Welfare Of Broiler Breeders Research Articles

Diet dilution and feeding frequency have only minor effects on the behaviour of broiler breeder pullets

During the rearing period, broiler breeders are feed restricted to prevent the negative impact of fast growth and high body weight on health and reproduction. Feed restriction causes frustration and stress, resulting in stereotypic pecking and hyperactivity. Nutritional strategies have the potential to reduce these welfare issues. Using a 2 × 2 factorial completely randomized block design, pullets were fed with two diet densities and two feeding frequencies during rearing. From 3–23 weeks of age (WOA), pullets received either a standard control diet (CON) or a 16% diluted diet (DIL) containing oat hulls. These diets were provided either once (FO) or twice (FT) a day. After 23 WOA, all pullets received the same standard layer diet once a day. Home pen behaviour was observed by scan sampling at 5, 10, 15, 20, 30 and 39 WOA over eight observation sessions. Furthermore, pullets were subjected to Novel Food Tests (12 and 17 WOA) and Novel Object Tests (5, 10, 15 and 20 WOA). Minor treatment effects were found for foraging and sitting behaviour that varied with age during rearing. Feeding frequency influenced the behavioural patterns of all home pen behaviours (P < 0.001; object pecking P = 0.034), while diet dilution only affected the expression of foraging behaviour during the day (P = 0.007). In all treatment groups, many pullets were observed standing and walking in anticipation of the first meal. After the first meal and before the second meal, more FT pullets were observed standing and walking, while during and after the second meal more FO pullets were observed sitting and performing comfort behaviour. Feeding twice a day resulted in lower daily peaks in drinking behaviour. In the laying period, when all birds received the same layer diet at the same frequency, those who were fed twice daily during rearing foraged more than those who were fed once (P = 0.028) and birds that received a diluted diet during rearing tended to drink more than birds that received the control diet (P = 0.083). Few treatment effects were found in the Novel Food and Novel Object Tests, indicating that diet dilution and/or feeding frequency, as applied here, did not affect fearful behaviour or the motivation to explore. In conclusion, this study showed that neither diet dilution, twice-daily feeding, or the combination of these, improved broiler breeder welfare during rearing and laying. Some changes in the pattern of home pen behaviour were found that indicated a response to the frequency of food provisioning.

Gregarious nesting in relation to floor eggs in broiler breeders

Gregarious nesting has often been observed in laying hens, where hens prefer to visit a nest already occupied by other hens over empty nests. This may result in overcrowding of the nests which is considered a welfare issue and, moreover, can increase the economic issue of floor eggs. This study aimed to describe gregarious nesting and spatial behavior in broiler breeders and how this relates to genetic background, fearfulness and mating behavior. Five commercially available genetic lines of broiler breeders were housed in 21 pens of 550 females and 50 males (six pens for lines 1 and 2, five pens for line 3 and two pens for lines 4 and 5) during the ages 20–60 weeks. Every 10 weeks, the plumage condition and wounds were assessed of 50 random hens per pen. Avoidance distance and novel object tests were performed to assess fearfulness at four time points. Distribution of eggs over nests was observed for 6 weeks at the onset of egg production at 26 weeks of age, and use of space was recorded at four time points, while (floor) egg production was noted daily per pen. We found differences between genetic lines over time in plumage condition and prevalence of wounds. Fear of humans was highest at the earliest age tested and did not correlate with general fearfulness as assessed by the novel object test. The distribution of eggs over nests was related to genetic background and was more uneven at the earliest age compared to later ages, and a more uneven distribution was correlated with an increased percentage of floor eggs. Distribution of birds over the litter area differed between the genetic lines, and less use of the litter area was correlated with an increased fear of humans and presence of wounds, suggesting an association with aggressive mating behavior. This difference in distribution of the birds could also explain the correlation between increased presence of wounds and decreased percentage of floor eggs. It is concluded that broiler breeders do show gregarious nesting, which is affected by genetic background. Both increased gregarious nesting and wounds are related to increased floor egg percentage, which should be studied further in broiler breeder research. Genetic selection for even use of the available nests and of the litter and slatted area would therefore support both broiler breeder welfare and performance.

