Control Pens Research Articles

Wet litter not only induces footpad dermatitis but also reduces overall welfare, technical performance, and carcass yield in broiler chickens

This study investigated whether a high level of footpad dermatitis (FPD) in broiler chickens induced by increased litter moisture content is accompanied by negative effects on technical performance, carcass yield, and other welfare aspects. Litter moisture content was increased by systematically spraying water over the litter from 6 d of age onward (lesion-induction treatment). Results were compared with a control group kept on relatively good quality litter and having a very low prevalence of footpad lesions. Litter quality significantly decreased from 7 d of age onward in the pens with the lesion-induction treatment compared with the control pens. At 21 and 36 d of age, significantly more FPD was observed in the lesion-induction groups compared with the control groups. Technical performance of the broilers was negatively affected for the lesion-induction groups from 28 d of age onward; lesion-induction groups had significantly lower BW gain, feed intake, and water intake and significantly higher FCR compared with control groups. As a result of the lower BW gain, carcass weight was less for the lesion-induction group and significantly more rejections for commercial parts were found. The lesion-induction groups also had significantly more hock burns and breast irritations at d 21 and 36, and were dirtier but had fewer thigh scratches at d 35 compared with the control groups. In addition, locomotion was negatively affected among the lesion-induction group, as they had a higher gait score at d 36 compared with the control group. We concluded that increased litter moisture content not only caused severe FPD but also reduced broiler performance and carcass yield and had a negative effect on other welfare aspects.

Reduction of Escherichia coli O157 and non-O157 O groups in the feces of commercial feedlot cattle using a high-dose of NP51, a Lactobacillus-based pre-harvest intervention

Lactobacillus acidophilus strain NP51 is a commercially available direct-fed microbial. This specific direct-fed microbial is recommended by the United States Department of Agriculture, Food Safety and Inspection Service (USDA FSIS) to be a pre-harvest management control and intervention option for the reduction of Escherichia coli (E. coli) O157:H7 in cattle. The addition of NP51 to cattle diets at a dose of 109 /head/day (high dose) has been proven to reduce E. coli O157:H7 and Salmonella in cattle feces. Currently, there has been no research conducted on the impact of feeding NP51 and the reduction of the “Big Six” non-O157 O serogroups which include E. coli O26, O45, O103, O111, O121 and O145 in cattle feces. The purpose of these studies was to evaluate the impact of NP51 fed at a dose of 109/head/day on the reduction of E. coli O157:H7 and six non-O157 O serogroups in cattle feces in two separate cattle feeding studies. Both studies were randomized complete block design. In one study, conducted in a commercial feedlot, approximately 1,800 cattle were blocked by weight and randomized into treatment and control pens. The pens contained 75 head/pen and included 12 control pens and 12 treatment pens. The control pens included cattle not fed NP51 and treatment pens included cattle supplemented with 109 CFU/head/day NP51 (Bovamine Defend®). Twenty-five fecal pats were taken from each pen (n = 600 samples) prior to transport for slaughter. In the research feedlot study, 112 head of cattle were blocked by weight and randomized into treatment or control pens at the Texas Tech University Research Feedlot. The pens included 14 control pens and 14 treatment pens and four head per pen. Fecal grabs were collected from each animal (n = 112 samples) prior to transport for slaughter. All samples were analyzed for the presence E. coli O157 using Immunomagnetic separation (IMS) and the genes that encode for the “Big 6” non-O157 serogroup (E. coli O26, O45, O103, O111, O121 and O145) antigens using a commercially available real time PCR system (BAX Q7, DuPont Qualicon, Wilmington, DE). Quantitative estimates were derived from fecal samples that were positive for E. coli O157 using direct-plating and MPN analysis. Generalized linear mixed models were used to analyze the qualitative data and general linear mixed models were used to analyze the quantitative data. In the commercial feedlot study, a significant (44%) reduction of E. coli O157 in fecal samples was observed when comparing control groups to treatment groups (P = 0.001) in that E. coli O157 was recovered from 15.7% of the treatment cohort and 28.0% of the control cohort. Overall E. coli O157 enumeration resulted in a significant reduction of 0.33 log10 CFU/g when comparing control and treatment groups (P = 0.1). Of the “Big Six” Non-O157 serogroups, results indicated a reduction in O serogroups O26, O45, O103 and O121 with a reduction of 52.7% (P = 0.02), 36.0% (P = 0.001), 33.0% (P = 0.03) and 42.0% (P = 0.02), respectively. In the research feedlot…

