The effect of sea transport from Ireland to the Lebanon on inflammatory,adrenocortical, metabolic and behavioural responses of bulls

The objective was to investigate the effect of sea transport on the physiological, behavioural and performance responses of bulls. One-hundred and eleven bulls (mean body weight (standard error of the mean) 429 (5.7 kg)) were randomly assigned to one of three treatments; control (C; n = 54) bulls were housed in 6 pens at Teagasc, Grange Research Centre at a stocking density of (1), 1.7 m²/head (C1.7; 3 pens) and (2), 3.4 m²/head (C3.4; 3 pens) and (3), transported (T) bulls (n = 57) were penned at a space allowance of 1.7 m²/head (6 pens) and allocated to one of five decks on the shipping vessel. C and T bulls were subjected to the same live weight (d −2), blood sampling and rectal temperature (d −1) measurements pre-transport and on d 3, d 6, d 9 and d 11 of the study. T bulls had greater (P < 0.05) live weight gain (+4.4%) compared with C1.7 bulls (−2.0%) and C3.4 (+0.13%)). Time spent lying was greater (P < 0.05) among C1.7 and C3.4 bulls (9.9% and 53.3%, respectively) compared with T bulls (45.8%). Rectal body temperature was not different (P > 0.05) among treatment groups throughout the study. At d 11, neutrophil % was greater (P < 0.05) in transported bulls on decks 1, 2, 4 and 5 compared with C1.7 and C3.4 treatments. Plasma cortisol concentrations were not different (P > 0.05) between control and transported bulls. Plasma creatine kinase (CK) activity was lower (P < 0.05) among C3.4 and T bulls on decks 2, 3, 4 and 5 compared with d 3 values. In conclusion, the welfare of bulls transported by sea on the sea journey was not adversely affected. Housing control bulls at a reduced space allowance (1.7 m²) had a negative effect on live weight gain.     

Rough Agave Flowers as a Potential Feed Resource for Growing Goats

The objective of this study was to evaluate the effect of different levels of rough agave (Agave scabra Ortega) flowers on dry matter intake (DMI), average daily gain (ADG), volatile fatty acid (VFA) production in the rumen, and particular serum metabolites and minerals of native × dairy growing goats (Capra hircus L.). Forty female goats with an initial weight of 11.1 ±  kg (mean ± SD) were used in a completely randomized design experiment that lasted for 84 d. Goats were fed a completely mixed ration (30% roughage, 70% ground corn [Zea mays L.] and soybean [Glycine max {L.} Merr] meal). Treatments consisted of offering goats (4 pens · group⁻¹, 2 goats · pen⁻¹) air-dry rough agave flowers, which replaced alfalfa (Medicago sativa L.) hay at 0% (control; T0), 25% (T25), 50% (T50), 75% (T75), and 100% (T100) of the of the roughage portion of the diet. Values of nutritional parameters for rough agave flowers were in vitro organic matter digestibility, 493 g · kg⁻¹; crude protein, 115 g · kg⁻¹; and metabolizable energy, 6.29 MJ · kg⁻¹ DMI. There were differences (P < 0.05) in ADG (range, 108–155 g · d⁻¹) between diets. Goats fed T0 had higher (P < 0.05) gains than goats fed T50 and T100. DMI was not affected by dietary treatments (range, 3.4% to 3.6% of body weight). Feed conversion ratio (FCR, defined as DMI/ADG) increased (P < 0.05) 27% with total substitution of alfalfa by rough agave flowers, in comparison with T0. Lower (P < 0.05) values of total VFA were obtained with T100, in comparison with all other dietary treatments. These results demonstrated that totally replacing alfalfa with rough agave flowers in diets did not affect DMI but decreased AGD and compromised FCR. Thus, rough agave flowers have the potential to partially replace alfalfa in diets for growing goats.     