Motivation for feeding in broiler breeder pullets fed different types of restricted high-fibre diets

High-fibre diets have been suggested as alternative feeding strategies that potentially may alleviate the hunger felt by feed-restricted broiler breeders and fulfil their behavioural need for feeding behaviour. The aim of the present study was to investigate the effects of four dietary treatments, differing in fibre types and content, on the motivation for performing feeding behaviour, including both the appetitive and consummatory phase, in broiler breeder pullets. In total, 1200 female breeder chicks of the genotype Ross 308 were housed in 24 pens, six pens of initially 50 birds per treatment. The dietary treatments were: 1) standard feed (Control), 2) feed containing insoluble fibres (Insoluble), 3) feed containing a mix of insoluble and soluble fibres (Mixed) and 4) standard feed supplemented with maize silage (Roughage). Four measures of feeding motivation were obtained: feeding rate, behaviour indicating frustration during thwarted feeding, compensatory feed intake over 5 days and motivation to gain access to fresh litter. The latter was performed at 12–13 weeks of age, whereas the other measures were obtained both at 8–9 and 17–18 weeks of age. Litter quality in the home pens was assessed at age 13 weeks and dry matter content at 5, 13 and 14 weeks of age. Feeding rate was not affected by treatment (P = 0.26). Insoluble and Mixed birds showed fewer behavioural transitions, i.e. changes in activity, during thwarted feeding at 17/18 weeks of age than Control birds (P = 0.004), indicating less frustration and thus a lower feeding motivation. The compensatory feed intake was lower for Insoluble birds compared to Control birds, indicating that the Insoluble treatment reduced the hunger experienced by the birds. Mixed birds were clearly more motivated to gain access to the fresh litter with more and faster crossings into the litter compartment (P ≤ 0.01). Although foraging was the predominant behaviour performed in the litter compartment, Mixed birds spent less time on locomotion (P = 0.002), more time on comfort behaviour (P = 0.02) and more time resting (P < 0.0001) than Control birds, suggesting that they were also motivated to gain access to litter for increased comfort. The litter quality in the home pens was poorest in the Mixed treatment (P = 0.0001). In conclusion, none of the treatment diets seemed to improve the welfare of broiler breeders markedly during the rearing period, although the Mixed and Insoluble diets may, to some extent, have reduced the feeding motivation.

Impact of an alternate feeding program on broiler breeder pullet behavior, performance, and plasma corticosterone

Broiler breeders are commonly feed restricted using some variation of skip-a-day feeding to prevent excessive body weight (BW) gain and poor flock uniformity that results in lower production levels. However, the level of feed restriction has increased leading to negative effects on broiler breeder welfare. Research needs to be conducted to evaluate alternative feeding programs to diminish the negative impact of restricted feeding on bird welfare. This research examined pullets that were fed soybean hulls (alternate day feeding, ATD) on the off day of a traditional skip-a-day feeding program in comparison to the standard skip-a-day program (SAD). The 2 dietary feeding treatments each had 3 replicate pens of 210 pullets each and were fed from wk 5 to 21 of age. Nitrogen-corrected true metabolizable energy and digestible amino acid coefficients of soybean hulls were determined. Body weight in the ATD feed program was significantly higher (P < 0.001) than the birds on the SAD feed program until 16 wk of age. Feed allocations for the SAD feeding program was increased at 11 wk of age to achieve similar BW prior to photo stimulation. The ATD feed program significantly improved BW uniformity of the birds for weeks 8, 12, 16, and 20. Hens fed on the SAD feed program had a lower mean egg production than the hens fed on the ATD program. There were significant differences on plasma corticosterone concentrations between the feeding days (24 or 48 h after feeding) in both feed programs. There was a shift in the behavior of the birds with significant differences in the feeding, foraging, and comfort behaviors between the feeding programs on the same feed day. Overall, feeding the ATD females soybean hulls on the off feed day improved the BW uniformity and egg production, but further research will be needed to determine potential differences in nutrient utilization or behavior of the pullets that positively impacted this flock performance.

