National Research Council Recommendations Research Articles

Maternal obesity downregulates microRNA let-7g expression, a possible mechanism for enhanced adipogenesis during ovine fetal skeletal muscle development

Obesity in women of childbearing age is increasing at an alarming rate. Growing evidence shows that maternal obesity induces detrimental effects on offspring health, including pre-disposition to obesity. We have shown that maternal obesity increases fetal intramuscular adipogenesis at mid-gestation. However, the mechanisms are poorly understood. MicroRNAs (miRNAs) regulate mRNA stability. We hypothesized that maternal obesity alters fetal muscle miRNA expression, thereby influencing intramuscular adipogenesis. Non-pregnant ewes received a control diet (Con, fed 100% of National Research Council (NRC) recommendations, n=6) or obesogenic diet (OB; 150% NRC recommendations, n=6) from 60 days before to 75 days after conception when the fetal longissimus dorsi (LD) muscle was sampled and miRNA expression analyzed by miRNA microarray. One of miRNAs with differential expression between Con and OB fetal muscle, let-7g, was further tested for its role in adipogenesis and cell proliferation in C3H10T1/2 cells. A total of 155 miRNAs were found with a signal above 500, among which, three miRNAs, hsa-miR-381, hsa-let-7g and bta-miR-376d, were differentially expressed between Con and OB fetuses, and confirmed by quantitative real-time PCR (QRT-PCR) analyses. Reduced expression of miRNA let-7g, an abundantly expressed miRNA, in OB fetal muscle was correlated with higher expression of its target genes. Overexpression of let-7g in C3H10T1/2 cells reduced their proliferation rate. Expression of adipogenic markers decreased in cells overexpressing let-7g, and the formation of adipocytes was also reduced. Overexpression of let-7g decreased expression of inflammatory cytokines. Fetal muscle miRNA expression was altered due to maternal obesity, and let-7g downregulation may enhance intramuscular adipogenesis during fetal muscle development in the setting of maternal obesity.

Early maternal undernutrition programs increased feed intake, altered glucose metabolism and insulin secretion, and liver function in aged female offspring

Insulin resistance and obesity are components of the metabolic syndrome that includes development of cardiovascular disease and diabetes with advancing age. The thrifty phenotype hypothesis suggests that offspring of poorly nourished mothers are predisposed to the various components of the metabolic syndrome due to adaptations made during fetal development. We assessed the effects of maternal nutrient restriction in early gestation on feeding behavior, insulin and glucose dynamics, body composition, and liver function in aged female offspring of ewes fed either a nutrient-restricted [NR 50% National Research Council (NRC) recommendations] or control (C: 100% NRC) diet from 28 to 78 days of gestation, after which both groups were fed at 100% of NRC from day 79 to lambing and through lactation. Female lambs born to NR and C dams were reared as a single group from weaning, and thereafter, they were fed 100% NRC recommendations until assigned to this study at 6 yr of age. These female offspring were evaluated by a frequently sampled intravenous glucose tolerance test, followed by dual-energy X-ray absorptiometry for body composition analysis prior to and after ad libitum feeding of a highly palatable pelleted diet for 11 wk with automated monitoring of feed intake (GrowSafe Systems). Aged female offspring born to NR ewes demonstrated greater and more rapid feed intake, greater body weight gain, and efficiency of gain, lower insulin sensitivity, higher insulin secretion, and greater hepatic lipid and glycogen content than offspring from C ewes. These data confirm an increased metabolic "thriftiness" of offspring born to NR mothers, which continues into advanced age, possibly predisposing these offspring to metabolic disease.

The relationship between weight, age, and average daily gain to show performance of Georgia 4-H and Future Farmers of America (FFA) commercial dairy heifers

