Effects of late incubation temperature and moment of first post-hatch feed access on neonatal broiler development, temperature preference, and stress response.

Early life experiences are known to be of great importance for later life. For instance, exposure to stress during early life can increase fearfulness at later age. In broilers, delayed feeding after hatch may cause metabolic stress. Besides, delayed feeding after hatch may affect neonatal broiler development and thermogenesis and consequently preferred ambient temperature. Moreover, these effects of feeding strategy may be dependent on late incubation temperature. To study this, eggs (n = 1,338) from a 54-wk-old Ross broiler breeder flock were incubated at 37.8°C (control) or 36.7°C (lower) eggshell temperature (EST) during late incubation (≥ embryonic d 17). At hatch, two feeding strategies were applied (direct access (early feeding) or 51 to 54 h delayed access (delayed feeding)). Broilers (n = 960) were equally divided over 32 pens and grown for 3 wk. Stress was assessed by determination of corticosterone in blood at 0 h, 48 h, 96 h and d 21 after hatch. Fearfulness was assessed by tonic immobility at d 13. Temperature preference was assessed at d 2 and d 12. Broiler development was determined at 0 h, 48 h, and 96 h after hatch. There was no EST × feeding strategy interaction for any parameter (P ≥ 0.07). Early feeding resulted in a 2.5× lower plasma corticosterone concentration at 48 h (P < 0.01) and a 2.2°C and 2.0°C lower preference temperature for d 2 and d 12 respectively (P = 0.01) compared to delayed feeding. Tonic immobility was not affected. In conclusion, early feeding reduces exposure to stress in the short term and stimulates thermoregulatory ability of broilers in the longer term.

Broiler resilience to colibacillosis is affected by incubation temperature and post-hatch feeding strategy.

Colibacillosis is a poultry disease that negatively affects welfare and causes economic losses. Treatment with antibiotics raises concerns on antimicrobial resistance. Consequently, alternative approaches to enhance poultry resilience are needed. Access to feed and water directly after hatch (early feeding) may enhance resilience at later ages. Additionally, a high eggshell temperature (EST) during mid incubation may improve chick quality at hatch, supporting potential positive effects of early feeding. Effects of EST [37.8°C (control) or 38.9°C (higher)] during mid-incubation (embryo days 7-14) and feeding strategy (early feeding or 48 h delayed feeding) were tested in a 2 × 2 factorial arrangement. At hatch, Ì´ 1,800 broilers were divided over 36 pens and grown for 6 wk. At d 8 post hatch, avian pathogenic E. coli (APEC) was inoculated intratracheally as model to investigate broiler resilience against respiratory diseases. Incidence and severity of colibacillosis, local infection, and systemic infection were assessed at 6 moments between 3 h and 7 d postinoculation. Broilers were weighed daily during 13 d postinoculation and weekly thereafter. At higher EST, early feeding resulted in higher incidence of systemic infection compared to delayed feeding whereas at control EST, systemic infection was not different between feeding strategies. Regardless of EST, early compared to delayed feeding resulted in lower incidence of local infection, fewer BW deviations, and higher growth until d 35. In conclusion, early feeding could be considered as a strategy to enhance broiler resilience, but only when EST is not too high.

Effects of eggshell temperature pattern during incubation on primary immune organ development and broiler immune response in later life.

Eggshell temperature (EST) during incubation greatly affects embryo development, chick quality at hatch, and subsequently various broiler physiological systems. Until now, a constant EST of 37.8°C seems optimal. Data on effects of EST patterns on immune organ development and subsequent broiler immune response are, however, scarce. A higher EST of 38.9°C in week 2 and/or a lower EST of 36.7°C in week 3 of incubation potentially positively affect embryo immune organ development and broiler immune response post hatch. Broiler eggs (n = 468) were incubated at 4 different EST patterns (n = 117 eggs/treatment) from week 2 of incubation onward. Week 1 (embryonic age (E)0 < E7) EST was 37.8°C for all eggs. Week 2 (E7 < E14) EST was either 37.8°C (Control) or 38.9°C (Higher), and week 3 (E14 - /hatch) EST was either Control or 36.7°C (Lower). At hatch, histology of bursal follicles and jejunum villi and crypts were determined as well as heterophil to lymphocyte ratio (H:L) (n = 49). Posthatch, both sexes were grown in 8 pens/treatment for 6 wk (n = 320). Natural antibodies (NAb) were determined at day 14, 22, and slaughter (day 41 or 42) as an indicator of immunocompetence and response to a Newcastle disease (NCD) vaccination was determined by antibody levels at day 22 and slaughter (n = 128). Results showed no interaction EST week 2 × EST week 3, except for jejunum histology. Higher EST in week 2 resulted in lower cell density within bursal follicles (P = 0.02) and a tendency for lower H:L (P = 0.07) at hatch, and higher NCD titers at slaughter (P = 0.02) than Control EST. Lower EST in week 3 resulted at hatch in higher cell density within bursal follicles, higher H:L (both P < 0.05), and a tendency for a higher posthatch mortality rate than control EST (P = 0.10). In conclusion, higher EST in week 2 during incubation may benefit embryonic immune organ development and posthatch broiler immunocompetence, while lower EST in week 3 showed opposite indications.