Stocking Rate and Fuels Reduction Effects on Beef Cattle Diet Composition and Quality

An experiment was conducted to evaluate the influence of forest fuels reduction on diet quality, botanical composition, relative preference, and foraging efficiency of beef cattle grazing at different stocking rates. A split plot factorial design was used, with whole plots (3 ha) being fuel reduced or no treatment (control), and split plots (1 ha) within whole plots were grazed to three levels of forage utilization; (low) 3 heifers · ha^?1, (moderate) 6 heifers · ha^?1, (high) 9 heifers · ha^?1, with a 48-h grazing duration. Grazing treatments were applied in August of 2005 and 2006. Cattle diet composition and masticate samples were collected during 20-min grazing bouts using six ruminally cannulated cows in each experimental unit. Relative preference indices indicated a strong preference for grass regardless of treatment and stocking rate. Grass consumption was lower in control pastures (P < 0.05) and tended (P < 0.095) to decrease with increased stocking rates. Shrub use was higher in control pastures displaying a quadratic effect (P < 0.05) due to stocking, whereas shrub use increased with stocking rate across all treatments. Cattle grazing control pastures consumed diets higher in crude protein compared to cattle grazing treated pastures (P < 0.05). In vitro dry matter digestibility values were lower (P < 0.05) in control sites and tended (P = 0.10) to decrease with increased stocking rates. In both control and treated pastures, bites per minute and grams consumed per minute declined (P = 0.003) with increased stocking, indicating foraging efficiency of cattle decreases with increased stocking rates. Our data indicated cattle grazing late season grand fir habitat types have a strong preference for grasses regardless of treatment or stocking rate. However, as stocking rate increased in both control and treated pastures, grass consumption decreased, shrub consumption increased, and foraging efficiency decreased.     

Systemic and local immune response in pigs intradermally and intramuscularly injected with inactivated Mycoplasma hyopneumoniae vaccines

The systemic and respiratory local immune response induced by the intradermal administration of a commercial inactivated Mycoplasma hyopneumoniae whole-cell vaccine (Porcilis^® MHYO ID ONCE – MSD AH) in comparison with two commercial vaccines administered via the intramuscular route and a negative control (adjuvant only) was investigated. Forty conventional M. hyopneumoniae-free pigs were randomly assigned to four groups (ten animals each): Group A = intradermal administration of the test vaccine by using the needle-less IDAL^® vaccinator at a dose of 0.2 ml; Group B = intramuscular administration of a commercially available vaccine (vaccine B); Group C = intramuscular administration of the adjuvant only (2 ml of X-solve adjuvant); Group D = intramuscular administration of a commercially available vaccine (vaccine D). Pigs were vaccinated at 28 days of age. Blood and bronchoalveolar lavage (BAL) fluid samples were collected at vaccination (blood only), 4 and 8 weeks post-vaccination. Serum and BAL fluid were tested for the presence of antibodies by ELISA test. Peripheral blood monomorphonuclear cells (PBMC) were isolated to quantify the number of IFN-γ secreting cells by ELISpot. Moreover, cytokine gene expression from the BAL fluid was performed. Total antibodies against M. hyopneumoniae and specific IgG were detected in serum of intradermally and intramuscularly (vaccine B only) vaccinated pigs at 4 and 8 weeks post-vaccination. M. hyopneumoniae specific IgA were detected in BAL fluid from vaccinated animals (Groups A and B) but not from controls and animals vaccinated with the bacterin D (p < 0.05). Significantly higher gene expression of IL-10 was observed in the BAL fluid at week 8 post-vaccination in the intradermally vaccinated pigs (p < 0.05). The results support that the intradermal administration of an adjuvanted bacterin induces both systemic and mucosal immune responses. Moreover, the intramuscularly administered commercial vaccines each had a different ability to stimulate the immune response both systemically and locally.     

Evaluation of peripheral lymphocytes after weaning and vaccination for Mycoplasma hyopneumoniae

This study evaluated immune cell populations in pigs following weaning and vaccination for Mycoplasma hyopneumoniae. Piglets (n = 24) were weaned (day 0) at 16 (±1) days of age, and randomly assigned to the vaccination group (n = 16) or control group (n = 8). Complete blood cell counts, flow cytometry and serology were completed for blood samples collected on days 0 (within hours of weaning), 3, 7, 14, 30 and 60. The M. hyopneumoniae S:P ratios (sample optical density: positive control optical density) were negative in the vaccination group until days 30 and 60, when the S:P ratios were 1.3 and 1.0, respectively. Control animals remained serologically negative. The percentage of CD4⁺ T cells was less (P < 0.01) in control pigs than vaccinated pigs at day 3. In contrast, numbers of CD8⁺ and CD4⁺CD8⁺ T cells were greater (P < 0.01) in control pigs than in vaccinated pigs at days 3 and 7. After day 7, few differences in immune cell types were evident between the groups. Differences in lymphocyte populations could not be solely attributed to vaccination, due at least in part, to the confounding influence of weaning. It was difficult to distinguish the influence of vaccination from the impact of weaning on peripheral immune cell populations.     

