Percentage Of Hens Research Articles

Effect of range use on endo- and ectoparasite infestation in italian organic egg production

In organic farms, hens can freely access the outdoor areas, a potential source of helminth infections. This study aimed to evaluate the effective use of free-range access in organic laying hen’s farms located in Italy. The other objective was to quantify the major risk factors for endo- and ectoparasite infestation and its effect on performance, health and welfare, correlated to the use of free-range access. Fifteen organic farms of laying hens were assessed and visited twice. The total number of hens in the three zones was counted and recorded three times daily. Indirect indicators (characteristics of vegetation cover, amount and weight of droppings) were recorded. To evaluate parasite infestation, 15 fresh faecal samples per flock were collected from the ground/floor or perches. From seven farms, 15 gastrointestinal tracts from end-of-lay hens were qualitatively and quantitatively examined for the presence of endoparasites at different developmental stages. The percentage of hens observed outdoors in zone 3 was affected by free-range features. As expected, zone 1 was more frequented by hens than the others. The correlations among number and weight of droppings collected outside, vegetation score and the percentage of hens showed interesting results. Only three species of parasites were found during faecal samples analysis. There was a significantly and positively correlation between the number of Capillaria and Ascaridia eggs. The results showed that the presence in the free-range area of mounds, trees and bushes attracted more animals outside and allowed them to show their natural behaviour.HighlightsConsumer’s motivations to buy organic food are related to human health, environmental concerns and animal welfare. The higher animal welfare standards of organic production lead consumers to buy organic instead of conventional food of animal origin. However, some health and welfare problems that could affect organic egg production need to be addressed. The characteristics of the outdoor range are one of the factors that can most affect its use. Moreover, the use of the free range is considered one of the major risk factors for endo- and ectoparasite infestation in organic layers that can affect performance, health and welfare.

Analysis of skin color change and related gene expression after crossing of Dongxiang black chicken and ISA layer.

This study evaluated the effects of the autosomal domi-nant Fm gene in conjunction with the sex-linked Id gene on skin color and related gene expression. Ten Dongxiang black cocks were selected to build ten families by mating 60 individuals of ISA B-line layers. The skin color of the F1 generation was observed at different time points. At 126 days, 36 chickens were slaughtered, and gene expression of TYRP1, TYRP2, MC1R, and EDNRB in breast skin was assessed by quantitative RT-PCR. The ratio of Dongxiang black chickens with white skin chicks in the F1 generation to that of non-white was 3:7 (HoFF: HeFf). At 126 days, all F1 generation cocks showed white skin (115/115), while the percentages of hens with black skin were 100% (HoFF, 27/27) and 53.75% (HeFf, 43/80). The change in skin color peaked between 42 and 84 days. The offspring of HoFF displayed significantly higher expres-sion of MC1R, compared with those of HeFf (P < 0.05). The "L" value of hen's skin was significantly lower, and TYRP1 and TYRP2 expres-sion was significantly higher (P < 0.05) than in cocks with the same Fm/fm genotype. These findings indicate the presence of homozygous and heterozygous Fm in Dongxiang black chickens, with the offspring of homozygous birds showing a higher percentage of black skin percentage. The expression of the four genes studied was correlated with skin color, with TYRP1 and TYRP2 representing the most suitable molecular markers.

Prevalence of nematode infection and faecal egg counts in free-range laying hens: relations to housing and husbandry

1. Faecal samples from 19 commercial, 65 week old free-range egg laying flocks were examined to assess the prevalence and number of parasitic nematode eggs. Data were collected to characterise the housing, husbandry, behaviour and welfare of the flocks to examine possible relationships with the egg counts. 2. Eggs of at least one genus of nematode were present in the faeces of all 19 flocks. Heterakis eggs were detected in 17 (89%) flocks, Ascaridia in 16 (84%), Trichostrongylus in 9 (47%), and Syngamus in 6 (32%). Faecal egg counts (FEC) were greatest for Ascaridia and Heterakis. 3. For each nematode genus, there was no significant difference in FEC between organic (N = 9) and non-organic (N = 10) flocks, or between static (N = 8) and mobile (N = 11) flocks. 4. FEC were correlated with a range of housing, husbandry and management practices which varied between the nematode genus and included depth of the litter, percentage of hens using the range, and number of dead hens. Statistical analysis indicated relationships with FEC that included light intensity above the feeder, indoor and outdoor stocking density, fearfulness in the shed and on the range, distance to the nearest shelter, and swollen toes. 5. None of the FEC for any of the genera was correlated with weekly egg production or cumulative mortality. 6. Although nematode FEC were highly prevalent among the flocks, the overall lack of relation to other welfare and production measures suggests that these infections were not severe.

