Four fistulated Holstein cows were arranged in a 4 x 4 Latin square design to study the effects of level and type of energy source on milk yield and composition. Treatments consisted of a basal diet fed alone (low energy treatment) or with 3.3 Mcal of net energy for lactation from extra nutrients perfused either into the rumen (either propionic acid or a mixture of volatile fatty acids) or into...

A close link between intrauterine growth restriction and development of chronic adult diseases such as obesity, diabetes, and hypertension has been established both in humans and animals. Modification of growth velocity during the early postnatal period (i.e., lactation) may also sensitize to the development of metabolic syndrome in adulthood. This suggests that milk composition may have long-l...

The efficacy of conjugated linoleic acid (CLA) in diet supplements for milk fat reduction is well documented in several species. However, the mechanisms by which fatty acids regulate mammary lipogenesis remain largely unknown, especially with regard to gene expression of enzyme and regulators. In this study, 8 Holstein dairy cows in their mid-lactation period were randomly divided into 2 groups...

Fat is the major energy component in milk and it accounts for many of the physical properties, manufacturing characteristics and organoleptic qualities of milk and milk products. It is estimated that the milk fat of dairy cows contains over 400 different fatty acids (Jensen, 2002). While most are present in minor amounts, it is generally recognized that the major fatty acids in milk fat include...

For a long time, the perception of consumers about fat from animal origin was linked to the increased risk of cardiovascular diseases, especially due to the large amounts of saturated fatty acids. The dairy products provide 15 to 25% of fat consumed by humans and 25 to 35% of saturated fat (Chilliard et al., 2001). This statement of cognizance, even if the potential effects of saturated fatty a...

Levels of n-6, n-3, and medium-chain fatty acids (MCFA) in milk are highly variable. Higher carbohydrate intakes are associated with increased mammary gland MCFA synthesis, but the role of unsaturated fatty acids for milk MCFA secretion is unclear. This study addressed whether n-6 and n-3 fatty acids, which are known to inhibit hepatic fatty acid synthesis, influence MCFA in rat and human milk ...

Many studies show concentrations of nutritionally desirable fatty acids in bovine milk are lower when cows have no access to grazing, leading to seasonal fluctuations in milk quality if cows are housed for part of the year. This study investigated the potential to improve the fatty acid profiles of bovine milk by oilseed supplementation (rolled linseed and rapeseed) during a period of indoor fe...

Feeding dairy cows a ration containing whole flax seeds (linseed), flax (linseed) oil or milled, extruded or micronized linseed has five beneficial effects on the fat profile of cow’s milk: (1) increasing the content of alpha-linolenic acid (ALA); (2) increasing the content of conjugated linoleic acid (CLA); (3) decreasing the omega-6/omega-3 ratio; (4) decreasing the overall saturated fat cont...

The objective of the study was to investigate the effects of supplementing different plant oils to the basal diet on milk yield and milk composition in mid-lactating dairy cows. Forty Chinese Holstein dairy cows averaging 120 days in milk (DIM) at the start of the experiment (body weight = 580 ± 18.2 kg; milk yield = 33.0 ± 2.00 kg/day) were used in a completely randomized block design. The ani...

the aim followed in the present study was to investigate the effects of different metabolizable protein (mp) levels on holstein cows, milk yield and composition, and as well on concentration of plasma metabolites in the cow,s early lactation. twenty - four holstein cows(bw 580±23, dim 30±7, parity 2.4±0.5) were randomly assigned to each one of the 4 dietary treatments containing 1) 10.60% (diet...