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The Research-based Developmentally Informed (REDI) program enriched Head Start classrooms with teacher-delivered curriculum components designed to enhance child social-emotional learning and language-literacy skills. Parents received information about the program via backpack express, including weekly handouts about program topics and three DVDs illustrating REDI interactive strategies and suggesting home learning activities. In addition to effects on child skill acquisition and school performance (reported previously), positive effects emerged on a family-based outcome: parents of children in REDI-enriched classrooms reported higher quality preschool parent-child conversations than parents in the randomized control group (usual practice) classrooms. This study examined the long-term benefits associated with intervention-related improvements in preschool conversations. The original sample included 356 children (58% White, 24% Black, and 18% Latinx; 54% girls, 46% boys); 77% had the high school follow-up data used in this study. Longitudinal GLM analyses documented significant REDI intervention effects on parent-adolescent communication quality (assessed in the 7th and 9th grades) and on parent- and youth-reported high school behavior problems (assessed in 11th grade). Path analyses revealed significant serial mediation from intervention-related improvements in preschool conversations to parent-adolescent communication quality (grades 7-9) to reductions in later youth-reported (but not parent-reported) behavior problems (grade 11). The findings suggest that including "light touch" parent engagement materials with preschool classroom interventions can contribute to long-term program benefits., Competing Interests: Declarations. Conflict of Interest: The authors declare no competing interests. Ethics Approval: All study procedures followed the American Psychological Association standards for the ethical conduct of research and had the approval of the Pennsylvania State University IRB. This study was performed in accordance with the standards laid down in the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards. Consent to Participate: Parents provided written informed consent for their own and their child’s participation in the study. Children under age 18 gave their assent., (© 2024. Society for Prevention Research.)

The objective of this study was to investigate the effect of restricting total mixed ration (TMR) eating time with or without supplemental long hay offered on diurnal total intake, rumination, and rumen pH patterns in mid-lactation dairy cows. Eight multiparous Holstein cows were used in a replicated 4 × 4 Latin square design study with 21-d periods. The basal diet was the same for all 4 treatments with or without additional long grass hay (the same hay used in the TMR). For cows on limited-time TMR, diets were taken away at 1500 h (5 h before evening milking and feeding), and dry matter intake (DMI), ruminating, and rumen pH were monitored and summarized every 10 m for 7 d in each period. With restricted feeding, cows changed DMI patterns by consuming a large meal after feed was reinstated, resulting in lower DMI. Ruminating patterns closely mirrored intake patterns, as could be expected. Rumen pH was not different between groups but resulted in different diurnal patterns due to differences in eating and rumination patterns between the groups. Limiting feed availability can be used to change eating and rumination patterns, resulting in different rumen pH patterns., (© 2021.)

Objective: Living in poverty increases exposure to adversities that undermine healthy development, impeding growth in the social-emotional and language skills that support adaptive coping and promote mental health. Evidence-based programs have the potential to improve current preschool practice and strengthen these early skills, potentially reducing risk for later psychopathology. The authors tested the hypothesis that an enrichment program in preschool would be associated with reduced levels of psychopathology symptoms at the transition from middle to secondary school., Methods: The Head Start REDI (Research-Based, Developmentally Informed) intervention was used to enrich preschool classrooms serving children from low-income families with an evidence-based social-emotional learning (SEL) program and a coordinated interactive reading program. Centers were randomly assigned to the intervention or usual practice, and 356 4-year-olds (58% White, 25% Black, 17% Latino; 54% female) were followed into early adolescence. Hierarchical linear models were used to evaluate intervention effects on teacher-rated psychopathology symptoms using the Strengths and Difficulties Questionnaire in grade 7 (ages 12-13) and grade 9 (ages 14-15), 8-10 years after the end of the intervention., Results: Statistically significant intervention-related reductions were observed in conduct problems and emotional symptoms in the intervention group. In addition, the proportion of youths with clinically significant levels of conduct problems, emotional symptoms, and peer problems was reduced in the intervention group, with rates one-third of those in the control group., Conclusions: The study findings indicate that enriching preschool programs serving at-risk children with a relatively inexpensive evidence-based SEL program with interactive reading substantially improved the later benefits for adolescent emotional and behavioral health. This kind of SEL enrichment represents an approach that can leverage public investments in preschool programs to enhance public health.