Einsatz von Gummimatten im Liegebereich tragender Sauen - Teil 2: Klauen, Gelenke und Gangweise

During a two year lasting study the floor in the lying area in a pen for 30-40 pregnant sows was fitted with rubber mats, while in an identically designed control pen, the lying area was equipped with slatted (with holes) concrete floor. The activity area of both pens consisted of slatted concrete floor.To evaluate the effect of rubber mats on the sows, claws and joints were judged regularly. Sows entered in the study with their second pregnancy and stayed, depending on their lifetime and their time of entering, up to five pregnancies in the study. Lateral abrasions of claw horn were significantly reduced by rubber mats in the sow’s lying area. The other criteria, alterations of the ball, injuries of the skin above of the claws, fractures of the claw horn, comparison of the length of the inner and outer claw, length of dewclaw, alterations of the joints and motion were not influenced by the type of floor in the lying area.

Behavioural and Brain Gene Expression Profiling in Pigs during Tail Biting Outbreaks – Evidence of a Tail Biting Resistant Phenotype

Abnormal tail biting behaviour is a major welfare problem for pigs receiving the behaviour, as well as an indication of decreased welfare in the pigs performing it. However, not all pigs in a pen perform or receive tail biting behaviour and it has recently been shown that these ‘neutral’ pigs not only differ in their behaviour, but also in their gene expression compared to performers and receivers of tail biting in the same pen. To investigate whether this difference was linked to the cause or a consequence of them not being involved in the outbreak of tail biting, behaviour and brain gene expression was compared with ‘control’ pigs housed in pens with no tail biting. It was shown that the pigs housed in control pens performed a wider variety of pig-directed abnormal behaviour (belly nosing 0.95±1.59, tail in mouth 0.31±0.60 and ‘other‘ abnormal 1.53±4.26; mean±S.D) compared to the neutral pigs (belly nosing 0.30±0.62, tail in mouth 0.13±0.50 and “other“ abnormal 0.42±1.06). With Affymetrix gene expression arrays, 107 transcripts were identified as differently expressed (p<0.05) between these two categories of pigs. Several of these transcripts had already been shown to be differently expressed in the neutral pigs when they were compared to performers and receivers of tail biting in the same pen in an earlier study. Hence, the different expression of these genes cannot be a consequence of the neutral pigs not being involved in tail biting behaviour, but rather linked to the cause contributing to why they were not involved in tail biting interactions. These neutral pigs seem to have a genetic and behavioural profile that somehow contributes to them being resistant to performing or receiving pig-directed abnormal behaviour, such as tail biting, even when housed in an environment that elicits that behaviour in other pigs.

Assessment of Heterogeneity of Efficacy of a Three-Dose Regimen of a Type III Secreted Protein Vaccine for Reducing STEC O157 in Feces of Feedlot Cattle

Preharvest control of Escherichia coli O157:H7 (STEC O157) may prevent human illness by reducing the presence of STEC O157 throughout the beef production chain. Immunization of cattle with a type III secreted protein vaccine inhibits colonization of cattle with STEC O157 and reduces the probability of fecal shedding and hide contamination. Our objectives were to perform a meta-analysis to estimate efficacy of a three-dose regimen of TTSP vaccine at reducing the presence of STEC O157 in the feces of feedlot cattle and to test factors that might modify vaccine efficacy. Pen-level data (n=184 pens, 1462 cattle) from four randomized controlled vaccine trials conducted from 2002 to 2008 at the University of Nebraska-Lincoln were analyzed. Factors explaining a culture-positive fecal sample were tested in generalized estimating equations logistic regression and log-binomial models. An autoregressive correlation structure was defined to account for clustering of repeated test-periods within block. Clustering or potential confounding by study was accounted for by treating study as a fixed effect. STEC O157 was detected from 661 of 5451 postvaccination fecal samples. The probability to detect STEC O157 postvaccination was 8.4% and 15.8% in vaccinated and unvaccinated cattle, respectively. Interactions between vaccination and (1) study; (2) prevalence of control pens within each time-place cluster; and (3) days from vaccination were not significant or fit poorly with observed data. Adjusting for study, cattle in pens receiving three doses of vaccine were less likely to shed STEC O157 (odds ratio=0.46, p<0.0001). Model-adjusted vaccine efficacy was 48% (95% confidence interval: 0.37-0.57). We concluded that a three-dose regimen type III secreted protein vaccine was efficacious at reducing the probability of detecting STEC O157 in the feces of cattle and that vaccine efficacy was not modified by study or level of prevalence observed in control pens.

