ABSTRACT
The objective of this study was to evaluate effects of forage inclusion and sources on performance, metabolism, and feeding behavior of dairy calves. Forty-eight Holstein calves were blocked and randomly assigned to 1 of 4 dietary treatments according to sex and BW at 28 d of life to determine the effects of feeding forage sources (ensiled and dry), with different quality on performance, metabolites, and behavior. Treatments consisted of a no-forage coarsely ground starter (CON); or total mixed ration (TMR) containing 7.5% on a dry matter (DM) basis of Tifton hay of either medium quality (MH) or low quality (LH); or 10% on a DM basis of corn silage (CS). During the first 28 d of life, all calves received 3 L of whole milk twice daily, a commercial pelleted starter and no forage, and water ad libitum. After that, the solid diet was changed to the respective dietary treatments. Calves were gradually weaned from 52 to 56 d of age, and followed for 14 d postweaning. Individual solid feed and milk intakes were recorded daily, and BW and metabolic indicators of intermediate metabolism were recorded weekly. Behavior was recorded, and the analysis was conducted on wk 7 (preweaning) and 10 (postweaning). Solid feed intake increased at wk 7 and 8 when MH, LH, and CS were included in TMR; the same results were observed postweaning. The diets did not affect the average daily gain and BW, but the feed efficiency increased with the CON diet. The ß-hydroxybutyrate concentration was greater in calves receiving TMR-containing forage than CON diet. Furthermore, calves supplemented with forage had a greater rumination time. In conclusion, all forage sources included in the TMR showed feed intake and behavior benefits, reinforcing the need for fiber from forage in pre- and postweaning diets.
Subject(s)
Animal Feed , Diet , Animals , Cattle , Diet/veterinary , Weaning , Silage , Milk/chemistry , Milk/metabolism , Female , Animal Nutritional Physiological PhenomenaABSTRACT
A regulação do metabolismo lipídico com drogas ou alimentos naturais é um alvo importante para diminuir o risco de doenças cardiovasculares. O objetivo deste estudo foi verificar o efeito da lecitina de soja na dislipidemia e na hipertrofia ventricular de camundongos hipercolesterolêmicos. Utilizaram-se quatro grupos de camundongos LDLr-/- com 3 meses de idade que receberam a seguintes dietas: Grupo S- ração padrão; Grupo S+Lec- ração padrão e lecitina de soja; Grupo HL- ração hiperlipídica; e Grupo HL+Lec- ração hiperlipídica e lecitina de soja. Após 15 dias, o sangue foi coletado para análise sérica dos lipídeos e da proteína C reativa. O ventrículo esquerdo foi separado, a proporção peso ventricular (mg) pelo peso do animal (g) foi calculada e, em seguida, processado histologicamente. Cortes histológicos foram corados com hematoxilina/eosina e picrosírius red para avaliar alterações morfológicas e morfométricas ventriculares. A lecitina de soja apresentou efeito antidislipidêmico e aumentou os níveis séricos de HDL nos camundongos do grupo S+Lec. Entretanto, nos camundongos do grupo HL+lec, a lecitina de soja não preveniu a dislipidemia, apenas aumentou o nível sérico do HDL. Este efeito nestes animais influenciou no processo inflamatório cardiovascular, reduzindo o nível sérico de proteína C reativa; e prevenindo a hipertrofia ventricular esquerda. A utilização da lecitina de soja representa um tratamento e/ou uma prevenção alternativa de baixo custo para as dislipidemias não associadas com dieta hiperlipídica. Contudo, a lecitina de soja aumenta os níveis séricos do HDL prevenindo o desenvolvimento da HVE mesmo em dislipidemias associadas com dieta hiperlipídica.
The regulation of lipid metabolism with drugs or natural foods is an important target for reducing the risk of cardiovascular disease. The aim of this study was to investigate the effects of soy lecithin on left ventricular hypertrophy (LVH) and dyslipidemia in hypercholesterolemic mice. We used four experimental groups of LDLr-/- mice (aged 3 months), which received the following diets: Group S: standard diet, Group S+Lec: standard diet and soy lecithin; Group HL: hyperlipidic diet and Group HL+Lec: hyperlipidic diet and soy lecithin. After 15 days on these diets, blood was collected for analysis of serum lipids and C-reactive protein. The left ventricle was dissected out and weighed and the ratio of its weight to the body weight of the animal was calculated, after which it was processed histologically. Sections were stained with hematoxylin-eosin and picrosirius red, to assess morphological and morphometric changes in the ventricle. In Group S+Lec, the soy lecithin had an antidyslipidemic effect and enhanced the serum levels of HDL. However, in the mice in group HL+Lec, soy lecithin did not prevent dyslipidemia, only increasing the serum level of HDL. These effects in these animals influenced the cardiovascular inflammatory process, reducing the level of serum C-reactive protein and preventing LVH. Soy lecithin could thus be used as a treatment or a low-cost alternative preventative measure against dyslipidemia associated with a non-fat diet. However, soy lecithin increases the serum level of HDL, reducing the risk of LVH even in dyslipidemia associated with a high-fat diet.