Effects of incubation temperature pattern on broiler performance.

During incubation, development of embryos is affected by eggshell temperature (EST). A constant EST of 37.8°C has been considered so far to result in most optimal embryo development. However, it can be hypothesized that a higher EST in week 2 in combination with a lower EST in week 3 stimulates embryo development and subsequent grow-out performance. In this study, 468 eggs of a 44-week-old Ross 308 breeder flock were incubated at different incubation temperature patterns in a 2 × 2 factorial arrangement. In week 2, EST was either 37.8°C or 38.9°C, and in week 3, EST was either 37.8°C or 36.7°C. At hatch, chick quality was determined. Thereafter, 320 broilers were grown in 32 pens (8 replicates/treatment) for 6 wk. Weekly BW and ADFI were determined, and at day 40, slaughter yield from 128 broilers (4 per pen) was determined. Results showed that EST in week 2 did not interact with EST in week 3 for any variable. An EST of 38.9°C in week 2 resulted in a 1 mm longer chick length (P < 0.001) and 0.4 mmol/L lower blood glucose level (P = 0.04) at hatch than an EST of 37.8°C. Grow-out performance was not affected by EST in week 2 of incubation. An EST of 36.7°C in week 3 resulted in a 1 mm shorter chick length (P = 0.02), 1.0 mmol/L higher blood glucose level (P < 0.001), and higher relative heart (P = 0.01) and stomach weights (P = 0.03) at hatch than an EST of 37.8°C. Additionally, an EST of 36.7°C in week 3 resulted in lower BW, ADG, and ADFI on slaughter age (all P < 0.03) than an EST of 37.8°C. In conclusion, no interaction between EST in week 2 and 3 of incubation was found for any variable. A higher EST in week 2 had minor effects at hatching and during rearing, whereas a lower EST in week 3 seemed to result in better organ development, but resulted in lower grow-out performance.

Damaging biting behaviors in intensively kept rearing gilts: the effect of jute sacks and relations with production characteristics.

Pigs may display biting behavior directed at pen mates, resulting in body damage such as tail wounds. We assessed the suitability of jute sacks (hung vertically at wall) to reduce biting behaviors and tail wounds in rearing gilts. Additionally, we assessed several characteristics of different types of tail biters. Tail docked rearing gilts originated from 72 litters, which were kept in partly slatted pens with jute sacks (J) or barren control pens (CON; 36 litters per treatment). Tail and ear damage were observed at weaning (4 wk) and during the weaner and rearing phase (17 J and 19 CON pens). Sow (dam) damage was also considered. Biting behaviors (tail, ear, and other) were observed during the weaner and rearing phase. Weight was recorded at birth, weaning, and end of the weaner phase and ADG was calculated from birth till weaning and from weaning till 9 wk. Furthermore, estimated breeding values for litter size, litter birth weight, back fat, and growth between birth and ∼ 105 kg, and ∼ 25 to 105 kg were determined. Jute sacks reduced tail and ear damage at weaning (both P < 0.001) and tended to reduce sow tail damage (P = 0.09). Jute sacks also reduced tail damage post-weaning (P < 0.001 to 0.03), with a 5-fold reduction of (mild) tail wounds at the age of 13 wk. Biting behaviors directed at pen mates were up to 50% lower in J pens (P < 0.001 to 0.04). Higher genotypic litter size, litter birth weight, growth, and lower back fat seemed associated with higher levels of ear or tail-biting behavior (P = 0.002 to 0.09), albeit dependent on treatment and phase. Higher phenotypic litter sizes were associated with higher levels of biting behaviors (P = 0.004-0.08). High-tail-biters and Medium-tail-biters (the latter less pronounced) stemmed from larger litters (P = 0.01 to 0.05), were heavier (P = 0.03 to 0.04), grew faster (P = 0.05 to 0.08), and displayed higher levels of all kinds of biting behavior directed to pen mates and the jute sack (P < 0.001 to 0.10) compared with non-tail-biters, the effect size dependent on treatment and phase of life. To conclude, jute sacks may profoundly reduce damaging behaviors and tail wounds in rearing gilts, probably because they partly meet the behavioral need of pigs for rooting and chewing. Furthermore, (tail) biting is associated with production level of the gilts (phenotypically and genetically), which suggests a role for breeding programs and additional research focusing on metabolic demands of (tail) biting pigs.