Using data from electronic feeders on visit frequency and feed consumption to indicate tail biting outbreaks in commercial pig production1

The long term aim with this study was to identify predictors or early indicators of tail biting outbreaks using registrations from electronic feeders. This study is based on information about daily frequency of feeder visits (DFV) and daily feed consumption (DFC) recorded in electronic feeders from 460 noncastrated boars in tail biting pens (TB pens, n = 21) and matched control pens (Con pens, n = 21) from 10 wk before to 10 wk after the first injured tail in the pen. The results showed lower average DFV among pigs in TB pens compared with pigs in Con pens 6 to 9 wk before the start of the tail biting outbreak (first treatment for tail damage due to tail biting; P ≤ 0.1, df = 487) but a greater DFV for tail biting victims 2 to 5 wk before the start of the tail biting outbreak compared both to other pigs in the TB pen and to pigs in the Con pen (P < 0.1, df = 6,500). Tail biting victims had decreased DFC during and after the tail biting outbreak [wk 0 to 2 after the tail biting outbreak (P < 0.1, df = 6,500)]. In conclusion, information from electronic feeders can be used for surveillance of tail biting outbreaks in pigs. Due to common casual factors, low feeding frequencies observed on the group level can predict future tail biting in the pen as early as 9 wk before the first tail injuries. Moreover, increased feeding frequencies for individual pigs in potential tail biting pens may predict which pigs will be become the victims in the tail biting outbreak. The results further support previous findings that pigs with tail injuries due to tail biting consume decreased amounts of feed.

The influence of a magnesium-rich marine extract on behaviour, salivary cortisol levels and skin lesions in growing pigs

Growing pigs can display undesirable behaviours, reflecting or causing poor welfare. Addition of magnesium (Mg) to the diet could reduce these, as Mg supplementation has been associated with improved coping ability in response to stress. This study examined the effect of supplementation with a Mg-rich marine extract-based product (Supplement) on the behaviour, skin and tail lesion scores and salivary cortisol concentrations of growing pigs. At weaning (28 days), 448 piglets were assigned to either Control or Supplement (0.05%) diets in single-sex groups of 14. Four weeks later (c. 17 kg), pigs were blocked according to weight and back test scores. Seven piglets from each pen were mixed with seven from another pen of the same sex and dietary treatment to yield the following groups: control male, Supplement male, control female and Supplement female (n = 4 of each). This marked the start of the 9-week experimental period. Instances of the following behaviours were recorded in each pen for 8 × 2 min periods 1 day/week: aggression (fight, head-knock and bite); harmful (tail-in-mouth, ear-chewing and belly-nosing); and sexual/mounting behaviour. Four focal pigs were selected from each pen, and their behaviour was continuously recorded for 2 × 5 min periods on the same day. Saliva was collected once per week at 1000 h by allowing pigs to chew on a cotton bud for c. 1 min. Salivary cortisol was analysed in duplicate by an enzyme immunoassay. Skin and tail lesions were scored according to severity 1 day/week. There were fewer aggressive incidents in Supplement pens (P < 0.01), and mounting behaviour (performed only by males) was almost three times lower in Supplement than in control pens (P < 0.01). However, there was no effect of Supplement on the incidence of each of the harmful behaviours. Behaviour of the focal pigs showed no treatment effect on the duration or incidence of aggressive behaviour. However, Supplement pigs spent less time performing harmful behaviours compared with control pigs (P < 0.001). Supplement had no effect on the occurrence or severity of tail-biting outbreaks or on tail lesion scores. However, Supplement females had lower skin lesion scores, in particular in the ears and shoulders (P < 0.01). Finally, Supplement pigs had lower salivary cortisol concentrations (P < 0.01). Mounting is a major welfare concern in uncastrated pigs, and therefore this represents an important welfare benefit of Supplement. Reduced salivary cortisol, in conjunction with reduced skin lesion scores in supplemented females, suggests that addition of a Mg-rich marine extract improved pig welfare in this system.

