The effect of hot season and nutrition on the oxidative status and metabolic profile in dairy goats during mid lactation

Abstract

The aim of this study was to evaluate the effects of the hot season and nutrition on the oxidative status and metabolic\ud profile of lactating goats during mid lactation. Twenty-four Red Syrian goats were allocated into three groups that were\ud offered the following diets: natural pasture (P), pasture þ 500 g/h per day of concentrate (PC) and hay plus 500 g/h per\ud day of concentrate (HC). Blood samples were taken in spring (85 ^ 7 days in milk (DIM)) and summer (120 ^ 7 DIM)\ud and assayed for reactive oxygen metabolites (ROMs), a-tocopherol, glucose, triglycerides, cholesterol, non-esterified\ud fatty acids, total protein, albumin and globulin concentrations and glutathione peroxidase (GHS-Px) and superoxide\ud dismutase (SOD) activities. Milk yield and milk composition were also measured. SOD, GSH-Px and ROMs levels\ud increased during summer when temperature humidity index values were high. The increase in ROMs in the PC and HC\ud groups could be ascribed to the improved nutritional regime and to their higher production level. The markers of the\ud oxidative status and of the metabolic profile measured in this study indicate that goats may have experienced moderate\ud oxidative stress. It seems that, seasonal rather than nutritional factors have a more pronounced effect on oxidative\ud status markers. Concentrate supplementation sustained milk yield and may represent a useful means to extend the\ud lactation period in dairy goats during late spring and summer

Effects of Sulla forage (Sulla coronarium L.) on the oxidative status and milk polyphenol content in goats

“…From a general perspective, the observations that both the GSH-Px and SOD activities exhibited the same trend exhibited by the ROM are supported by the positive correlation that was detected between the ROM and the SOD (r = 0.32; P < 0.05). This relationship agrees with findings from goats at pasture (Di Trana et al, 2006) and confirms the specific role of the defensive role of intracellular antioxidants as free radical scavengers.…”

“…These factors might have induced greater mobilization of body fat. The observations that glucose decreased and NEFA increased in the nonsupplemented goats (SUL) are consistent with observations that have been made of goats at pasture without any supplement during the spring season (Di Trana et al, 2006). Plasma BHBA increased in the SULB and HB groups compared with the nonsupplemented SUL group.…”

“…Conversely, according to Celi and Raadsma (2010), TAC does not seem to be influenced by dietary supplementation of dairy cows with yerba mate leaves, whereas the same variable is affected by the energy level of the feeding regimen of goats on the day of parturition . Di Trana et al (2006) observed that feeding regimens based on green forage improve the oxidative statuses of goats due to the elevated antioxidant contents of green grass; indeed, spring grazing has been shown to provide benefits to animal health due to the higher α-tocopherol contents compared with summer grazing. In the current experiment, increases in TAC were observed in the samples from the SUL-and SULB-fed goats.…”

“…Unlike that observed in human species, for which reference values of total oxidants and antioxidants are reported (Cesarone et al, 1999;Dohi et al, 2005), the lack of the same reference values in ruminant species leads to difficulties in the interpretation of analytical data and in establishing if animals are experiencing oxidative stress. According to the literature, plasma oxidant levels in goats are higher in the hot season and in the peripartum period and depend on the nutritional regimen and on the production level Di Trana et al, 2006). Moreover, observing the total oxidant concentrations shown by the cited papers, ROM levels range from low values (64-83 U. Carr) for the current study to high values (250-280 U. Carr) observed by , almost as much as those listed as physiological values of the human species.…”

“…With regard to farm animals, oxidative stress has been shown to result from both disease and from some physiological stages, such as the peripartum period of dairy cows and dairy goats. Moreover, the balance between pro-oxidants and the antioxidant system is influenced by nutrition, season, body condition at calving, heat stress, and milk yield (Castillo et al, 2006;Di Trana et al, 2006;Celi, 2011).…”