Feeding nanoparticles of copper oxide coated with lysine with or without added antagonists affects the copper status but not the performance of Holstein dairy cows.

The apparent absorption of copper (Cu) in ruminants is low, with between 0.01 and 0.07 g/g absorbed from sources such as copper oxide (CuO) under typical feeding conditions, resulting in high levels of excretion.

Overfeeding copper during rearing affects the liver function and fertility of replacement dairy heifers.

Background: Oversupply of dietary copper (Cu) is common among UK dairy herds, but studies on the long-term outcomes of this oversupply are scarce.

Methods: A longitudinal study was undertaken to determine the long-term implications when 80 Holstein‒Friesian heifers with a mean (±standard error) age of 4.1 ± 0.

Why isn't the transition period getting the attention it deserves? Farm advisors' opinions and experiences of managing dairy cow health in the transition period.

During the transition period three weeks before and after calving the dairy cow is at greater risk of developing disease, to the detriment of welfare and production. An understanding of the reasons why and how farmers and their advisors engage in efforts to control metabolic disease during the transition period is required if these diseases are to be more successfully controlled. The study reported here, based on interview research, investigates the opinions and behaviours of farm advisors on transition cow management and nutrition, their experiences of working with their respective farm clients, and interactions with other farm advisors to help manage transition cow health and productivity.

Dairy cow health and management in the transition period: The need to understand the human dimension.

During the transition from the dry period to lactation the dairy cow undergoes a period of physiological, metabolic and immunological change, and is at greater risk of developing disease, to the detriment of health, welfare and production. Many studies have been undertaken to determine appropriate management strategies to improve health and welfare during the transition period, however the incidence of disease, particularly metabolic disease, in this period remains high. To date, a lack of research attention has been paid to the social factors which may affect the management of transition dairy cows.

Long term dietary supplementation with microalgae increases plasma docosahexaenoic acid in milk and plasma but does not affect plasma 13,14-dihydro-15-keto PGF concentration in dairy cows.

The aims of the study were to determine the long-term effects of dietary supplementation with microalgae (SCIM) on milk and blood fatty acid (FA) composition and reproductive hormones in early lactation dairy cows. Sixty Holstein-Friesian dairy cows (30 per treatment) were unsupplemented (Control) or supplemented with 100 g of SCIM (Schizochytrium limacinum sp.) per cow per day from 25 ± 0.

The motivation of dairy cows for access to pasture.

Several factors influence whether dairy cattle prefer to be indoors or at pasture, including weather conditions and milk yield, but it is unclear how motivated cows are for access to pasture. One way to measure motivation is to require the animal to work (e.g.

A supplement containing trans-10, cis-12 conjugated linoleic acid reduces milk fat yield but does not alter organ weight or body fat deposition in lactating ewes.

Conjugated linoleic acids (CLA) have been demonstrated to be a potent inhibitor of milk fat synthesis in ruminants, but effects on carcass composition and organ weight are unknown. Our objectives in this experiment were to determine the dose response of ruminally protected CLA on the performance, organ weight, and fatty acid (FA) composition of early lactation dairy ewes. Twenty-four multiparous dairy ewes were fed a basal diet for 10 wk that was supplemented with a lipid-encapsulated CLA at 1 of 3 levels: no CLA (control, CON), low CLA (L-CLA), or high CLA (H-CLA) to supply 0, 1.

Polyunsaturated fatty acid supplementation during pregnancy alters neonatal behavior in sheep.

The objectives of the study were to determine whether supplementation of pregnant ewes with long-chain (n-3) fatty acids present in fish oil, in combination with dietary vitamin E, would alter neonatal behavior in sheep. Twin- (n=36) and triplet- (n=12) bearing ewes were allocated at d 103 of gestation to 1 of 4 dietary treatments containing 1 of 2 fat sources [Megalac, a calcium soap of palm fatty acid distillate or a fish oil mixture, high in 20:5(n-3) and 22:6(n-3)] and 1 of 2 dietary vitamin E concentrations (50 or 500 mg/kg) in a 2 x 2 factorial design. Feeding fish oil increased gestation length by 2 d and increased the proportion of 22:6(n-3) within neonatal plasma by 5.

The effect of dietary vitamin E and fatty acid supplementation of pregnant and lactating ewes on placental and mammary transfer of vitamin E to the lamb.

The present study investigated the effect of maternal vitamin E and fatty acid supplementation on lamb antioxidant status. Forty-eight ewes were fed one of four concentrate diets supplemented with a basal (50 mg/kg) or supranutritional (500 mg/kg) level of vitamin E plus a source of either saturated fat (Megalac; Volac Ltd, Royston, Hertfordshire, UK) or long-chain PUFA (fish oil) from 6 weeks prepartum until 4 weeks postpartum. Blood samples were taken from ewes and lambs at intervals throughout the experiment and, at parturition, muscle, brain and blood samples were obtained from twelve lambs (three per treatment).

Dietary manipulation of fatty acid composition in lamb meat and its effect on the volatile aroma compounds of grilled lamb.

The effect on lamb muscle of five dietary supplements high in polyunsaturated fatty acids (PUFA) was measured. The supplements were linseed oil, fish oil, protected lipid (high in linoleic acid (C18:2 n-6) and α-linolenic acid (C18:3 n-3)), fish oil/marine algae (1:1), and protected lipid/marine algae (1:1). Eicosapentaenoic acid (C20:5 n-3) and docosahexaenoic acid (C22:6 n-3) were found in the highest amounts in the meat from lambs fed diets containing algae.