Jejunal morphology and blood metabolites in tail biting, victim and control pigs

Tail biting has several identified feeding-related risk factors. Tail biters are often said to be lighter and thinner than other pigs in the pen, possibly because of nutrition-related problems such as reduced feed intake or inability to use nutrients efficiently. This can lead to an increase in foraging behavior and tail biting. In this study, a total of 55 pigs of different ages were selected according to their tail-biting behavior (bouts/hour) and pen-feeding system to form eight experimental groups: tail-biting pigs (TB), victim pigs (V) and control pigs from a tail-biting pen (Ctb) and control pen (Cno) having either free access to feed with limited feeding space or meal feeding from a long trough. After euthanasia, a segment of jejunal cell wall was cut from 50 cm (S50) and 100 cm (S100) posterior to the bile duct. Villus height, crypt depth and villus : crypt ratio (V : C) were measured morphometrically. Blood serum concentration of minerals and plasma concentration of amino acids (AA) was determined. Villus height was greater in Cno than Ctb pigs in the proximal and mid-jejunum (P < 0.05), indicative of better ability to absorb nutrients, and increased with age in the proximal jejunum (P < 0.001). Serum mineral concentration of inorganic phosphate (Pi) and calcium (Ca) was lower in Ctb compared with Cno pigs, and that of Pi in V compared with all the other pigs. Many non-essential AA were lower in pigs from tail-biting pens, and particularly in victim pigs. Free access feeding with shared feeding space was associated with lower levels of essential AA in blood than meal feeding with simultaneous feeding space. Our data suggest that being a pig in a tail-biting pen is associated with decreased jejunal villus height and blood AA levels, possibly because of depressed absorption capacity, feeding behavior or environmental stress associated with tail biting. Victim pigs had lower concentrations of AA and Pi in plasma, possibly as a consequence of being bitten.

Effects of nicarbazin on the blood glucose and liver glycogen statuses of male broilers ,

Nicarbazin (NCZ), an effective anticoccidial widely used by the global broiler industry, is known to produce some side effects in broilers. Recent field observations have suggested that NCZ could be associated with spiking mortality syndrome, a disease of uncertain etiology that is most commonly characterized by hypoglycemia. In turn, 2 trials were conducted to investigate the effects of NCZ on the blood glucose levels and liver glycogen content of Ross × Ross 708 male broilers. In 6 of 12 pens beginning at 1 d of age, NCZ was added to basal broiler diets at a rate of 125 mg/kg, and the other 6 pens were control pens in which birds received salinomycin instead of NCZ, at a rate of 66 mg/kg. Feed and water were provided ad libitum, feed was closely monitored in all pens to avoid shortages, no coccidial challenge was imposed, and room temperature never exceeded 29.4°C. At the end of the second trial, a photoperiod increase from 8L:16D to 24L:0D was imposed in an effort to induce stress due to feed engorgement. In response to NCZ in trial 1, 0 to 28 d feed conversion and relative liver weights on d 21 and 28 were higher, whereas 0 to 28 d cumulative BW gain was lower. In response to NCZ in trial 2, 0 to 13 d feed conversion was higher, whereas 0 to 13 d cumulative BW gain was lower. The added NCZ increased blood glucose on d 13 in trial 2, but did not affect at any time the liver constituents analyzed in both trials. In conclusion, the uninterrupted feeding of NCZ at 125 mg/kg in the starter and grower diets of male Ross × Ross 708 broilers increased feed conversion and reduced BW gain, but despite an increase in relative liver weight on d 21 and 28 posthatch, liver glucose and glycogen concentrations were not affected.