This study evaluated the sustained effects of the Research-based Developmentally Informed Parent program (REDI-P) at fifth grade, six years after intervention. Participants were 200 prekindergarten children attending Head Start (55% White, 26% Black, 19% Latinx, 56% male, mean age of 4.45 years at study initiation) and their primary caregivers, who were randomly assigned to a control group or a 16-session home-visiting intervention that bridged the preschool and kindergarten years. In addition, the study explored moderation of sustained effects by parenting risks (e.g., less than high-school education, single-parent status, parental depression, and low parent-child warmth). Growth curves over the course of the elementary years examined outcomes in three domains: child academic performance, social-emotional adjustment, and parent-child functioning. At fifth grade, significant main effects for intervention were sustained in the domains of academic performance (e.g., reading skills, academic motivation, and learning engagement) and parent-child functioning (e.g., academic expectations and parenting stress). Significant moderation by parenting risk emerged on measures of social-emotional adjustment (e.g., social competence and student-teacher relationships); parenting risk also amplified effects on some measures of academic performance and parent-child functioning, with larger effects for children from families experiencing fewer risks. Implications are discussed for the design of preschool home visiting programs seeking to enhance the school success and social-emotional well-being of children living in poverty.

Growing up in poverty increases youth risk for developing aggressive behavior problems, which, in turn, are associated with a host of problematic outcomes, including school drop-out, substance use, mental health problems, and delinquency. In part, this may be due to exposure to adverse school contexts that create socialization influences supporting aggression. In the current study, 356 children from low-income families (58% White, 17% Latinx, 25% Black; 54% girls) were followed from preschool through seventh grade. Longitudinal data included measures of the school-level contexts experienced by study participants during their elementary and middle school years, including school levels of poverty (percentage of students receiving free or reduced-price lunch) and academic achievement (percentage of students scoring below the basic proficiency level on state achievement tests). Regression analyses suggested little impact of these school-level contexts on teacher or parent ratings of aggression in fifth grade, controlling for child baseline aggression and demographics. In contrast, school-level contexts had significant effects on child aggression in seventh grade with unique contributions by school-level achievement, controlling for child fifth grade aggression and elementary school contexts along with baseline covariates. These effects were robust across teacher and parent ratings. Findings are discussed in terms of understanding the school-based socialization of aggressive behavior and implications for educational policy and prevention programming.