Three studies were conducted to determine the relationship between dairy heifer growth and placing in the show ring. In the first study, 1,744 commercial dairy heifers (all breeds and crossbred animals) were evaluated to determine effects of growth on placing within Georgia Commercial Dairy Heifer Shows from 2007 to 2010. Birth weights were determined using breed birth weight averages, with crossbreeds being the average of 2 parent breeds. Average daily gains (ADG) were calculated and heifers were given rankings based on placing in show and for age and weight. Data was analyzed using the Spearman correlation calculations in the SAS software (SAS Institute Inc., Cary, NC). Age and ADG were inversely correlated (r=−0.89). Mean ADG for all heifers was determined to be 0.65kg, below National Research Council recommendations of 0.7 to 0.8kg. No strong relationship (r=−0.07) was observed between ADG and placing. Heavier heifers within a class showed a small positive relationship (r=0.10) with placing. For study 2, 238 heifers shown at the 2010 Georgia Junior National Livestock Show (Perry, GA) were measured and evaluated for ADG, placing, body weight, age, withers height, hip height, hip width, and jaw width. Height at withers had a moderate relationship (r=0.42) with placing, followed by hip height (r=0.32). A positive relationship (r=0.65) was observed between withers height and hip height. The correlation between weight and placing was determined (r=0.11). Age and ADG had a strong inverse relationship (r=−0.87). Study 3 evaluated 1,489 Holstein heifers shown from 2007 to 2010. Data was analyzed using the Penn State Growth Monitor Spreadsheet Curves. In total, 63.75% did not meet Penn State recommendations for body weight gain. Performance and physical features associated with age indicates that commercial dairy heifers are underfed. The effects of heat stress and high feed costs also play a role. This has economic implications because these animals will likely require more time before they enter the milk herd. The Commercial Dairy Heifer Program is vital for youth development in Georgia. However, those involved need to be encouraged to improve nutritional management practices.

The impact of maternal overnutrition and obesity on hypothalamic-pituitary-adrenal axis response of offspring to stress

We evaluated the effect of maternal obesity before and throughout gestation on offspring hypothalamic-pituitary-adrenal axis function. Multiparous Rambouillet by Columbia crossbred ewes were fed either 100% of National Research Council (NRC) recommendations (control, C) or 150% of NRC recommendations (obese, OB) from 60 d before mating until lambing. Ten lambs born to OB ewes (five males and five females), and eight lambs born to C ewes (three male and five female) were studied. From delivery to weaning lambs were maintained with their mothers, who were all fed 100% NRC recommendations. After weaning, all lambs were group housed and fed the same diet to meet NRC requirements. At 19 mo of age lambs were placed in individual pens and fed a pelletized diet to meet maintenance requirements. Jugular vein catheters were placed and 2 d later lambs received an intravenous (i.v.) adrenocorticotropic hormone (ACTH) challenge followed by an i.v. corticotropin-releasing hormone (CRH)/arginine vasopressin (AVP) challenge 1 d later. Thirty d later offspring were again catheterized and placed into metabolism crates for 2 d before receiving an isolation stress test. ACTH and cortisol responses to the isolation stress test and CRH/AVP challenge and cortisol responses to ACTH challenge were determined. Cortisol was quantified via radioimmunoassay and ACTH was quantified using an Immulite 1000; both were analyzed using repeated measures using the MIXED procedure of SAS. Offspring from OB ewes had elevated basal plasma ACTH and cortisol compared with C offspring before all three challenges (P < 0.05). Offspring from OB mothers tended (P = 0.06) to have a greater ACTH response after an i.v. CRH/AVP injection than offspring from C mothers (12,340 ± 1,430 vs 8,170 ± 1,570 area under the curve, respectively). Cortisol response to the CRH/AVP and ACTH challenges was not influenced by maternal nutrition (P = 0.46) and averaged 4.77 ± 0.2 μg/dL and 1.94 ± 0.01 μg/dL, respectively. The ACTH response following the isolation stress test was also similar (P = 0.82) for OB and C offspring (147 ± 20 pg/mL), and cortisol response during the isolation stress test was similar between C and OB offspring (P = 0.64, 5.25 ± 0.3 μg/dL). These findings suggest that maternal obesity before and during gestation does not affect stress responses by the offspring, but has an impact on hypothalamic-pituitary-adrenal sensitivity. The lack of differences in cortisol release under the influence of difference concentrations of ACTH during the CRH/AVP challenge could indicate adrenal dysfunction in OB offspring.

Effect of different amino acids density diets on lysine, methionine and protein efficiency in Arian broiler

The advantages provided by amino acid (AA) densities to broiler performance have been well documented, but little research has been reported on comparing the effect of different densities, i.e. high, medium, standard and low amino acid levels (HAA, MAA, SAA, and LAA), on protein and energy efficiency in broiler. This study evaluated the effects of the four different amino acid densities in a completely randomized experimental design on 800 male (10 replicates per treatment) broilers. All diets were isocaloric and isonitrogenous. In broilers receiving HAA, there had been a significant increase in body weight at Day 42. Feeding broilers with HAA diets significantly increased protein and energy intake in the grower period and during the overall study period (0–42 days of age) (P<0.05). There was a significant difference in efficiency of lysine and methionine during all time periods (P<0.05) and HAA levels were significantly higher than SAA. Protein efficiency ratio (PER) and energy efficiency ratio (EER) were not affected by an increase in AA density. AA levels had a significant effect on production efficiency factor (PEF). The results of this study suggest that additional lysine and methionine at 120% and other AA at 110% of National Research Council recommendations in starter and grower diets significantly improved body weight and PEF.