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.

Cool perch availability improves the performance and welfare status of broiler chickens in hot weather

A study was conducted to determine whether water-cooled perches would be preferred by commercial broilers exposed to a hot ambient environment, and subsequently, whether utilization of these perches would improve performance and the well-being of birds, beyond those provided by normal perches. Four hundred and thirty-two 14-d-old male chickens from a commercial fast-growing strain (Arbor Acres) were housed in the following conditions: 1) cool perches, 2) normal perches, and 3) control pens with no perches. The results showed that there was greater use of cool perches than normal perches for broiler chickens during summer (F1, 4=125, P=0.0004). Cool perches increased BW gain (F2, 6=5.44, P=0.0449) and breast (F2, 24=3.31, P=0.0539) and thigh muscle yields (F2, 24=6.29, P=0.0063), while decreasing abdominal fat deposition (F2, 24=7.57, P=0.0028), cooking loss (pectoralis major, F2, 24=3.30, P=0.0542; biceps femoris, F2, 24=3.42, P=0.0493), percentage of panting birds (F2, 6=102, P<0.0001), and scores of footpad (F2, 6=122, P<0.0001) and hock (F2, 6=68.2, P<0.0001) burn, and abdominal plumage condition (F2, 6=52.0, P=0.0002), particularly toward the end of the rearing period. In contrast, normal perches hardly affected growth performance, carcass composition, meat quality and behavioral patterns, and appeared to worsen the welfare status, including footpad and hock burns and abdominal plumage condition, due to a lower occupancy rate. Cool perches offer a thermoregulatory and performance advantage to broilers exposed to a hot environment and appear to be a management strategy for improving the production and well-being of commercial broilers.

FORNECIMENTO DE PLASMA SUÍNO SPRAY-DRIED DILUÍDO EM ÁGUA ACIDIFICADA PARA LEITÕES COM SINTOMAS DE CIRCOVIROSE NO INÍCIO DA FASE DE CRESCIMENTO E TERMINAÇÃO

The effect of the spray-dried porcine plasma diluted in drinking acidified water for recovery of piglets with clinical signs of the Post-Weaning Multisystemic Wasting Syndrome (PMWS) was studied. The experiment was conducted in eight finishing units of an agroindustry of Santa Catarina State, Brazil, with positive diagnosis of PMWS by histopathology, immunohistochemistry (IHC) and polimerase chain reaction (PCR). The study was initiated around 14 days after the lodging of the piglets and concluded 42 days later. The experiment was randomly designed by weight and sex with two treatments: T 1 - water ad libitum as a control group and T 2 – a solution constituted of porcine plasma (250g) in drinking acidified water (10L). The animals were distributed into two batch pens in the same facility with nine or ten piglets per pen, being one the control pen and the other one the treated pen. The following variables were evaluated: pH of water and solution; individual weight and clinical conditions of the piglets; solution intake within the period from 0 to 14 days, feed intake and feed conversion rate; mortality rate, histopathology and IHC analysis of the animals that died. The piglets of T 2 presented clinical improvement during the 14 days of the experiment and a better feed conversion rate at 28 days of the experiment. Performance data did not show statistical difference between the treatments, except for feed conversion in the group that received T 2 , which was better than control group (T 1 ) p= 0.0372 for the main effect. It was concluded that piglets with PMWS signs, which received plasma in acidified water, presented clinical improvement during the 14 days of the experiment, in comparison with control animals and better feed conversion ratio at the first 28 days of the experiment. KEYWORDS : porcine circovirus associated diseases; porcine plasma; post-weaning multisystemic wasting syndrome; swine.

Cooperia punctata: Effect on cattle productivity?

