Treatment Pen Research Articles

Place conditioning as evaluation of affective valence in piglets

The emotional valence of animals is challenging to assess, despite being a key component of welfare. In this study, we attempted to assess emotional valence through memory in 1- and 3-week-old piglets. It was hypothesized that piglets would spend less time in a pen where they experienced a negative event (castration) and more time in a pen where they experienced a positive event (enrichment). A testing apparatus was designed with three equally sized pens: two outer sections serving as treatment pens containing unique visual and tactile cues and a center section remaining neutral. Piglets received either negative or positive condition in one outer treatment pen and a sham treatment in the opposite. Various methods were tested (age of piglets, number and length of conditioning sessions, passive vs. active conditioning). Contrary to expectations, piglets did not decrease their time in the pen associated with the negative condition or increase their time in the pen associated with the positive condition. However, when exposed to the positive condition, results indicate older piglets developed an aversion towards the sham treatment. This study provides methodological groundwork for the application of place conditioning in piglets and highlights the nuances important for the use of cognitive tests to assess animal welfare.

The necessity of pen replication to account for and understand the impacts of social dynamics on individual laying hen behavior

Individual laying hens within the same group show variation in their temperament traits and cognitive learning abilities, which can be affected by both their early rearing experiences and housing environments. Hens also have distinct individual patterns of movement within housing systems that may correlate with temperament and cognition. Individual behavioral tests can measure treatment impacts, but social dynamics may impact on an individual’s behavior. The aims of this perspective piece are to provide further evidence of pen-level variation using original data on social ranging patterns and fear assessment of free-range hens exposed to different, enriched rearing environments; and to encourage more studies to consider pen replicate variation as a means to better understand causes and mechanisms. A literature review showed that, while most published studies over the past decade assessing individual laying hen behavior included group-level replication (i.e., 83% of 54 articles reviewed), almost none considered inter-pen variation. The original data analysis of individual hens’ range use recordings showed significant treatment pen replicate variation in pop-hole following movements and hen–pair associations in the time spent together inside or outside. Significant inter-pen variation was also seen in tonic immobility tests on a subset of hens from the same study. Pen-level replication is important for scientific validity and for improving our understanding of why commercial flocks in the same environment can be so variable in their behavior to inform management practices. Further research could help to understand the mechanisms behind why groups of hens reared and housed in the same environments will show significant inter-group variation.

PSI-13 Effect of Targeted Metaphylaxis Using Blood Leukocyte Status on Health, Performance, and Economic Outcomes of Auction-Derived Feedlot Heifers

Abstract The study objective was to evaluate health, performance, and antimicrobial costs of heifers where targeted metaphylaxis was guided by a commercial blood leukocyte analyzer compared to a traditional metaphylaxis regimen. Using a randomized complete block design, heifers (n=1,271; initial body weight (BW) = 233.3±1.08 kg) were randomly allocated to treatment pens (n=20; 10 blocks). Treatments were: 1) cattle administered metaphylactic treatment with gamithromycin at arrival (META), and 2) cattle administered metaphylaxis with gamithromycin according to the blood leukocyte analyzer outcome (TARGETED). The blood leukocyte analyzer indicated immune status of individual animals according to the number and proportion of different leukocytes in the blood; red signified “abnormal” and green signified “normal” status. Only cattle with a red outcome were administered antimicrobial in the TARGETED treatment. Of all cattle enrolled in the study, 73% were deemed normal and 27% were deemed abnormal by the chute side blood analyzer. Treatment groups had an equal distribution of normal (META = 73% TARGETED = 74%) and abnormal (META = 28% TARGETED = 26%) cattle enrolled in the study. Cattle were fed a common starter ration for the duration of the 62-d study. Pen riders were blinded to treatment pen status. Data was analyzed using PROC MIXED and GLIMMIX in SAS. Final BW, ADG, and feed conversion were less for TARGETED (P≤0.02). However, the arrival processing antimicrobial cost (META = 11.77 and TARGETED = $3.27/heifer) and total antimicrobial cost (META = 17.77 and TARGETED = $9.12/heifer) was reduced (P< 0.01) for TARGETED. TARGETED had an arrival processing antimicrobial cost savings of $8.50/heifer and an overall drug input cost savings of $8.65/heifer. The BRD morbidity rate for normal status heifers was 18.85% and more than abnormal (26.49%; P< 0.01). Normal status heifers had a mortality rate of 3.17 vs. 5.80% for abnormal (P=0.03). In conclusion, drug costs were reduced but performance of TARGETED was also less.

