title: Biofibre Production from Chicken Feather

authors: Tseng, Fan-Chen Jeanie

subjects: feather

abstract: The global poultry industry generates at least 2 million tonnes of chicken feather every year. Feathers are currently hydrolysed into meal used for animal feed and fertilizer. Feather consists of 91% keratin, 1% lipid and 8% water. Raw feather also contains preen oil, offal, faecal matter and poultry processing water. Its morphology consists of barbs extending at an angle from a central hollow rachis. Impurities coat the entire feather, and particulates are trapped by layers of barbules and hooked barbicels holding adjacent barbs together. These substructures present an extensive and tortuous hydrophobic surface. Feather fibre is a multipurpose, cost effective reinforcement for polymer composites. Its incorporation in plastic, wood, concrete and cardboard makes the product lighter, insulate from heat loss and improve sound attenuation properties. The objective of this study was to develop a process to produce clean fibre recovered from chicken feather. In the treatment process, the heterogeneous characteristics of feather had to be considered. Raw feather was suspended in 25 L water in a pulper to be decontaminated using 2 stages of 0.1485% sodium hypochlorite adjusted to pH 10.0 with 1 M sodium hydroxide and cleaned in 3 stages of 0.15% hydrogen peroxide. The pulper disc impeller agitated the suspension at 10 Hz for 30 minute at each stage. Bacteriological tests confirmed pathogens such as Campylobacter, Salmonella and Enterobacteriaceae were removed during treatment. Off-white clean feathers were more than 10% whiter than dull yellow raw feather. Cleaned feather was comminuted in 300 L water using a centrifugal pump at a flow rate of 30Hz on full recycle for 4 hours. Rachis and partially cut feather were removed using a 5 mm aperture filter and fibre was recovered using a 1 mm filter. Wet fibre was dried to constant mass in an air-forced oven at 70°C. Fibre yield was 27% of feather input, or 54% of theoretical yield. Surface morphology showed no damage.

text: Biofibre Production from Chicken Feather The global poultry industry generates at least 2 million tonnes of chicken feather every year. Feathers are currently hydrolysed into meal used for animal feed and fertilizer. Feather consists of 91% keratin, 1% lipid and 8% water. Raw feather also contains preen oil, offal, faecal matter and poultry processing water. Its morphology consists of barbs extending at an angle from a central hollow rachis. Impurities coat the entire feather, and particulates are trapped by layers of barbules and hooked barbicels holding adjacent barbs together. These substructures present an extensive and tortuous hydrophobic surface. Feather fibre is a multipurpose, cost effective reinforcement for polymer composites. Its incorporation in plastic, wood, concrete and cardboard makes the product lighter, insulate from heat loss and improve sound attenuation properties. The objective of this study was to develop a process to produce clean fibre recovered from chicken feather. In the treatment process, the heterogeneous characteristics of feather had to be considered. Raw feather was suspended in 25 L water in a pulper to be decontaminated using 2 stages of 0.1485% sodium hypochlorite adjusted to pH 10.0 with 1 M sodium hydroxide and cleaned in 3 stages of 0.15% hydrogen peroxide. The pulper disc impeller agitated the suspension at 10 Hz for 30 minute at each stage. Bacteriological tests confirmed pathogens such as Campylobacter, Salmonella and Enterobacteriaceae were removed during treatment. Off-white clean feathers were more than 10% whiter than dull yellow raw feather. Cleaned feather was comminuted in 300 L water using a centrifugal pump at a flow rate of 30Hz on full recycle for 4 hours. Rachis and partially cut feather were removed using a 5 mm aperture filter and fibre was recovered using a 1 mm filter. Wet fibre was dried to constant mass in an air-forced oven at 70°C. Fibre yield was 27% of feather input, or 54% of theoretical yield. Surface morphology showed no damage.

