Evaluating agro-industrial by-products as dietary roughage source on growth performance of fattening steers

Silages from pineapple peel, sweet corn husk and cob mixed with bagasse and vinasse were evaluated to determine their chemical composition and fermentation characteristics as well as feeding performance in fattening steers. The experiment, which lasted 90 days, involved 48 fattening steers (264 ± 37.4 kg BW) randomly allocated to three diets. Treatments included: a control diet containing rice straw and molasses (T1); diet containing bagasse–vinasse mixture including sweet corn husk and cob silage (BS; T2); and diet containing bagasse–vinasse mixture including pineapple peel silage (BP; T3). All treatments included a commercial concentrate feed (13% CP) and ad libitum rice straw throughout the experiment. Results from chemical analysis showed that dry matter (DM) of BS was higher than BP (P < 0.05), whereas the protein content of BS and BP was similar (P > 0.05). For fermentation characteristics, pH in BP was lower than BS (P < 0.05); in addition, acetic and butyric acids in BS were higher than BP (P < 0.05). Findings from growth trial showed that total DM intake in steers fed T1 was higher compared to the other dietary treatments (P < 0.05), whereas the average BW gain was found to be grater in T3 steers (P < 0.05). As result from our findings, bagasse–vinasse mixture with pineapple peel silage appeared to be a viable feed ingredient in fattening steer diet and moreover it could become an economically feasible agro-industrial by-product for farmers.     

Behavioural effects of embryonic exposure to corticosterone in chickens

We tested the hypothesis that exposure of chick embryos to corticosterone leads to increased fear, reduced competitive ability, reduced ability to cross a barrier and reduced growth in juvenile chicks. Behaviour was studied in birds subjected to three different egg injection treatments: a negative control (no treatment of eggs), a positive control (100 μl sesame oil vehicle) and a corticosterone treatment (0.6 μg corticosterone in 100 μl sesame oil). Eggs were injected prior to incubation and the behaviour of chicks was studied during the first 4 weeks of life. Corticosterone treatment increased fear in chicks, as indicated by greater avoidance of an observer in the home pen at 2 weeks of age (P < 0.0001), reduced ability to cross a wall to access feed at 2 weeks of age (P < 0.05) and reduced ability to compete for a wormlike object at 4 weeks of age (P < 0.01). Treatment with corticosterone also reduced body weight at 1 week of age (P < 0.003) and 4 weeks of age (P < 0.04), but not at hatch (P < 0.28). The sesame oil vehicle reduced fear (P < 0.0001), but had no other significant effects. These results indicate that embryonic exposure to corticosterone leads to behavioural and growth deficits in chicks.     

Effect of corticosterone on growth and welfare of broiler chickens showing long or short tonic immobility

Tonic immobility (TI) test is commonly used to assess fear. Animals showing different TI durations demonstrate distinct behavior and biochemical responses to stress. However, less is known about how TI phenotype affects growth and welfare of domestic fowl. In this study, broiler chickens (Gallus gallus) were classified into short and long TI duration (STI and LTI) phenotypes and treated chronically with vehicle (CON) or corticosterone (CORT). STI broilers demonstrated significantly higher growth rate with higher breast muscle yield (P < 0.05) and liver weight relative to BW tended to be lower (P = 0.053), which was accompanied by higher serum concentration of CORT (P < 0.05) and uric acid (P < 0.01), but lower serum level of T4 (P = 0.01). CORT severely reduced body weight, as well as the relative weight of muscle, bursa of Fabricius and spleen (P < 0.001), but relative liver weight was increased (P < 0.001). CORT-treated chickens had reduced serum CORT, elevated heterophile/lymphocyte ratio, and increased serum levels of total and free T3. STI broilers displayed more preening behavior (P < 0.05), yet CORT elicited more walking behavior (P < 0.05). No difference was observed in the welfare assessment scores between STI and LTI phenotypes under basal situation, while LTI chickens showed significantly increased incidence of pad dermatitis compared to STI under CORT exposure. The results suggest that STI broilers demonstrate better growth performance and higher adaptability to stress compared to LTI chickens.     

