Restriction of behavioral opportunities and uneven use of space are considerable welfare concerns in modern broiler production, particularly when birds are kept at high densities. We hypothesized that increased environmental complexity by provision of barrier perches would help address these issues by encouraging perching and enhancing use of the pen space across a range of stocking densities. 2,088 day-old broiler chicks were randomly assigned to one of the following barrier and density treatment combinations over four replications: simple barrier, complex barrier, or control (no barrier) and low (8 birds/m2), moderate (13 birds/m2), or high (18 birds/m2) density. Data were collected on focal birds via instantaneous scan sampling from 2 to 6 weeks of age. Mean estimates per pen for percent of observations seen performing each behavior, as well as percent of observations in the pen periphery vs. center, were quantified and submitted to an analysis of variance with week as the repeated measure. Barrier perches, density and age affected the behavioral time budget of broilers. Both simple and complex barrier perches effectively stimulated high perching rates. Aggression and disturbances were lower in both barrier treatments compared to controls (P<0.05). Increasing density to 18 birds/m2 compared to the lower densities suppressed activity levels, with lower foraging (P<0.005), decreased perching (P<0.0001) and increased sitting (P = 0.001) earlier in the rearing period. Disturbances also increased at higher densities (P<0.05). Use of the central pen area was higher in simple barrier pens compared to controls (P<0.001), while increasing density above 8 birds/m2 suppressed use of the central space (P<0.05). This work confirms some negative effects of increasing density and suggests that barrier perches have the potential to improve broiler welfare by encouraging activity (notably by providing accessible opportunities to perch), decreasing aggression and disturbances, and promoting more even distribution of birds throughout the pen space.

These associations further elucidate the components of mental health that contribute to poor appetite in this population. Simple measures of self-reported mental health administered to older adults may predict poor appetite and lend themselves to potential interventions to prevent malnutrition and negative health outcomes.

Deterioration of footpad and hock condition and increased stress are important welfare concerns in high-density broiler production. It has been argued that environmental enrichment may help address these issues. We hypothesized that increasing environmental complexity by providing access to barrier perches across a range of densities should improve footpad and hock health, reduce leg fluctuating asymmetry (FA), and mitigate fear in broilers without compromising bird performance. In this study, 2,088 one-day-old broiler chicks were randomly assigned to one of the following barrier and density treatment combinations over 4 replications: simple barrier, complex barrier, or no barrier (control) and low (8 birds/m(2)), moderate (13 birds/m(2)), or high (18 birds/m(2)) density. In wk 7, data were collected on average tibia width and length, FA of tibia width and tibia length, footpad and hock lesions, tonic immobility, feed conversion, final BW, and mortalities. Broilers at higher densities had more severe footpad (P < 0.0001) and hock lesions (P < 0.0001). Their tibias were also longer (P < 0.0001) and less symmetric in length (P < 0.05). The tibias of birds in complex barrier pens were more symmetric in length compared with controls (P < 0.05). Barrier treatment had no effect on hock lesions, although there was a trend for simple barriers to reduce the severity of footpad lesions compared with the control treatment (P = 0.089). Birds kept in simple barrier pens were more susceptible to tonic immobility induction (P < 0.05). Final BW, feed conversion, and mortalities were neither affected by stocking density nor by barrier inclusion. In conclusion, this study shows a negative effect of high density on broiler footpad health and FA. Although barrier perches did not appear to reduce fearfulness, the improvement in footpad health suggests that simple barriers may provide key welfare benefits to broiler chickens.