Total loss and distribution of nitrogen and phosphorus in the outdoor run of organic laying hens

1. The objective of this study was to determine the level and variation of the total mass, and load of nitrogen (N) and phosphorus (P) excreted into the outdoor run of organic egg production systems. 2. Three egg production farms with an aviary system and an outdoor run were selected for this study. Four measurements, one per season, were executed on each farm. 3. Mean content of N and P of a manure dropping was 14·0 g N kg−1 and 3·12 g P kg−1, mean mass of a dropping was 6·36 g and mean dry matter content of a dropping was 238 g kg−1. Mean rate of excretion in the outdoor run was 2·99 droppings per hen per h. Mean percentage of hens outside during the time the outdoor run could be accessed was lowest on Farm 1 (1·7%), highest on Farm 2 (16·0%), and intermediate on Farm 3 (7·1%). 4. On all farms an exponential decrease of the number of hens and of the load of N and P with increasing distance from the hen house was found. Load of N exceeded the fertilisation standard (of 170 kg ha−1 y−1) in the region at a 0 to 19 m distance from the hen house on Farm 1, 0 to 146 m on Farm 2 and 0 to 52 m on Farm 3. 5. It is concluded that the husbandry system should be redesigned to solve the problem of overloading, unwanted loss of N and P to the environment and loss of N and P from the organic production cycle.

Factors affecting changes in grey partridge population dynamics in a French arable farmland over an eleven-year period

The grey partridge Perdix perdix is of conservation concern owing to habitat heterogeneity losses and the negative impact of other environmental factors, e.g., pesticide use, predators, weather or shooting pressure, which are known to be associated with population decline. By an 11-year-period study in an intensively cultivated farmland located in the Paris basin, we aimed to relate the changes in grey partridge population dynamics with the changes in agriculture, monthly rainfall and shooting pressure. Summer drought occurred at the middle time of the study period. At the start of our study, a new cultivation, winter-wheat broadcast in maize-stubble fields, was introduced that probably improved the habitat. But in the next years, there was a loss in habitat diversity due to the disappearance of pastures dedicated to sheep rearing, removal of non-cropped areas and field boundaries and increase in the mean field size. Shooting was annually adjusted to what the owner believed to be a wise harvest. In post-breeding coveys, both percentages of hens with young among total hens and young-to-successful hens ratios first increased and then decreased. The mean brood size was rather weak during the dryness incident. The number of pairs in a more heterogeneous sector was always greater than in a less one. In both sectors, spring abundance first increased and then decreased. In the second half of the study period, the shooting quotas were reduced, especially when the mean brood size fell down. Low hatching rates of clutches and low chick survival rates explain the population decline, as the results are convincing. To stop the population decline in intensive arable farmland, good breeding success is needed. This can be provided by favourable habitats for hens to nest and for chicks to feed.

Results of the Animal Needs Index (ANI-35L) compared to animal-based parameters in free-range and organic laying hen flocks in Austria

AbstractThe aim of this study was a comparison of Animal Needs Index (ANI) data, derived from annual inspections by a control agency, with data collected from 164 selected on-farm flocks concerning feather damage, injuries, egg production, mortality, bodyweight, foot pad dermatitis, keel bone deviations and reactions towards humans (eg flock showed marked avoidance when the observer walked through the hen-house [yes/no]).Analysis of data showed a low number of significant correlations with total ANI scores and category scores: 1) Locomotion, 2) Social interaction, 3) Flooring, 4) Light, air and noise and 5) Stockmanship. Correlations found were low and total ANI score showed only a positive correlation with egg production at week 52. Category 3 scores correlated positively with egg production at week 70 and negatively with the percentage of hens with featherless areas and total pecking injuries. Category 5 scores showed positive correlations with egg production at week 52 as well as week 70 and negative correlations with mortality at week 52, the percentage of hens with featherless areas, pecking injuries &lt; 0.5 cm and total pecking injuries.Flocks showing marked avoidance had a lower total ANI score and lower category 3 and category 5 scores.In conclusion, welfare-related animal-based parameters are poorly reflected by the ANI-35-L/2001. To assess animal welfare more adequately, animal-based parameters have to be considered additionally in a welfare assessment scheme.

Effect of chronic progesterone injection on egg production in Japanese quail

Young laying turkey hens ceased laying and developed a polycystic ovarian follicle (PCOF) syndrome 3 wk after injections of progesterone (P4) ceased. It was hypothesized that laying Japanese quail chronically injected with progesterone (P4) would respond with reduced or arrested egg production and altered ovarian morphology similar to that seen in turkeys expressing the PCOF syndrome, and could thus serve as a model to study the PCOF syndrome. To test these hypotheses, 6 trials were conducted with young photosensitive Japanese quail photostimulated to induce sexual maturity with either 24L:0D or 14L:10D at 6 or 8 wk of age, and used after 3 to 5 wk of egg production. The quail were injected once daily at dosages of 0, 0.17, 0.33, 0.5, 1.5, 3.0, or 4.5 mg of P4/kg per d, or twice daily at dosages of 0 and 1.5 mg of P4/kg for 8 to 14 d and were then necropsied 1 d after the last injection or after waiting an additional 8 to 14 d. During the injection period, egg production was not different among P4 dosages <1.5 mg of P4/kg per d, but decreased at dosages of 1.5 mg of P4/kg per d or greater. A decrease in egg production was found with twice daily injections of 1.5 mg of P4/kg. The decrease in egg production rate ceased and egg production resumed 5 to 7 d after the last injections of 3.0 and 4.5 mg of P4/kg per d or twice-daily injections of 1.5 mg of P4/kg. Compared with control hens, a high percentage of hens (from 12 to 75%) held a hard-shelled egg in the uterus during single daily injections at dosages of 3.0 and 4.5 mg of P4/kg per d and twice daily injections of 1.5 mg of P4/kg. Ovary and oviductal weights, and number of hierarchical follicles were not changed after chronic P4 injection, but more atretic follicles were found in hens at the end of 8 to 12 d of P4 injection. In conclusion, a decreasing egg production rate was induced by chronic P4 injection, but the decrease ceased and egg production resumed 5 to 7 d after the last injections in laying Japanese quail. Young quail hens, unlike young turkey hens, did not develop a PCOF-like syndrome after P4 injection.

