Access to Barrier Perches Improves Behavior Repertoire in Broilers

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

A large-sample QTL study in mice: III. Reproduction

Using lines of mice having undergone long-term selection for high and low growth, a large-sample (n ≈ 1000 F2) experiment was conducted to gain further understanding of the genetic architecture of complex polygenic traits. Composite interval mapping on data from 10-week-old F2 females (n = 439) detected 15 quantitative trait loci (QTLs) on 5 chromosomes that influence reproduction traits characterized at day 16 of gestation. These QTL are broadly categorized into two groups: those where effects on the number of live fetuses (LF) were accompanied by parallel effects on the number of dead fetuses (DF), and those free of such undesirable effects. QTL for ovulation rate (OR) did not overlap with QTL for litter size, potentially indicating the importance of uterine capacity. Large dominance effects were identified for most QTL detected, and overdominance was also present. The QTL of largest effects were detected in regions of Chromosome 2, where large QTL effects for growth and fatness have also been found and where corroborating evidence from other studies exists. Considerable overlap between locations of QTL for reproductive traits and for growth traits corresponds well with the positive correlations usually observed among these sets of phenotypes. Some support for the relevance of QTL • genetic background interactions in reproduction was detected. Traits with low heritability demand considerably larger sample sizes to achieve effective power of QTL detection. This is unfortunate as traits with low heritability are among those that could most benefit from QTL-complemented breeding and selection strategies in food animal production

Algunos factores que influyen en el peso al nacer de los corderos de raza Santa Inés en el estado de Sergipe

Os pesos de nascimento (Pv) de cordeiros coletados de 1983 a 1989 pelo Centro Nacional de Pesquisa de Coco (CNPCO), Arcaju, SE, na Fazenda Experimental de Queimadas, no município de Frei Paulo, totalizaram 720 animais (174 machos e 183 fêmeas nascidos solteiros, e 193 homens e 170 mulheres nascidos como gêmeos). Os dados foram analisados por meio de um modelo linear ajustado por procedimentos de mínimos quadrados. A média geral do BrW foi de 3,69 ± 0,02 kg. Sexo da prole, tipo de nascimento e ano de nascimento não foram fontes significativas de variação. O mês de nascimento afetou o PV, cordeiros nascidos em março, abril, maio e junho com peso de 2,81 ± 0,07, 3,37 ± 0,07, 3,89 ± 0,05 e 4,70 ± 0,07 kg, respectivamente. O peso do parto teve efeito quadrático no PV, sendo o mais pesado nascido de ovelhas com 33,67 kg.Birth weigths (BrW) of lambs collected from 1983 to 1989 by the Centro Nacional de Pesquisa de Coco (CNPCO), Arcaju, SE, at the Queimadas Experimental Farm in the municipality of Frei Paulo, included 720 total animals (174 males and 183 females born singally, and 193 males and 170 females born as twins). The data were analyzed by means of a linear model fitted by least squares procedures. Overall mean BrW was 3.69±0.02 kg. Sex of offspring, type of birth, and year of birth were not significant source of variation. Month of birth did affect BrW, lambs born in March, April, May and June weighing 2.81±.07, 3.37±.07, 3.89±.05, and 4.70±.07 kg, respectively. Weigth of ewe al lambing had a quadratic effect on BrW, the heaviest being born of ewes weighing 33.67 kg.Los pesos al nacer (BrW) de los corderos recolectados de 1983 a 1989 por el Centro Nacional de Pesquisa de Coco (CNPCO), Arcaju, SE, en la Granja Experimental Queimadas en el municipio de Frei Paulo, incluyeron 720 animales en total (174 machos y 183 hembras). nacieron individualmente, y 193 varones y 170 mujeres nacieron como gemelos). Los datos se analizaron mediante un modelo lineal ajustado mediante procedimientos de mínimos cuadrados. La media global de BrW fue de 3,69 ± 0,02 kg. El sexo de la descendencia, el tipo de nacimiento y el año de nacimiento no fueron una fuente significativa de variación. El mes de nacimiento sí afectó el BrW, los corderos nacidos en marzo, abril, mayo y junio con un peso de 2.81 ± .07, 3.37 ± .07, 3.89 ± .05 y 4.70 ± .07 kg, respectivamente. El peso de las ovejas paridas tuvo un efecto cuadrático sobre el BrW, siendo el más pesado el nacido de ovejas con un peso de 33,67 kg

Density by age interaction effect on mean percent perching (LSM ± SEM).