A method to assess ecosystem services developed from soil attributes with stakeholders and data of four arable farms.

Ecosystem-service indicators and related accounting units are crucial for the development of decision frameworks for sustainable land management systems. With a management concept using ecosystem services, land-use expectations can be linked to quantifiable soil features in a defendable and transparent way. A method to define a set of site-specific ecosystem services and indication system for quantification was set-up and run. First, we interviewed a wide group of land users profiting from ecosystem services of the soil at four arable farms in the polder Hoeksche Waard (S-SE of Rotterdam, the Netherlands). Subsequently, site-specific ecosystem services were defined and weighted according to land use expectations at different spatial and temporal scales. Second, a practical set of indicators was taken from 'Best Professional Judgment' and used to quantify the performance of the ecosystem services for these four farms. The indicators were derived from biotic and abiotic soil parameters. The performance of ecosystem services was related to a reference situation (MEP: maximum ecological potential) with the same land use and soil type combination (i.e., arable fields on silt loam) taken from the database of our national soil survey. In many cases, the performance of ecosystem services was relatively poor if compared to MEP. However, the performances of natural attenuation and/or climate-related services were better. In addition, the different management of these farms (i.e. conventional, intensive and organic farming) was reflected in the performance of the ecosystem services of their soils. Third, land management measures to improve the targeted ecosystem services were incorporated in the outlined method, but not worked out with illustrative field data in this study. Together with concordant data, we show opportunities for a quantification of ecosystem services to improve land-users' awareness and to assess management sustainability.

How to calculate the spatial distribution of ecosystem services--natural attenuation as example from The Netherlands.

Maps play an important role during the entire process of spatial planning and bring ecosystem services to the attention of stakeholders' negotiation more easily. As example we show the quantification of the ecosystem service 'natural attenuation of pollutants', which is a service necessary to keep the soil clean for production of safe food and provision of drinking water, and to provide a healthy habitat for soil organisms to support other ecosystem services. A method was developed to plot the relative measure of the natural attenuation capacity of the soil in a map. Several properties of Dutch soils were related to property-specific reference values and subsequently combined into one proxy for the natural attenuation of pollutants. This method can also be used to map other ecosystem services and to ultimately integrate suites of ecosystem services in one map.

Colposcopic findings and intraepithelial neoplasia in diethylstilbestrol-exposed offspring. The Dutch experience.

Data from two regional diethylstilbestrol clinics for colposcopic evaluation of young women with a history of diethylstilbestrol exposure in utero are presented: A total of 224 subjects with a well-documented history were enrolled in this study. Structural anomalies of the cervix and vagina were found in 30%. Vaginal epithelial changes were colposcopically observed in 65%, including vaginal adenosis in 22%. The prevalence rate of abnormal cytologic findings in the study group was 9%. In half of these patients a low-grade intraepithelial neoplasia of the cervix and vagina was found. It was concluded that colposcopy in diethylstilbestrol-exposed offspring in inexperienced hands can result in many unnecessary biopsies. Therefore colposcopic examination should be performed by expert colposcopists in referral diethylstilbestrol centers.

Noradrenaline concentration and turnover in nuclei of the hyothalamus and the medulla oblongata at two stages in the development of renal hypertension in the rat.

The noradrenaline concentration and the alpha-methyl-para-tyrosine (alpha-MPT)-induced disappearance of noradrenaline were determined in several nuclei of the hypothalamus and the medulla oblongata of renal hypertensive rats (two-kidney Goldblatt hypertension). A decreased alpha-MPT-induced disappearance of noradrenaline was found in the nucleus interstitialis striae terminalis and the nucleus paraventricularis 3 days after renal artery constriction, when blood pressure was slightly, but significantly higher than that of sham operated rats. At this stage the alpha-MPT-induced disappearance of noradrenaline was enhanced in the nucleus commissuralis and the A1-region of hypertensive rats while the noradrenaline concentration in the A1-region was significantly elevated. No significant differences were found in both parameters in hypothalamic and medullary nuclei 3.5 weeks after the operation, when hypertension had fully developed. These findings are indicative of the occurrence of transient changes in the activity of noradrenergic neurons located in the medulla oblongata and projecting to the hypothalamus during the initiation of the development of two-kidney Goldblatt hypertension.

Adrenergic innervation of the rat hypothalamus.

The adrenergic innervation of the hypothalamus was studied by measuring hypothalamic adrenaline levels following surgical transection of the lower brain stem or electrolytic lesion of the medullary adrenaline-containing cell groups. The adrenaline levels in some hypothalamic nuclei and in the median eminence showed a slight decrease after partial transection of the medulla oblongata, whilst there was a pronounced decrease (by 59-78%) 7-10 days following total hemisection or unilateral lesion of the C1-catecholaminergic cell group in the medulla oblongata.