Mastleistung von Bruderhähnen bei Fütterung mit unterschiedlichen Proteinquellen

In drei Mastversuchen wurden die Wachstumsleistungen männlicher Legehybriden bei Fütterung mit unterschiedlichen Proteinquellen und -gehalten untersucht. Der Vergleich der Genotypen Lohmann Braun (LB) und Lohmann Selected Leghorn (LSL) mit dem Masthybriden Hubbard JA 757 (HUB) zeigte, dass die Bruderhähne erwartungsgemäss geringere Mastleistungen aufwiesen. Sowohl die Lebendgewichte und täglichen Zunahmen als auch die Schlachtgewichte wurden vom Genotyp beeinflusst. Die LB-Hähne wiesen jedoch deutliche Vorteile in den Leistungen gegenüber den LSL-Tieren auf. Der partielle Ersatz von Soja durch Luzernegrünmehl in den Rationen, der mit einer Proteinreduktion einhergeht, führte vor allem bei HUB zu Leistungseinbussen. Im Gegensatz dazu konnten für den Genotyp LB Vorteile in der Umsetzung von Rationen mit reduziertem Proteingehalt festgestellt werden, was für die Mast der Bruderhähne die Möglichkeit bietet, mit der Rationsgestaltung der niedrigen Effizienz der Tiere entgegenzuwirken

Performance d’engraissement de poulets mâles nourris avec différentes sources de protéines

Les performances de croissance de mâles d’hybrides de ponte recevant une alimentation comportant des sources et des teneurs différentes en protéines ont été étudiées dans trois essais d’engraissement. Par rapport aux hybrides d’engraissement Hubbard JA 757 (HUB), les poulets mâles des génotypes Lohmann Braun (LB) et Lohmann Selected Leghorn (LSL) présentent une moins bonne performance d’engraissement. Le poids vif, la prise de poids journalière et le poids à l’abattage sont influencés par le génotype. Les mâles LB présentent cependant de nets avantages en termes de performance par rapport aux mâles LSL. Le remplacement partiel du soja par de la farine de luzerne verte dans les rations, qui s’accompagne d’une réduction de l’apport en protéines, entraîne une perte de rendement, en particulier pour la lignée HUB. À l’inverse, le passage à des rations à plus faible teneur en protéines s’est avéré avantageux pour le génotype LB, ce qui offre la possibilité pour l’engraissement de poulets mâles de compenser, par la composition de la ration, la moindre efficacité alimentaire des mâles

Bedarfsgerechte Riboflavin-(Vitamin B2-)Versorgung bei langsam wachsenden Masthühnern

In zwei Durchgängen mit jeweils 800 gemischtgeschlechtlichen Eintagsküken der Genetik Ranger Gold™ wurde ein auf Basis der Fermentation des Hefe-Pilzes Ashbya gossypii hergestelltes Trockenprodukt untersucht. Es wurden vier unterschiedliche Riboflavingehalte je Durchgang getestet. Eine Kontrollmischung enthielt ausschließlich native Riboflavingehalte ohne Zudosierung. In den ersten zwei Wochen erhielten die Tiere Starterfutter, in den folgenden vier Wochen Aufzuchtfutter 1 und in den letzten zwei Wochen Aufzuchtfutter 2. Wöchentlich wurden Tiergewicht und Futterverbrauch erfasst. Bei der Schlachtung wurden Schlachtparameter erhoben. Die nativen Riboflavingehalte konnten den Bedarf der langsam wachsenden Masthühner nicht decken. Hohe Zudosierungen hingegen zeigten keinen positiven Effekt auf die Leistungs- und Schlachtparameter. Eine Reduktion der Riboflavin-Supplementierung insbesondere in den späteren Mastabschnitten scheint daher geeignet, die erhöhten Kosten, die beim Einsatz des getesteten Produktes im Vergleich zu günstigeren Produkten, welche mit gentechnisch veränderten Mikroorganismen hergestellt werden, auszugleichen

Behavioural changes to moderate heat load in grazing dairy cows under on-farm conditions