A cross-sectional study of risk factors associated with pulmonary lesions in pigs at slaughter

A cross-sectional study was conducted to identify herd-level factors that may influence the prevalence and severity of macroscopically visible pulmonary lesions in pigs at slaughter. Data were collected following abattoir inspection of 50 randomly-selected batches of 6335 pigs and by interviewing the producers. Macroscopic lung lesions were identified and scored semi-quantitatively in ?80 pigs/herd and the prevalence of pleuritis and pneumonia was 20.76% and 23.85%, respectively. Following multivariable analysis, the seroprevalence of Actinobacillus pleuropneumoniae (P < 0.001) and Mycoplasma hyopneumoniae (P = 0.018) and the number of pigs/nursery pen (P = 0.023) were positively associated, whereas average weaning age was negatively associated (P = 0.001) with the pleuritis score. Risk factors associated with a higher prevalence of pneumonia were the presence of pleuritis (P = 0.001) and the frequent purchasing of pigs (P = 0.020). The findings of this study indicate that the prevalence of pleuritis and pneumonia remains high in Belgium and management factors are central to disease control.     

Evaluation of the risk of transmission of Trichinella in pork production systems in Argentina

Recently, there has been interest in programs that certify pork production practices that minimize the risk of exposure of pigs to Trichinella spiralis. Certification might be useful for reducing the risk of human trichinellosis from pork in Argentina, but more information is needed on pig production practices and sources of Trichinella infection in Argentinian pigs. In this study, 21 pig farms were assessed for Trichinella infection including some farms using total and partial confinement management, and others with pigs raised exclusively outdoors. A total of 3224 muscle samples were collected from pigs raised on these farms and tested to determine the presence of T. spiralis larvae by artificial digestion. Serum samples from the same 3224 pigs were tested for antibodies to T. spiralis by ELISA. For each farm, a questionnaire was completed summarizing information about management factors and this information was used to assess risk factors for exposure of T. spiralis. Based on the results, pigs raised outdoors were more likely to be infected than pigs raised in total or partial confinement (p ≤ 0.05). Pigs fed waste products containing meat were 12.5 times more likely to be infected than pigs not fed waste containing meat (p < 0.01). The role played by rats in transmission of Trichinella is unclear; however, on farms with evidence of wild animals and access of pigs to wildlife carcasses, the prevalence of Trichinella infection was significantly higher. All pigs raised under good hygienic and sanitary conditions were negative for Trichinella infection by both artificial digestion and ELISA.     

Relevance of ovarian follicular development to the seasonal impairment of fertility in weaned sows

A field study was conducted to estimate seasonal differences in follicular development in weaned sows and to evaluate the implication of these differences on seasonal infertility. A total of 110 sows were selected at weaning during winter–spring (WS, n = 58) and summer–autumn (SA, n = 52). Ovaries were scanned once daily from weaning to the onset of oestrus and twice daily from then until ovulation. Six sows during WS were removed from study for not showing growing follicles at weaning. Oestrus was evaluated twice daily from day 1 after weaning to day 14 post-weaning. One of 52 (1.9%) sows in WS and 9/52 (17.3%) in SA showed no signs of oestrus within 14 days of weaning (P < 0.05). The diameters of the follicles at weaning, at the onset of oestrus and just before ovulation were smaller (P < 0.01) in SA sows than in WS sows. There were fewer follicles in SA sows than in WS sows just before ovulation (P < 0.05). Fifty of 51 (98.0%) sows in WS and 31/43 (72.1%) sows in SA experienced a weaning-to-oestrus interval (WOI) of 3–6 days (P < 0.05). Fifty-one of 52 (98.1%) sows in WS and 43/52 (82.7%) sows in SA were inseminated; the percentage of pregnant sows that failed to farrow was lower in WS (1/51, 2.0%) than in SA (5/43, 11.6%; P < 0.05). The percentage of farrowed sows was greater in WS (46/51, 90.2%) than in SA (32/43, 74.4%; P < 0.05). Sows in WS had on average 1.5 more piglets than sows in SA (P < 0.05). Sows with a WOI of 3–6 days had lower rates of pregnancy losses (P < 0.05) and higher farrowing percentages (P < 0.01) than those with a WOI > 6 days, irrespective of season.     

