MANAGEMENT ▶▶▶
Longer feeders lead to better plumage
BY RICK VAN EMOUS AND ANNEMARIE MENS, WAGENINGEN LIVESTOCK RESEARCH G
ood plumage also contributes to better animal welfare and reproduction. Balder hens have a greater chance of being wounded by other hens during feeding and by males during mating. For
breeder hens specifically, bad plumage leads to reduced fer- tilisation. Mating causes the bald hen pain and the risk of skin damage increases. This may lead to avoidance behaviour be- cause they do not allow mating. Earlier research by Wagenin- gen Livestock Research (WLR) showed that bad plumage is caused, among other things, by a high percentage of male breeders at the start of the laying period, males that have matured too early, a litter surface that is too small (<40%) and too much occupancy of the feeding system. WLR re- search into the effect of the grill type on preventing chest blisters also took into account the effect of different feeder lengths on plumage.
Practice farm The farm where the research took place had four poultry houses with a total of 21,000 females and 2,000 males (Ross 308). Poultry houses 1 and 2 were similar, as were poultry houses 3 and 4. Poultry houses 1 and 2 measured 14×50 metres, while 3 and 4 measured 15×60 metres. Be- fore the start of the laying period, 4,500 hens (+9% males) were placed in poultry houses 1 and 2 and 6,000 females (+9% males) were placed in 3 and 4. The birds in poultry houses 1 and 2 had 13.6 centimetres of feeder length at their disposal, whereas the birds in poultry houses 3 and 4 had 15.9cms.
Observations Thirty (30) random animals per poultry house were assessed externally at various ages (35, 45, 51 and 58 weeks). At 35 and 45 weeks, they received a complete plumage score, while at 51 and 58 weeks, they were scored for seven parts per bird (neck, chest, abdomen, back, wings, tail and flanks). Scores of between 0 (plumage fully intact) and 5 (bald) were given. During the final assessment at 58 weeks, the hens in poultry houses 3 and 4 (with more feeder length) had better plum- age. After studying the data this effect was also observed at the ages of 35 and 51 weeks (see Table). In general, the
The condition of a breeder hen’s plumage is important for her internal thermal regulation. Hens with bad plumage are not well insulated which causes them to take in more feed. This leads to suboptimum feed conversion. Research shows that hens that are 50% bald take up almost 20% more feed compared to laying hens with intact plumage.
plumage of broiler parent hens depends on two factors: the percentage of males and feeder length (centimetres per hen). The table shows a minimal difference between the poultry houses in the average percentage of males during the laying period. The hens in poultry houses 3 and 4, however, had 17% more feeder length at their disposal (15.9cms versus 13.6cms). Therefore, we expect that the percentage of males hardly influenced the hens’ plumage, while feeder length did show a significant effect on plumage quality. This corres- ponds with earlier observations in practice poultry houses, where higher feeder (or pan) occupancy resulted in worse hen plumage.
Behaviour during feeding Bad plumage can possibly be explained by pushing, climbing over each other and aggressive behaviour during feeding. Due to the feed control in the breeding phase, hens are used to eating as fast as possible. At the start of the laying period they are still focused on eating quickly, even though they get more feed. In this period there is still a lot of activity around
Plumage score with longer feeder
House % males feeder length 35 weeks 45 weeks 51 weeks 58 weeks 1 9.1 13.6 2 9.3 13.6 3 9.0 15.9 4 8.9 15.9
1.7 3.0 3.7 4.4 1.7 3.0 3.9 4.4 1.3 2.9 3.5 3.7 1.4 3.2 3.6 3.8
1+2 3+4
9.2 13.6 9.0 15.9
# plumage score from 0 (perfect) to 5 (bald) ▶ POULTRY WORLD | No. 8, 2020 15
1.7 3.0 3.8 4.4 1.4 3.0 3.6 3.8
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