The effect of alternative feeding strategies on the feeding motivation of broiler breeder pullets

Due to genetic selection for fast growth and high breast meat yield, commercial strains of broiler chickens and broiler breeders are predisposed to high feed intake; however, feeding broiler breeders ad libitum impairs their health and reproductive performance. Broiler breeders are feed-restricted throughout rearing to maintain health and performance, yet feed restriction results in hunger, feeding frustration and lack of satiety. The objective of this study was to examine the effect of alternative feeding strategies, including feed additives (separately or combined) and a fixed non-daily feeding schedule, on the feeding motivation and welfare of broiler breeders during rearing. At 3 weeks of age, 180 Ross 308 breeder pullets were allocated to 90 cages and fed with one of five isocaloric treatments: (1) daily control diet (control), (2) daily calcium propionate diet (CaP), (3) daily soybean hull diet (SBH), (4) daily alternative diet (alternative: CaP + SBH) and (5) 4/3 control diet (four on-feed days and three non-consecutive off-feed days per week). The CaP diet included calcium propionate at 1.4% from 3 to 6 weeks of age, and at 3.2% from 7 to 12 weeks of age, and the SBH diet contained soybean hulls included at 40%. The alternative diet included both soybean hulls and calcium propionate at the same inclusion rate as the SBH and CaP diets, respectively. Pullets were weighed and scored for feather coverage every week. A feed intake test was conducted at 3, 4, 8, 10 and 11 weeks of age for 10 min during on- and off-feed days. At 12 weeks of age, feather samples were analysed for fault bars. Data were analysed using linear mixed regression models, with cage nested in the models and age as a repeated measure. At 4 weeks of age, pullets fed soybean hull-enriched diets (SBH and alternative diets) and those on the 4/3 schedule had lower feed intake than control pullets (P = 0.02). Feathers from pullets fed the SBH diet had fewer fault bars than those fed the CaP diet (P = 0.04). The results indicated that the inclusion of soybean hulls (alone or combined with calcium propionate) and a 4/3 feeding schedule can reduce feeding motivation of broiler breeders during early rearing.

The effect of alternative feeding strategies for broiler breeder pullets: 1. Welfare and performance during rearing.

ABSTRACTBroiler breeders have impaired reproductive performance when fed to satiety but they can achieve an optimal hatching egg production under feed restriction. Feed restriction is a welfare concern due to signs of hunger, lack of satiety, and frustrated feeding motivation. The objective of this research was to examine the effect of a rationed alternative diet and non-daily feeding schedules on the performance and welfare of broiler breeder pullets reared under simulated commercial conditions. At 3 wk of age, 1,680 Ross 308 pullets were allocated to 24 pens fed with 1 of 4 treatments: 1) daily control diet (control); 2) daily alternative diet (40% soybean hulls and 1 to 5% calcium propionate); 3) 4/3 control diet (4 on-feed days per week; 3 non-consecutive off-feed days per week); and 4) graduated control diet (feeding frequency varied with age). Body weight and body weight uniformity were recorded at 3, 5, 7, 11, 17, and 21 wk of age. Pullets were scored for feather coverage, foot lesions, and hock burns biweekly. Physiological indicators (plasma glucose, corticosterone, hematology, and feather traits) and feeding motivation were also determined throughout rearing during on- and off-feed days. Data were analyzed using a linear mixed regression model, with pen nested in the model and age as a repeated measure. Compared to control, pullets under the 3 alternative feeding strategies had a lower feeding motivation during early rearing (P = 0.03), better feather coverage throughout rearing (P = 0.001), fewer feather fault bars (P = 0.006), and a delayed increase in the basophil to lymphocyte ratio (P = 0.001). These results indicate that the 3 alternative feeding strategies (the alternative, the graduated, and the 4/3 schedule) may decrease feeding motivation and alleviate stress compared to the control, suggesting an overall improvement in broiler breeder welfare without negative consequences on their performance.

