Ragnar Tauson

Effects of a Perch in Conventional Cages for Laying Hens

Abstract A total of 720 Single Comb White Leghorn laying hens (SCWLs Shaver 288) were studied from 22 to 82 weeks of age for the effect of a perch on production, egg weight, exterior egg quality and egg rolling-out efficiency, plumage condition, foot health, claw length, throat skin health, mortality, live weight, behaviour and usage of the perch at different times of day. Video technique and manual registrations were used for the behaviour studies. Treatments were cages with perch (P) and without perch (NP). Each cage contained 5 birds, implying a perch length of 12 cm per bird and 480 cm2 cage floor space per bird. There was no significant difference in laying rate per hen-day (hd) or mortality between P-and NP-birds. However, P-birds had significantly lower egg weights giving a significantly lower egg output in g of egg mass produced per hd. P-birds had lower live weight than NP-birds. There were no significant differences in foot health (lesions on pads or digits), claw length or health of throat ski...

Aviary Systems and Conventional Cages for Laying Hens: Effects on Production, Egg Quality, Health and Bird Location in Three Hybrids

Abstract In two experiments, a total of 4346 laying hens housed in battery cages, with three hens per cage (C), and in two aviary systems, both with tiered wire floors and litter (Lovsta with two tiers (L) and Marielund with three tiers (M)), were used for studies on production, egg quality, health, plumage and foot condition, bone strength and bird location. Three hybrids were used: Lohmann Selected Leghorn (LSL) were kept in all three systems, Dekalb XL (DK) were kept in both aviaries and Lohmann Brown (LB) in M only. Production and feed conversion in M were inferior but not significantly different from C but significantly better than in L. Proportions of dirty eggs were significantly higher in the avaries. No significant differences were found in interior egg quality traits between keeping systems. LSL showed higher production and better feed conversion than the other hybrids and a tendency for a lower proportion of mislaid eggs. Mortality varied considerably between the aviary pens, reaching 35% in LB...

Effects of group size on performance, health and birds’ use of facilities in furnished cages for laying hens

A total of 1584 Lohmann Selected Leghorn hens were kept in 144 modified cages furnished with—perch, nest and sandbath for 5, 6, 7 or 8 hens per cage or in 162 conventional cages for 4 hens. Cage floor area was 600 cm2 per hen excluding nest and sandbath. Doors to nests and sandbaths were time monitored. Production, mortality, exterior egg quality, health, integument and the birds use of facilities were registered from 20 until 80 weeks. No effects of group size or keeping system on production or mortality were detected, but the furnished cage gave more cracked and less dirty eggs than the conventional cage. Hens in the furnished cage had better plumage condition, less toe pad hyperkeratosis, shorter claws, less rear body wounds and stronger humerus, but dirtier feet than hens in the conventional cage. Hens in the larger group sizes had the dirtiest feet. In the furnished cage, on average, 86% of all eggs were laid in the nests and 0.6% in the sandbaths. The rolling out efficiency from nests was best in th...

Foot and skeletal disorders in laying hens: Effects of perch design, hybrid, housing system and stocking density

Abstract In four experiments a total of 3660 SCWL laying hens kept in conventional cages at low and high stocking densities with and without a perch, Get-away (GA) cages and aviaries with litter (AL), were used for studies on the presence of bumble foot (BF), distal toe pad hyperkeratosis (TPH), keel bone lesions (KBL) and of the breaking strength of tibia and humerus. Commercial hybrids were used: LSL (Expts. 1, 2 and 4); LSL and Shaver (Expt. 3). Only clearly observed in systems with perches, the incidence of BF and KBL was mostly affected by perch design, while BF was also strongly affected by strain and housing system. LSL showed significantly higher incidence of BF, especially in GA and AL. TPH, only found in conventional cages, was affected both by strain and stocking density, LSL hens and lower stocking density showing significantly lower incidence. Apart from welded wire net platforms, a European beech hardwood circular prototype perch with a flattened upper and lower surface seemed to combine in ...