No abstract

Artificial insemination plays a key role in the genetic management of elephants in zoos. Because freshly extended semen is typically used for artificial insemination in elephants, it has become imperative to optimize conditions for liquid storage and semen transport. The objectives of this study were to examine the interactions between different extenders and storage temperatures on sperm total motility, progressive motility, and acrosomal integrity in Asian (Elephas maximus) and African (Loxodonta africana) elephants. Ejaculates were collected by rectal massage, diluted using a splitsample technique in 5 semen extenders: TL-Hepes (HEP), Modena (MOD), Biladyl (BIL), TEST refrigeration medium (TES), and INRA96 (INR), maintained at 35uC, 22uC, or 4uC. At 0, 4, 6, 12, and 24 hours, aliquots were removed and assessed for sperm total motility, progressive motility, and acrosomal integrity. After 24 hours of storage, African elephant spermatozoa exhibited greater longevity and higher values in sperm quality parameters compared with those of Asian elephants. In both species, semen storage at 35uC resulted in a sharp decline in all sperm quality parameters after 4 hours of storage, whereas storage at 22uC and 4uC facilitated sperm survival. In Asian elephants, MOD and HEP were most detrimental, whereas BIL, TES, and INR maintained motility up to 12 hours when spermatozoa were cooled to 22uC or 4uC. In African elephants, there were no differences among extenders. All media maintained good sperm quality parameters at 22uC or 4uC. However, although MOD, BIL, and INR were most effective at lower temperatures, HEP and TES maintained sperm motility at all storage temperatures. This study demonstrated sperm sensitivity to components of various semen extenders and storage temperatures and offers recommendations for semen extender choices for liquid semen storage for both Asian and African elephants.

The effect of individual and dam (maternal) inbreeding was quantified for preweaning traits in an Angus nucleus herd that has been closed to outside breeding for 70 yr. The effectiveness of 5 models (linear, quadratic, exponential, Michaelis-Menten, and Rumford-Newton) was evaluated for describing the effect of inbreeding on growth traits, hock length (HL), and scrotal circumference (SC). Pedigree information and production records were retrieved for 10,938 animals and analyzed in an animal model that included the fixed effects of year of birth, age of the dam, sex, and age at weaning (for traits measured at weaning). Average individual and maternal inbreeding in the herd were 0.068 and 0.066, respectively, for all animals; in the last calf crop these values were 0.120 for the calves and 0.121 for their dams. Inbreeding depression was observed for BW at birth (WB), weaning weight (WW), BW adjusted to 205 d of age (W205), ADG, HL, and SC. The effect of maternal inbreeding was smaller than for individual inbreeding for WB, WW, W205, and ADG. Nonlinear prediction was done more effectively by the exponential and Michaelis-Menten models. Quadratic polynomials were an inadequate descriptor of inbreeding effects. Genetic gain from selection at an intensity equivalent to 0.25 can be nullified by an inbreeding accumulation of 0.187 (WB), 0.056 (WW), 0.068 (W205), 0.065 (ADG), or 0.092 (SC). Inbreeding accumulation of 0.018 is required to nullify genetic gain for HL; this particular prediction is valid for non-inbred cows due to an observed interaction between individual and maternal inbreeding. At current inbreeding accumulation levels in this herd, 7 generations of inbreeding accumulation will be necessary to nullify the genetic progress from 1 generation of selection in growth traits.