<p>Density by age interaction effect on mean percent perching (LSM ± SEM).</p

Efeito do tamanho da leitegada sobre natimortalidade e mortalidade dos leitoes Large White do nascimento ate 21 dias de idade

Observations from 3,032 piglets born between 1984 and 1987 were used to study the effect of litter size at birth on mortality up to 21 days of age, estimated by polynomial regression analysis. A high number of stillborns was observed in litters with fewer and more piglets than the optimum of 9. The number of born piglets had a positive linear effect on mortality, with 0.026 additional deaths per additional piglet in the litter.Se utilizaron observaciones de 3.032 lechones nacidos entre 1984 y 1987 para estudiar el efecto del tamaño de la camada al nacer sobre la mortalidad hasta los 21 días de edad, estimada mediante análisis de regresión polinomial. Se observó un elevado número de mortinatos en camadas con menos y más lechones que el óptimo de 9. El número de lechones nacidos tuvo un efecto lineal positivo sobre la mortalidad, con 0,026 muertes adicionales por cada lechón adicional en la camada.Utilizaram-se observações feitas de 3 032 leitões nascidos entre 1984 e 1987, para estudar o efeito do tamanho da leitegada ao nascer sobre a mortalidade ate 21 dias de idade, estimado por analise de regressão polinomial. Foi observado elevado numero de natimortos em leitegadas com menor e maior numero de leitões de que ótimo de 9. O numero de leitões nascidos apresentou efeito linear positivo sobre a mortalidade, com 0.026 morte adicional por leitão adicional na leitegada

Behaviors¹ (mean %) affected by age.

1<p>Values are LSM ± SEM. “Foraging,” “running,” “aggression” and “disturbance” data were pooled over weeks. “Sitting” and “perching” were affected by age×density (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0029826#pone-0029826-g001" target="_blank">Figs. 1</a> & <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0029826#pone-0029826-g002" target="_blank">2</a>). “Central area use” was not affected by age (F_4,108 = 1.00).</p>2<p>Mixed model repeated measures ANOVA, df = 4,108.</p>a<p>Means within a row with different superscripts are significantly different (P<0.05) after Tukey's comparison.</p

Heterogeneity in lots of fiscalized rice seeds cv. BR IRGA 409

O presente trabalho teve por objetivo verificar a uniformidade dos lotes de sementes de arroz (Oryza sativa L.) cv. BR IRGA 409, pelo teste de heterogeneidade. Utilizaram-se oito lotes de tamanhos 1-50, 51-100, 101-150, 151-200, 201-250, 251-300, 301-350 e 351-400 sacos, submetidos às intensidades de amostragens de 17, 25, 30, 40, 50, 60, 70 e 80 sacos, respectivamente. Os atributos testados foram: percentagem de pureza física, sementes nocivas (arroz vermelho e preto), número de sementes sem casca, percentagem de germinação e número de plântulas normais verificadas no teste de frio. Os resultados obtidos permitiram as seguintes conclusões: independentemente do tamanho de lotes e da intensidade de amostragens a eles submetidas, os valores de (H) não indicaram heterogeneidade significante nos atributos estudados; o teste de frio modificado foi o melhor atributo para a determinação da heterogeneidade de lotes de sementes de arroz.The objective of the present work was to verify the uniformity of rice seeds (Oryza sativa L.) lots cv. BR IRGA 409, by the heterogeneity test. Eight lots of size 1-50, 51-100, 101-150, 151-200, 201-250, 251-300, 301-350 and 351-400 bags were used, and submitted to the sampling intensities of 17, 25, 30, 40, 50, 60, 70 and 80 bags, respectively. The attributes tested were physical purity percentage, number of red and black rice seeds, number of seeds dehulled, germination percentage and number of normal seedlings verified in the cold test. The obtained results showed the following conclusions: independently of the lots sizes and sampling intensities, the values of (H) didn't showed significant heterogeneity for the studied attributes; and the modified cold test was the better attribute for the determination of the heterogeneity of rice seed lots

Behaviors¹ (mean %) affected by barrier treatment.

1<p>Values are LSM ± SEM. “Foraging” (F_2,26 = 0.38), “sitting” (F_2,27 = 0.46), “walking” (F_2,27 = 1.68), and “preening” (F_2,27 = 2.54) were not affected by barrier treatment. “Perching” (F_1,18 = 0.41) was not affected by barrier <i>type</i>. “Disturbance” was affected by barrier×density (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0029826#pone-0029826-g003" target="_blank">Fig. 3</a>).</p>2<p>Mixed model repeated measures ANOVA, df = 2,27, with the exception of running with df = 2,26 as running means were pooled across weeks.</p>a<p>Means within a row with different superscripts are significantly different (P<0.05) after Tukey's comparison.</p

Behaviors¹ (mean %) affected by density treatment.

1<p>Values are LSM ± SEM. “Feeding” (F_2,27 = 1.21), “drinking” (F_2,27 = 2.93), “standing” (F_2,27 = 1.29), “running” (F_2,26 = 0.37), “preening” (F_2,27 = 2.63) and “aggression” (F_2,26 = 1.71) were not affected by density. “Sitting” and “perching” were affected by age×density (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0029826#pone-0029826-g001" target="_blank">Figs. 1</a> & <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0029826#pone-0029826-g002" target="_blank">2</a>) and “disturbance” by barrier×density (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0029826#pone-0029826-g003" target="_blank">Fig. 3</a>).</p>2<p>Mixed model repeated measures ANOVA, df = 2,27, with the exception of foraging with df = 2,26 as foraging means were pooled across weeks.</p>a<p>Means within a row with different superscripts are significantly different (P<0.05) after Tukey's comparison.</p

Barrier by density interaction effect on mean percent disturbances (LSM ± SEM).

<p>Barrier by density interaction effect on mean percent disturbances (LSM ± SEM).</p