Logistic regression to estimate the welfare of broiler breeders in relation to environmental and behavioral variables

The increasing demand of consumer markets for the welfare of birds in poultry house has motivated many scientific researches to monitor and classify the welfare according to the production environment. Given the complexity between the birds and the environment of the aviary, the correct interpretation of the conduct becomes an important way to estimate the welfare of these birds. This study obtained multiple logistic regression models with capacity of estimating the welfare of broiler breeders in relation to the environment of the aviaries and behaviors expressed by the birds. In the experiment, were observed several behaviors expressed by breeders housed in a climatic chamber under controlled temperatures and three different ammonia concentrations from the air monitored daily. From the analysis of the data it was obtained two logistic regression models, of which the first model uses a value of ammonia concentration measured by unit and the second model uses a binary value to classify the ammonia concentration that is assigned by a person through his olfactory perception. The analysis showed that both models classified the broiler breeder's welfare successfully.

Sistema fuzzy para estimativa do bem-estar de matrizes pesadas

Entender o comportamento e suas pequenas variações decorrentes das mudanças do ambiente térmico e desenvolver modelos que simulem o bem-estar a partir de respostas das aves ao ambiente constituem o primeiro passo para a criação de um sistema de monitoramento digital de aves em galpões de produção. Neste trabalho, foi desenvolvido um sistema de suporte à decisão com base na teoria dos conjuntos fuzzy para a estimativa do bem-estar de matrizes pesadas em função de frequências e duração dos comportamentos expressos pelas aves. O desenvolvimento do sistema passou por cinco etapas distintas: 1) organização dos dados experimentais; 2) apresentação dos vídeos em entrevista com "especialista"; 3) criação das funções de pertinência com base nas entrevistas e na revisão da literatura; 4) simulação de frequências de ocorrências e tempos médios de expressão dos comportamentos classificados como indicadores de bem-estar utilizando equações de regressão obtidas na literatura, e 5) construção das regras, simulação e validação do sistema. O sistema fuzzy desenvolvido estimou satisfatoriamente o bem-estar de matrizes pesadas, tendo na sua última versão, com maior número de regras, acertado 77,8% dos dados experimentais, comparados com as respostas esperadas por um especialista. O sistema pode ser utilizado como instrumento matemático-computacional para apoiar decisões em galpões de produção de matrizes pesadas.

Economic and Welfare Benefits of Environmental Enrichment for Broiler Breeders

Designs to enrich the environment are crucial in the effort to fully address the biological needs of domestic animals. Although enrichment programs have been shown to improve health and welfare, little is known of their potential for application to commercial broiler breeder environments. We investigated the potential benefits of cover panels for broiler breeder reproductive performance in a commercial setting. This demonstration trial occurred on 5 commercial broiler breeder farms, each with a control and panel treatment room containing approximately 7,000 females and 800 males. Reproductive performance was measured from 25 to 60 wk by the number of eggs laid per female per week as well as weekly fertility and hatchability rates. The location of marked males was recorded weekly to quantify male movement. Access to cover panels improved egg production by 2.1% and maintained better hatchability and fertility throughout the breeding cycle (significant interactions of age and panel treatment) leading to an additional 4.5 chicks/female. Male home ranges, based on minimum convex polygons, were larger in the enriched (259 +/- 24.4 m(2)) vs. control flocks (184 +/- 23.1 m(2)). Providing enrichment in the form of cover panels improved reproductive performance, most likely by increasing males' mating opportunities and reducing female stress. We found a clear economic benefit to providing enrichment, an estimated $3 million if all breeder houses within the participating company were outfitted with the panels. These results demonstrate that environmental enrichment is not only beneficial for broiler breeder welfare, but can also be economically advantageous, resulting in a win-win situation for poultry welfare and production.

Behaviour and welfare of broiler breeders fed qualitatively restricted diets during rearing: Are there viable alternatives to quantitative restriction?