Conditioned place aversion of caustic paste and hot-iron disbudding in dairy calves

Cauterization by hot iron and application of caustic paste are 2 common methods of disbudding calves. In this study, we compared the affective experience of these 2 procedures on young dairy calves using conditioned place aversion. Male dairy calves (n = 14; 7 ± 2 d old) were disbudded by both thermal and chemical methods (1 horn bud at a time, 48 h apart). Calves received treatments in pens made visually distinct with either red squares or blue triangles on the walls. Calves were restricted to these treatment pens for 6 h following disbudding. For all treatments, calves received a sedative (xylazine, 0.2 mg/kg), local anesthetic (lidocaine, 5 mL), and analgesic (meloxicam, 0.5 mg/kg). Calves were then tested for conditioned place aversion at 48, 72, and 96 h after their last treatment. During tests, calves were placed in a neutral pen connected to both treatment pens where they had previously been disbudded. Time spent in each treatment pen was recorded until calves chose to lie down for 1 min (latency to lie down: 31.0 ± 8.6 min). During the first test (48 h after last disbudding), calves spent more time in the pen associated with hot-iron disbudding compared with what would be expected by chance (intercept: 73.5%, 95% CI: 56.5, 90.5) and fewer calves lay down in the caustic paste pen than in the hot-iron pen (3 vs. 10 lying events). No evidence of preference for the hot-iron pen was found in the following test sessions (72 and 96 h since last disbudding). These results suggest that calves initially remember caustic paste disbudding as a more negative experience than hot-iron disbudding, even with the use of sedation, local anesthesia, and analgesia.

Lignite effects on NH3, N2O, CO2 and CH4 emissions during composting of manure

Production of compost from cattle manure results in ammonia (NH3) and greenhouse gas emissions, causing the loss of valuable nitrogen (N) and having negative environmental impacts. Lignite addition to cattle pens has been reported to reduce NH3 emissions from manure by approximately 60%. However, the effect of lignite additions during the manure composting process, in terms of gaseous emissions of NH3, nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4) is not clear. This composting study was conducted at a commercial cattle feedlot in Victoria, Australia. Prior to cattle entering the feedlot, we applied 4.5 kg m−2 of dry lignite to a treatment pen, and no lignite to a control pen. After 90 days of occupancy, the cattle were removed and the accumulated manure from each pen was used to form two separate compost windrows (control and treatment). During composting we collected manure samples regularly and quantified gaseous emissions of NH3, N2O, CO2, and CH4 from both windrows with an inverse-dispersion technique using open-path Fourier transform infrared spectroscopy (OP-FTIR). Over the 87-day measurement period, the cumulative gas fluxes of NH3, N2O, CO2, and CH4 were 3.4 (± 0.6, standard error), 0.4 (± 0.1), 932 (± 99), and 1.2 (± 0.3) g kg−1 (initial dry matter (DM)), respectively for the lignite amended windrow, and 7.2 (± 1.3), 0.1 (± 0.03), 579 (± 50) and −0.5 (± 0.1) g kg−1 DM, respectively for the non-lignite windrow. The addition of lignite reduced NH3 emissions by 54% during composting, but increased total greenhouse gas (GHG) emissions by 2.6 times. Total N losses as NH3–N and N2O–N were approximately 11 and 25% of initial N for the lignite and non-lignite windrows, respectively. The effectiveness of retaining N was obvious in the first three weeks after windrow formation. A cost-benefit analysis indicated that the benefit of lignite addition to cattle pens by reduced NH3 emission could justify the trade-off of increased GHG emissions.