Postpartum resumption of ovarian cycling activity in first-calf suckled beef cows exposed to familiar or unfamiliar bulls

The objective of this experiment was to determine if the proportion of first-calf suckled beef cows that resumed ovulatory cycles and the interval to resumption of ovarian cycling activity differ after exposure to either “unfamiliar” bulls or cows on d 35 postpartum, after exposure to either “familiar” bulls or cows for the first 30–32 d after calving. Fifty Angus × Hereford cows were stratified by calving date, calf BW, and calf sex by d 3 postpartum, and assigned to be exposed to familiar epididectomized bulls (BEF; n = 25) or familiar mature ovariectomized (OVX) cows (CEF; n = 25). On d 35 after calving, 12 BEF cows were assigned to be exposed to unfamiliar bulls (BEU); likewise, 12 CEF cows were assigned to be exposed to unfamiliar OVX cows (CEU). Cows were in their treatments for either 95 d (BEF and CEF) or 60 d (BEU and CEU) during the experiment. Blood samples were collected every third d from the beginning to the end of the experiment. A rise in progesterone concentration of >0.5 ng/mL in consecutive samples was used as the criterion for resumption of ovulatory cycles. Exposing cows to bulls on d 5 after calving and then switching a subset of these cows to be exposed to unfamiliar bulls 30–32 d later did not (P > 0.10) alter: (1) the proportion of cows that resumed cycling activity; and (2) postpartum interval to resumption of ovarian cycling activity compared to cows exposed to familiar bulls. However, 32% more (P < 0.05) cows exposed to bulls (BEF and BEU) resumed cycling activity by approximately 14.8 d before cows that were exposed to OVX cows (CEF and CEU). We conclude that the familiarity of first-calf cows to either bulls or ovariectomized cows, did not affect the postpartum occurrence of cycling activity or the interval from calving to resumption of ovulatory cycles. However, bull exposure, whether familiar or unfamiliar, stimulates first-calf cows to resume ovulatory cycles sooner after calving than if they are not exposed to bulls.     

Biochemical and histological impact of Vernonia amygdalina supplemented diet in obese rats

This study was carried out to evaluate the anti-obesity effect of Vernonia amygdalina Del. (VA) supplemented diet. VA leaf powder was fed at 5% and 15% to diet-induced obese rats for 4 weeks and its effect compared with orlistat (5.14 mg/kg p.o.), an anti-obesity drug. Food intake, body and organ weights, total body fat, some lipid components and amino transaminase activities in serum, hepatocytes and brain; as well as serum glucose, were measured during or at end of the study. Result showed respective decrease of 12.78% and 38.51% in body weight gain, of VA fed rats against 17.45% of orlistat at end of study (P < 0.05); but with no effect on food intake. Total body fat was lowered by 28.04% and 30.02% vs. obese control rats (CDC) (P < 0.05). Furthermore, serum triacylglycerol (TG), serum and brain total cholesterol (TCHOL), were down regulated at 15% VA supplementation (P < 0.05). Serum glucose which increased in obese rats by 46.26% (P < 0.05) vs. NC, indicating intolerance, was restored by VA (38.75% and 34.65%) and orlistat (31.80%) vs. CDC (P < 0.05). VA diet also exerted hepato-protection, via lowering serum alanine amino transaminase (ALT) (41.35% and 27.13%) and aspartate amino transaminase (AST) (17.09% and 43.21%) activities (P < 0.05). Orlistat had no effect on these enzymes. Histology of adipose tissue corroborated the changes on total body fat. We concluded that, diet supplemented with VA can attenuate dietary obesity as well as ameliorates the potential risks of hepato-toxicity and glucose intolerance associated with obesity.     

Partial replacement of barley grain for corn grain: Associative effects on lambs’ growth performance