Supplementing Guinea grass with fresh sweet potato foliage for milk production by Bunaji and N'Dama cows in early lactation

Forage from three sweet potato cultivars (A = TIS-87/0087; B = TIS-8164; C = TIS-2532.OP.1.13 at 30% daily dry matter intake), dried brewers' grains (DBG) and cottonseed meal (CSM) each at 2.5 kg were supplemented to Guinea grass (GG) to form four diets: Diet A = GG + TIS-87/0087; Diet B = GG + TIS-8164; Diet C = GG + TIS-2532.OP.1.13, and Diet D = GG + DBG + CSM (as control). Treatments were assigned as 4 × 4 Latin squares design over 60 days (10-day adaptation and 5-day sampling) using Bunaji and N'Dama cows in early lactation. The 48-h rumen dry matter (DM) degradation ranged (P < 0.01) from 407 g kg^? 1 DM for GG to 791 g kg^? 1 DM for sweet potato cultivar TIS-87/0087. Bunaji dry matter intake varied (P < 0.05) between 7.1 kg day^? 1 in Diet B and 8.9 kg day^? 1 in Diet D, but was similar (P > 0.05) among diets for the N'Dama cows. The metabolisable energy (ME) intakes were higher for Diet D although, it recorded the least efficiency of ME utilization for milk production. Milk yields were significantly (P < 0.01) higher in the Bunaji than the N'Dama cows, which is typical of their true breed differences. Total solids, ash, protein, fat, and sugar contents of the milk were similar among diets for both cow breeds, except Bunaji ash contents that ranged (P < 0.05) from 0.77 g 100 g^? 1 for Diet B to 0.83 g 100 g^? 1 for Diet D. The results suggest that sweet potato forage could be utilized as whole or partial replacement for DBG and CSM to save cost under smallholder farming systems.     

Effect of Lactation Diet Fat Level on Sow and Litter Performance

The primary objective of this study was to determine the effects of supplemental dietary fat during lactation on sow BW, sow backfat thickness, sow feed consumption, litter size, and pig growth rate. Dietary treatments included 0, 3, 6, and 9% supplemental low acid yellow fat in a traditional corn-soybean meal basal lactation diet. A total of 160 Landrace and crossbred sows (approximately 40 per treatment) were included in the study. Sows fed 3 and 6% supplemental fat had greater (P<0.10) average backfat thickness at weaning. Sow weight change and feed consumption were inconsistent among dietary fat levels. Dietary fat level during lactation did not affect number of pigs born alive or number of stillborns. However, the 9% fat level was associated with more mummified pigs at birth. Number of pigs weaned was greater for the 0% supplemental fat than for the 9% fat level. The largest average pig weights at 21 (5.8±0.29 kg) and 28 (7.48±0.38) d of age were those from sows fed the 3% added fat diet. Sows with ≤25.4 mm backfat at farrowing had more pigs born alive (P<0.05), had less backfat at 21 and 28 d of lactation (P<0.05), and consumed more feed during wk 2 and 3 of lactation. Of all sows fed the control diet, sows with >25.4 mm backfat at farrowing consistently had heavier pigs throughout the lactation phase (P<0.05). Backfat loss during lactation was lower (P<0.05) for sows with ≤25.4 mm at farrowing within all dietary treatments. Consistent significant differences were not observed in sow weight loss or feed consumption between low and high backfat sows for each dietary treatment. Sow backfat loss during lactation is dependent on body condition at farrowing, in that, fatter sows at farrowing have greater backfat loss during lactation. Sows with ≤25.4 mm of backfat at farrowing responded to added dietary fat treatments and produced heavier pigs throughout the lactation period.     