Two hundred ninety-four children from low-income families (58% White, 17% Latinx, 25% Black; 54% girls; Mage = 4.49 years old at study entry) were recruited from Head Start classrooms to participate in a randomized-controlled trial of the project Research-based, Developmentally Informed (REDI) preschool intervention and then followed longitudinally for 10 years through 9th grade. At study entry, parents reported on their children's exposure to adverse childhood experiences (ACEs). Youth reported on their feelings of social-emotional distress and school bonding after making the transition into middle school (7th grade) and high school (9th grade). Multilevel latent profile analyses revealed three profiles of adolescent distress and school bonding. Increased rates of ACEs in early childhood predicted membership in adolescent profiles characterized by heightened social-emotional distress and reduced levels of school bonding. The REDI intervention that focused on promoting early social-emotional and language skills in preschool moderated the impact of early ACEs on adolescent adjustment and promoted youth resilience, significantly buffering children from the negative impact of early ACEs on their levels of social-emotional distress and school bonding. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Wet sieving of manure can be used as a means of evaluating the nutrient utilization of diets by dairy cows. A commercially available system for this analysis (Nasco Digestion Analyzer, Nasco, Fort Atkinson, WI; NDA) employs principles of wet sieving for on-farm assessment. The objective of this study was to evaluate effects of diet manipulations and sampling techniques on fecal particle dry matter (DM), neutral detergent fiber (NDF), and starch distribution on NDA sieves. Eight Holstein heifers (means ± SD; age 18.4 ± 0.6 mo and BW 457.2 ± 27.3 kg), were randomly assigned to a split-plot 4 × 3 incomplete Latin square experimental design with 18-d periods (15 d of adaptation and 3 d of sampling). Treatment rations differed in forage quality (high ADF <35%, low ADF >35%) and fiber content (high NDF >45%, low NDF <40%) and were offered to heifers for ad libitum and restricted intakes. Diets were fed to allow 900 to 1,000 g/d of body weight gain and fed once daily. Fecal grab samples were collected 0, 6, 12, and 18 h after feeding all 3 d of the sampling period, and the remaining feces was collected in the manner of total fecal collection to represent a daily composite sample. After wet sieving of each sample using a NDA kit, the retained material on sieves was dried and analyzed for DM, NDF, and starch content. Sampling day and feeding regimen did not affect distributions of nutrients. Distributions of total fecal particle DM were greater for high forage quality and high fiber content diets (14.66 to 20.37% of sample DM). The NDF content in retained material decreased with decreasing sieve size (from 89.81 to 86.86%) and was not affected by forage quality and fiber content, whereas NDF retained on NDA (% DM) followed the same pattern as the retained particle DM weight. Starch content in retained material was below 0.5% in the majority of diets. Average retained fecal particle DM and NDF content varied depending on the time after feeding, resulting in the large differences between grab fecal samples and a daily total composite sample. However, average values of retained particle DM and NDF weight for all sampling time points were similar to ones from total daily composite sample., (Copyright © 2019 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Importance: Home visiting programs targeting the school readiness of preschool children (age range, 4-5 years) show promise in short-term and quasi-experimental studies but rarely are evaluated with rigorous designs and follow-up assessments., Objectives: To examine the sustained effects of a preschool home visiting program on child and family competencies and on child need for services 4 years later., Design, Setting, and Participants: In a randomized clinical trial, individual families with preschool children were assigned to receive the Research-Based and Developmentally Informed-Parent home visiting program (REDI-P) (intervention group) or math home learning games in the mail (control group). Follow-up assessments occurred in third grade. Families were recruited from 24 Head Start centers in 3 Pennsylvania counties serving rural and urban areas. Four-year-old children from 200 low-income families participated. Families were recruited in fall 2008 and fall 2009. The follow-up data used were collected in spring 2013 and spring 2014. The analyses were conducted in 2016 to 2017., Interventions: REDI-P visits followed a well-specified curriculum, with 10 home visits during preschool and 6 booster visits in kindergarten. Parents received coaching to enhance parent-child relationships and home learning materials to support child development and school readiness., Main Outcomes and Measures: Intervention focused on boosting competencies in academic performance and social-emotional adjustment and reducing child problems at home. Direct assessments, teacher ratings, and parent reports were collected. In addition, third-grade teachers recorded all services that children needed and received at school., Results: Two hundred participating children (110 [55.0%] white, 52 [26.0%] black, and 38 [19.0%] Latino; 112 [56.0%] male) had a mean (SD) age of 4.45 (0.29) years at the start of intervention. Third-grade outcomes were available for 153 (76.5%) of the initial sample and revealed statistically significant effects on multiple measures in each competency domain. In addition, REDI-P reduced child need for educational and mental health services at school. Significant effect sizes were small to moderate, averaging approximately one-third of 1 SD (Cohen d = 0.27 to 0.45). Mediation models demonstrated that intervention effects on services were accounted for by intervention effects on the targeted competencies., Conclusions and Relevance: REDI-P produced sustained benefits evident 4 years after intervention, significantly reducing child need for school services. The results of this study appear to validate the value of preschool home visiting as a strategy to help close the gap in school readiness and child well-being associated with poverty.

This study examined three components of parent engagement in an enriched Head Start home visiting program: intervention attendance, the working alliance between parents and home visitors, and parents' use of program materials between sessions. The study identified those family and child characteristics that predicted the different components of parent engagement, and the study tested whether those components predicted sustained growth in children's school readiness skills across four years, from preschool through second grade. Ninety-five low-income parents with four year-old children attending Head Start (56% white; 26% black; 20% Latino; 44% girls) were randomly assigned to receive the home visiting program. Assessments included home visitor, parent, and teacher ratings, as well as interviewer observations and direct testing of children; data analyses relied on correlations and hierarchical multiple regression equations. Results showed that baseline family characteristics, like warm parent-child interactions, and child functioning predicted both working alliance and use of program materials, but only race/ethnicity predicted intervention attendance. The use of program materials was the strongest predictor of growth in children's literacy skills and social adjustment at home during the intervention period itself. In contrast, working alliance emerged as the strongest predictor of growth in children's language arts skills, attention skills, and social adjustment at school through second grade, two years after the end of the home visiting intervention. To maximize intervention effectiveness across school readiness domains over time, home visiting programs need to support multiple components of parent engagement, particularly working alliance and the use of program materials between sessions.