Assessing the affective component of pain, and the efficacy of pain control, using conditioned place aversion in calves.

Pain in animals is typically assessed using reflexive and physiological responses. These measures allow inferences regarding nociception but provide little basis for conclusions about the affective component of pain (i.e. how negatively the experience is perceived). Calves routinely undergo painful procedures on commercial farms, including hot-iron disbudding, providing a convenient model to study pain in animals. The aim of this study was to investigate the affective component of post-procedural pain due to hot-iron disbudding, using conditioned place aversion. Calves (n = 31) were subjected to two procedures (one bud at a time): one without post-procedural pain control and the other with the use of a nonsteroidal anti-inflammatory drug (either meloxicam (n = 16) or ketoprofen (n = 15)). All procedures included the use of local anaesthesia (lidocaine). Place conditioning was tested 2 days after the last treatment by allowing calves to freely roam between the pens where they had previously been disbudded. Calves spent more time, and lay down more frequently, in the pen where they received meloxicam compared with the pen where they only received a local block. Surprisingly, calves avoided the pen where they received ketoprofen compared with the control treatment pen. We hypothesize that the shorter duration of action of ketoprofen resulted in increasing pain at the end of the conditioning period, explaining the increased aversion to this treatment. These results illustrate the value of place conditioning paradigms to assess the affective component of pain in animals, and suggest that the animal's evaluation of painful events depends upon the time course of when the pain is experienced.

Calf aversion to hot-iron disbudding

Dairy calves are routinely disbudded by cauterization with a hot iron. To mitigate the intra-operative and initial post-operative pain associated with this procedure some farmers provide calves general and local anesthetics, but it is unknown if the procedure remains aversive. We used a place-conditioning paradigm to assess aversion caused by hot-iron cautery with a local anesthetic compared to a sham procedure. A test area was divided into three equally sized pens: two ‘treatment’ pens with distinct visual cues were connected by a central ‘neutral’ pen. Each calf went through the disbudding procedure and a 6-h recovery period in one treatment pen and the control procedure in the other treatment pen. In three tests (48, 72 and 96 h after the second treatment), calves could freely roam among the pens until they chose to lie down, ending the session. Calves spent less time in either of the treatment pens compared to the central pen. When only comparing the two treatment pen, calves spent less time in the disbudding pen, especially during the first test. Calves were also less likely to lie down in the pen associated with the disbudding procedure. We conclude that even with the use of a local anesthetic, hot-iron disbudding is salient and aversive for calves, indicating the need to refine or avoid the procedure.

Effect of injectable trace mineral administration on health, performance, and vaccine response of newly received feedlot cattle