Cooperia spp. have become the most prevalent parasites in United States cow/calf operations as observed in the USDA NAHMS (National Animal Health Monitoring System) Beef Cow/Calf survey in 2008. This is at least in part due to the widespread use of macrocyclic lactones that have recently been shown to have a reduced activity against these parasites. The effects of Cooperia spp. on cattle productivity are largely unknown. This study was conducted to assess their effect upon cattle housed under conditions found in American feedlots. Two hundred yearling calves (average weight 460lb/209kg) were acquired from northwestern Arkansas and northeastern Oklahoma and were vaccinated and dewormed upon arrival at the feedlot. Animals were comingled and preconditioned for approximately one month, and were fed a standard growing ration throughout the study. Calves were randomly divided into two groups (n=80, infected and control) and each group was further divided into two replicate pens (n=40). Calves from the two infected pens were orally inoculated with a gavage of 1×105 and 0.825×105 infective larvae of a recent isolate of Cooperia punctata on day 0 and 14, respectively, with the two control pens receiving a similar volume of tap water. Data collected included biweekly fecal egg counts, daily individual feed consumption and weight gain over the 60-day test period. The presence of C. punctata (>99% of recovered worms) was confirmed by necropsy and recovery from the small intestine on days 35 and 60 post infection (PI) in a subset of animals. Egg counts were positive by day 14 PI and remained at numbers similar to values seen in field studies. The control group gained weight 7.5% more rapidly (p=0.02) than infected animals (3.24lb/1.47kg per day vs. 3.0lb/1.36kg per day, respectively). The Cooperia-infected calves also consumed 1.5lb (0.68kg) less dry feed per day than the control animals (p=0.02). These data suggest that C. punctata has a deleterious effect on both appetite and nutrient uptake or utilization. At necropsy (days 35 and 60), the draining mesenteric lymph nodes of infected animals were increased in size and the small intestinal mucosa was thickened and covered with a thick layer of mucus in the infected animals. The most prominent histological changes in the Cooperia- infected animals included a moderate increase in the number of intraepithelial lymphocytes and globule leukocytes, as well as aggregates of eosinophils within the lower lamina propria. The only significant difference was an increase in the goblet cell density at day 60. Anthelmintic sensitivity/resistance of the Cooperia isolate used was determined by treatment of one pen of infected calves with a macrocyclic lactone and the other pen with a benzimidazole at the completion of the study. The macrocyclic lactone treatment (n=40) did not remove the parasites (FECRT=8.8%), while treatment with a benzimidazole was very effective (FECRT=98.1%). This study demonstrated that C. punctata has a significant effect on cattle productivity, both reduced weight gain and decreased feed intake compared to controls.

Rolling behaviour of sows in relation to piglet crushing on sloped versus level floor pens

The study focused on the rolling behaviour of sows and the crushing of piglets by sows' rolling behaviour. The experiment examined the influence of sloped floor in loose housed farrowing pens on the rolling behaviour of sows and crushing of piglets. The experimental unit was made up of 24 pens. There were two experimental pen designs with piglet creep in the corner of the pen and piglet creep across the end of the pen, respectively. Both of the experimental pen designs had a 10% sloped floor in the sow's resting area. The two control pen designs were identical to the experimental pen designs, but with a level floor. The behaviour of 85 sows and their litters was continuously video recorded. Behavioural observations were made from birth of the first piglet and until 3days after birth of the first piglet. Rolling behaviour of sows caused significantly more trapped piglets under the sow than lying down from standing (P=0.04). Rolling behaviour caused 64% of the trapped piglets and lying down from standing caused 36% of the trapped piglets. Rolling from udder to side without protection trapped significantly more piglets than rolling from udder to side near slanted wall or piglet protection rails and rolling from side to udder (P<0.001). With a certain pen design sloped floor reduced rolling from udder to side without protection (P=0.007) and reduced the number of trapped piglets (P=0.01), but results concerning lying behaviour showed that sloped floor pushed sows to rest on the level part of the floor. The results indicate that rolling behaviour that crushes piglets can be reduced, and sows prefer to lie on a level floor.