This study investigated whether feeding female broiler breeders on qualitatively, rather than quantitatively, restricted diets during rearing could improve their welfare while also achieving desired growth rates. There were six treatments, each with four replicate pens of 12 birds. From 1 to 20 weeks of age, birds in a control treatment (T1) received a quantitatively restricted amount of a standard mash diet while birds in five additional treatments (T2–T6) had ad libitum access to experimental diets. The latter were based on standard mash and contained supplements of calcium propionate (CaP, an appetite suppressant), or oat hulls (OH, a dietary diluent), or both, that were increased with bird age. Birds received diets with either increasing CaP (T2), low protein and increasing CaP (T3), OH and increasing CaP (T4), CaP and increasing OH (T5), or increasing both CaP and OH (T6). Effects of treatment on body weight, behaviour, response to a feeding motivation test, and blood indices of stress were recorded. Results showed that different qualitative restriction treatments can limit growth rate close to target. T4, with 40% OH and increasing CaP, limited body weight closest to the desired level. Between 6 and 20 weeks of age, control birds (T1) spent 47–54% of their time in object pecking, which was almost absent (<1%) in all experimental treatment groups. Time spent inactive (sitting) and total time observed in all oral behaviours differed little between treatments. In a feeding motivation test, T1 birds consumed more food in 2 min after 2 or 4 h of food deprivation than did birds in any experimental treatment group. Treatment had no effect on the ratio of heterophils to lymphocytes or on the frequencies of other white blood cells. Plasma corticosterone level was raised in T5 birds, whose mean body weight was suppressed to below the commercial target for most of the study, but was otherwise unaffected by treatment. The results suggest that appropriate appetite suppression, with or without dietary dilution, can be an effective method of controlling broiler breeder growth rate. However, although there was some indication that such dietary treatments may be beneficial for bird welfare (e.g. the absence of abnormal pecking at non-food objects), other behaviours and physiological indices of stress did not differ consistently between experimental and control birds.

Do low-density diets improve broiler breeder welfare during rearing and laying?

Low-density diets may improve welfare of restricted fed broiler breeders by increasing feed intake time with less frustration of feed intake behavior as a result. Moreover, low-density diets may promote satiety through a more filled gastrointestinal tract, and thus feelings of hunger may be reduced. Broiler breeders were fed 4 different diets during the rearing and laying periods. Behavioral and physiological parameters were measured at different ages as indicators of hunger and frustration of the feeding motivation. A diet of 8.4 MJ/kg as compared with a standard diet of 10.9 MJ/kg extended feeding time and reduced stereotypic object pecking at 6 and 10 wk of age. Furthermore, compensatory feed intake at 12 wk of age was reduced. During lay, differences in behavior were observed between the treatments that could be attributed to differences in feeding time. However, birds fed the diet with the lowest energy content (i.e., 9.2 MJ/kg) had higher heterophil to lymphocyte ratios (H/L) at 40 wk of age compared with the other treatments, indicating that they experienced more stress during the laying period than the other treatments. This result could have been due to the very long feeding time of this treatment group during lay, which may be stressful. In conclusion, a low-density diet of 8.4 MJ/kg may reduce hunger and frustration in the first half of the rearing period. However, for substantial improvement of broiler breeder welfare during rearing, more extreme diet modifications are required.

Effect of scattered feeding and feeding twice a day during rearing on indicators of hunger and frustration in broiler breeders

Broiler breeders are routinely fed restricted during rearing which has a major negative effect on their welfare. They suffer from hunger and frustration from thwarting of feeding. The aim of this experiment was therefore to study if broiler breeder welfare can be improved by changes in the feeding system that can easily be applied in practical broiler breeder husbandry. We investigated the effects of scattered feeding in the litter and/or feeding twice a day on parameters of hunger and frustration in broiler breeders. Scattered feeding reduced the time spent object pecking but has no effect on other indicators of hunger like the compensatory feed intake, the plasma glucose/NEFA ratio and plasma corticosterone concentrations. Broiler breeders fed two meals a day show more walking, which may indicate food searching-related activity or frustration of the feeding motivation. Moreover, compensatory feed intake, the glucose/NEFA ratio and plasma corticosterone concentrations were similar in birds fed either one or two meals a day. It is unclear if the reduced time spent on object pecking, but the large proportion of time spent on foraging activities in scattered fed birds can be interpreted as reduced frustration and thus as an improvement of broiler breeder welfare. We conclude that scattered feeding, feeding twice a day and a combination of these two feeding strategies do not significantly improve broiler breeder welfare during rearing as indicators of hunger have not changed.