ABSTRACT Previous research has established that trace minerals are necessary for optimal growth and immunity, yet challenges exist with intake of dietary trace minerals in cattle newly received at feedlots. A total of 128 crossbred beef bull (n = 40) and steer (n = 88) calves were used for this 42-d receiving study. Cattle were stratified by initial BW (275 ± 9.54 kg) and sex (steer or bull) and then assigned equivalently to treatment pens (n = 8 per treatment). Treatments were (1) negative control (CON) or (2) injectable trace mineral solution containing 60 mg of Zn/mL (as Zn disodium EDTA), 10 mg of Mn/mL (as Mn disodium EDTA), 5 mg of Se/mL (as sodium selenite), and 15 mg of Cu/mL (as Cu disodium EDTA) administered s.c. at 2.2 mL/100 kg of BW on d 0 (ITM). Health was monitored daily by trained personnel blinded to treatment pen assignment. Blood samples and BW were obtained on d 0, 14, 28, and 42 to determine bovine viral diarrhea virus (BVDV) type 1a antibody titer and gain performance. Standard processing procedures were applied on d 0, including administration of a respiratory vaccine containing modified-live BVDV antigens. No difference in overall ADG (P = 0.21) was detected between CON (1.36) and ITM (1.25 kg/d) steers. Overall DMI was not different (P = 0.83) between CON (6.98) and ITM (7.02 kg/d), but G:F tended (P = 0.08) to be less for ITM from d 28 to 42. The morbidity rate observed in this study was low (14% average), and there was no difference (P = 0.71) in morbidity between treatments, which averaged 15.6 and 12.5% for CON and ITM, respectively. There was a treatment × d interaction (P = 0.09) for BVDV-specific antibody titer. On d 14, ITM had a greater (P = 0.02) BVDV antibody titer than CON. These data suggest that ITM did not improve performance or morbidity when the incidence was low; however, the BVDV-specific antibody response to a respiratory vaccine was greater for ITM on d 14.

Effects of lignite application on ammonia and nitrous oxide emissions from cattle pens

Beef cattle feedlots are a major source of ammonia (NH3) emissions from livestock industries. We investigated the effects of lignite surface applications on NH3 and nitrous oxide (N2O) emissions from beef cattle feedlot pens. Two rates of lignite, 3 and 6kgm−2, were tested in the treatment pen. No lignite was applied in the control pen. Twenty-four Black Angus steers were fed identical commercial rations in each pen. We measured NH3 and N2O concentrations continuously from 4th Sep to 13th Nov 2014 using Quantum Cascade Laser (QCL) NH3 analysers and a closed-path Fourier Transform Infrared Spectroscopy analyser (CP-FTIR) in conjunction with the integrated horizontal flux method to calculate NH3 and N2O fluxes. During the feeding period, 16 and 26% of the excreted nitrogen (N) (240gNhead−1day−1) was lost via NH3 volatilization from the control pen, while lignite application decreased NH3 volatilization to 12 and 18% of the excreted N, for Phase 1 and Phase 2, respectively. Compared to the control pen, lignite application decreased NH3 emissions by approximately 30%. Nitrous oxide emissions from the cattle pens were small, 0.10 and 0.14gN2O-Nhead−1day−1 (<0.1% of excreted N) for the control pen, for Phase 1 and Phase 2, respectively. Lignite application increased direct N2O emissions by 40 and 57%, to 0.14 and 0.22gN2O-Nhead−1day−1, for Phase 1 and Phase 2, respectively. The increase in N2O emissions resulting from lignite application was counteracted by the lower indirect N2O emission due to decreased NH3 volatilization. Using 1% as a default emission factor of deposited NH3 for indirect N2O emissions, the application of lignite decreased total N2O emissions.

A new cost-effective method to mitigate ammonia loss from intensive cattle feedlots: application of lignite.

In open beef feedlot systems, more than 50% of dietary nitrogen (N) is lost as ammonia (NH3). Here we report an effective and economically-viable method to mitigate NH3 emissions by the application of lignite. We constructed two cattle pens (20 × 20 m) to determine the effectiveness of lignite in reducing NH3 emissions. Twenty-four steers were fed identical commercial rations in each pen. The treatment pen surface was dressed with 4.5 kg m−2 lignite dry mass while no lignite was applied in the control pen. We measured volatilised NH3 concentrations using Ecotech EC9842 NH3 analysers in conjunction with a mass balance method to calculate NH3 fluxes. Application of lignite decreased NH3 loss from the pen by approximately 66%. The cumulative NH3 losses were 6.26 and 2.13 kg N head−1 in the control and lignite treatment, respectively. In addition to the environmental benefits of reduced NH3 losses, the value of retained N nutrient in the lignite treated manure is more than $37 AUD head−1 yr−1, based on the current fertiliser cost and estimated cost of lignite application. We show that lignite application is a cost-effective method to reduce NH3 loss from cattle feedlots.