Effects of dietary calcium content and vitamin D source on skeletal properties in growing turkeys

1. The aim of the study was to investigate the effects of feeding fast growing turkeys with differentiated dietary calcium (Ca) content, and the partial replacement of vitamin D3 in the feed with 25-hydroxycholecalciferol (25(OH)D3), on skeletal properties. 2. One-day-old Big-6 male turkeys (n = 1008) were randomly divided into 4 groups, and two subgroups were created within each group. The groups were differentiated with 4 levels of Ca provision in the feed, namely 85% of the National Research Council (NRC) recommendation (Group Ca1); 95% as above (Group Ca2); 105% as above (Group Ca3); and 115% as above (Group Ca4). The first subgroup received the recommended dosage of cholecalciferol (vitamin D3 subgroup) in the feed, while in the second subgroup (Hy-D subgroup), half of the dosage of cholecalciferol was replaced with 25(OH)D3. At the ages of 4, 8, 12 and 20 weeks, 7 turkeys from each subgroup were randomly selected and killed to obtain the right tibia for densitometric, geometric and mechanical analyses. 3. This study showed advantageous effects of increased calcium supply in the diet on skeletal system properties, that were increased and produced the most desirable traits in turkeys receiving 95%, 105% and 115% of the NRC calcium recommendation. Benefits resulting from administration of 25(OH)D3 in the diet were also obtained in the skeletal formation of turkeys, and the most advantageous effects were present in the group receiving 105% of recommended dietary Ca. 4. Effects on the metabolic response of the skeleton of turkeys to manipulation of dietary calcium content and vitamin D3 source were the most evident in the groups between 4 and 12 weeks of life, and demonstrated a limited ability to induce a positive influence on bone properties at advanced stages of the production cycle by alteration of these dietary factors.

A Weather and Climate Enterprise Strategic Implementation Plan for Generating and Communicating Forecast Uncertainty Information

The American Meteorological Society (AMS) Weather and Climate Enterprise Strategic Implementation Plan for Generating and Communicating Forecast Uncertainty (the Plan) is summarized. The Plan (available on the AMS website at www.ametsoc.org/boardpges/cwce/docs/BEC/ACUF/2011-02-20-ACUF-Final-Report.pdf) is based on and intended to provide a foundation for implementing recent recommendations regarding forecast uncertainty by the National Research Council (NRC), AMS, and World Meteorological Organization. It defines a vision, strategic goals, roles and respon- sibilities, and an implementation road map to guide the weather and climate enterprise (the Enterprise) toward routinely providing the nation with comprehensive, skillful, reliable, and useful information about the uncertainty of weather, water, and climate (hydrometeorological) forecasts. Examples are provided describing how hydrometeorological forecast uncertainty information can improve decisions and outcomes in various socioeconomic areas. The implementation road map defines objectives and tasks that the four sectors comprising the Enterprise (i.e., government, industry, academia, and nongovernmental organizations) should work on in partnership to meet four key, interrelated strategic goals: 1) understand social and physical science aspects of forecast uncertainty; 2) communicate forecast uncertainty information effectively and collaborate with users to assist them in their decision making; 3) generate forecast uncertainty data, products, services, and information; and 4) enable research, development, and operations with necessary information technology and other infrastructure. The Plan endorses the NRC recommendation that the National Oceanic and Atmospheric Administration and, in particular, the National Weather Service, should take the lead in motivating and organizing Enterprise resources and expertise in order to reach the Plan's vision and goals and shift the nation successfully toward a greater understanding and use of forecast uncertainty in decision making.