year: 2011

title: Selective attention in dairy cattle

authors: Blackmore, Tania Louise

subjects: Social Sciences

abstract: In a replication of Reynolds (1961), two cows learned to discriminate between compound stimuli in a forced choice procedure where pushing through a one-way gate marked with a red cross (S+) gave access to food. Pushing through a one-way gate marked with a yellow triangle (S−) gave no access to food. To investigate whether shape or colour was controlling behaviour, probe tests varied either the shape or the colour of the stimuli (e.g., a red vs. a yellow cross, and a red cross vs. a red triangle). Results suggested control by colour rather than shape, as the gate marked with the red stimulus was chosen more than the gate marked with the yellow stimulus regardless of stimulus shape, and when two shapes of the same colour (either red or yellow) were presented, cows chose both equally. Further probe tests with painted red, white, and yellow stimuli showed that the cows had learned to avoid yellow rather than to approach red, suggesting discriminative behaviour was controlled by the colour of the negative stimulus and not by either aspect of the positive stimulus. It is not clear why the negative stimulus was more salient, but it may reflect a tendency for cows to learn to avoid farm handling practices which involve mainly negative stimuli.

text: Selective attention in dairy cattle In a replication of Reynolds (1961), two cows learned to discriminate between compound stimuli in a forced choice procedure where pushing through a one-way gate marked with a red cross (S+) gave access to food. Pushing through a one-way gate marked with a yellow triangle (S−) gave no access to food. To investigate whether shape or colour was controlling behaviour, probe tests varied either the shape or the colour of the stimuli (e.g., a red vs. a yellow cross, and a red cross vs. a red triangle). Results suggested control by colour rather than shape, as the gate marked with the red stimulus was chosen more than the gate marked with the yellow stimulus regardless of stimulus shape, and when two shapes of the same colour (either red or yellow) were presented, cows chose both equally. Further probe tests with painted red, white, and yellow stimuli showed that the cows had learned to avoid yellow rather than to approach red, suggesting discriminative behaviour was controlled by the colour of the negative stimulus and not by either aspect of the positive stimulus. It is not clear why the negative stimulus was more salient, but it may reflect a tendency for cows to learn to avoid farm handling practices which involve mainly negative stimuli.

year: 2016

title: Improving prediction of potential for treatment completion at Tai Aroha

authors: Astridge Clarke,  Abigail Darcy

subjects: Treatment

abstract: Participant non-completion can be a major problem for treatment programmes. Staff may try to minimise non-completion by deciding who to select for treatment using professional intuition and referral information. It can be difficult for treatment staff to make these decisions regarding the potential for programme completion due to a lack of clear guidelines about what information to consider. This lack of clear guidelines can increase susceptibility to biases, and lead to unreliable and potentially inaccurate decisions. Research has identified ‘simple rules’ that are tools to aid decision-making quickly, effectively, and consistently. Therefore, using past treatment data, we1 aimed to identify predictors of programme completion vs. non-completion at Tai Aroha—a residential treatment programme based in Hamilton—to explore whether a “simple rule” can be developed from information readily available at the time of referral, to support staff decision-making when selecting offenders to attend treatment, with the potential to increase programme completion. We were successful in the development of a simple rule to aid Tai Aroha staff selection decisions. The implications, and limitations of our rule and our study are discussed, and future research relating to simple rules are identified.

text: Improving prediction of potential for treatment completion at Tai Aroha Participant non-completion can be a major problem for treatment programmes. Staff may try to minimise non-completion by deciding who to select for treatment using professional intuition and referral information. It can be difficult for treatment staff to make these decisions regarding the potential for programme completion due to a lack of clear guidelines about what information to consider. This lack of clear guidelines can increase susceptibility to biases, and lead to unreliable and potentially inaccurate decisions. Research has identified ‘simple rules’ that are tools to aid decision-making quickly, effectively, and consistently. Therefore, using past treatment data, we1 aimed to identify predictors of programme completion vs. non-completion at Tai Aroha—a residential treatment programme based in Hamilton—to explore whether a “simple rule” can be developed from information readily available at the time of referral, to support staff decision-making when selecting offenders to attend treatment, with the potential to increase programme completion. We were successful in the development of a simple rule to aid Tai Aroha staff selection decisions. The implications, and limitations of our rule and our study are discussed, and future research relating to simple rules are identified.

year: 2023