Milk production and reproductive performance of pluriparous dairy cows was compared for cows whose lactations were induced by hormonal treatment or followed natural calving. The study was conducted on 179 high-yielding dairy cows in a large dairy operation in a hot arid environment of northern Mexico, where bovine somatotropin (bST) was routinely used in all cows. To induce lactation, 98 cows that had previously failed to become pregnant were treated with 500 mg bST on days 1, 8 and 21. From days 2 to 8, cows were treated with oestradiol cypionate (0·30 mg/kg live weight (LW) per day) and progesterone (0·28 mg/kg LW per day). From days 9 to 15, oestradiol cypionate alone was given. PGF2α was given on day 16. Nothing was administered on days 17 and 18, and 15 mg flumetasone was administered from days 19 to 21. Lactation was induced successfully in all 98 cows subjected to the hormone treatment. All cows received 500 mg bST every 14 days throughout lactation from 63±7 days after lactation had started. Cows with induced lactations produced less (P<0·01) milk per 305-day lactation (9599±1387 kg) than controls (12 302±1245 kg). Proportion of cows pregnant was similar in induced cows and non-treated cows (71 v. 75%). Induction of lactation was associated with increased numbers of services per pregnancy (5·8±4·0 v. 4·22±2·98; P<0·01) compared with controls; however, impaired reproduction might not necessarily have been related to the hormonal treatment to induce lactation, but due to the nature of the cows utilized for this treatment group. This protocol can be used on dairy farms where bST treatment and prolonged steroid administration of dairy cows is legally permitted.

No abstract

No abstract

No abstract

Mellado, M., Olivares, L., Rodriguez, A. and Mellado, J. 2006. Relation among blood profiles and goat diets on rangeland. J. Appl. Anim. Res., I n this study the hypothesis that botanical composition of goat diets are related to metabolites and mineral levels in blood serum was tested, Diet composition (microhistological analysis of fecal samples) was investigated among adult mixed-breed goats grazing on rangeland during the dry (n=20) and wet (n=20) periods. I n the dry period levels of serum creatinine decreased with increasing proportions of Acacia farnesiana in goat diets. Serum levels of urea increased with the consumption of Parthenium incanum while goats consuming high levels of Larrea tridentata had decreased serum cholesterol level. Serum phosphorus showed a positive correlation with Atriplex canescens but a negative association with Buddkja scordioides. I n the rainy season ascending levels of Croton dioicus in the diet were related to higher serum urea, Cu and Mg. Increased consumption of Buchloe dactyloides was positively related to serum urea and creatinine. The results of this study may help in evolving supplementary feeding strategies based on nutritional status of goats, particularly during the lean period.

No abstract

BackgroundSystemic lupus erythematous (SLE) shows increased DNA demethylation. An intermediate step to DNA demethylation is the DNA hydroxymethylation, where 5-mC is oxidized into 5-hmC. Hydroxymethylation is not completely understood and it may be related to oxidative stress in SLE patient.ObjectivesTo analyze the association between the hydroxymethylation and demethylation, with the antioxidant response and SLE pathophysiology.MethodsWe analyzed in 142 SLE patients and 34 healthy controls the serum concentration of glutathione (GSH) and glutathione disulphide (GSSG) by UPLC-MS/MS, superoxide dismutase (SOD) and total antioxidant capacity (TAC) by colorimetric methods. 5-mC and 5-hmC levels were measured by colorimetric methods. Complete blood-test was made and clinical data by personal interview was collected. Biostatistical analysis with R (3.3.2.) was performed.ResultsThere is a correlation between the methylation and hydroxymethylation rate (P<0.001), and both were lower in patients than in controls (P=0.024; P<0.001). GSH and GSSG values were lower in patients (P=0.033 y P=0.003), but GSH/GSSG ratio was not statistically different in both groups. SOD levels were higher in patients (P=0.001), but TAC did not show significant differences. Higher demethylation is associated to lower TAC values in patients and healthy controls (P=0.005; P=0.01). In patients, decreased SOD values are associated with higher demethylation and lower hydroxymethylation rates (P<0.001; P=0.007). SOD and TAC levels are increased in SLE patients with higher demethylation and lower hydroxymethylation (P=0.001; P<0.001). We did not observe any association between 5-mC or 5-hmC levels and GSH, GSSG or GSH/GSSG ratio. Higher demethylation is associated to vascular symptoms (defined by RELESSER study) and lupus anticoagulant (AL) positivity (P=0.041; P=0.015), and lower hydroxymethylation to mucocutaneous damage (defined by RELESSER study) and AL positivity (P=0.015; P=0.009). Lower levels of GSH and GSSG were associated to increased accumulated damage assessed by SLICC (P=0.01; P=0.005), and lower SOD values with longer disease duration (P=0.001).ConclusionsWe observed higher demethylation and lower hydroxymethylation in SLE patients than in controls, related to increased SOD activity. Moreover higher demethylation leads to lower TAC levels. These epigenetic disorders are related to antioxidant response disruptions in SLE patients, probably because of the chronic inflammatory condition. Our results suggest that epigenetic processes are involved in SLE physiopathology.AcknowledgementsFinancial support by GVA (GV15/83) is acknowledged.Disclosure of InterestNone declared