Group space allowance has little effect on sow health, productivity, or welfare in a free-access stall system1,2

Free-access stalls allow sows to choose the protection of a stall or use of a shared group space. This study investigated the effect of group space width, 0.91 (SS), 2.13 (IS), and 3.05 (LS) m, on the health, production, behavior, and welfare of gestating sows. Nine replications of 21 (N = 189) gestating sows were used. At gestational d 35.4 ± 2.3, the pregnant sows were distributed into 3 pens of 7 sows, where they remained until 104.6 ± 3.5 d. Each treatment pen had 7 free-access stalls and a group space that together provided 1.93 (SS), 2.68 (IS), or 3.24 (LS) m(2)/sow. Baseline measurements were obtained before mixing. Back fat depth, BW, BCS, and lameness were measured monthly, and skin lesions were scored weekly. Blood was collected monthly for hematological, immunological, and cortisol analyses. Sow behavior was video recorded continuously during the initial 4 d of treatment and 24 h every other week thereafter. Behavior was analyzed for location, posture, pen investigation, social contact, and aggression. Skin response to the mitogen concanavalin A (Con A) was tested at mean gestational d 106. Litter characteristics including size and weight were collected at birth and weaning. The data were analyzed using a mixed model. Multiple comparisons were adjusted with the Tukey-Kramer and Bejamini-Hochberg methods. Group space allowance had no effect on any measure of sow health, physiology, or production (P ≥ 0.10). Sows in the SS, IS, and LS pens spent 77.88% ± 3.88%, 66.02% ± 3.87%, and 63.64% ± 3.91%, respectively, of their time in the free-access stalls (P = 0.12). However, SS sows used the group space less than IS and LS sows (P = 0.01). Overall, pen investigatory behavior was not affected by group space allowance (P = 0.91). Sows in the LS pens spent more time in a social group than SS sows (P = 0.02), whereas sows in IS pens were intermediate to, but not different from, the other treatments (P ≥ 0.10). The size of the social groups was also affected by the group space allowance (P = 0.03), with SS sows forming smaller groups than LS sows; again, IS sows were intermediate to, but not different from, the other treatments. Although the group space allowance had no measurable impact on the health, physiology, or productivity of the sows, the lower group space use and social contact of the SS sows reduced the behavioral diversity benefits of group housing and may indicate an avoidance of social stressors or a lack of physical comfort in the smallest pens.

The effects of plastic spectacles on the condition and behaviour of pheasants

Plastic spectacles are often fitted to pheasants in laying pens to reduce feather pecking and egg eating. This study examined the effects of spectacles on the physiological condition and behaviour...

Cool perches improve the growth performance and welfare status of broiler chickens reared at different stocking densities and high temperatures

The present study investigated the interaction of stocking density and cool perch availability on broiler chickens raised at high ambient temperature (>30.8°C). Behavior, live performance, and the incidence of footpad and hock burns and abdominal plumage damage were investigated over a 4-wk experimental period. A total of 1,152 one-day-old Arbor Acres chicks were subjected to a 2 (cool perches) × 3 (stocking densities) factorial arrangement of treatments. From 1 d of age, birds were provided with or without cool perches at each of 3 stocking densities (12, 16, or 20 birds/m(2); low, medium, or high stocking density, respectively) and corresponded to 48, 64, and 80 birds per pen. The perch design provided 380 cm of linear perching space in each treatment pen. The results showed that high stocking density decreased the growth (P < 0.05) and welfare (P < 0.01) of broilers. Cool perch availability increased BW gain and feed conversion efficiency of broilers (P < 0.05) regardless of stocking density. The birds' use of cool perches increased with age (P < 0.01) and decreased with higher stocking density (P < 0.05). The accessibility of cool perches changed birds' behavior patterns (P < 0.01) and reduced footpad or hock burns and damage to abdominal plumage (P < 0.05). These results suggest that cool perches have a favorable effect on the performance and welfare of broilers.