Effect of permethrin impregnated plastic strips on Dermanyssus gallinae in loose-housing systems for laying hens

The effect of permethrin impregnated plastic strips (Die No Mite Strips) was evaluated on Dermanyssus gallinae populations in aviary systems for layers in Sweden. Two application strategies of the strips were tested: (A) attached in the housing system, allowing the birds to rub against the strips and thereby get the acaricide released onto their plumage, and (B) attached out of reach of the hens, at two different sites (perches and egg-belt lids) of the inner surfaces of the system, where the mites sheltered during the day. On two farms with 2030 (A) and 3384 (B) hens, and existing mite populations, strips were mounted for 20 and 10 weeks, respectively, and mite numbers were monitored by traps. With application A an overall mite reduction of 53% was observed, while with B the mean mite numbers decreased by 39% at the perches and 92% at the egg-belt lid. The strips were originally designed for caged hens afflicted by ectoparasites that stay on the host for most of their life cycle. However, since D. gallinae spends most of its time off the host, it was not possible to control the parasite with application A. Resistance tests performed on mites from both treated and control compartments where application A was used showed no indication of resistance to permethrin, while 95% of the mites survived a 48 h exposure to the compound where application B was performed. Thus, permethrin resistant mites appeared to be the main reason for the failure to control D. gallinae with application B.

Traps containing acaricides for the control of Dermanyssus gallinae.

In Sweden, the poultry red mite, Dermanyssus gallinae, is the only haematophagous mite of poultry. After obtaining a blood meal the parasite spends most of its life off the host aggregated in cracks and crevices where mating and reproduction occur. Cardboard traps (1000 mm x 40 mm x 3 mm; 160 mm x 140 mm x 3 mm and 100 mm x 70 mm x 3 mm) containing 2% metriphonate were placed where mites gathered, out of reach of the hens, in two different types of multi-tiered floor systems for layers. In two separate trials, treated traps were replaced every second day for 2 weeks and every week for 8 weeks. In the 2-week trial the whole floor system was treated while in the 8-week trial six of 12 existing compartments studied were treated. The untreated compartments were used as controls. Throughout the study, the parasite populations were monitored by collections of mites with untreated cardboard traps (100 mm x 70 mm x 3 mm). A 95% reduction of mites was recorded in the 8-week trial whereas a 99% reduction of mites was recorded in the 2-week trial. The placement of treated traps near mite aggregation sites was essential for satisfactory control.

Effect of Perches at Different Positions in Conventional Cages for Laying Hens of Two Different Strains

Production, health and behaviour were studied in 648 White Leghorn hens of two strains, LSL and Shaver 288, housed in three-tier battery cages (four hens per cage, 600 cm2 per hen) with three treatments; two with a perch fitted across the cage, 17 (PB) or 24 cm (PC) from the back of the cage, respectively, and control cages without perch (NP). Introducing a perch did not significantly affect production, but PC gave more dirty eggs, and both PC and PB tended to give more cracked eggs. The perch caused inferior keel bone condition and hygiene of the cage floor and a stronger tibia. LSL hens showed higher production, better feed conversion ratio, fewer cracked eggs, better keel bone health and shorter claws than Shavers. Use of the perch averaged 25 and 90% during day and night, respectively. The perch did not significantly affect other behaviours. There were significant interactions between strain and cage design regarding laying percentage, egg weight, cracked eggs, live weight, foot- and perch hygiene, ke...