Parameters for quantification of hunger in broiler breeders

The commercial restricted feeding programme of broiler breeders has a major negative effect on welfare, as the birds are continuously hungry. Objective parameters of hunger are needed to evaluate new management or feeding systems that may alleviate hunger and thus improve broiler breeder welfare. The aim of this experiment was to develop such parameters. Female broiler breeders (Hybro G), n=10 per treatment, were subjected to different levels of feed restriction and we assumed that we thus induced different levels of hunger. Treatment groups were fed ad libitum and at 90%, 70%, 50%, 35% and 25% of ad libitum. In addition, female broiler breeders that were less intensively selected on growth and food conversion (JA57, n=10 per treatment) were fed ad libitum and at 70% of ad libitum. At 6–7 weeks of age, home pen behaviour, behaviour in the open field and baseline plasma corticosterone, glucose and nonesterified fatty acid (NEFA) concentrations were determined. Thereafter, birds were subjected to the feed intake motivation (FIM) test that measures compensatory feed intake. Linear relationships between the level of restriction and the compensatory feed intake on the first days of the FIM test and the glucose/NEFA ratio were found which indicate that these parameters can be used to quantify the level of hunger. Curvilinear relationships between sitting and standing in the home pen, walking in the open field and level of restriction were found. A third-grade hyperbolic relationship between the level of restriction and the baseline plasma corticosterone concentration was found. Thus, these parameters do not seem to represent a straightforward relation with the level of hunger. Intensive selection on growth and food conversion seems to have affected the behaviour but not the physiological responses to feed restriction, because the JA57 birds responded behaviourally, but not physiologically, different to feed restriction as compared with the Hybro birds.

Broiler breeders: feed restriction and welfare

Broiler breeders are truly caught in a welfare dilemma, because the management practices that are necessary to ensure health and reproductive competence may also result in a reduction in other aspects of welfare. In this paper I review the welfare concerns associated with feed restriction of broiler breeders. Broiler breeders show evidence of physiological stress as well as an increased incidence of abnormal behaviours, and are also chronically hungry. Alternative methods of decreasing feed intake, dietary dilution or the use of anorexic agents, are also discussed. Thus far, all of these methods have proven unsatisfactory in terms of body weight control, and in addition they do not necessarily improve welfare. Emphasis needs to continue to be placed on developing alternatives to, and modifications of, current feed restriction programmes in order to improve broiler breeder welfare. In addition, the use of genetic selection to decrease the need for restriction should be further explored.

Effects of qualitative and quantitative food restriction treatments on feeding motivational state and general activity level of growing broiler breeders

Growing broiler breeder chickens are fed restricted rations to limit body weight at sexual maturity. This experiment tested a proposal (Brouns, F., Edwards, S.A., English, P.R., 1994. Effect of dietary fibre and feeding system on activity and oral behaviour of group housed gilts. Appl. Anim. Behav. Sci. 39, 215–223.) that feeding motivation is reduced by using qualitative rather than quantitative food restriction, and it examined relationships among suppression of growth rate, feeding motivational state and general activity level. From 2 to 15 weeks of age, female broiler breeders were reared in six groups of 20, each with a different feeding treatment. The six treatments were: high and low levels of diet dilution (600–700 g/kg and 300–350 g/kg oat feed, ad libitum), appetite suppression (50–60 g/kg and 25–30 g/kg calcium propionate, ad libitum) and quantitative restriction (recommended daily ration and twice that amount). Birds were conditioned to an operant (PR1 schedule) feeding procedure with their respective treatment diets from 3 to 7 weeks, and this was used to measure feeding motivation in 12-min tests at three times of day (1000, 1300 and 1600 h) at 8, 10, 12 and 14 weeks. Proportions of time spent sitting were measured as an index of general inactivity in systematic observations at 9, 11, 13 and 15 weeks. Although the diet dilution and appetite suppression (qualitative) treatments did not limit growth rates as intended, they and the quantitative treatments produced a range of mean body weights to compare with feeding motivation whenever birds were tested. With body weight as a covariate, there were significant effects on numbers of operant responses in 12 min (the measure of feeding motivation) of weight, age, time of day and treatment×time interaction, but not treatment. Feeding motivation was positively correlated with suppression of growth rate, regardless of how that suppression was achieved. However, the experimental procedure required all test birds to be without food from 0900 or 0915 h, and motivation was lowest in the earliest (1000 h) test with qualitative but not quantitative treatments. Hence, there was some evidence that feeding motivation may be partially suppressed with qualitative food restriction; distinction can be made between short-term and longer-term feeding motivation. General activity level (inversely reflected by time spent sitting) was closely correlated positively with both suppression of growth rate and feeding motivation. As a fundamental relationship between feeding motivation and reduction of growth rate was not altered by using qualitative rather than quantitative food restriction, these results support an earlier conclusion (Savory, C.J., Hocking, P.M., Mann, J.S., Maxwell, M.H., 1996. Is broiler breeder welfare improved by using qualitative rather than quantitative food restriction to limit growth rate? Anim. Welfare 5, 105–127.) that broiler breeder welfare is not improved with qualitative restriction methods.