Short communication: Prediction of energy requirements of Murciano-Granadina preruminant female kids using the National Research Council

Data collected on metabolizable energy (ME) intake and growth performance of preruminant female kids of the Murciano-Granadina breed was used to assess the accuracy of the latest U. S. National Research Council (NRC) recommendations to predict their energy requirements. Female kids were fed a milk replacer individually, according to appetite three times a day from two to five weeks of age. The mean initial body weight and average daily weight gain (&plusmn; SE) were 3.31 &plusmn; 0.08 kg/d and 120 &plusmn; 3 g/d. Daily ME intake, expressed relative to metabolic body weight (BW0.75), decreased linearly with age from 1085 to 970 kJ/kg BW0.75/d, and there was nearly a constant ratio of ME requirements for maintenance. The observed ME intake was 5.4% higher than the ME requirements, calculated according to NRC, probably due to the energy content of the weight gain. It was concluded that the energy system model of the NRC is accurate enough to calculate the ME requirements of preruminant female kids of the Murciano-Granadina breed.Keywords: Goats, pre-weaning period, suckling female kids, NRC

Bacteriologic and Nutritional Evaluation of a Commercial Raw Meat Diet as Part of a Raw Meat Safety Program

This study evaluated selected bacteriologic and nutritional components of a commercially prepared ground raw horsemeat diet as part of a raw meat safety program. Six lots of meat were analyzed in triplicate. Frozen meat samples were thawed for 44 hr at 5°C. Meat samples were tested at three times during thawing (t = 0, 24, 44 hr) for selected bacteria. Samples were screened for Salmonella sp. using an enzyme-linked immunosorbent assay. Escherichia coli and total coliform bacteria were quantified using a ready-made culture medium system. Proximate, energy, macro and trace mineral composition was determined at a reference laboratory. Salmonella sp. antigen was detected in one sample of meat at t = 0 hr. Frozen meat samples had low average maximum expected numbers of E. coli and coliforms. The average maximum number of E. coli did not change significantly at t = 24 or 44 hr, but the average maximum number of coliforms increased significantly by t = 44 hr. These bacteriologic tests were easily incorporated into a raw meat safety program. Median concentrations of moisture, dry matter, crude protein, crude fat, ash, calcium, and phosphorus conformed to the guaranteed analysis but median crude fiber exceeded the guaranteed maximum. Median magnesium, potassium, and sodium concentrations conformed to the approximate nutrient content. Median concentrations of copper exceeded, whereas iron, zinc, and manganese fell below, the approximate nutrient content. Median copper and manganese concentrations exceeded the National Research Council's recommendation for adult domestic cats, whereas iron and zinc were below the National Research Council's recommendations for adult cats.

Maintenance energy requirement determination of cats after spaying

Neutering is often associated with obesity in companion animals. However, the maintenance energy requirement (MER) for these animals has not been clearly defined. The present study investigated the MER for spayed cats whose body weights (BW) began to increase shortly after ovariohysterectomy. A total of twenty-two shorthair adult female cats were fed complete and balanced diets in amounts to maintain their BW and body condition score (BCS) before the present study. All cats were spayed and the diet was fed for 11 weeks using the same MER as previously. During these weeks, all cats gained weight. Beginning with week 12, a weight-loss regimen was initiated until each cat achieved a BCS of 5 out of 9. After each cat obtained a BCS of 5, an appropriate amount of diet was fed to maintain its BW for at least 4 weeks to determine a modified MER. Daily food consumption, weekly BW and BCS were monitored. Blood was collected before and after weight loss for plasma biochemistry profiles. BW and BCS increased by 16 % and one point (P < 0.01), respectively, during the first 11 weeks after surgery, although food consumption was constant both pre- and post-surgery. The mean MER after obtaining a BCS of 5 was 313.6 (SEM 23.6) kJ/BW(0.67), which is 25 % lower than the current National Research Council recommendation and lower than the cat's requirement before surgery (P < 0.05). In conclusion, spaying significantly increased BW when using MER values for intact cats. Thus, 313.6 × ideal BW(0.67) kJ is proposed for the MER of spayed adult cats.

Estimation of dietary lysine requirement based on broken line and quadratic model analyses with the use performance and immune responses criterion