Pen Culture of the Black-Chinned Tilapia, &lt;i&gt;Sarotherodon Melanotheron&lt;/i&gt; in the Aglor Lagoon in Ghana

Pen-fish-culture as a culture-based fisheries approach was investigated in the Aglor Lagoon from December 2003 to June, 2004. The fish used in the study was the Black-chinned tilapia Sarotherodon melanotheron. The growth performance of S. melanotheron cultured for six months in the Aglor Lagoon under three different treatments were monitored. In the first treatment, the cultured fish was fed with a feed of 29.80 % protein at 3 % body weight once a day. In the second treatment, bamboo was stacked at a density of 6 per metre square in pens to serve as substrate for periphyton growth and development. In the third treatment, there was no feeding (control). There was significant difference in growth between the fed and the unfed S. melanotheron in the pens, with no significant difference in growth between the fish that subsisted on periphyton de-veloped on bamboo and the other treatments. S. melanotheron cultured in the bamboo equipped pens had the best condition factor of 3.57 ± 0.23. The experimental values of b obtained from the length-weight relationship (W = aLb) for the three treatments were 2.07, 2.13 and 2.80 for feeding, unfed and bamboo respectively. From the results, the least yield was obtained from the unfed control pen (0.045 kg/m2), whilst the highest was from the bamboo equipped pens (0.183 kg/m2).

Provision of additional walls in the resting area—The effects on resting behaviour and social interactions in goats

The aim of this study was to investigate the effects of providing extra walls, in addition to the already existing pen walls, in the resting area on resting behaviour and social interactions in goats. Twenty-four dehorned dairy goats (7 weeks pregnant) were distributed into six groups with four goats in each group. The groups were systematically rotated between six pens; five experimental pens with additional walls and one control. The experimental pens were equipped with wooden walls with the following configurations: parallel wall (PAR), cross walls (CRO), perpendicular wall (PER), cubicles (CUB) and three walls (THR). Each pen had a total area of 1.5 m 2/goat with a separate activity and resting area of equal size (0.75 m 2/goat). For each treatment the goats were given 3 days to get accustomed to the treatments before they were video recorded for 24 h. Resting behaviour and general activity were observed using instantaneous sampling with 10 min intervals in the entire 24 h period, whereas social interactions were continuously scored for 6 h between 09.00 and 15.00 h. Except from the PER treatment ( P < 0.05), the goats were resting more frequently against walls in pens with any additional walls than in the control pen. The additional walls did not have any significant effects on the goats total resting time, synchronization of resting, time spent resting in the activity area or resting in body contact. Furthermore, additional walls in the resting area had no significant effects on the goats’ social interactions. In conclusion, the goats’ preference to rest against a wall was better met in pens with addition walls compared to in the control pen (CON), but the design of the additional walls needs further investigation in order to optimize the goats’ use of the resting area.

Effects of early contact between non-littermate piglets and of the complexity of farrowing conditions on social behaviour and weight gain

In this study we tested if contact possibilities between non-littermate piglets and complexity of farrowing conditions affect the pre- and post-weaning behaviour, weight gain and skin lesions of piglets. Suckling sows were either kept in a group housing system (GH), in a single pen loose housing system (LH), or in conventional farrowing crates (FC). In the single pen systems a piglet door to the adjacent pen was opened on d 10 after farrowing in half of the pens so that piglets were able to enter the neighbouring pen (LH+ and FC+). For control, in the other half of single pens no piglet doors were opened (LH− and FC−). In the group housing system piglets also were allowed to freely move within the whole system on d 10 after farrowing. After weaning on d 28 piglets were kept in littered rearing pens in an open stable holding 20 piglets each. Piglets from contact pens were mixed with those they previously had contact to whereas piglets from control pens were mixed with unfamiliar litters. Data were obtained from 230 litters (113 sows with 1935 farrowed piglets). All piglets were scored for skin lesions immediately before and 4 days after opening the piglet doors, as well as immediately before and 4 days after moving into rearing pens. Behaviour (biting, fighting, drinking and laying) of piglets was recorded in the rearing pens in a 48-h period after weaning for 2 × 4 h. Treatments did not affect the level of skin lesions in the rearing period ( H = 8.72, df 4, ns) nor daily weight gain until weaning ( F 4,216 = 1.21, ns). In the 48 h after moving to rearing pens, less intensive agonistic behaviour (fighting and biting) was observed in contact piglets ( H = 53.36, df 4, P < 0.0001). Four days after weaning control piglets showed significantly higher numbers and more severe skin lesions than contact piglets and, in addition, lesion scores of piglets from the larger single farrowing pens with straw bedding were significantly lower compared to the single farrowing crate ( H = 33.86, df 4, P < 0.0001). The latency for lying in the new rearing pen was decreasing ( F 4,93 = 25.76, P < 0.001) and the latency for drinking ( F 4,81 = 3.43, P = 0.01) was increasing with decreasing complexity and space allotment of the housing system but were not related to whether the piglets have had contact to other litters before weaning. Five weeks after weaning weight gain ( F 4,204 = 7.01, P < 0.0001) and BW ( F 4,207 = 5.34, P < 0.001) were higher in treatments offering contact. Our results show that familiarising piglets from different litters 10 day post partum by establishing contact possibilities through a piglet door reduces social stress at weaning and increases weight gain after weaning. Farrowing pens with straw bedding and enlarged space as offered in the farrowing pens and the group housing system can further decrease the level of harmful agonistic interactions after mixing unacquainted litters at weaning and can improve the adaptation of piglets towards the new environment of the rearing pen.