Our objective was to study the positive effects of partial replacement of barley grain for corn in high concentrate diets on growth performance of growing lambs, and to determine the minimum amount of corn needed to produce such effects. Thirty-three male Awassi lambs weaned at 60 days of age were divided into three groups of 11 according to their live weight and offered three isonitrogenous diets. The control diet (B) contained 81 and 14% barley grain and wheat straw, respectively (DM basis). Corn grain replaced barley grain at 10 and 20% of dietary DM for low (LC) and high (HC) corn diets, respectively. Barley had a higher (P < 0.05) rate of digestion (11.5%/h) compared with corn (8.3%/h). The in vitro 30-h digestion extent was also higher (P < 0.05) for barley. The digestion rate for the B diet was higher (P < 0.05) compared with the HC diet, whereas the value for the LC diet was intermediate. Lambs fed LC and HC diets consumed more (P > 0.05) DM (average = 855 g/day) compared with lambs fed B diet (757 g/day). DM and CP digestibilities were similar among diets and averaged 67.0 and 64.2%, respectively. Final BW, BW change and average daily gain (ADG) for lambs fed HC were higher (P < 0.05) compared with B and LC. Moreover, lambs that consumed LC tended (P = 0.12) to grow faster than lambs fed B. Feed to gain ratio was lower (P < 0.05) for lambs fed HC (4.6) compared with B and LC (5.2). In summary, positive associative effects of partial replacement of barley with corn in high concentrate diets for fattening sheep were detected. However, a minimum of 20% replacement of dietary DM from barley with corn was needed to positively improve both performance and feed efficiency.     

Effects of feeding system on carcass and non-carcass composition of Churra Tensina light lambs

Thirty-eight single male lambs (3.6 ± 0.08 kg live weight at birth) were used to study the influence of feeding system on carcass and non-carcass composition of Churra Tensina light lambs. Treatments: indoor (IND), lambs housed indoors consuming concentrate ad libitum until weaning at 53 days of age, and ewes grazing 8 h a day without their offspring and receiving a supplement of barley meal after grazing; grazing (GR), ewes and lambs grazed continuously without concentrate and lambs were unweaned. When lambs reached 22–24 kg live weight they were slaughtered. Carcass and non-carcass composition was recorded. GR lambs displayed higher carcass shrink (P < 0.05) and lower dressing percentage (P < 0.01) than concentrate-fed lambs. IND lambs had more body fat mainly due to the heavier kidney (P < 0.001) and subcutaneous (P < 0.001) fat depots. Total non-carcass weight was not affected by treatment (P > 0.05), but red organ (heart, lung and trachea, thymus, liver, spleen, kidney, diaphragm, pancreas, gall bladder, bladder, and testicles and penis), digestive tract (stomach, small intestine and large intestine) and head, skin, and feet (HSF) weights differed between treatments (P < 0.05). IND lambs had heavier red organs and HSF (P < 0.05) although this difference disappeared when expressed as a percentage of empty body weight. Small intestine weight in grazing lambs was heavier (P < 0.001) and, consequently, the total digestive tract differed similarly (P < 0.01). Treatment influenced the weights (P < 0.05) of all joints except leg (P > 0.05), showing heavier joints for IND carcasses. The feeding system had a greater effect on subcutaneous fat (P < 0.001) than on intermuscular fat (P < 0.05) in most of the standardized joints. IND carcasses produced a greater proportion of muscle/bone in all joints, except neck, whereas GR produced a greater proportion of muscle/total fat due to the lower amount of fat recorded in this treatment. The percentage of fatty acids was not affected by treatment (P > 0.05) although the percentage of C18:3 was greater and the ratio of C18:2/C18:3 was lower in grazing-fed lambs. The absence of any effect of treatment on the fatty acid percentages may be influenced by the short raising period and by the similar amount of intramuscular fat in both treatments. It is concluded that light lambs reared under grazing conditions can produce carcasses of acceptable quality, due to the lower percentage of subcutaneous fat, but with a similar intramuscular fat content.     

Prevalence and loads of gastrointestinal parasites of goats in the communal areas of the Eastern Cape Province of South Africa

A longitudinal survey was conducted to determine the prevalence and loads of gastrointestinal parasites in goats raised by communal farmers of Qaukeni (QA) and Nkosana (NK) communities of Eastern Cape Province of South Africa between June 2007 and April 2008. One hundred and seventy one goats were weighed and had faecal samples collected from their recta in four seasons; cold-dry, hot-dry, hot-wet and the post-rainy seasons. The samples were examined by the modified McMaster technique for nematode egg types. Goats in QA weighed more (P < 0.05) than those in NK in the post-rainy, cold-dry and hot-dry seasons. However, in the hot-wet season, goats in NK had higher (P < 0.05) weights than those in QA. The most frequently detected gastrointestinal eggs were the strongyle egg type (68.4 ± 8.49 in QA and 96.1 ± 12.01 in NK), followed by coccidial oocysts (53.3 ± 8.76 in QA and 68.8 ± 8.00 in NK). The other identified nematodes were Strongyloides and Trichostrongylus egg types. Higher loads (P < 0.05) of strongyle eggs were observed in the hot-wet and post-rainy seasons, whilst the other egg types showed a peak in the hot-wet season. Strongyle egg counts were higher (P < 0.05) in NK compared to QA. The results indicate that strongyles are the major gastrointestinal egg types negatively affecting body weights of goats.     