The aim of this study was to determine the effects of supplementing Lysine (Lys) at on growth performance and immune responses of broiler chickens challenged with infectious bursal disease (IBD) and estimation of Lys requirement based on different response criterions. A total of 400-day-old male broiler chicks were assigned to eight dietary treatments. Chickens were fed by eight graded levels of Lys (0.8 National Research Council (NRC) (0.75% of diet), 0.9 NRC (0.85% of diet), NRC (0.94 of diet), 1.1 NRC (1.03% of diet), 1.2 NRC (1.13% of diet), 1.3 NRC (1.22% of diet), 1.5 NRC (1.41% of diet) and 1.8 NRC (1.69% of diet)) from day 21 to 42 of age. On day 28, all birds were challenged with a commercial live-IBDV vaccine. Body weight gains (BWG), feed conversion ratio (FCR) and carcass characterization (breast, thigh and fat pad percentage) were significantly influenced by dietary Lys levels. With increasing Lys level up to 1.22% of diet, performance improved significantly and with higher than this level decreased. Antibody titre against IBD was influenced by Lys levels. On 7 and 14 days after IBD challenge, antibody titre against IBD of broilers that receive diet that contain Lys higher than NRC recommendation wwas significantly higher than those receive lower level and the highest antibody level found in 1.22% Lys in diet. The highest (1.2519±0.0441) and the lowest (1.0408±0.11) Lys requirements with straightbroken line analysis were estimated for immune response and carcass efficiency percentage, respectively. The results obtained on the present study indicated that Lys requirements of broiler based on recommendation of NRC are not sufficient to meet the requirement of the new commercial poultry and commercial broiler companies under non-hygienic condition.

The [R]Evolving Relationship Between Risk Assessment and Risk Management

In Science and Decisions: Advancing Risk Assessment, the National Research Council recommends improvements in the U.S. Environmental Protection Agency's approach to risk assessment. The recommendations aim to increase the utility of these assessments, embedding them within a new risk-based decision-making framework. The framework involves first identifying the problem and possible options for addressing it, conducting related analyses, then reviewing the results and making the risk management decision. Experience with longstanding requirements for regulatory impact analysis provides insights into the implementation of this framework. First, neither the Science and Decisions framework nor the framework for regulatory impact analysis should be viewed as a static or linear process, where each step is completed before moving on to the next. Risk management options are best evaluated through an iterative and integrative procedure. The extent to which a hazard has been previously studied will strongly influence analysts' ability to identify options prior to conducting formal analyses, and these options will be altered and refined as the analysis progresses. Second, experience with regulatory impact analysis suggests that legal and political constraints may limit the range of options assessed, contrary to both existing guidance for regulatory impact analysis and the Science and Decisions recommendations. Analysts will need to work creatively to broaden the range of options considered. Finally, the usefulness of regulatory impact analysis has been significantly hampered by the inability to quantify many health impacts of concern, suggesting that the scientific improvements offered within Science and Decisions will fill an crucial research gap.

Prepartum nutrient intake alters palmitate metabolism by liver slices from peripartal dairy cows

We determined the effects of day relative to parturition and prepartum plane of nutrition on hepatic partitioning of palmitate metabolism to CO2, acid-soluble products (ASP), and esterified products (EP). Multiparous Holsteins (n=74) were fed different amounts of nutrients during the dry period in a 3 (far-off period diet) × 2 (close-up period diet) factorial arrangement. During the far-off period (d −60 to −25) cows received a low-energy control diet fed ad libitum (100NRC) to meet National Research Council (NRC) requirements, a moderate-energy diet fed ad libitum to exceed NRC recommendations for net energy of lactation (NEL) by >50% (150NRC), or the same diet fed at restricted intake to provide 80% of NEL requirements (80NRC). During the close-up period (d −24 until parturition), cows were fed a diet for ad libitum intake to meet NRC recommendations or in restricted amounts to provide 80% of calculated NEL requirements. After parturition, all cows had ad libitum access to a lactation diet. Liver slices from biopsies on d −30, −14, 1, 14, and 28 relative to parturition were used to determine conversion of [1-14C] palmitate to CO2, ASP, and EP. Across diets, oxidation of palmitate to CO2 was decreased postpartum, whereas oxidation to ASP was increased at d 1 postpartum compared with other times. Conversion of palmitate to EP increased markedly postpartum, with the greatest rates at d 1 postpartum. Conversion of palmitate to CO2 and ASP on d 1 postpartum was lower and the proportion of palmitate metabolism as EP was greater for cows fed 150NRC than for those fed 100NRC or 80NRC. Hepatic triacylglycerol concentration at d 1 postpartum was greatest for cows fed 150NRC. Palmitate metabolism did not differ between close-up diets. Hepatic triacylglycerol was negatively correlated with tissue metabolism of palmitate to CO2 and ASP but positively correlated with metabolism to EP. Hepatic triacylglycerol was highly correlated with NEFA concentrations on the day of calving and d 1 postpartum but not with NEFA prepartum. In contrast, plasma BHBA postpartum was not correlated with hepatic palmitate metabolism by liver slices but was highly correlated with NEFA concentration prepartum. Excessive energy intake during the far-off dry period decreased hepatic palmitate oxidation and shifted palmitate metabolism toward greater esterification, consistent with greater hepatic triacylglycerol accumulation postpartum.