Summary Ten transgenic (sheep metallothionein 1a‐sheep growth hormone transgene, oMt1a‐oGH) homozygous male mice were mated to females of two lines with distinct selection backgrounds. Inter se matings yielded F2 mice in each line: selected background and control background. Genotypes with respect to the transgene insert were obtained in all mice. Weekly body weights were taken. Males were dissected at 8 weeks of age and fat pads and organs were weighed. Females were mated at 10 weeks; reproductive data were collected on the 16th day after detection of a copulatory plug. Gene action on body, fat pads and organs weights showed dominance effects. The oMt1a‐oGH transgene caused body and organ weights to increase and fat pad weights to reduce. No unfavourable effects of the transgene insert were found on reproductive traits. Results indicate that incorporation of the oMt1a‐oGH in populations of mice should be successful. Résumé Dix mâles souris, homozygotes pour le oMt1a‐oGH (mouton métallothionein 1a‐mouton hormone de croissance) ont été accouplés aux femelles de deus lignées avec différents fonds de sélection. Inter se accouplés ont rendu F2 souris dans chaque lignée: sélectionnée et contrôle. Les génotypes en ce qui concerne le transgène ont été mésurés dans tous les souris. Poids corporeles ont été obtenus chaque semaine. Les mâles ont été disséqués à huit semaines; dépôts adipaux et orgues ont été pesés. Les femelles ont été accouplés à dix semaines; données de reproduction ont été assemblés au seizième jour après la détéction d'un tampon de copulation. Dominance a été l'action génique sur le poids corporel, dépôts adipaux et orgues. Le transgène a augmenté les poids corporels et les poids des orgues mais il a réduit les poids des dépôts adipaux. Pas d'effects défavourables on été trouvés dans les caractères reproductives. Les résultats indiquent que l'incorporation du oMt1a‐oGH transgène dans populations de souris pourrai réussir. Zusammenfassung Genwirkung bei oMt1a‐oGH Transgenen in zwei Mäuselinien mit unterschiedlichem Selektionshintergrund Zehn transgene (Schaf Metallothionein 1a‐Schaf Wachstumshormon, oMt1a‐oGH) homozypote Mäuseböcke wurde an Weibchen zweier Linien unterschiedlichen Selektionshintergrundes gepaart. Inter se Paarungen resultierten in F2 Mäusen mit Selektions bzw. Kontrollhintergrund. Alle Genotypen bezüglich des Transgeninserts wurden festgestellt. Gewichte wurden wöchentlich erhoben, Männchen im Alter von 8 Wochen seziert und Fettpolster unf Organgewichte bestimmt. Weibchen wurden im Alter von 10 Wochen gepaart und Reproduktionsdaten am 16. Tag nach Erscheinen des Kopulationspfropfen erhoben. Bei Körper‐, Fettpfropfen und Orangewichten zeigten sich Dominanzwirkungen. Das oMt1a‐oGH Transgen steigert Körper und Organgewichte und reduziert jenes des Fettpfropfens. Es zeigt keine ungünstigen Wirkungen auf Reproduktion, sodaß seine Einführung in Mäusepopulationen erfolgreich sein sollte.

The purpose of this study was to evaluate selection in lines of transgenic mice. Two replicates of lines that either carried or did not carry the sheep metallothionein-1a sheep growth hormone transgene (oMt1a-oGH) were established. The host lines had been previously selected for rapid growth or selected randomly. Within-litter selection for increased 8-wk body weight was carried out for 13 generations. The frequency of oMt1a-oGH was monitored in all generations in the transgenic lines, but no genotypic information regarding the transgene was used as an aid to selection. The oMt1a-oGH was activated from weaning, at 3 wk, until 8 wk of age by adding ZnSO4 to the drinking water. Zinc stimulation of the transgene was not done during mating, gestation, or lactation. Data on body weights and weight gains were analyzed with a conventional mixed model and with an animal model. Genetic progress was achieved in all lines subjected to directional selection. In the control background, response to selection for 8-wk body weight was larger in the nontransgenic lines than in the transgenic lines, whereas no difference was found in the selected background. The frequency of the transgene was increased from the initial .5 to .62 in the randomly selected background but decreased to .04 in lines from a selected background. The REML estimates of variance components and genetic gain estimates varied greatly between the two methods. In general, there was better agreement between the realized heritability estimates and the heritability estimates obtained from the conventional mixed model analysis than between realized heritability estimates and results obtained using the animal model. Favorable correlated responses were obtained for 3- and 6-wk body weights and on 3- to 6- and 6- to 8-wk weight gains. Correlated responses to selection were larger in the selected than in the nonselected background but were not affected by the presence of the transgene. Results suggest that constructs similar to the oMt1a-oGH, which allow tight regulation, may be successfully incorporated into commercial livestock and should have larger effects in populations that have not been subject to selection.