Growth,carcass and cooked meat characteristics of lambs sired by Dorset rams heterozygous for the Callipyge gene and Suffolk and Texel rams

Dorset (D) rams heterozygous for the Callipyge gene were single—sire mated to non-carrier ewes to produce Callipyge heterozygous (CLPG, n = 49) and normal (D, n = 33) lambs. Suffolk (S) and Texel (T) rams were mated to similar ewes to produce non-carrier crossbred S (n = 55) and T (n = 52) lambs. Lambs were finished on a high-energy diet to a target live weight of 57 kg. Pre-slaughter weight was recorded for each lamb prior to its transfer and slaughter through a commercial facility. Hot carcass weight and kidney and pelvic fat (KPF) were recorded at slaughter. Chilled carcasses were measured then fabricated into trimmed retail cuts by plant personnel. Each cut was weighed, and two loin chops were collected from each carcass for later cooking. CLPG lambs had the highest dressing % (53.6 versus 49.8–50.6; P < 0.05). At the same cold carcass weight, CLPG lambs had larger longissimus muscle areas (19.5 cm² versus 14.0–15.2 cm² for the rest; P < 0.05), less KPF (0.9 kg versus 1.04–1.13 kg; P < 0.05), less carcass fat (P < 0.05 for all measures), shorter carcasses (60.7 cm versus 61.8–64.7 cm; P < 0.05), and heavier trimmed sirloins, legs, and shoulders than any other group (a11 P < 0.05). They were similar to S lambs in receiving the lowest mean USDA yield grade. CLPG carcasses had the highest proportion of carcass weight represented by trimmed cuts (70% versus 65.7–67.8% for the rest; P < 0.05), the highest proportion of trimmed cuts (62.2% versus 59.7–60.6% for the rest; P < 0.05) represented by the most valuable cuts (leg + loin + rack + sirloin), and the highest composite carcass value ($135.8 versus $125–129 for the rest; P < 0.05). CLPG lambs also produced loin chops with the highest mean Warner–Bratzler shear values (5.4 kg versus 2.8–2.9 kg for the rest; P < 0.05) and the highest % cooking loss (31% versus 29–29.6% for the rest; P < 0.05).     

Effect of substitution of groundnut with high glucosinolate mustard (Brassica juncea) meal on nutrient utilization,growth, vital organ weight and blood composition of lambs

Twenty-four 14-day-old weaner Avivastra (Russian Merino×Nali) male lambs were maintained for 180 days on ad libidum Cenchrus (Cenchrus ciliaris) hay and concentrate mixture (CM) contained groundnut meal (control) and mustard meal (MM group) as major protein source. The two CMs were isonitrogenous (21% CP) and isocaloric (2.78 Mcal ME kg⁻¹ DM), while, CM fed to MM group contained 24.6 mg glucosinolates g⁻¹ DM. Digestibility of nutrients was similar (P>0.05) in the two groups except for CP and hemicellulose, which was higher (P<0.05) in control. Urinary N loss was higher (P<0.01) in control than in MM group, whereas N retention (% of N intake and absorbed) was higher (P<0.01) in MM group compared to control. Dry matter (g kg⁻¹ BW) and glucosinolate intakes were higher in MM fed group, whereas DCP and ME intakes were similar (P>0.05) in the two groups. Average daily gain (ADG) was, however, 22% higher (P<0.01) in control than in MM group. Hemoglobin and albumin contents were lower (P<0.01) in MM group than in control. Serum thiocyanate content was 26.7 μg g⁻¹ in MM fed group, while it was not detected in control group. Thyroid weight was higher (P<0.01) while liver and kidney weights were lower (P<0.01) in MM group. Meat from dissected carcass of control group contained more protein and less fat, whereas the reverse was noticed in MM group. It is concluded that feeding mustard meal as protein supplement reduced growth rate and induced iodine deficiency. Carcass of lambs fed mustard meal had more fat and less protein.     