Heat stress poses an increasing risk to welfare, health and productivity of dairy cows, especially for cows on pasture. To apply timely mitigation strategies for grazing cows, simple indicators are needed that signal heat stress. We conducted an exploratory study on the behaviour of grazing dairy cows in relation to the environmental heat load on four commercial dairy farms in Switzerland with herd sizes ranging from 20 to 57 cows. In a scan-sampling procedure standing/lying, feeding/ruminating, low inter-individual distances, proximity to drinker, use of natural shade and insect infestation were observed during 30 days (5–9 days/per farm). Additionally, 10 focal cows per farm were equipped with accelerometers to analyse lying duration and locomotor activity during on average 46 days per farm. On one farm all cows (N = 57) were equipped with GPS devices which were used to calculate inter-individual distances among cows continuously during 69 days. Air temperature and relative humidity were recorded to calculate the temperature-humidity index (THI). For behaviours recorded in direct observations, a principal component analysis was performed for variable reduction. The first three principal components (PC) as well as the variables from automatic measurements were used as outcome variables in mixed effects models with daily maximum THI (THImax), time of day (continuous, in 10 min intervals) and their interaction as explanatory variables. The three PCs could be described as: “feeding and standing”, “proximity to drinker” and “standing in close proximity and seeking shade”. The daily pattern of these PC's differed by THImax (interaction time of day * THImax; all p < 0.01). On days with high THImax compared to days with lower THImax cows were seen more often close to the drinker in the morning, but not in the afternoon when they were observed standing close to each other and in the shade. On days with high THImax, cows also were lying less and increased their locomotor activity towards noon (interaction time of day * THImax; p < 0.001). Data from GPS devices confirmed the findings: On days with high THImax, cows reduced their inter-individual distances over the course of the day, while this was not observed on days with lower THImax (interaction time of day * THImax; p < 0.001). Insect infestation increased with higher THImax. We conclude that a distinct change in daily behavioural patterns, especially a reduction of lying behaviour, an increase in locomotor activity and a decrease in inter-individual distances could be used to monitor heat stress of dairy cows on pasture

TSPO acts as an immune resistance gene involved in the T cell mediated immune control of glioblastoma

Glioblastoma (GB) IDH-wildtype is the most malignant primary brain tumor. It is particularly resistant to current immunotherapies. Translocator protein 18 kDa (TSPO) is upregulated in GB and correlates with malignancy and poor prognosis, but also with increased immune infiltration. Here, we studied the role of TSPO in the regulation of immune resistance of human GB cells. The role of TSPO in tumor immune resistance was experimentally determined in primary brain tumor initiating cells (BTICs) and cell lines through genetic manipulation of TSPO expression and subsequent cocultures with antigen specific cytotoxic T cells and autologous tumor-infiltrating T cells. Death inducing intrinsic and extrinsic apoptotic pathways affected by TSPO were investigated. TSPO-regulated genes mediating apoptosis resistance in BTICs were identified through gene expression analysis and subsequent functional analyses. TSPO transcription in primary GB cells correlated with CD8+ T cell infiltration, cytotoxic activity of T cell infiltrate, expression of TNFR and IFNGR and with the activity of their downstream signalling pathways, as well as with the expression of TRAIL receptors. Coculture of BTICs with tumor reactive cytotoxic T cells or with T cell-derived factors induced TSPO up-regulation through T cell derived TNFα and IFNγ. Silencing of TSPO sensitized BTICs against T cell-mediated cytotoxicity. TSPO selectively protected BTICs against TRAIL-induced apoptosis by regulating apoptosis pathways. TSPO also regulated the expression of multiple genes associated with resistance against apoptosis. We conclude that TSPO expression in GB is induced through T cell-derived cytokines TNFα and IFNγ and that TSPO expression protects GB cells against cytotoxic T cell attack through TRAIL. Our data thereby provide an indication that therapeutic targeting of TSPO may be a suitable approach to sensitize GB to immune cell-mediated cytotoxicity by circumventing tumor intrinsic TRAIL resistance

Ausweg aus dem Kükentöten

Das Töten der männlichen Küken wird von der Gesellschaft immer stärker als ethisch nicht vertretbar angesehen und somit abgelehnt. Alternativen sind derzeit in der Testphase. An der Biolegehennentagung werden sie vorgestellt und diskutiert

Is reticular temperature a useful indicator of heat stress in dairy cattle

The present study investigated whether reticular temperature (RT) in dairy cattle is a useful indicator of heat stress considering the effects of milk yield and water intake (WI). In total, 28 Holstein-Friesian dairy cows raised on 3 farms in Lower Saxony, Germany, were studied from March to December 2013. During the study, RT and barn climate parameters (air temperature, relative humidity) were measured continuously and individual milk yield was recorded daily. Both the daily temperature-humidity index (THI) and the daily median RT per cow were calculated. Additionally, the individual WI (amount and frequency) of 10 cows during 100d of the study was recorded on 1 farm. Averaged over all farms, daily THI ranged between 35.4 and 78.9 with a mean (±standard deviation) of 60.2 (±8.7). Dairy cows were on average (±standard deviation) 110.9d in milk (±79.3) with a mean (±standard deviation) milk yield of 35.2kg/d (±9.1). The RT was affected by THI, milk yield, days in milk, and WI. Up to a THI threshold of 65, RT remained constant at 39.2°C. Above this threshold, RT increased to 39.3°C and further to 39.4°C when THI ≥70. The correlation between THI ≥70 and RT was 0.22, whereas the coefficient ranged between r=-0.08 to +0.06 when THI70. With increasing milk yield, RT decreased slightly from 39.3°C (30kg/d) to 39.2°C (≥40kg/d). For daily milk yields of ≥40kg, the median RT and daily milk yield were correlated at r=-0.18. The RT was greater when dairy cows yielded ≥30kg/d and THI ≥70 (39.5°C) compared with milk yields30kg and THI70 (39.3°C). The WI, which averaged (±standard deviation) 11.5 l (±5.7) per drinking bout, caused a mean decrease in RT of 3.2°C and was affected by the amount of WI (r=0.60). After WI, it took up to 2h until RT reached the initial level before drinking. In conclusion, RT increased when the THI threshold of 65 was exceeded. A further increase was noted when THI ≥70. Nevertheless, the effects of WI and milk yield have to be considered carefully when RT is used to detect hyperthermia in dairy cattle