Natality of ruffed grouse Bonasa umbellus in central Wisconsin, USA

Radio‐marked female ruffed grouse Bonasa umbellus were monitored in central Wisconsin, USA, during 1983–1988 to estimate nesting rates (the percentage of hens that initiate a clutch), clutch size, nest success, and the prevalence and success of renests. All 23 radio‐marked females initiated a clutch, 22 completed a first clutch; the remaining hen was killed by a predator during laying. Mean clutch size of first nests was 11.0 ± 0.5 eggs (range = 7–13). Five of nine (56%) hens attempted to renest with a mean clutch size of 7.4 ± 1.3 eggs (range = 6–9). Mean nest success was 46%; 43% for yearlings and 60% for adults. First nests produced the large majority of eggs that hatched (86.1%) compared to renests (13.9%). Productivity was estimated at 5.8 chicks hatched for each hen alive on 20 April, the mean date of the first egg laid.

Signs Observed in Commercial Laying Hens fed a Low Dietary Salt Level

Much research has studied the use of a low salt diet to force rest laying hens, but little focuses on the accidental omission of salt from a commercial laying hen diet. In this study sixty hens were fed a low salt diet (0.02% sodium) to investigate the effects on ovarian activity. Hens were necropsied on predetermined days and the ovaries carefully examined. Follicular development was unaffected for at least five days from initiation of the low salt diet. The follicles then underwent regression, beginning with the largest follicle and continuing to progressively smaller follicles. Serum sodium levels were significantly lower and potassium higher for hens receiving the low salt diet for eleven days compared to hens receiving a control diet. Egg production, feed consumption, and egg weight decreased in groups receiving the low salt diet for six or more days. The longer the hens received the low salt diet, the greater the decrease for these parameters. The percentage of hens that molted was significantly higher in the low salt groups than in the control group; the longer hens received this diet the more significant the molting they experienced.

Effects of short-term thyroxine administration during the laying period on egg production and moulting by turkeys.

1. Effects of thyroxine (T4) administration on egg production, moulting and photorefractoriness in laying turkeys were determined. Thyroxine dosages of 0.075 to 2 mg/bird/d were injected IM for periods of either 2 or 3 weeks following 10 weeks of photostimulation. Control groups were administered saline vehicle. 2. Plasma T4 concentrations were increased in a dose dependent manner by T4 administration, while triiodothyronine (T3) was decreased. 3. Egg production and percentage of hens in production were transiently decreased in a dose dependent manner by T4 administration, but returned to levels similar to controls within 4 weeks of T4 treatment termination. Moulting was stimulated in a dose-dependent manner by T4 administration, but was similar to controls after T4 treatment termination. Only dosages of 2 mg/bird/d resulted in cessation of egg production and complete moulting. 4. Results indicate that although short term elevation of plasma T4 causes cessation of egg production and moulting these effects are transient and not indicative of photorefractoriness.

Changes in endocrinological parameters and production performances in Turkey hens ( [formula omitted][formula omitted]) submitted to different broody management programs

Occurrence of broodiness, egg production, feed consumption index and changes in the LH and prolactin levels were compared for turkey hens raised under 3 broody management programs. All hens (n = 60 per group) were regularly ejected from the nest (basic treatment). Moreover, one group of hens was also rotated weekly (partial treatment), while in the third group (full treatment) hens showing broody symptoms were also identified daily and isolated for 24 hours. The percentage of hens which were identified as broody at least once was similar under the 3 programs (30%), although the use of the full and partial programs were more effective in inducing the disruption and/or preventing further expression of broody behavior. Plasma LH concentrations decreased progressively throughout the reproductive cycle under the 3 treatments. Maximum plasma concentrations of prolactin were measured between the 5 th and the 10 th weeks of production; higher concentrations of prolactin were maintained for a longer period under the full treatment, while a lower amplitude rise in plasma prolactin concentrations was observed in the hens submitted to the partial treatment. The egg production and feed consumption indices were lower and higher, respectively, under the full treatment than the basic treatment and partial treatments. We conclude that management programs need to be carefully evaluated under commercial conditions not only with respect to broodiness expression but also to egg production.