Apolipoprotein A-I inhibits chemotaxis,adhesion, activation of THP-1 cells and improves the plasma HDL inflammatory index

The anti-inflammatory effects of high density lipoprotein (HDL) are well described, however, such effects of Apolipoprotein A-I (ApoA-I) are less studied. Building on our previous study, we further explored the mechanism of anti-inflammatory effects of ApoA-I, and focused especially on the interaction between monocyte and endothelial cells and plasma HDL inflammatory index in LPS-challenged rabbits. Our results show that ApoA-I significantly decreased LPS-induced MCP-1 release from THP-1 cells and ox-LDL-induced THP-1 migration ratio (P < 0.01, respectively). ApoA-I significantly decreased sL-selectin, sICAM-1 and sVCAM-1 release (P < 0.01, P < 0.01, P < 0.05, respectively) from LPS-stimulated THP-1 cells. Furthermore, ApoA-I significantly inhibited LPS-induced CD11b and VCAM-1 expression on THP-1 cells (P < 0.01, P < 0.05, respectively). ApoA-I diminished LPS-induced mCD14 expression (P < 0.01) and NFκB nuclear translocation in THP-1 cells. After single dose treatment of ApoA-I, the value of plasma HDL inflammatory index in LPS-challenged rabbits was improved significantly (P < 0.05). These results suggest that ApoA-I can inhibit chemotaxis, adhesion and activation of human monocytes and improve plasma HDL inflammatory index with presenting beneficial anti-inflammatory effects.     

Validation of an algorithm for real-time measurement of sheep activity in confinement by recording movement within a commercial weighing crate

This study reports a method of measuring sheep activity in confinement based on recording movement of sheep during weighing. The aim was to show that an algorithm to analyse continuous weight records could be used to measure activity quickly and efficiently using commercial weighing equipment and that this measurement is related to animal productivity, specifically liveweight. A prototype method required magnetic switches on the weighing crate to record gate positioning and enclosure of the animal, with data analysis subsequent to the completion of weighing. The method reported here does not require additional equipment, instead using a computer program to analyse weights in real-time to record the degree of sheep movement. The result is summarised as the coefficient of variation of the weight over a period of 8–20 s and reported as an activity score.The real-time method had a higher repeatability (P < 0.05) than the prototype method and gave a stronger association with liveweight with heavier lambs and heavier young sheep being less active under confinement at 6 months and 18 months, respectively (P < 0.05).These findings indicate that a simple system could be developed enabling real-time reporting of activity scores during normal weighing.     

Fluctuations in energy-related metabolites during the peri-parturition period in Lori-Bakhtiari ewes

This study describes the fluctuations in serum energy-related metabolites during a period of 2 weeks before, to 2 weeks after parturition in Lori-Bakhtiari ewes. The effect of parity was also studied. Blood profiles were determined in 60 healthy pregnant ewes with single (n = 30) and twin (n = 30) lambings. Blood was collected from each ewe on days 14 and 7 prepartum, and days 7 and 14 postpartum to determine the serum non-esterified fatty acid (NEFA), β-hydroxybutyrate (BHBA), glucose, cholesterol, blood urea nitrogen (BUN) and calcium (Ca) levels. The age of the ewes had no significant effect on the energy metabolism indicators. Serum NEFA, BHBA, glucose, BUN and calcium concentrations recorded peak levels 7 days before parturition. However, NEFA and BHBA recorded significant changes (P < 0.05) during the peri-parturition period. All metabolites changed significantly in ewes carrying twin-bearing ewes, compared to single-bearing ewes. Serum BHBA concentrations recorded positive correlations with the serum NEFA (P < 0.01) and cholesterol (P < 0.05), while blood glucose had negative correlations (P < 0.01) with NEFA, BHBA and Ca. Blood NEFA and BHBA recorded positive correlations (P < 0.05) with the BUN levels and negative correlations (P < 0.05) with Ca. The results showed that blood NEFA and BHBA levels are sensitive indicators of the energy balance during the peri-parturition period in ewes.     