The relationship of feeding patterns and obesity in dogs

The rates of dog obesity are increasing and a greater understanding of feeding patterns is required to combat the problem. This study examined relationships between dietary patterns and caloric intake, and nutrient content of foods fed as it relates to obesity in dogs in the United States. Sixty-one owners and their dogs were enrolled, and lifestyle surveys, food frequencies, and 3-day food records were collected. Significant differences in overall kcal intake per kilogram of body weight were found (p< 0.04). Crude fibre in dog food was positively associated with protein and negatively associated with fat regardless of the dog's weight (p< 0.001). Lean dogs received significantly more crude fibre in relation to overweight dogs regardless of the number of treats they received (p< 0.01), and their diets had greater micronutrient densities (p< 0.03) suggesting that high fibre influences body condition. Additionally, owners who ate nutrient-rich, calorie-poor diets had normal weight dogs, and owners that fed more table scraps had overweight dogs. Regardless of body condition, 59% of dogs received table scraps, which constituted 21% of daily caloric intake. The nutrient density of scraps fed was variable and did not meet National Research Council's recommendations for micronutrient adequacy.

The effect of threonine on mucin2 gene expression, intestinal histology and performance of broiler chicken

Threonine needs based on Ross manuals might be 14% of the National Research Council (NRC) recommendation, thus the effect of threonine on mucin2 gene expression, histological characteristics and performance were evaluated in Ross male broilers fed diets containing 0.8% (NRC requirement), 0.87% (average of NRC and Ross requirement), 0.94% (Ross requirement) and 1.01% (more than Ross requirement) total threonine. The dietary treatments consisted of an isonitrogenous corn-soybean meal-based diet with incremental levels of threonine. At the first day of chicken age, 24 pens were equalized to 12 birds per pen, in a completely randomized design and dietary treatments were randomly distributed for the 14-d period. Live performance measurements improved (P<0.05) as dietary threonine increased from 0.8% to 0.87%. The least performance was related to diet containing 1.01% threonine. Histological assays showed that villi height, crypt depth and villi surface increased as dietary threonine increased from 0.8% to 0.87% and decreased in 0.94% and 1.01% threonine. There was no effect of threonine on mucin2 gene expression and goblet cells density. According to these results, threonine needs in starter period in Ross (308) broilers is more than NRC recommendation.

Maternal obesity induces fibrosis in fetal myocardium of sheep

Maternal obesity (MO) has harmful effects on both fetal development and subsequent offspring health. The impact of MO on fetal myocardium development has received little attention. Fibrogenesis is regulated by the transforming growth factor-β (TGF-β)/p38 signaling pathway. Using the well-established model of MO in pregnant sheep, we evaluated the effect of MO on TGF-β/p38 and collagen accumulation in fetal myocardium. Nonpregnant ewes were assigned to a control diet [Con, fed 100% of National Research Council (NRC) nutrient recommendations] or obesogenic diet (OB, fed 150% of NRC recommendations) from 60 days before conception. Fetal ventricular muscle was sampled at 75 and 135 days of gestation (dG). At 75 dG, the expression of precursor TGF-β was 39.9 ± 9.9% higher (P < 0.05) in OB than Con fetal myocardium, consistent with the higher content of phosphorylated Smad3 in OB myocardium. The phosphorylation of p38 tended to be higher in OB myocardium (P = 0.08). In addition, enhanced Smad complexes were bound to Smad-binding elements in 75 dG OB fetal myocardium measured by DNA mobility shift assay (130.2 ± 26.0% higher, P < 0.05). Similar elevation of TGF-β signaling was observed in OB fetal myocardium at 135 dG. Total collagen concentration in OB was greater than Con fetal myocardium (2.42 ± 0.16 vs. 1.87 ± 0.04%, P < 0.05). Matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-3 were higher in the Con group compared with OB sheep (43.86 ± 16.01 and 37.23 ± 7.97% respectively, P < 0.05). In summary, MO results in greater fetal heart connective tissue accumulation associated with an upregulated TGF-β/p38 signaling pathway at late gestation; such changes would be expected to negatively impact offspring heart function.

