Metabolic response of early-lactating cows exposed to transport and high altitude grazing conditions

Abstract

The metabolic response of dairy cows to high as opposed to low altitude conditions (2000 m v. 400

Effect of diet type on performance and metabolic traits of Peruvian local and introduced cow types kept at 200 and 3600 m of altitude

“…The only clear sign for persistent high altitude stress was given by the elevated plasma cortisol levels, consistent with findings of Kreuzer et al (1998). However, altitude effects might have been masked by adverse effects the lowland cows had been exposed to including transport stress (Kreuzer et al,1998) and heat (temperatures at the highland site remained in the thermoneutral zone). Mild to severe heat stress has been estimated to increase maintenance requirements by 7 to 25%, respectively (NRC, 2001).…”

“…(above sea level) (Bianca and Puhan, 1974), and in various experiments where the cows were transported to summer pastures at altitudes of about 2000 m a.s.l.. These studies investigated the effects of transport (Kreuzer et al, 1998) and supplementary feeding (Berry et al, 2001;Bovolenta et al, 2002) on metabolic status and milk production of cows at high altitudes or have been carried out to determine the altitude-caused extra energy requirements (Christen et al, 1996). Only two studies explicitly attempted to differentiate between the individual factors associated with grazing at higher altitude, such as site specific forage quality, grazing activity and hypoxic conditions (Leiber et al, 2004(Leiber et al, , 2006.…”

“…Cows exposed to oxygen partial pressure equivalent to 4500 m a.s.l. responded with effective adaptation mechanisms (Bianca and Hays, 1975), but the time needed for sufficient adaptation was found to be too long to prevent massive depressions in performance (Christen et al, 1996;Kreuzer et al, 1998). This may be different in cows fully adapted to high altitude.…”

Effects of supplying leucine and methionine to early-lactating cows fed silage-concentrate based diets with a calculated deficiency in leucine and methionine

“…All other analyses in blood were carried out according to standard procedures [20]. Most metabolites and hormones were determined in plasma obtained from heparinised samples.…”

Are cheese-making properties of dual purpose cattle impaired by highland grazing? A case study using Aosta Red Pied cows

“…One of the drawbacks of the HI dairy systems is the impairment of milk coagulation properties (MCP) reported from studies with specialised dairy cattle breeds, such as Holstein Friesian, Brown Swiss and Brown Italian (Leiber et al 2005b(Leiber et al , 2006Bovolenta et al 2008). The main reason explaining the longer rennet coagulation time (RCT) and the less favourable curd properties, measured as curd-firming time (k 20 ) and curd firmness (a 30 ), is the energy deficit these cows are experiencing at high altitude, harsh climatic conditions and steep slopes (Christen et al 1996;Kreuzer et al 1998). This results in a lower milk protein content (Leiber et al 2005b) which reduces both cheese yield and milk coagulation performance, with the latter due to the lower density of the casein (CN) molecules in milk.…”