Fluoxetine, 17-β estradiol or folic acid combined with intra-lateral septal infusions of neuropeptide Y produced antidepressant-like actions in ovariectomized rats forced to swim

Folic acid is antidepressant, either alone or combined with several antidepressant drugs. However, the antidepressant-like actions of folic acid combined with intra-lateral septal (LSN) infusions of neuropeptide Y (NPY) in the forced swimming test (FST) have not been tested before. Thus, systemic injections of fluoxetine (20.0 mg/kg, P < 0.05; s.c.) or 17-β estradiol (10.0 μg/rat, P < 0.05; s.c.) or oral administrations of folic acid (50.0 mg/kg, P < 0.05; 75.0 mg/kg, P < 0.05) or NPY intra-LSN (3.0 μg, P < 0.05; 3.5 μg, P < 0.05) reduced immobility of ovariectomized Wistar rats. Subthreshold doses of: folic acid (25.0 mg/kg) or 17-β estradiol (5.0 μg/rat, P < 0.05) or fluoxetine (15.0 mg/kg, P < 0.05; s.c.) combined with subthreshold doses of NPY (2.5 μg/rat, P < 0.05; intra-LSN) and these combinations produced antidepressant-like actions; which were canceled by BIBP 3226 (a NPY-Y1 receptor antagonist). It is concluded that folic acid produced antidepressant-like effects probably through the participation of the NPY Y1 receptors found in the lateral septal nuclei.     

Effects of scrotal insulation in Nellore bulls (Bos taurus indicus) on seminal quality and its relationship with in vitro fertilizing ability

The objectives of this study were to assess the effects of induced testicular degeneration in Bos taurus indicus (Nellore) bulls on changes in seminal characteristics and fertilizing ability of sperm. Four Nellore bulls (30–36-month-old, 500–550 kg) with good seminal quality (>80% motile and morphologically normal sperm) had scrotal insulation applied for 5 d. Semen was collected by electroejaculation and cryopreserved at the pre-insulation moment, and 7, 14, and 21 d after insulation was removed. Gross motility, vigor of sperm movement (1–5), acrosome integrity, sperm morphology (phase-contrast microscopy), nuclear vacuoles and abnormal chromatin (Feulgen-stain) were determined after sperm preparations for in vitro fertilization (IVF). Prior to IVF, sperm were separated using a Percoll gradient (45% and 90%). Normal sperm decreased (P < 0.05) 14 and 21 d after insulation was removed. On 14 and 21 d, the incidence of head defects (9.7 ± 0.6 and 17.0 ± 0.8, respectively; mean ± S.E.M.) was higher (P < 0.05) in agreement with the incidence of nuclear vacuoles (14.0 ± 5.0 and 12.3 ± 2.3) and abnormal chromatin (24.4 ± 7.2 and 30.8 ± 2.8). Although the frequency of cleaved oocytes decreased only on 21 d (P < 0.05), blastocyst rates were lower (P < 0.05) than pre-insulation on 14 and 21 d. In regression analyses, only nuclear vacuoles, head defects and intact acrosome accounted for differences in cleavage (R² = 0.38, 0.48, and 0.30, respectively) and blastocyst rates (R² = 0.35, 0.37, and 0.44). Abnormal chromatin was associated only with blastocyst rates (R² = 0.35). In conclusion, blastocyst rate was more sensitive than cleavage rate and the assessment of nuclear integrity is recommended to predict the fertilizing ability of bull sperm.     

Solar-dried citrus pulp as an alternative energy source in lamb diets: Effects on growth and carcass and meat quality