Effects of stage of lactation and dietary concentrate level on energy utilization by Alpine dairy goats

Twenty-four lactating and 13 nonlactating Alpine goats were used to determine effects of stage of lactation and dietary concentrate level on energy utilization. Diets comprising 60 or 20% concentrate (60%C and 20%C, respectively) were consumed ad libitum by lactating animals and at a level of intake near maintenance by nonlactating animals. Measurement periods were d 25 to 31 (early), 87 to 94 (mid), and 176 to 183 (late) of lactation. Eleven observations were made in early and mid lactation for each diet, and 8 and 7 were made in late lactation for the 60%C and 20%C diets, respectively. Efficiency of metabolizable energy (ME) use for maintenance (66.9, 71.4, and 61.1% for early, mid, and late lactation, respectively) and the maintenance ME requirement (479, 449, and 521 kJ/kg of BW0.75 for early, mid, and late lactation, respectively) determined with nonlactating animals differed among stages of lactation. The efficiency of ME use for maintenance was similar between diets, but the maintenance requirement tended to be greater for the 60%C than for the 20%C diet (504 vs. 463 kJ/kg of BW0.75). The latter difference may have involved greater ME intake for the 60%C diet, resulting in a slightly greater difference between ME intake and total heat energy for the 60%C compared with the 20%C diet (11 vs. −8 kJ/kg of BW0.75). Intake of ME by lactating goats was greater for the 60%C than for the 20%C diet (18.6 vs. 16.3 MJ/d). Recovered energy in lactation from mobilized tissue tended to be greater for the 60%C than for the 20%C diet (8.44 vs. 6.55 MJ/d) and differed among stages of lactation (2.60, 1.59, and 1.13 MJ/d in early, mid, and late lactation, respectively). Recovered energy in tissue gain was similar among stages of lactation and between diets and was not different from 0. Efficiency of use of dietary ME for lactation differed among stages of lactation (59.5, 51.9, and 65.4% for early, mid, and late lactation, respectively) and tended to be greater for the 60%C than for the 20%C diet (64.2 vs. 54.9%). The efficiency of use of dietary ME for maintenance and lactation was similar among stages of lactation and was greater for the 60%C compared with the 20%C diet (64.3 vs. 60.9%). Predicted milk yield from National Research Council requirements was reasonably accurate. In conclusion, using data of nonlactating goats to study energy utilization for maintenance in lactation has limitations. Efficiency of energy use by lactating dairy goats consuming diets high in concentrate appears greater than that by goats consuming diets low in concentrate. Despite differences in nutrient requirement expressions, observations of this study support National Research Council recommendations of energy requirements of lactating dairy goats.

Maternal obesity markedly increases placental fatty acid transporter expression and fetal blood triglycerides at midgestation in the ewe

Obesity of women at conception is increasing, a condition associated with offspring obesity. We hypothesized that maternal obesity increases placental fatty acid transporter (FATP) expression, enhancing delivery of fatty acids to their fetuses. Sheep are a commonly utilized biomedical model for pregnancy studies. Nonpregnant ewes were randomly assigned to a control group [100% of National Research Council (NRC) recommendations] or obese group (OB, 150% of NRC) from 60 days before conception to 75 or 135 days of gestation (dG; term = 150 dG), when placental cotyledonary tissue was collected for analysis. Fetuses of OB ewes were markedly heavier (P < 0.05) on 75 dG than fetuses from control ewes, but this difference disappeared by 135 dG. Maternal obesity markedly increased (P < 0.05) cholesterol and triglyceride concentrations of both maternal and fetal blood. There is no difference in lipoprotein lipase mRNA expression between control and OB group at either gestational age. On 75 dG, the mRNA expression of FATP1 (P < 0.05), FATP4 (P = 0.08), and fatty acid translocase CD (cluster of differentiation) 36 (P < 0.05) proteins were more enhanced in cotyledonary tissue from OB than control ewes; consistently, protein expression of FATP1 and FATP4 was increased (P < 0.05). Similarly, on 135 dG, the mRNA levels of FATP1, FATP4, and CD36 were all higher (P < 0.05), but only FATP4 protein content was enhanced (P < 0.05) in OB cotyledonary tissue. Peroxisome proliferator-activated receptor (PPAR)-γ regulates the expression of FATPs. Both the mRNA expression and protein content of PPARγ were increased in OB cotyledonary in the midgestation. In conclusion, maternal obesity enhances the mRNA expression and protein content of FATPs in cotyledonary in the midgestation, which is associated with higher PPARγ content in cotyledonary.