High-fibre sunflower cake affects small intestinal digestion and health in broiler chickens

1. An experiment was conducted to evaluate high-fibre sunflower cake (HF-SFC); a feed ingredient distinguished by large amounts of crude fibre and insoluble non-starch polysaccharides (i-NSP). 2. Broiler chickens (n = 160) were fed on pelleted maize-based diets free from coccidiostats and antibiotic growth promoters between 15 and 31 d of age. Diets included 0, 10, 20 or 30% HF-SFC. Performance and small intestinal health were assessed. 3. In general, HF-SFC inclusion mediated significant linear increases in ileal digestibility of fat and protein and significant linear decreases in ileal digestibility of dry matter, ash and energy. 4. Weight gain increased linearly with HF-SFC inclusion. Feed conversion was negatively affected by 30% HF-SFC but not by 20% HF-SFC. 5. In the jejunal lumen, inclusion of HF-SFC was associated with significant decreases in colony counts of Clostridium spp. 6. HF-SFC inclusion resulted in significant linear reductions of villus height, thickness of muscularis mucosa, and the circular and longitudinal layers of muscularis in the jejunum. Crypt depth and submucosal thickness were not affected. 7. The data indicate that broiler chickens may thrive on feeds with insoluble fibre contents far exceeding those used in practice, and that HF-SFC exerts some positive effects on digestion and small intestinal health.

Effects of a xylanase and protease, individually or in combination, and an ionophore coccidiostat on performance, nutrient utilization, and intestinal morphology in broiler chickens fed a wheat-soybean meal-based diet

The effects of 2 single exogenous and monocomponent feed enzymes, and their combination, and an ionophore coccidiostat on production performance, feed AME(n), nutrient utilization, and intestinal morphology were studied in broiler chickens. One-day-old unvaccinated and unsexed Ross 308 birds (n = 320) were kept in groups of 8 on wood shavings in pens raised from the floor and fed one of 5 experimental diets, replicated 8 times, for 36 d. Treatments were 1) a wheat-soybean meal-based feed with no added coccidiostats or exogenous enzymes (CON), 2) CON + ionophore coccidiostat (Narasin), 3) CON + xylanase (Ronozyme WX CT; XYL), 4) CON + serine protease (Ronozyme ProAct CT; PRO), or 5) CON + xylanase + serine protease (XYL+PRO). Enzymes were added on top in the feed formulation. Diets contained 0.5% TiO₂ to facilitate estimations of total tract apparent nutrient utilization. Treatments had no effect on BW gain or feed intake, but feed conversion, apparent digestibility of starch and fat, and feed AME(n) were improved with all enzyme treatments. The relative length of the ileum was reduced with XYL+PRO. For all parameters measured, the effects of XYL+PRO were similar to when XYL and PRO were fed individually. Narasin had no effect on production performance or nutrient utilization but reduced the relative lengths of jejunum and ileum. Relative lengths and weights of duodenum and cecum were unaffected by treatments. In conclusion, the improved feed conversion with both a xylanase and a protease was reflected in increased nutrient utilization, but their combination was not superior to when supplied separately. Narasin did not affect performance or nutrient utilization but reduced the relative lengths of the jejunum and ileum.

EFFECTS ON PLUMAGE CONDITION, HEALTH AND MORTALITY OF DIETARY OATS/WHEAT RATIOS TO THREE HYBRIDS OF LAYING HENS IN DIFFERENT HOUSING SYSTEMS

The effects on plumage condition and health when feeding diets with varying oats/wheat ratios to different non‐beak‐trimmed hybrids housed in various systems were studied in two experiments. In experiment 1 (Expt. 1) 1146 Lohmann Selected Leghorn (LSL) and 1006 Lohmann Brown (LB) birds were housed in eight aviary pens; four in each of the systems Lovsta (L) and Marielund (M), or in six groups of 24 conventional cages each (C). Two diets with a high proportion of either oats or wheat were used. Experiment 2 (Expt. 2) included 1740 LSL and 1632 SLU‐1329 birds housed in 6 pens each of system M. Diets with varying proportions of oats and wheat were given. In Expt. 1, LB hens housed in C showed better plumage condition compared with those housed in the aviaries, whereas LSL birds showed the opposite trend. Housing system affected most health traits, showing superior results for system C regarding, for example, bumble foot, cleanliness of feet and keel bone lesions. In Expt. 2, feather cover deteriorated in LSL...