Background: In a prior experiment, treatment of goats with the putative PPARγ agonist 2,4-thiazolidinedione (2,4-TZD) did not affect milk fat or expression of milk-fat related genes. The lack of response was possibly due to deficiency of vitamin A and/or a poor body condition of the animals. In the present experiment, we tested the hypothesis that PPARγ activation affects milk fat synthesis in goats with a good body condition and receiving adequate levels of vitamin A. Methods: Lactating goats receiving a diet that met NRC requirements, including vitamin A, were injected with 8 mg/kg BW of 2,4-TZD (n = 6) or saline (n = 6; CTR) daily for 26 days. Blood metabolic profiling and milk yield and components were measured including fatty acid profile. Expression of genes related to glucose and lipid metabolism was measured in adipose tissue and in mammary epithelial cells (MEC). Size of adipocytes was assessed by histological analysis. Results: NEFA, BHBA, and fatty acids available in plasma decreased while glucose increased in 2,4-TZD vs. CTR. Size of cells and expression of insulin signaling and glucose metabolism-related genes were larger in 2,4-TZD vs. CTR in adipose tissue. In MEC, expression of SCD1 and desaturation of stearate was lower in 2,4-TZD vs. CTR. Conclusions: Overall data revealed a lack of PPARγ activation by 2,4-TZD and no effect on milk fat synthesis despite a strong anti-lipolysis effect on adipose tissue.

The hypothesis of the study was that feeding a relatively low amount of Se biofortified alfalfa hay during the dry period and early lactation would improve selenium status and glutathione peroxidase activity in dairy cows and their calves. Ten Jersey and 8 Holstein primiparous dairy cows were supplemented with Se biofortified (TRT; n = 9) or non-biofortified (CTR; n = 9) alfalfa hay at a rate of 1 kg/100 kg of BW mixed with the TMR from 40 d prior parturition to 2 weeks post-partum. Se concentration in whole blood, liver, milk, and colostrum, the transfer of Se to calves, and the glutathione peroxidase (GPx) activity were assessed. TRT had 2-fold larger (P < 0.05) Se in blood v. CTR that resulted in larger Se in liver and colostrum but not milk and larger GPx activity in plasma and erythrocytes but not in milk. Compared to CTR, calves from TRT had larger Se in blood but only a numerical (P = 0.09) larger GPx activity in plasma. A positive correlation was detected between Se in the blood and GPx activity in erythrocytes and plasma in cows. Our results demonstrated that feeding pregnant primiparous dairy cows with a relatively low amount of Se-biofortified alfalfa hay is an effective way to increase Se in the blood and liver, leading to greater antioxidant activity via GPx. The same treatment was effective in improving Se concentration in calves but had a modest effect on their GPx activity. Feeding Se biofortified hay increased Se concentration in colostrum but not in milk.

Background: the peripartum is the most critical period in dairy cows with high incidence of diseases due to immune dysfunctions, often paired with systemic inflammation and oxidative stress. Selenium is a trace mineral that plays an important role in anti-oxidative function and immune response. We hypothesize that supplementing dairy cows with a relatively small amount of Se-biofortified hay during the last 40 days of pregnancy and early lactation improves performance, metabolism, oxidative status, and immune response.Methods: ten Jersey and 8 Holstein pregnant dairy heifers were divided into two groups and supplemented with 1 kg/100 kg BW of Se-biofortified (Sel; n=9; 3.2 ppm Se) or non-biofortified (Ctr; n=9; 0.4 ppm Se) alfalfa hay from 40 days prior- to 2 weeks post-partum. Heifers were monitored daily for feed intake, activity, and milk yield, and weekly for BW and BCS. Milk samples were assessed for components and fatty acid profile. Blood samples were collected regularly to assess metabolic, oxidative, and inflammatory biomarkers, and to evaluate leukocytes phagocytosis and differential through flow cytometry.Results: supplementation of Se biofortified hay did not affect feed intake, milk yield, BW, BCS, milk components, and any of the parameters measured on leukocytes but increased the hematocrit. Animal receiving Se biofortified hay had larger concentration of plasma albumin and a tendency for larger blood urea, indicating a possible better liver status, especially post-partum. None of the parameters measured in plasma related to the oxidative status were affected, except the concentration of advanced oxidation protein products that was greater in Sel vs. Ctr. The concentration of advanced oxidation protein products was negatively correlated with parameters related to inflammation but positively associated to plasma albumin suggesting a possible improved anti-oxidative function of circulating albumin by Se-biofortified hay supplementation.Conclusions: feeding Se-biofortified hay during pregnancy in dairy heifers had little effect on metabolic, inflammatory, and oxidative status parameters with no effect on performance or immune response. Supplementation with Se-biofortified hay increased plasma level of albumin, possibly as consequence of improved liver function, promoting the antioxidant role of albumin as indicated by increased AOPP.

70 Holstein cows were randomly chosen from the herd at the Nasr Dairy Cattle Station, United Company for Animal Resources Ltd ., Al-Soueira (50 Km south of Baghdad) and over period from December, 2003. The aim of this investigation was to study the effects of some factors on somatic cell count (SCC) in milk. The overall mean of the SCC in milk was (1584.314 x 10 3 cell/ml). Cows which produced milk less than 3000 kg/season, showed higher level of SCC (2047.461 x10 3) cell/ml. Also the infected cows had higher SCC compared with healthy cows and the difference was not significant in this study. The regression coefficient of SCC on age at first calving (A.F.C.) was significant (P <0.01) (9x10 3 cell / month). The correlation coefficient between lactation period, milk production and SCC were negative P < 0.01 and were (-0.16,-0.09) respectively.