The Effects of Replacing Inorganic with a Lower Level of Organically Complexed Minerals (Cu, Zn and Mn) in Broiler Diets on Lipid Peroxidation and Antioxidant Defense Systems

In this study, the effects of replacing inorganic copper, zinc and manganese with different levels of organic complexes of the same trace minerals on the lipid peroxidation and antioxidant defense systems in broilers were investigated. Two-hundred Ross-308 one-day-old broiler chickens were placed on controlled diets until 42 d of age. The experimental animals were divided into four groups comprising three experimental groups and one control group, each consisting of 50 chickens. All groups were also divided into five subgroups each containing 10 broiler chicks. The mineral content of the control group diet was controlled using a standard inorganic mineral premix with supplement levels and sources of trace minerals typical of commercial broiler diets according to the National Research Council (NRC) (containing 8 mg Cu as CuSO 4 , 40 mg Zn as ZnSO 4 , and 60 mg Mn as MnO, per kg). In the experimental diets, mineral premix was also comprised of inorganic formulations, except for those of Cu, Zn and Mn. Organically-complexed Cu, Zn, and Mn were separately added to the basal diet at 1/3 (L1), 2/3 (L2) and 3/3 (L3) levels with respect to the NRC recommendation, as Bioplex Cu ™ , Bioplex Zn ™ , Bioplex Mn ™ . At the end of the trial, the plasma Zn level significantly increased when the plasma Cu level significantly decreased (p<0.05) in chickens fed at 2/3 and 3/3 levels of organically complexed minerals. The liver trace mineral concentrations were significantly higher in chickens fed inorganic trace minerals in comparison to those fed organically-complexed minerals. The plasma malondialdehyde (MDA) level of experimental chickens was decreased in groups receiving levels of organic Cu, Zn and Mn in comparison to those fed inorganic forms (p<0.01). The erythrocyte superoxide dismutase (SOD) activity was higher in all groups receiving the organic mineral supplements in comparison to those fed inorganic forms (p<0.01). No differences were observed on either the erythrocyte catalase (CAT) activity or the plasma ceruloplasmin (Cp) levels, and the liver MDA levels and liver CAT and SOD activities in any of the groups that received the organic supplements of Cu, Zn, and Mn. It was concluded that supplementation of lower levels of organically-complexed copper, zinc, and manganese instead of their inorganic forms in diets had no negative effects on the antioxidant defense system in broilers.

Broiler responses to supplementation of phytase and admixture of carbohydrases and protease in maize–soyabean meal diets with or without maize Distillers’ Dried Grain with Solubles

1. This experiment investigated growth performance and nutrient utilisation responses of broilers to partial replacement of maize and soyabean meal in broiler diets with 100 g kg−1 maize Distillers’ Dried Grain with Solubles (mDDGS) as well as responses to supplementation of an admixture of carbohydrases and protease (XAP) or phytase individually or in combination in the diets. 2. A total of 288 one-day-old broilers were allocated to 8 treatments in a randomised complete block design and a 2 × 2 × 2 factorial arrangement of treatments. The three factors were two levels each of mDDGS (0 or 100 g kg−1), phytase (0 or 1000 FTU kg−1), and XAP (0 or 500 mg kg−1). 3. Each treatment had 6 replicate cages with 6 birds per replicate cage. The control diets were formulated to meet all nutrient requirements of broilers according to National Research Council recommendations of 1994, but were marginally deficient in non-phytate P and ME. 4. Weight gain and gain:food were higher in broilers receiving diets containing mDDGS. The coefficient of apparent ileal N digestibility was lower in diets with mDDGS. Phytase increased the coefficient of apparent ileal DM digestibility in all diets. 5. Phytase improved the coefficient of the apparent total tract DM retention independently of mDDGS and tended to improve the coefficient of apparent P retention in the diets without mDDGS. The enzymes were additive in their effects in the diets with mDDGS. Overall, the results showed that adding 100 g kg−1 mDDGS to a maize–soyabean meal diet had no negative effect on growth when energy and nutrient concentrations were similar to the maize–soyabean meal diet, and that phytase or an admixture of carbohydrases and protease individually or in combination modestly improved nutrient utilisation independently of mDDGS addition. Combination of the enzymes did not produce greater benefit than the use of phytase alone.