Effects of Body Condition Score on the Reproductive Physiology of the Broodmare: A Review

The feeding management of broodmares is essential for breeding and successfully raising a healthy foal. A feeding regime will depend on the breed of mare, her age, body condition score (BCS), and general health and management. To maintain the broodmare in adequate body condition, her BCS should be ascertained and a feed regime implemented to maintain her optimum BCS and body weight, thus increasing fertility, milk yield, and the health of the mare and foal. Excesses and deficits in nutrition of the broodmare are regularly observed because nutritional recommendations are not well known or often not well instigated by horse breeders. Some short-term unbalanced rations are of little detriment to the health of the broodmare, but prolonged unbalanced rations can predispose the broodmare and foal to nutritional- and pathologic-related problems. By providing the broodmare with sufficient dietary energy, key nutrients, protein, and minerals in a balanced form, the risk of the foal developing orthopedic diseases will be greatly diminished. Obesity in the broodmare causes increased fetal adiposity, which can affect growth and performance of the adult horse. Conversely, undernutrition of the broodmare can cause intrauterine growth retardation of the fetus, resulting in altered development of the system(s) involved, which may have long-term effects on the horse that manifest during fetal, neonatal, or even adult life.     

Use of starting condition score to estimate changes in body weight and composition during weight loss in obese dogs

Prior to starting a weight loss programme, target weight (TW) is often estimated, using starting body condition score (BCS). The current study assessed how well such estimates perform in clinical practice. Information on body weight, BCS and body composition was assessed before and after weight loss in 28 obese, client-owned dogs. Median decrease in starting weight per BCS unit was 10% (5–15%), with no significant difference between dogs losing moderate (1–2 BCS points) or marked (3–4 BCS points) amounts of weight (P = 0.627). Mean decrease in body fat per BCS unit change was 5% (3–9%). A model based on a change of 10% of starting weight per unit of BCS above ideal (5/9) most closely estimated actual TW, but marked variability was seen. Therefore, although such calculations may provide a guide to final TW in obese dogs, they can either over- or under-estimate the appropriate end point of weight loss.     

FBW7 inhibits ox-LDL-induced granulosa cell apoptosis by promoting NOX1 degradation

AIM To investigate the effect of F-box and WD repeat domain containing protein 7 （FBW7） on the injury of granulosa cells （GCs） induced by oxidized low-density lipopretion （ox-LDL） stimulation and its potential mechanism. METHODS The GCs isolated from women of reproductive age with different obesity levels, the GCs isolated from high fatty diet （HFD）-fed rats, and the ox-LDL-treated rat GCs were collected, and the expression of FBW7 was detected by Western blot. After the rat GCs were infected with adenovirus encoding FBW7 （Ad-FBW7）, the cells were treated with ox-LDL （80 mg/L） for 48 h, and then the cell viability, apoptosis, NADPH oxidase （NOX） activity and the key subunit proteins of NOX were detected by CCK-8 assay, Annexin V/PI staining, lucigenin chemiluminescence and Western blot, respectively. The effect of FBW7 over-expression on NOX1 degradation was evaluated by cycloheximide （CHX） chase assay. RESULTS The expression of FBW7 was lower in the GCs isolated from obese women of reproductive age, the GCs isolated from HFD-fed rats, and the ox-LDL-treated rat GCs （P<0.05）. Over-expression of FBW7 inhibited ox-LDL-induced injury of GCs, NOX activity, and NOX1 expression （P<0.05）. The results of CHX chase assay showed that over-expression of FBW7 accelerated the degradation of NOX1 protein under ox-LDL condition （P<0.05）. CONCLUSION Over-expression of FBW7 reduces ox-LDL-induced injury of GCs by accelerating NOX1 degradation and then weakening NOX activity.     