The estimation of Holstein heifer body weight (BW) from heart girth measurements is needed, as many farms do not have animal scales to make the management decisions that require BW. The correlation between heart girth and BW is known to vary with differing animal conformation. The previous equation to correlate the 2 measures for Holstein dairy heifers was done 25 yr ago. Data were derived from 6 US experiment stations that are part of Regional Research Project NC-2042: Management Systems to Improve the Economic and Environmental Sustainability of Dairy Enterprises. After deriving a new equation from a data set of observations and using a second validation data set, it was determined that the equation developed in 1992 was still valid and further equation development was not needed at this time., (Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Background: Growing up in poverty undermines healthy development, producing disparities in the cognitive and social-emotional skills that support early learning and mental health. Preschool and home-visiting interventions for low-income children have the potential to build early cognitive and social-emotional skills, reducing the disparities in school readiness that perpetuate the cycle of poverty. However, longitudinal research suggests that the gains low-income children make during preschool interventions often fade at school entry and disappear by early elementary school., Methods: In an effort to improve the benefits for low-income children, the REDI program enriched Head Start preschool classrooms (study one) and home visits (study two) with evidence-based programming, documenting positive intervention effects in two randomized trials. In this study, REDI participants were followed longitudinally, to evaluate the sustained impact of the classroom and home-visiting enrichments 3 years later, when children were in second grade. The combined sample included 556 children (55% European American, 25% African American, 19% Latino; 49% male): 288 children received the classroom intervention, 105 children received the classroom intervention plus the home-visiting intervention, and 173 children received usual practice Head Start., Results: The classroom intervention led to sustained benefits in social-emotional skills, improving second grade classroom participation, student-teacher relationships, social competence, and peer relations. The coordinated home-visiting intervention produced additional benefits in child mental health (perceived social competence and peer relations) and cognitive skills (reading skills, academic performance). Significant effects ranged from 25% to 48% of a standard deviation, representing important effects of small to moderate magnitude relative to usual practice Head Start., Conclusions: Preschool classroom and home-visiting programs for low-income children can be improved with the use of evidence-based programming, reducing disparities and promoting complementary benefits that sustain in elementary school., Competing Interests: The authors have declared that they have no competing or potential conflicts of interest in relation to this work., (© 2016 Association for Child and Adolescent Mental Health.)

Objective: This study assessed the sustained effects of Head Start REDI (Research-based, Developmentally Informed), a randomized controlled preschool preventive intervention, on children's developmental trajectories of social-emotional functioning into elementary school., Method: Twenty-five Head Start centers with 44 classrooms were randomly assigned to deliver Head Start REDI or Head Start as usual. Head Start REDI featured an integrated language-emergent literacy and social-emotional skills curriculum and enhanced support for positive teaching practices. The 356 4-year-old children (54% girls; 25% African American; 17% Latino; 70% living in poverty) in those centers and classrooms were followed for 5 years (from preschool through third grade; 91% retention rate). Each year, teachers rated multiple domains of social-emotional functioning. Person-oriented latent class growth models were used to identify the different developmental trajectories of social-emotional functioning that children followed., Results: Tests of proportions revealed that children who had been in the Head Start REDI intervention were statistically significantly more likely than children in the control condition to follow the most optimal developmental trajectories of social competence, aggressive-oppositional behavior, learning engagement, attention problems, student-teacher closeness, and peer rejection (odds ratio = 1.60-1.93)., Conclusions: These findings suggest that enriching Head Start with evidence-based curriculum components and teaching practices can have long-lasting benefits for children's social-emotional functioning. These findings elucidate how high-quality preschool experiences promote core competencies that are critical to the school success of children living in poverty., ((c) 2016 APA, all rights reserved).)