Vaccination with a genotype 1 modified live vaccine against porcine reproductive and respiratory syndrome virus significantly reduces viremia,viral shedding and transmission of the virus in a quasi-natural experimental model

The present study assessed the efficacy of vaccination against genotype 1 porcine reproductive and respiratory syndrome virus (PRRSV) in terms of reduction of the transmission. Ninety-eight 3-week-old piglets were divided in two groups: V (n = 40) and NV (n = 58) that were housed separately. V animals were vaccinated with a commercial genotype 1 PRRSV vaccine while NV were kept as controls. On day 35 post-vaccination, 14 NV pigs were separated and inoculated intranasally with 2 ml of a heterologous genotype 1 PRRSV isolate (“seeder” pigs, SP). The other V and NV animals were distributed in groups of 5 pigs each. Two days later, one SP was introduced into each pen to expose V and NV to PRRSV. Sentinel pigs were allocated in adjacent pens. Follow-up was of 21 days. All NV (30/30) became viremic after contact with SP while only 53% of V pigs were detected so (21/40, p < 0.05). Vaccination shortened viremia (12.2 ± 4 versus 3.7 ± 3.4 days in NV and V pigs, respectively, p < 0.01). The 50% survival time for becoming infected (Kaplan–Meier) for V was 21 days (CI_95% = 14.1–27.9) compared to 7 days (CI_95% = 5.2–8.7) for NV animals (p < 0.01). These differences were reflected in the R value as well: 2.78 (CI_95% = 2.13–3.43) for NV and 0.53 (CI_95% = 0.19–0.76) for V pigs (p < 0.05). All sentinel pigs (10/10) in pens adjacent to NV + SP pens got infected compared to 1/4 sentinel pigs allocated contiguous to a V + SP pen. These data show that vaccination of piglets significantly decrease parameters related to PRRSV transmission.     

The impact of dystocia on dairy calf health,welfare, performance and survival

Up to one-third of dairy calves are born after dystocia and this is a major cause of calf mortality. This study investigated the neonatal physiology, survival, health and subsequent growth of dairy calves following dystocia and is the first longitudinal study to analyse multiple effects and to look beyond the perinatal period.A total of 455 live born Holstein calves (N: No assistance, n = 360; FN: Farmer assistance but normally presented calf, n = 82; FM: Farmer assistance of malpresented calf, n = 13) were followed from birth to first service (heifers) or until leaving the farm (bulls). Compared to N calves, FN and FM animals had higher salivary cortisol concentrations at day 1 (P < 0.001) and FN calves had lower passive immune transfer (P = 0.03). Dystocia had no biologically significant impact on rectal temperature throughout the first 4 days (P > 0.05). During the first 60 days, FM calves had a higher proportion of days with non-routine health treatments (P < 0.05) and, by the time of weaning, mortality in FN and FM heifers was higher than in N calves (2.8×; P < 0.01). However, in surviving calves, growth to first service was not affected by dystocia category (P > 0.05).Calves which survive dystocia experience lower passive immunity transfer, higher mortality and higher indicators of physiological stress. Such calves have poorer welfare in the neonatal period and possibly beyond. Strategies need to be implemented to improve the subsequent health and welfare of such calves and to lower the incidence of dystocia.     

Effect of floor cooling and dietary amino acids content on performance and behaviour of lactating primiparous sows during summer

