Effect of body condition loss in early lactation Holstein cows on plasma IGF-I, prolactin and NEFA during breeding period and its association with some reproductive indices

The associations between early lactation changes of the body condition score (BCS) and mid-lactation levels of blood insulin like Growth Factor-I (IGF-1), prolactin, insulin, non-esterified fatty acids (NEFA), milk production and some reproductive indices were investigated. Monthly milk yield and BCS were recorded. Blood samples were collected on days 60, 90 and 120 (±5 days) of lactation. Twelve and 17 cows showed BCS losses ≤0.75 and >0.75 on day 60, respectively. BCS losses ≤0.75 till d60 after calving enhanced the IGF-I concentration on d90 (57.8±10.7 vs 35.6±17.8 ng/ml; P=0.001). The differences of blood metabolites were prominent on d90. Trends of insulin changes between d60 BCS (P=0.04) groups were different. Inverse correlations were detected between IGF-I and NEFA (-0.6, P=0.001), IGF-I and milk production (-0.4, P=0.05), NEFA and prolactin (-0.8, P<0.001) on d90. Higher percentages of cows with BCS loss >0.75 (d60) showed their first heat after d40 postpartum. In conclusion, irrespective of BCS at the time of breeding, the level of BCS loss during the first 60 days of lactation may affect further reproductive performance due to prolonged alterations of IGF-I, NEFA, prolactin and insulin levels. The extent of postpartum BCS loss may be a predictor of metabolic status of cows during mid-lactation.

Effect of age and of reproductive status on reproductive indices in horse mares carrying mule pregnancies

Mules (Equus mulus) are interspecific hybrids derived from crossing horse (Equus caballus) mares with jackasses (Equus asinus). In Italy, the production of mules is very important for the special environmental areas, where they are used as working animals, instead of the forbidden agricultural machines. Although many horse mares carry mule pregnancy successfully at term, low fertility of mares used for producing mules was reported, but limited data about reproductive efficiency in mares carrying mule pregnancy, especially when age and reproductive status are concerned, are available. Therefore, the present study aimed to assess the effect of age and of reproductive status on some reproductive indices of horse mares carrying mule pregnancy, in the final purpose to better clarify factors affecting reproductive performances in the valuable production of mules as working animals under special environmental areas in Italy.

The study, performed on 96 draft mares inseminated with Martina Franca donkey semen, showed a satisfactory 89.6% 14 days PO pregnancy rate, lower pregnancy losses (19.8%) than those previously reported for mule pregnancies, leading to satisfactory foaling rates (71.9%), similar to those reported for intraspecific horse pregnancies. A clear, significant detrimental effect of mare's age on pregnancy losses, foaling rate, and on number of estrous cycles needed to achieve pregnancy, was found. Reproductive status also affected the reproductive indices, with significantly higher pregnancy losses and lower foaling rate in barren mares, reopening the question about the possible lower reproduction efficiency in horse mares carrying mule pregnancy. The present study results, although mostly descriptive, add useful information about some factors affecting reproductive performances in the valuable production of mules as working animals under special environmental areas in Italy.

Interactive effects of nonylphenol and bisphenol A exposure with oxidative stress on fetal reproductive indices

Nonylphenol (NP) and/or bisphenol A (BPA) may have reproductive effects. Although the mechanisms of action remain unclear, steroid hormones biosynthesis, hypothalamus pituitary adrenal axis activity, oxidative stress, and crosstalk interaction of NP and BPA mixture and its pathways may play a contributory role. This cross-sectional study examined whether the interactive effects of NP/BPA and oxidative stress biomarkers played a role in reproductive indices (penis length and anogenital distance (AGD)) in 244 mother-fetus pairs. Four biomarkers of oxidative stress, (8-hydroxy-2'-deoxyguanosine (8-OHdG), 8-nitroguanine (8-NO₂Gua), 8-iso-prostaglandin F_2α (8-isoPF_2α), and 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA)) were simultaneously analyzed using the high-performance liquid chromatography-electrospray ionization tandem mass spectrometry method. No significant associations were found between reproductive indices and NP/BPA or oxidative stress biomarkers. Maternal exposure to a mixture of NP and BPA may enhance 8-OHdG. Interactive effects were found in the high 8-isoPF_2α group, and prenatal NP exposure was inversely associated with penis length (β = -3.68 mm; p = 0.01). Similar results were noted among boys who were born to mothers in the high 8-isoPF_2α group, in which BPA was inversely associated with penis length (β = -4.43 mm; p = 0.005). Our findings suggest important implications for prenatal exposure to oxidative stress, as evidenced by the 8-isoPF2α level. Thus, NP and BPA may interact to shape fetal reproductive tract development, particularly in boys. The interactive effects of NP/BPA, oxidative stress, and reproductive indices should be considered.