Sorting by parity to reduce aggression toward first-parity sows in group-gestation housing systems1

Young sows are subordinate and vulnerable in group-housing systems because they usually lose most fights and suffer more injuries than mature sows at mixing. This study was conducted to evaluate effects of sorting by parity on reducing aggression and associated stress with the aim to improve welfare and performance of first-parity sows in a group-housed system. Sows and gilts (n = 180) from 6 breeding groups were used. Within each group, 2 groups of 15 females were mixed in each of 2 treatment pens after weaning and remained there throughout the entire gestation period. The control pen consisted of 11 multiparous and 4 first-parity sows, and the treatment pen consisted of 11 gilts and 4 first-parity sows. Before mixing and at the end of the gestation period, sows and gilts were weighed individually, assessed for BCS, and measured for backfat thickness. Injury scores were assessed before and 48 h after mixing and wean-to-mating intervals, farrowing rate, and litter performance at the subsequent farrowing were recorded for all females. Aggressive interactions involving first-parity sows were video recorded for 72 h immediately after mixing in each pen. Data were analyzed using the Glimmix procedure of SAS with a Poisson regression model for count data and a Gaussian model for continuous data. All females in treatment pens sustained fewer scratches (P = 0.01) after mixing than females in control pens. First-parity sows in treatment pens fought more frequently (P = 0.01), tended to fight for longer periods (P = 0.08), and won more fights (P = 0.04) of parallel pressing but had fewer injures (P = 0.03) after mixing, gained more BW (P = 0.01) during gestation, and had greater farrowing rates (P = 0.03) compared with first-parity sows in control pens. The results suggest that sorting by parity shielded first-parity sows from severe injuries caused by mixing-induced aggression so that their welfare and performance can be improved in group housing systems.

Niacin delivery to the intestinal absorptive site impacts heat stress and productivity responses of high producing dairy cows during hot conditions

Heat stress resulting in animal production losses costs the dairy industry hundreds of millions of dollars annually, especially in tropical and semi-tropical areas. Niacin is a dietary supplement which typically induces flushing (i.e., increased blood flow to the skin), causing a decrease in core body temperature, which has been shown to reduce heat stress in dairy cows. Our objective was to determine if use of a rumen protection technology to deliver niacin (RPNi) to the intestinal absorptive site is effective in alleviating heat stress in dairy cows and increasing productive performance. Two 2×2 factorial experiments, each with 28d periods, were conducted on a commercial dairy farm in central California (USA). In Experiment 1, 2 pens of ∼180 early lactation multiparity Holstein cows were used and, in Experiment 2, 2 pens of ∼180 mid-lactation mixed parity Holstein cows were used. The basal total mixed ration, of 171g/kg crude protein, 332g/kg neutral detergent fiber and 147g/kg starch on a dry matter (DM) basis, was the same for all cows with the exception of RPNi added to the treatment total mixed ration. The RPNi was added to treatment pen diets at a consumption level of 19g of RPNi/d, which was estimated to deliver ∼6g of intestinally absorbable niacin/d as determined by evaluation of the RPNi. In Experiment 1, respiration rates (RR) and panting scores (PS; a 1–4.5 visual score of the extent of panting in a cow) were measured 4times/d in subgroups of ∼35cows/pen. The RR were lower (P=0.02) at 09:00h, but not impacted at other times of the day, while PS were lower (P≤0.01) at 04:30, 09:00 and 20:30h, but not impacted at 16:30h, in cows fed RPNi compared to control. However, RR and PS were relatively low overall due to the cooler than normal summer weather. There was no difference in DM intakes or milk yields, but milk fat proportion was lower in RPNi cows (P<0.01). In Experiment 2, where PS and RR were not measured, DM intake and milk yield did not differ between treatments, with the exception of fat proportion, which was higher in RPNi cows (P<0.01). While indicators of heat stress were improved for cows fed RPNi, this slight increase in cow comfort did not result in increased DM intake or productivity. Differences in milk fat responses in our early lactation cows suggest lipid metabolism in the cows was affected by intestinal niacin delivery, most likely by reducing plasma triglyceride production. A reduction of plasma triglyceride production was also likely in the mid-lactation cows but, because they were producing less milk and consuming a similar amount of DM, dietary fat intake was likely able to compensate for the reduced de novo synthesis.