Fifty nine primiparous sows PIC Camborough 23 were distributed in a completely randomized 2 × 2 (with and without floor cooling × two dietary treatments) factorial design with 16 sows/treatment, each sow being considered as an experimental unit. Four replicates of sixteen sows each were used during the trial with the objective of evaluating the effects of floor cooling and the use of dietary amino acid contents on their performance and behaviour during summer. The sows were distributed among the treatments according to body weight and backfat thickness after farrowing. The sows were maintained in the experiment until weaning at 21 days of lactation. The two experimental diets supplied the same levels of crude protein (22%), metabolizable energy (ME; 14.65 MJ/kg) and levels of essential digestible AA relative to digestive lysine and differed according to the digestible lysine to ME ratio (0.75 vs. 0.82 g/MJ of ME). The temperature of the water circulating in the cooled floor was maintained at about 17 °C. Based on the average minimum and maximum temperatures (21.5 and 29.5 °C) obtained during the experimental trial, it can be assumed that the sows were exposed to periods of heat stress. The replicate and the interaction between replicate and treatment effects on all the measurements were not significant. Similarly, no effect of diet or interaction between diet and floor cooling system was found for all criteria measured. An effect (P < 0.05) of floor cooling on average daily feed intake was observed and floor cooling sows showed a higher average (P < 0.05) digestible lysine (61.5 vs. 51.8 g/d) and ME (78.2 vs. 65.9 MJ/d) intakes. The sows submitted to floor cooling showed, consistently, higher absolute values for average weight (+ 8.5 kg) and backfat (+ 0.75 mm) at weaning, compared with the control sows. The sows submitted to the cooled floor showed a shorter (P < 0.01) weaning-to-oestrus interval. The piglet and litter's daily weight gain (DWG), average weight at weaning (AWW) and total weight gain during lactation (TWG) were higher (P < 0.01) for the floor cooling sows. The floor cooling sows showed a higher (P < 0.01) daily milk production. The respiratory rate and rectal temperature values were lower (P < 0.01) for the floor cooling sows. There were differences (P < 0.01) on the cutaneous temperatures measured on the different parts of the sow's body, with the animals submitted to the cooled floor having lower values. The sows submitted to floor cooling spent less (P < 0.01) time in lateral recumbency inactive, more time nursing (P < 0.05) and more time feeding (P < 0.01) compared with control sows. The floor cooling under the sows increased daily feed intake and lysine intake, leading to a lower body weight loss, a lower weaning-to-oestrus interval and also improved nursing behaviour of the sows, leading to a higher milk production and, consequently, higher weight gains of piglets and litter during the lactation period.     

Effect of restricted suckling on physiological and behavioural stress parameters in dual-purpose cattle in the tropics

The present study evaluated the effect of restricted suckling (RS) on some physiological and behavioural stress measures compared to artificial rearing (AR). Thirty Holstein × Zebu cows and their calves were randomly assigned to one of two treatments. Cows were milked once daily. All calves were tethered in front of their dams during milking permitting physical contact between them in order to stimulate milk ejection, starting at 5 days of age. Calves in the RS treatment were allowed to suckle during 60 min daily, 30 min after milking and 30 min in the afternoon, while calves in the AR treatment were fed milk from teat bottles at the same times. Data were collected from day 4 to day 9, while treatments started on day 5. Heart and respiratory rates, body weight and temperature were measured (in that order) 15 min before entry into the milking parlour. Blood samples and pedometer readings were collected about 50 min later, immediately on return to their home pens. Higher heart rate in calves was found in the RS group than in the AR group. However, cortisol concentration was higher (P < 0.05) in the AR than in the RS group. No difference was found in average weight gain, milk consumption, number of steps counted, body temperature and respiratory rate in RS and AR calves. AR induced significantly (P < 0.05) higher level of serum cortisol concentration in the cows than did RS. No difference (P > 0.05) was found in body temperature, heart and respiratory rates in RS and AR treatments. It was concluded that suckling and nursing reduces some stress parameters in calves and cows in the AR treatment.     

Serum paraoxonase type-1 activity in pigs: Assay validation and evolution after an induced experimental inflammation

Paraoxonase 1 (PON1) is a serum enzyme synthesised and secreted primarily by the liver. It possesses anti-inflammatory properties limiting the production of pro-inflammatory mediators. The objectives of this study were to validate three spectrophotometric assays for the quantification of PON1 activity in pig serum, and to determine if PON1 activity in porcine behaves as a negative acute phase protein (APP), decreasing in inflammatory conditions. An analytical validation using three different substrates – 5-thiobutil butyrolactone (TBBL), phenylacetate (PA) and 4-(p)-nitrophenyl acetate (pNA) – was performed. In addition, inflammation was experimentally induced in five pigs by subcutaneous injection of turpentine oil, while five control pigs were left untreated. The treated pigs showed significant increases in CRP and decreases in albumin, indicating an inflammatory condition. The three substrates used would be suitable for PON1 activity measurements in serum samples, since they offer adequate precision (coefficients of variation < 10%), sensitivity (0.01, 0.15, 0.02 U/mL for TBBL, pNA and PA respectively) and accuracy (r = 0.99). In addition, PON1 behaves as a negative APP in pigs since a significant decrease (P < 0.05) in its activity after 72 h of the induction of the inflammation was observed with all substrates.     