Twenty-seven Italian Merino male lambs, equally divided into three groups, were used to evaluate the effects of the dietary incorporation of citrus pulp dried by exploiting solar energy (solar-dried citrus pulp, SDCP) on growth and carcass and meat quality. The diet consisted of oat hay and concentrate, with a hay/concentrate ratio of 30/70. The concentrates of the SDCP-0, SDCP-30 and SDCP-45 groups were formulated to incorporate 0, 30 and 45% of SDCP, respectively, as partial replacement of cereal grain. The lambs were slaughtered after 80 days of feeding (at 150 days of age) and carcass and some meat quality parameters were measured. No significant differences were found in final live-weights and average daily gains among the groups. Lambs in the SCP-45 group showed impaired (P < 0.001) feed conversion efficiency, lower (P < 0.05) carcass weight and lower (P < 0.05) dressing percentage compared with the other two groups. The majority of SDCP-45 carcasses (88.9%) fell within the bis-grid EU system (light carcasses weighing ≤13 kg), while most SDCP-0 (66.7%) and SDCP-30 (77.8%) carcasses fell within the SEUROP system (heavy carcasses weighing >13 kg). The bis-grid EU carcass classification highlighted how all carcasses produced an ideal meat colour and fatness, while the SEUROP grid carcass classification showed good carcass conformation and optimal fatness in the SDCP-0 and SDCP-30 groups. Carcass compactness was found to be significantly higher (P < 0.05) in groups SDCP-0 and SDCP-30 compared to group SDCP-45. The histological dissection of the pelvic limb evidenced a higher (P < 0.01) adiposity in the SDCP-0 and SDCP-30 groups. Chemical analysis of meat did not differ significantly among the groups. Physical analysis of the meat showed higher (P < 0.05) redness value and higher (P < 0.05) chroma value in the SDCP-0 and SDCP-30 groups. Based on the results of the present study it may be concluded that SDCP can be incorporated in concentrate mixtures for fattening lambs at levels equal to 30% without adverse effects both in growth and slaughter performances as well as in carcass and meat quality and, at this replacement level, it appears also to be economically convenient.     

Acute effects of a dopamine/norepinephrine reuptake inhibitor on neuromuscular performance following self-paced exercise in cool and hot environments

Dopamine/norepinephrine (DA/NE) reuptake inhibitors have been used to manipulate the central mechanisms affecting arousal and motivation during exercise. Eight healthy, physically active males performed 30 min fixed-intensity cycling at 50% W_max followed by 30 min of self paced time trial (TT) with each section interspersed with a 30 s maximal sprint at 9, 19 and 29 min. The DA/NE re-uptake inhibitor administered was bupropion (BUP) versus a placebo (PLA) in either warm (32 °C, BUP32 or PLA32) or moderate (20 °C; BUP20, PLA20) ambient conditions. Core and skin temperature, heart rate and perceptual responses, neuromuscular and hormonal measures were assessed at multiple times throughout the trials and post exercise. Time trial performance remained unchanged across conditions (12.7–13.1 km) although core temperature was elevated in the fixed intensity section of the trials for BUP32 and BUP20 but continued to rise only in BUP32 during the time trial reaching 38.6 °C (P<0.05). NE increased in all conditions from pre-exercise with BUP32 values peaking at the end of TT to 1245.3±203.1 pg/mL (P<0.05) compared to the other conditions. Neuromuscular responses were similar among conditions although peak force was significantly reduced from pre (262±31 N) to post (202±31 N, P<0.05) exercise along with contraction duration (22%, P<0.05) in BUP20. We conclude that DA/NE re-uptake inhibitors influenced thermoregulation in the heat but not exercise performance. DA/NE re-uptake inhibitors are likely to act centrally to override the inhibitory signals for the cessation of exercise with these drugs acting peripherally to reduce the twitch characteristics of skeletal muscle in cooler conditions.     

Behavioral and reproductive responses of female opossums to volatile and nonvolatile components of male suprasternal gland secretion

Female gray short-tailed opossums (Monodelphis domestica) lack an estrous cycle and are induced into estrus by exposure to a pheromone in male scent marks. Behavioral and physiological responses of females to the volatile and nonvolatile components of scent marks were examined in two experiments. Young females (n = 9) were tested prior to and during their first estrus for behavioral responses to scent marks, collected on a 7-ml glass vial rubbed over the suprasternal gland of a mature male. The response to volatile components of the scent mark, recorded when marked and unmarked vials were covered with a perforated shield, was compared to the response to these vials when unshielded. Estrous females nuzzled the shields over marked vials (55.8 ± 8.5 nuzzles/10 min) more than the shielded clean vial (10.9 ± 2.4) (P < 0.05); a similar response was observed in anestrous females. Nuzzling of unshielded, scent-marked vials was higher (P < 0.05) during anestrus than in the same females when in estrus. The role of nonvolatile pheromones in reproductive activation was tested in adult females (n = 11) exposed for up to 14 days to a shielded, marked vial or to an unshielded, marked vial in a crossover design. All females exposed to unshielded vials expressed estrus, and 10 copulated. Only 2 females expressed estrus (significantly fewer, P < 0.05), when exposed to shielded marked vials, and neither copulated. These results demonstrate that females detect and respond behaviorally to both volatile and nonvolatile components of male suprasternal gland secretion, but the estrus-inducing pheromone in these secretions is nonvolatile.     

