and performance. Methods: Eight cows with 72 ± 11 days of lactation were used. The experimental design was simultaneous in two 4 x 4 Latin squares. Four experimental diets were used: Diet 1 - sorghum silage as exclusive roughage; Diet 2 - sorghum silage associated with cactus pear in a proportion of 50% of the roughage (dry basis); Diet 3 - elephant grass (Pennisetum purpureum cv. Roxo) as exclusive roughage; Diet 4 - elephant grass associated with cactus pear in a proportion of 50% of the roughage. The roughage:concentrate ratio was 75:25. Dry matter intake (P = 0.01) was higher with sorghum silage. Results: There were differences in dry matter intake (P = 0.01), crude protein (P <0.01), ether extract (P = 0.01), non-fibrous carbohydrates (P <0.01) and total digestible nutrients (P = 0.01) among the diets. Cactus pear in the diet reduced water intake by 44.52% (P < 0.01). The nitrogen balance was 59.71% and 27.49% lower in animals treated with exclusive sorghum silage and sorghum silage associated with cactus pear in relation to diets with elephant grass and elephant grass associated with cactus pear, respectively (P < 0.01). The diets did not influence the milk production (P = 0.70), 3.5% fat corrected milk production (P = 0.72) or feed efficiency (P = 0.61). Conclusion: The association of cactus pear with sorghum or elephant grass silage does not alter milk production, reduces the intake of dry matter and water and improves the digestibility of nutrients.

Efeito da casca de banana na dieta de vacas em lactação sobre as características do leite e do queijo Minas frescal / Effect of banana peel in the diet of lactating cows on the characteristics of milk and cheese Minas frescal

Objetivou-se avaliar qualidade do leite e do queijo Minas frescal produzido do leite de vacas alimentadas com inclusão da casca de banana seca ao sol, com ou sem adição de agentes químicos durante o processo de secagem. Foram utilizadas oito vacas F1 Holandês x Zebu, em dois quadrados latinos 4 x 4, com as seguintes dietas experimentais: dieta convencional com silagem de sorgo sem a inclusão da casca de banana (controle); dieta com inclusão da casca de banana seca ao sol em substituição de 20% da silagem de sorgo; dieta com inclusão da casca de banana seca ao sol com 2% de calcário em substituição de 20% da silagem de sorgo; dieta com inclusão da casca de banana seca ao sol com 2% de óxido de cálcio em substituição de 20% da silagem de sorgo. As amostras de leite de cada vaca foram coletadas e analisadas quanto aos teores de gordura, proteína, lactose, cinzas, sólidos totais e extrato seco desengordurado. Após esta etapa, foi realizada a elaboração de queijo Minas frescal, sendo verificados rendimento, textura, acidez titulável, pH, proteína, teor de umidade, gordura, resíduo mineral fixo, extrato seco total e realizado o teste de aceitação pelo consumidor. A composição química do leite e do queijo não apresentou influência das dietas com casca de banana. Entretanto, o rendimento ajustado para produção de queijo foi estatisticamente inferior com as dietas contendo casca de banana tratada com os aditivos químicos. Quanto à aceitação geral dos queijos pelos consumidores, não houve diferenças entre os tratamentos. Desse modo, a utilização de casca de banana seca ao sol sem aditivos químicos em substituição parcial à silagem de sorgo na dieta de vacas em lactação pode ser uma alternativa viável para produção e processamento do leite, mantendo a qualidade do produto.

Produtividade e composição bromatológica de Brachiaria spp., no Alto Vale do Jequitinhonha / Productivity and bromatological composition of Brachiaria spp. in the Higher Jequitinhonha Valley

Avaliaram-se a produtividade de matéria seca (MS), proporção de lâminas e composição bromatológica de Brachiaria spp., colhidas com 42 dias de rebrotação, em Diamantina, MG. Para a determinação dos teores de MS, PB, FDN, FDA e lignina utilizaram-se o esquema em parcelas subsubdivididas, no DIC, com quatro repetições. Nas parcelas foram distribuídas as cultivares Basilisk, Marandu, Xaraés, Llanero e B. humidicola comum; nas subparcelas, dois cortes, e, nas subsubparcelas, dois anos experimentais. A produção de MS total e a proporção de lâminas foram analisadas em esquema de parcelas subdivididas, com espécies/cultivares nas parcelas e anos nas subparcelas. A produção de MS no segundo ano (3 cortes) foi mais alta que no primeiro (2 cortes), destacando-se as cultivares Basilisk, Xaraés e Llanero. De modo geral, as cultivares apresentaram teores satisfatórios de PB, mais altos no segundo ano. Os teores de FDN foram mais baixos no segundo ano e os de lignina mais baixos no primeiro ano. As cultivares Xaraés e Marandu destacam-se pela elevada proporção de folhas e apresentam composição bromatológica semelhante a da cultivar Basilisk. Associando-se a composição bromatológica com a produtividade de MS, recomendam-se as cultivares Xaraés e Basilisk para as condições do Alto Vale do Jequitinhonha.

Dry matter production, proportion of leaf blades and chemical composition of Brachiaria spp. harvested at intervals of 42 days of regrowth, in Diamantina, MG were evaluated. The DM, CP, NDF, ADF and lignin contents were analyzed in a split-split plot completely randomized design, with four replicates. Five cultivars of Brachiaria were distributed in the plots, two cuts in the split-plot, and two experimental years in the split-split plot. The dry matter production and the proportion of leaf blades were analyzed in a split plot completely randomized design, with cultivars in the plots and years in the subplots. The dry matter production in the second year (3 cuts) was higher than in the first (2 cuts), especially with the cultivars Basilisk, Xaraés and Llanero. Generally, the cultivars presented satisfactory levels of CP, with higher values in the second year. The contents of NDF were lower in the second year and the lowest levels of lignin were in the first year. Cultivars Xaraés and Marandu stand out for the high proportion of leaves and presented chemical composition similar to the Basilisk cultivar. Based on the chemical composition and dry matter production, Xaraés and Basilisk cultivars are recommended for cultivation in the Jequitinhonha High Valley.