Reducing post-mixing aggression and skin lesions in weaned pigs by application of a synthetic maternal pheromone

AbstractIn commercial pig production, piglets are often mixed after weaning which can result in severe aggression and lead to body damage, disruption of feeding behaviour and reduced growth. This experiment investigated whether application of a synthetic maternal pheromone to groups of weaned pigs in commercial housing would affect the level of aggression and skin lesions sustained after mixing. Two treatments (Pheromone and Control) were used with 16 replicate pens of pigs (20 pigs per pen). Treatments were applied on the day of weaning (average 28 days of age) on a per room basis in alternate weeks. In Pheromone pens, after routine washing and disinfection, the walls and feeders were treated one hour prior to occupation with a synthetic pheromone at a rate of 1.0 ml pig−1. Control pens were as for Pheromone except no product was applied. During the 24-h period, post mixing, pigs in pheromone-treated pens spent significantly less time fighting than those in control pens. This was reflected in reduced injury scores 24 h after mixing, with pigs in pheromone-treated pens having 39% fewer skin lesions on the front of the body compared to those in control pens. Treatment had no effect on growth rate or feed efficiency, although the feed intake for days 7–28 was significantly lower and feed efficiency tended to be lower in pheromone-treated pens. In conclusion, application of a synthetic maternal pheromone can be considered one of the arsenal of strategies to reduce aggression and safeguard the welfare of groups of weaned pigs where mixing is unavoidable.

Effects of syndyphalin-33 on feed intake and circulating measures of growth hormone, cortisol, and immune cell populations in the recently weaned pig

The synthetic met-enkephalin syndyphalin-33 (SD-33) increases feed intake in sheep and transiently increases circulating GH concentrations in sheep, rats, and pigs. Two experiments were performed to evaluate the effects of SD-33 on recently weaned pigs. In a preliminary experiment, pigs were administered SD-33 (0.5 micromol/kg, given intramuscularly) or saline immediately before a 3-h transport and subsequent placement into group pens. Treatment with SD-33 increased (P = 0.01) daily feed intake; cumulatively, pen intake over 7 d postweaning tended (P = 0.06) to be greater than in control pens. In Exp. 2, pigs were weaned and fitted with jugular catheters. The following day, pigs were treated with SD-33 or saline as described above. Transient increases (P < 0.05) in circulating concentrations of GH (at 1 and 1.5 h postinjection) and cortisol (at 3.5 and 4 h postinjection) were observed in pigs treated with SD-33 relative to controls. No difference in feed intake was observed between treatments over 4 d postinjection. Increased (P < 0.05) numbers of circulating neutrophils, lymphocytes, and monocytes were observed in both treatment groups over 4 d postinjection, and treatment with SD-33 tended (P = 0.07) to selectively increase monocyte numbers. Although SD-33 has potential to be used to increase feed intake and decrease the negative effects of stress during weaning in pigs, further investigation is needed to better understand the timing of effect and to rule out possible immunosuppressive effects.

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.