Age and Body Condition of Goats Influence Consumption of Juniper and Monoterpene-Treated Feed

Redberry juniper (Juniperus pinchotii Sudworth) is an invasive, evergreen tree that is rapidly expanding throughout western and central Texas. Goats will consume some juniper on rangelands; however, intake is limited. The objective of our research was to determine how the age and body condition of goats influence their consumption of juniper and an artificial feed containing 4 monoterpenes. Two separate experiments were conducted. Experiment 1 examined the intake of redberry juniper foliage and used 39 goats either young (2 yr) or mature (> 6 yr). One-half of each age group was fed appropriate basal rations to reach either a high (HBC) or low body condition (LBC). Goats in LBC ate more (P < 0.01, 8.6 g · kg⁻¹ body weight [BW] ± 0.7 SE) juniper than those in HBC (2.3 g · kg⁻¹ BW ± 0.3 SE), and young animals consumed more (P < 0.05, 7.2 g · kg⁻¹ BW ± 0.7 SE) juniper than mature goats (3.9 g · kg⁻¹ BW ± 0.5 SE) across body condition treatments. In experiment 2, 36 goats, either young (2 yr) or mature (> 6 yr) and in either HBC or LBC, were offered a synthetic ration treated with 20.8 g · kg⁻¹ of 4 monoterpenes found in redberry juniper. Goats in LBC ate more (P < 0.01, 25.3 g · kg⁻¹ BW ± 1.0 SE) of the terpene-treated feed than those in HBC (17.5 g · kg⁻¹ BW ± 0.7 SE), and young animals ate more (P < 0.05, 22.5 g · kg⁻¹ BW ± 0.8 SE) than mature goats (20.3 g · kg⁻¹ BW ± 0.8 SE) across body condition treatments. Total intake as a proportion of body weight was also affected by body condition. Age and body condition are important factors that influence intake of chemically defended plants. A better understanding of how these attributes affect diet selection will aid livestock producers in improving grazing management.     

Productivity and Morphologic Traits of Thickspike Wheatgrass,Snake River Wheatgrass,and Their Interspecific Hybrids

Many rangeland restoration sites in the Intermountain West are environmentally challenging due to low precipitation and invasive species competition; thus, more effective native plant materials are needed. We aim to develop improved Snake River wheatgrass (Elymus wawawaiensis) germplasm through hybridization of this widely used bunchgrass with its nearest relative, the rhizomatous thickspike wheatgrass (E. lanceolatus), followed by backcrossing to Snake River wheatgrass. This approach can potentially introduce desirable adaptive traits from thickspike wheatgrass into Snake River wheatgrass. We measured shoot and root dry matter per plant (DMPP), specific leaf area, C:N ratio, and specific root length (SRL) of nine Elymus populations at two planting densities (25 and 7.8 plants m^? 2) in two repeated field experiments established from transplants in May 2005 and 2006, both at Millville, Utah. Populations included “Bannock” thickspike wheatgrass; “Secar,” “Discovery,” and three experimental Snake River wheatgrass populations; and three interspecific backcross hybrid populations. Compared with Snake River wheatgrass, the backcross hybrids displayed 10.4 ? 33.7% greater shoot DMPP (P < 0.0001) but 12.5 ? 16.5% lower root dry matter (DM) density (P < 0.05) across 6 and 2 comparisons, respectively, resulting in reduced root-to-shoot ratio. Compared with Snake River wheatgrass, Bannock displayed 38.6 ? 158.2% greater shoot DMPP (P < 0.0001) across six comparisons. In addition, Bannock displayed 22.4% lower SLA (P < 0.01) and 11.1% higher C:N ratio (P < 0.05) than Snake River wheatgrass and the backcross hybrids, traits suggestive of a low-nutrient growth strategy. These data suggest that Bannock achieved its consistently greater shoot DMPP during each growth period despite such a strategy. Hence, its greater productivity likely relates to a superior temporal and/or spatial ability to sequester resources that fuel growth. In this regard, Bannock displayed similar (P > 0.05) or 17% greater (P < 0.05) root DM density and 13.4% greater (P < 0.05) SRL than Snake River wheatgrass, as well as rhizomes.     