The use of a mirror reduces isolation stress in horses being transported by trailer

Horse trailers are a common form of transportation for horses and ponies and often require the animal to travel alone or with a single companion. The current study investigated the effect of transporting horses alone, in company or with an acrylic safety mirror (measuring 81 cm × 61.5 cm) that provided surrogate companionship. The behavioural and physiological responses of 12 mature horses during a 30-min journey by trailer under the three treatments were compared. Behaviours (vocalisation, eating, head-tossing, pawing, and head-turning) were recorded. In order to assess circulatory changes that occur as part of the response to transport, heart rate (HR), rectal (T_r) and ear-pinna (T_p) temperatures were recorded. When travelling with a live companion significantly less time was spent vocalising (p < 0.001), head-turning (p < 0.001), head-tossing (p < 0.01) and pawing (p < 0.01); eating behaviour increased (p < 0.05). Physiological responses (increases in HR and T_r and decreases in T_p) were also significantly reduced when travelling with a live companion (p < 0.01). Travelling with the mirror did not significantly affect physiological responses compared with travelling alone, but the rise in T_r and fall in T_p was reduced (p = 0.052 and p = 0.051, respectively) and can be considered a trend. When travelling with a mirror significantly less time was spent turning the head (p < 0.01), vocalising (p < 0.05) and head-tossing (p < 0.05); eating behaviour increased (p < 0.05). The only significant difference between travelling with a live companion and a mirror was that the time spent turning the head round was less with a live companion (p < 0.05). The provision of surrogate companionship in the form of a mirror was found to be preferable to travel alone, but where possible a live companion is recommended. Isolation during transportation was found to suppress feeding behaviour. Although peripheral blood flow (T_p) has been used to assess transport stress in other species it has not previously been used in the horse. Further evaluation of this non-invasive measure is now required.     

Effects of selenium compounds on proliferation and epigenetic marks of breast cancer cells

Breast cancer is a global public health problem and the most frequent cause of cancer death among women. Mammary carcinogenesis is driven not only by genetic alterations but also by epigenetic disturbances. Because epigenetic marks are potentially reversible they represent promising molecular targets for breast cancer prevention interventions. Selenium is a promising anti-breast cancer trace element that has shown the modulation of DNA methylation and histone post-translational modifications in other malignancies. This study aimed to evaluate the effects of selenium compounds [methylseleninic acid (MSA) and selenite] on cell proliferation and death, expression of the tumor suppressor gene RASSF1A and epigenetic marks in MCF-7 human breast adenocarcinoma cells. Treatment with MSA or selenite markedly inhibited (P < 0.05) in a dose-dependent manner the proliferation of MCF-7 cells. MSA induced (P < 0.05) G2/M cell arrest while selenite presented the opposite effect. Regarding cell death induction, MSA acted mainly by inducing apoptosis (P < 0.05), while selenite only induced necrosis (P < 0.05). Furthermore selenite, but not MSA, markedly induced (P < 0.05) cytotoxicity and increased (P < 0.05) RASSF1A expression. Both selenium compounds inhibited (P < 0.05) DNMT1 expression. MSA decreased (P < 0.05) H3K9me3 and increased (P < 0.05) H4K16ac, while selenite decreased (P < 0.05) this latter histone mark. To the best of our knowledge this is the first report showing that selenite and MSA modulate epigenetic marks specifically in breast cancer cells. Our data reinforce the anti-breast cancer potential of selenium that is dependent on its chemical form. Furthermore the data show that epigenetic mechanisms represent relevant molecular targets involved in selenium inhibitory effects in breast cancer cells.