Effects of plastic bits on the condition and behaviour of captive-reared pheasants

Between 2005 and 2007, data were collected from game farms across England and Wales to examine the effects of the use of bits on the physiological condition and behaviour of...

Display of a peer's face picture enhances the preference for a pen in preference testing in cows

Using preference testing, we investigated the effect of a brush and a peer's face picture on the welfare of breeding beef cows. Four cows were used in experiment 1 and another four cows were used in experiment 2. An experimental barn consisted of two 3.5 square-meter pens, and a corridor measuring 1.6 m wide and 1.3 m long. During the experiment, either side of the pens were treated. In experiment 1, straw bedding was placed in a treated pen (condition B) in the first two trials, a brush was added in the treated pen (condition BB) in the next two trials, and a peer's face picture was displayed in the treated pen (condition BBF) in the last two trials. In experiment 2, condition B was applied for the first two trials, a peer's face picture was displayed in the treated pen (condition BF) in the next two trials, and condition BBF was applied for the last two trials. Each cow was housed alone from 09.00 hour to 15.00 h in the experimental barn during the six trials. The cows stayed in the treatment pen longer than in the non-treatment pen under all conditions in experiments 1 and 2. In experiment 1, the mean total time spent in the treatment pen was longer under condition BBF than under conditions B and BB. In experiment 2, the mean total time spent in the treatment pen was shorter under condition B than under conditions BF and BBF. The mean percentage of time spent ruminating was greater under condition BBF than under condition B. It is concluded that the cows preferred the peer's face picture in the isolated condition of preference testing in this study.

The effect of different pen partition configurations on the behaviour of sheep

The aim of our experiment was to test if different configurations of additional walls would increase total resting time and synchrony of resting behaviour while decreasing displacements from the resting area in small groups of sheep. A total of 24 adult pregnant ewes of the Nor-X breed were rotated between five treatment pens and one control pen (each with 4 ewes) in a Latin Square design. In five treatment pens solid walls were mounted on the resting area in different configurations (parallel wall: PAR; cross wall: CRO; perpendicular wall: PER; resting cubicles: CUB; three walls: THR), while one pen was kept without additional walls (control: CON). The ewes were acclimatized to each treatment pen for 6 days before 24 h video recordings were performed. Social interactions were scored continuously for 6 h during daytime while resting behaviour was scored using instantaneous sampling every 10 min during the entire 24 h. No significant differences were found between treatments in total resting time, resting synchrony or displacement behaviour. However, when housed in the CUB configuration the ewes performed more blocking behaviour ( P < 0.0001), consequently resulting in more ewes resting in the activity area ( P < 0.05). More head butting was observed in the THR treatment than in the CRO treatment ( P < 0.05). In conclusion, additional walls did not increase the resting time, reduce aggressive social interactions or increase the synchrony of resting behaviour in ewes. It is probably more important for sheep to have enough resting space to lie simultaneously and the ability to keep within visual contact with group mates.

