Intake, apparent digestibility, production, and composition of milk from cows fed diets with different sources of lipids

ABSTRACT The objective of this study was to evaluate the effect of different sources of lipids in the diets of dairy cows on the intake and digestibility of nutritional fractions, and milk production and composition. The experiment was conducted in a 42-hectare area divided into eight paddocks covered with Brachiaria brizantha. Twelve crossbred Holstein × Zebu cows were distributed into three simultaneous 4 × 4 Latin squares. The treatments consisted of different sources of lipids, as follows: diet with no extra source of lipids; diet with cottonseed as the source of lipids; diet with soy oil; and diet with used frying soy oil. The intakes of dry matter, neutral detergent fiber, crude protein, total carbohydrates, and non-fibrous carbohydrates were similar for all diets. The use of lipid sources caused a decrease in the apparent digestibility of dry matter, neutral detergent fiber, non-fibrous carbohydrates, and crude protein. The levels of protein, lactose, and defatted dry matter were reduced with the use of lipid sources but did not affect milk production. The use of cottonseed, soy oil, and used frying soy oil as sources of lipids in diets for lactating cows at pasture do not improve milk production, and their use is therefore optional

Intake, apparent digestibility, production, and composition of milk from cows fed diets with different sources of lipids

ABSTRACT The objective of this study was to evaluate the effect of different sources of lipids in the diets of dairy cows on the intake and digestibility of nutritional fractions, and milk production and composition. The experiment was conducted in a 42-hectare area divided into eight paddocks covered with Brachiaria brizantha. Twelve crossbred Holstein × Zebu cows were distributed into three simultaneous 4 × 4 Latin squares. The treatments consisted of different sources of lipids, as follows: diet with no extra source of lipids; diet with cottonseed as the source of lipids; diet with soy oil; and diet with used frying soy oil. The intakes of dry matter, neutral detergent fiber, crude protein, total carbohydrates, and non-fibrous carbohydrates were similar for all diets. The use of lipid sources caused a decrease in the apparent digestibility of dry matter, neutral detergent fiber, non-fibrous carbohydrates, and crude protein. The levels of protein, lactose, and defatted dry matter were reduced with the use of lipid sources but did not affect milk production. The use of cottonseed, soy oil, and used frying soy oil as sources of lipids in diets for lactating cows at pasture do not improve milk production, and their use is therefore optional

Qualitative parameters of sugarcane silages treated with urea and calcium oxide

Objetivou-se avaliar os parâmetros fermentativos, a composição química e o fracionamento de carboidratos das silagens de cana-de-açúcar tratadas com ureia e óxido de cálcio (CaO). Na ensilagem, os tratamentos aplicados à cana foram 1% de ureia; 0,5% de ureia + 0,5% de CaO; e 1% de CaO, em comparação a uma silagem controle, sem aditivo. Os aditivos químicos (ureia e CaO) foram adicionados no momento da ensilagem, em quantidade calculada com base na matéria natural. Utilizouse um delineamento inteiramente casualizado, composto de quatro tratamentos (silagens) e nove repetições. O material foi acondicionado em minissilos de PVC, durante cinco meses. Ao fim do período de armazenamento, foi feita uma nova pesagem e coletadas amostras, para quantificação das perdas decorrentes da fermentação, da recuperação de matéria seca, do pH e do nitrogênio amoniacal (N-NH3) das silagens e para avaliação da composição química e do fracionamento de carboidratos. A silagem com 1% de CaO apresentou maior recuperação de matéria seca, e em relação ao fracionamento dos carboidratos apresentou maior teor de carboidratos solúveis e potencialmente solúveis. A adição de 1% de CaO durante a ensilagem reduz as perdas fermentativas de silagens da cana-de-açúcar.The objective was to evaluate the fermentation parameters, chemical composition and fractionation of carbohydrates of sugarcane silages treated with urea and calcium oxide (CaO). Upon ensiling, the treatments applied to the sugarcane were: 1% urea; 0.5% urea + 0.5% CaO; and 1% CaO, in relation to a control silage, without additive. The chemical additives (urea and CaO) were added at ensiling, in an amount calculated based on the fresh matter (as is). A completely randomized design consisting of four treatments (silages) and nine replicates was adopted. The material was conditioned in PVC mini-silos for five months. At the end of the storage period, silos were weighed again and samples were collected to quantify the losses caused by fermentation, dry matter recovery, pH, and ammonia nitrogen (N-NH3) of the silages and to evaluate the chemical composition and fractionation of carbohydrates. The silage with 1% CaO showed the highest recovery of dry matter, and in terms of carbohydrate fractionation, it showed the highest levels of soluble and potentially soluble carbohydrates. Addition of 1% CaO during ensiling reduces the fermentation losses of sugarcane silages