Effects of vegetation type and breed on n-3 and n-6 fatty acid proportions in heart, lung and brain phospholipids of lambs

The known influence of forage composition on fatty acid (FA) profiles in ruminants’ meat and milk may be different for other organs. Therefore, in the present study FA profiles of phospholipids in lung tissue, heart muscle and brain (medulla oblongata) were examined in growing Engadine and Valaisian Blacknose sheep grazing 4 pastures of different botanical composition, whereof three were extensively managed natural mountain swards. An intensively managed lowland pasture represented the control. On each pasture type, 6–7 lambs of each breed (54 in total) grazed for 9 weeks and were subsequently slaughtered. Tissue samples were taken at slaughter, homogenized and analyzed for FA profiles after phospholipid extraction. Response to the diets was tissue specific, with the weakest effects being found in brain tissue. Despite for a strong site effect on linoleic acid (P < 0.001), brain lipids were rather resistant to influences of diet. Proportions of linoleic acid in phospholipids were increased by 15–25%, 35–76%, and 31–37% in heart, lung and brain, respectively, in lambs grazing mountain pastures (P < 0.05). Alpha-linolenic acid was increased in heart (18–33%; P < 0.05) and lung lipids (5–36%; P < 0.05) of lambs from the highland sites. Proportions of n-3 and n-6 FA acids in the organs were not unequivocally associated to the concentrations of bioactive plant constituents. Further, the significance of these associations was limited by confounding between phenolic compounds and other plant constituents within the respective sward samples. Some long-chain PUFA were affected by vegetation type, but effects were less clearly related to the pasture location. Most prominently, the proportion of 22:5n-3 in the heart muscle was higher for lambs from the lowland pasture compared to the mountain site with the highest phenol concentrations. Breed effects were fewer than vegetation influences, but concerned feed-derived (e.g. α-linolenic acid), rumen-derived (e.g. CLA) as well as endogenously synthesized FA (e.g. 16:0). Also for the breed effects a strong tissue specificity was found, with the most and strongest effects in lung tissue. In conclusion, even though the direct applicability of the results is limited to the vegetation types investigated, the study demonstrated that FA profiles in functional tissues of ruminants depend on dietary and genetic factors in a differentiated way. This implies that forage composition matters, not only for efficiency and product quality but also for the composition of functional lipids in organs that may influence endogenous processes and health status of the animal itself

Welche Verhaltensindikatoren eignen sich, um Hitzestress bei weidenden Milchkühen zu erkennen?

Weidende Kühe sind der Hitze besonders ausgesetzt. Wir haben daher auf vier Schweizer Milchviehbetrieben untersucht, wie sich beginnender Hitzestress bei Kühen (n=146) auf der Weide erkennen lässt. An 30 Tagen wurden folgende Verhaltensweisen erhoben: Fressen, Wiederkauen, Liegen, Stehen, Distanz zur Tränke, Kühe im Schatten sowie Anzahl zusammenstehender Kühe. Für jeden Beobachtungstag und Betrieb wurde über eine segmentierte Regression das Vorhandensein eines Knickpunktes geprüft. Anschliessend wurde getestet, ob der maximale Temperatur-Luftfeuchtigkeits-Index (THI) einen Einfluss auf die Verhaltensänderung (Knickpunkt ja / nein) hat. Als Beobachterabgleich wurde der Concordance Correlation Coefficient (CCC) berechnet. Das Verhalten der Kühe unterschied sich sehr stark zwischen den Betrieben. Für keinen der untersuchten Verhaltensindikatoren konnte eine durch den THI bedingte Änderung über alle vier Betriebe festgestellt werden. Der CCC war für alle Verhaltensindikatoren über 0.94. Bedingt durch die hohe Variabilität konnten allfällig vorhandene leichte Verhaltensänderungen aufgrund von Hitze in der vorliegenden Studie nicht eindeutig festgestellt werden