Promoting oocyte aging with abnormal mitochondrial function and antioxidant post ovulation in obesity mouse

AIM: To investigate the effects of obesity on mouse oocyte in vivo aging, its in vitro fertilization and embryo development. METHODS: The oocyte-cumulus granulosa cell complexes were obtained at the time points of 14 h, 18 h and 22 h after HCG injection. The in vitro fertilization and embryo culture were conducted. Hoechst 33342 and propidium iodide double staining were performed to determine the apoptotic rate of cumulus granulosa cells. JC-1 and DCFH-DA were used to detect the levels of mitochondrial membrane potential(MMP) and reactive oxygen species (ROS), respectively. The levels of ATP and glutathione (GSH) in oocytes were also detected. RESULTS: The GSH level in obese mouse oocytes just after ovulation was higher than that in control group (P<0.05). No difference of blastocyst formation rate, ATP, ROS and cumulus granulosa cell apoptotic rate between obesity group and control group was observed (P>0.05). However, 18 h after HCG injection, ATP content and blastocyst cell numbers in obese mouse oocytes were less than those in control group (P<0.05), while ROS level in oocytes and the apoptotic rate of cumulus granulosa cells were higher than those in control group (P<0.05). Compared with control group, MMP and blastocyst formation rate were significantly decreased in obesity group 22 h after HCG injection (P<0.05). CONCLUSION: Obesity promotes oocyte aging after ovulation, and oxygen free radicals may play an important role in obesity-induced decrease of maternal infertility.     

Maternal obesity in ewes results in reduced fetal pancreatic β-cell numbers in late gestation and decreased circulating insulin concentration at term

About 30% of U.S. women of reproductive age are obese, a condition linked to offspring obesity and diabetes. This study utilized an ovine model of maternal obesity in which ewes are overfed to induce obesity at conception and throughout gestation. At mid-gestation, fetuses from these obese ewes are macrosomic, hyperglycemic, and hyperinsulinemic, and they exhibited markedly increased pancreatic weight and β-cell numbers compared with fetuses of ewes fed to requirements. This study was conducted to establish fetal pancreatic phenotype and function in late gestation and at term in this ovine model. Multiparous ewes were fed a control (C, 100% National Research Council [NRC] recommendations) or obesogenic (OB, 150% NRC) diet from 60 days before conception to necropsy at day 135 of gestation or to lambing. No differences were observed in fetal size or weight on day 135 or in lamb birth weights between C and OB ewes. In contrast to our previously published results at mid-gestation, pancreatic weights (P < 0.01) and β-cell numbers (P < 0.05) of OB fetuses were markedly lower than those from C fetuses, whereas the β-cell apoptotic rate was increased (P < 0.05) in day 135 OB versus C fetuses. At birth, blood insulin concentration was lower (P < 0.05) and glucose level was higher (P < 0.05) in newborn lambs from OB versus C ewes. These data demonstrate differential impacts of maternal obesity on fetal pancreatic growth and β-cell numbers during early and late gestation. During the first half of gestation there was a marked increase in pancreatic growth, β-cell proliferation, and insulin secretion, followed by a reduction in pancreatic growth and β-cell numbers in late gestation, resulting in reduced circulating insulin at term. It is speculated that the failure of the pancreas to return to a normal cellular composition and function postnatally could result in glucose/insulin dysregulation, leading to obesity, glucose intolerance, and diabetes in postnatal life.     

Correlates of objectively measured physical activity in dogs

To increase physical activity (PA) levels in dogs and to better evaluate their energy requirements, there is a need to understand which factors or correlates are associated with PA and/or sedentary behaviour. Improving our understanding of these correlates also has implications for prescribed energy requirements in dogs. PA was measured using accelerometry in 62 dogs from two common breeds (Labrador retrievers and Cocker spaniels). Five potential correlates (age, sex, breed, neuter status, body condition score) were tested for associations with total volume of PA, light-moderate intensity PA, vigorous intensity PA and sedentary behaviour. Age and breed were associated with total volume of PA, light-moderate intensity PA and sedentary behaviour in the final models. Age was associated with vigorous intensity PA. The final models explained 60%, 40%, 63% and 44% of variance in total volume of PA, light-moderate intensity PA, vigorous intensity PA and sedentary behaviour, respectively. These results should improve understanding of the variation in energy requirements of dogs, as well as the development of age and breed-specific diets and the prevention and treatment of canine obesity.