Estimation of Protein Requirements of Feedlot Steers

Feedlot performance, carcass characteristics, and diet composition data were collected from a survey of finishing steer experiments (40 experiments; 347 kg average initial weight; data excluded Holstein steers). Data were analyzed by weighted (observations/mean) analyses of variance to determine effects of protein intake and implanting strategy on feedlot performance and carcass characteristics. Implanting strategies were defined according to prevalent or last implant type used: no implant (None); medium-potency implants (Medium): zeranol 72 mg per dose, steroid-based implants (Synovex-S or Compudose) or trenbolone acetate (TBA) alone; high-potency implants (High): TBA in combination with either steroids or zeranol. Regression procedures were utilized to estimate CP and DIP, or MP requirements. Implant effects were independent (P>0.60) of dietary protein effects and included faster (P<0.05) gains at higher intakes (P<0.05) that resulted in improved (P<0.05) feed efficiencies. Steers responded to higher dietary CP (13.3 vs 11.4%) by increasing intake (P<0.05) which resulted in faster (P<0.05) and more efficient (P=0.09) gains. Compared to nonimplanted steers, implanted steers had heavier (P<0.05) carcasses with larger (P<0.05) ribeyes and lower (P<0.05) marbling scores. Nonimplanted steers fed 13.3% CP diets had heavier (P<0.05) carcasses than nonimplanted steers fed 11.4% CP diets. Maintenance MP requirements of nonimplanted steers were greater than those of implanted steers and similar to established MP requirements. Diets of steers implanted with high-potency implants must be supplemented to contain more than 7.5 g MP/kg BW^0.75/d, especially at heavy (>450 kg) initial BW, to maximize implant response. Implanted steers have a greater ability to respond to increased dietary protein because of reduced protein requirements for maintenance.     

Antibody and T cell responses induced in chickens immunized with avian influenza virus N1 and NP DNA vaccine with chicken IL-15 and IL-18

We had examined the immunogenicity of a series of plasmid DNAs which include neuraminidase (NA) and nucleoprotein (NP) genes from avian influenza virus (AIV). The interleukin-15 (IL-15) and interleukin-18 (IL-18) as genetic adjuvants were used for immunization in combination with the N1 and NP AIV genes. In the first trial, 8 groups of chickens were established with 10 specific-pathogen-free (SPF) chickens per group while, in the second trial 7 SPF chickens per group were used. The overall N1 enzyme-linked immunosorbent assay (ELISA) titer in chickens immunized with the pDis/N1 + pDis/IL-15 was higher compared to the chickens immunized with the pDis/N1 and this suggesting that chicken IL-15 could play a role in enhancing the humoral immune response. Besides that, the chickens that were immunized at 14-day-old (Trial 2) showed a higher N1 antibody titer compared to the chickens that were immunized at 1-day-old (Trial 1). Despite the delayed in NP antibody responses, the chickens co-administrated with IL-15 were able to induce earlier and higher antibody response compared to the pDis/NP and pDis/NP + pDis/IL-18 inoculated groups. The pDis/N1 + pDis/IL-15 inoculated chickens also induced higher CD8+ T cells increase than the pDis/N1 group in both trials (P < 0.05). The flow cytometry results from both trials demonstrated that the pDis/N1 + pDis/IL-18 groups were able to induce CD4+ T cells higher than the pDis/N1 group (P < 0.05). Meanwhile, pDis/N1 + pDis/IL-18 group was able to induce CD8+ T cells higher than the pDis/N1 group (P < 0.05) in Trial 2 only. In the present study, pDis/NP was not significant (P > 0.05) in inducing CD4+ and CD8+ T cells when co-administered with the pDis/IL-18 in both trials in comparison to the pDis/NP. Our data suggest that the pDis/N1 + pDis/IL-15 combination has the potential to be used as a DNA vaccine against AIV in chickens.