The welfare of broiler breeders

In August 1998, the UK's Farm Animal Welfare Council (FAWC) published its most recent report: addressing the welfare of broiler breeders. Some 780 million broiler chicks are produced annually in the UK and at any one time the national population of broiler breeder hens that produce these chicks is about 6 million. Professor Sir Colin Spedding in his letter (reproduced on page iii of the report) introducing the report to the Minister of Agriculture Fisheries and Food, points out that broiler breeders are relatively valuable birds and that there is a strong commercial incentive to ensure they receive careful husbandry. However, commercial forces do not always pull in the same direction as welfare considerations and they have lead to some particular dilemmas in the welfare of broiler breeders.

Is Broiler Breeder Welfare Improved by Using Qualitative Rather Than Quantitative Food Restriction to Limit Growth Rate?

AbstractPossible welfare benefits of qualitative rather than quantitative food restriction were investigated with growing female broiler breeder chickens (Ross 1). In Experiment 1, body-weight gains from 2 to 6 weeks of age were compared among different diet dilution, appetite suppression and low protein treatments, with free access to food at all times, to identify qualitative treatments causing weight gains similar to that recommended in theRoss 1 Parent Stock Management Manual. Based on these results, four diet dilution (400g kg−1unmolassed sugar-beet pulp, 300 and 600g kg−1oat hulls, 500g kg−1softwood sawdust) and one appetite suppression (50g kg−1calcium propionate) treatments were compared with two quantitative restriction (the recommended daily ration and twice that amount) and one ad libitum control treatments, from 2 to 10 weeks of age, in Experiment 2. As well as growth, food intake, excreta production and digestibility, measurements were also made of behaviour and blood indices of stress. Several conclusions were drawn. Different methods of qualitative food restriction can be used to control growth rate within desired limits. Problems with these methods include reduced uniformity in weight gain, increased excreta production and/or increased cost. Although they appear to suppress abnormal oral behaviours, they do not alter the increased general activity which is correlated with suppression of growth rate, and which may more accurately reflect associated hunger. Suppression of abnormal oral behaviours may only rarely correspond with reduction in blood indices of stress, and so cannot be taken to indicate improved welfare. Some of these methods can add to physiological stress. Finally, there was insufficient evidence of improved welfare, based on both behavioural and physiological criteria, to justify advocating the suitability of any of these methods for commercial use.

Optimum size of feeder grids in relation to the welfare of broiler breeder females fed on a separate sex basis

1. The rate of eating food was studied in two experiments to assess the relationship between head width and size of feeder grids in broiler breeder females. 2. The optimum grid size for food intake was 4 mm wider than head width. 3. Physical injury should be avoided if the grid aperture is 2 mm wider than the maximum head width in the flock measured at the posterior edge of the mandibles. 4. The rate of eating was decreased in all grid sizes examined compared to feeders without grids but the importance of this observation for the welfare of broiler breeders is not clear.