Effect of dietary levels of vitamin E (all-rac-tocopheryl acetate) with or without added fat on weanling pig performance and tissue α-tocopherol concentration

Two experiments involving 496 cross-bred pigs evaluated the efficacy of various dietary levels of vitamin E, with or without supplemental fat, on postweaning pig performance and weekly serum and terminal tissue alpha-tocopherol concentrations. The first trial involved 248 pigs weaned at an average of 15 d of age and 4.8 kg BW. The experiment was a randomized complete block design conducted in seven replicates. Vitamin E was added as dl-alpha-tocopheryl acetate at 0, 20, 40, 60, 80, 100, 150, or 200 IU/kg diet. Pigs were bled initially and at 7-d intervals for a 42-d period. Liver and s.c. adipose tissue samples were collected from six pigs per treatment group at 42 d. In Exp. 2, a 2 x 4 factorial arrangement of treatments in a randomized complete block design was conducted in seven replicates. The experiment used a total of 248 pigs weaned at 19 d of age and averaged 6.4 kg BW. Four vitamin E levels (0, 20, 40, and 60 IU/kg diet) and two added fat levels of 0 or 5% were fed for 35 d. Four pigs per treatment pen were bled weekly, and at 35 d a total of four pigs per treatment group were killed and liver, heart, and s.c. adipose tissues were collected and analyzed for alpha-tocopherol. The basal diet in both experiments contained an average 7.9 IU for period 1, and later diets averaged 11.0 IU vitamin E/kg. In both experiments serum alpha-tocopherol concentrations declined from weaning to 7 d after weaning and continued to decline each week after weaning when the basal diets were fed. Serum alpha-tocopherol concentrations increased (P < 0.01) each week as the dietary vitamin E level increased in both experiments. In Exp. 2, when fat was added to the diet serum alpha-tocopherol concentrations were higher (P < 0.01) than in diets without added fat. Liver, heart muscle, and adipose tissue alpha-tocopherol concentrations increased (P < 0.01) as vitamin E level increased, but at the higher dietary vitamin E level the liver surpassed the adipose tissue in its alpha-tocopherol concentration. Liver and adipose alpha-tocopherol concentrations were higher (P < 0.01) when fat was added to the diet. These results indicate that supplementation of 40 to 60 IU/kg diet with added fat resulted in a relatively constant balance of serum and tissue concentration of alpha-tocopherol during the nursery period, but when fat was not supplemented a dietary vitamin E level of 80 to 100 IU/kg diet may be needed. The current NRC recommendations for vitamin E for the pig from 5 to 20 kg BW may need to be reevaluated.

Experimental ivermectin treatment of sarcoptic mange and establishment of a mange-free population of Spanish ibex.

Ivermectin was used to treat sarcoptic mange in Spanish ibex (Capra pyrenaica hispanica). Its therapeutic effectiveness was analyzed when it was administered through subcutaneous injection, to sick animals in the consolidation stage of mange (third phase) and, with double injections to chronically affected animals (fourth phase) at a dosage of 0.2 or 0.4 mg/kg body weight (bw). Three wk after treatment, the animals in the third phase of mange treated with a high dose (0.4 mg/kg bw) of ivermectin were completely cured. The same result was achieved after 4 wk of treatment in those animals in phase 3 of mange when 0.2 mg/kg body weight was used. Double injection with ivermectin, even at high doses, did not guarantee the complete cure of all cases of sarcoptic mange in the chronic stage (phase 4); only three of six animals were free of Sarcoptes scabiei. The second experiment consisted on the application of a sanitation program in order to obtain a population of Spanish ibex free from S. scabiei, starting with free-ranging animals, some of them healthy and others sick. After capture the animals were classified as chronically ill, in which case they were excluded from the program, mite carriers and healthy specimens. All the animals were treated first topically with foxim (500 mg/l) and subcutaneously with ivermectin (0.4 mg/kg bw). The infected animals were housed in the treatment pen, and received two doses of ivermectin (0.2 mg/kg bw) at an interval of 15 days, then spent 15 days in the quarantine pen, where they received a further dose before they were included in the pool of healthy animals, and immediately were placed in the quarantine phase. The sanitation we implemented was fully effective in curing the affliction of Spanish ibex affected by S. scabiei.