Head Start enhances school readiness during preschool, but effects diminish after children transition into kindergarten. Designed to promote sustained gains, the Research-based Developmentally Informed (REDI) Parent program (REDI-P) provided home visits before and after the kindergarten transition, giving parents evidence-based learning games, interactive stories, and guided pretend play to use with their children. To evaluate impact, two hundred 4-year-old children in Head Start REDI classrooms were randomly assigned to REDI-P or a comparison condition (mail-home math games). Beyond the effects of the classroom program, REDI-P promoted significant improvements in child literacy skills, academic performance, self-directed learning, and social competence, demonstrating the utility of the approach in promoting gains in cognitive and social-emotional skills evident after the transition into kindergarten., (© 2015 The Authors. Child Development © 2015 Society for Research in Child Development, Inc.)

This study examined the early childhood precursors and adolescent outcomes associated with grade school peer rejection and victimization among children oversampled for aggressive-disruptive behaviors. A central goal was to better understand the common and unique developmental correlates associated with these two types of peer adversity. There were 754 participants (46% African American, 50% European American, 4% other; 58% male; average age=5.65 at kindergarten entry) followed into seventh grade. Six waves of data were included in structural models focused on three developmental periods. Parents and teachers rated aggressive behavior, emotion dysregulation, and internalizing problems in kindergarten and Grade 1 (Waves 1-2); peer sociometric nominations tracked "least liked" and victimization in Grades 2, 3, and 4 (Waves 3-5); and youth reported on social problems, depressed mood, school adjustment difficulties, and delinquent activities in early adolescence (Grade 7, Wave 6). Structural models revealed that early aggression and emotion dysregulation (but not internalizing behavior) made unique contributions to grade school peer rejection; only emotion dysregulation made unique contributions to grade school victimization. Early internalizing problems and grade school victimization uniquely predicted adolescent social problems and depressed mood. Early aggression and grade school peer rejection uniquely predicted adolescent school adjustment difficulties and delinquent activities. Aggression and emotion dysregulation at school entry increased risk for peer rejection and victimization, and these two types of peer adversity had distinct as well as shared risk and adjustment correlates. Results suggest that the emotional functioning and peer experiences of aggressive-disruptive children deserve further attention in developmental and clinical research.

One year after participating in the Research-based, Developmentally Informed (REDI) intervention or "usual practice" Head Start, the learning and behavioral outcomes of 356 children (17% Hispanic, 25% African American; 54% girls; Mage  = 4.59 years at initial assessment) were assessed. In addition, their 202 kindergarten classrooms were evaluated on quality of teacher-student interactions, emphasis on reading instruction, and school-level student achievement. Hierarchical linear analyses revealed that the REDI intervention promoted kindergarten phonemic decoding skills, learning engagement, and competent social problem-solving skills, and reduced aggressive-disruptive behavior. Intervention effects on social competence and inattention were moderated by kindergarten context, with effects strongest when children entered schools with low student achievement. Implications are discussed for developmental models of school readiness and early educational programs., (© 2013 The Authors. Child Development © 2013 Society for Research in Child Development, Inc.)

This prospective study was designed to investigate possible carryover effects of calf management practices and how events occurring during the first 16 wk of life affect first-lactation and lifetime milk production as well as age when animals are removed from production. This is the final of 3 stages in a longitudinal study that encompassed 10 yr of data collection. First, management and nutritional data were collected in the first 16 wk of life. The second part of this study evaluated conditions of animals at the time of first calving as affected by calf management, nutrition, and health. Both of these studies have been previously reported. This third portion covers the same calf effects on lactation performance and age at culling. Observations for the current study were collected from on-farm and Dairy Herd Improvement records. The multiple imputation technique was used in this analysis to avoid bias due to missing data. This study concluded that delivery score, weaning dry matter intake, days of illness before 4 mo, days treated before 4 mo, and body weight at first calving all had significant effects on first-lactation production of Holsteins. Delivery score and grain intake at a young age affected lifetime production. Age at culling was only affected by early grain intake in this study., (Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Data were collected prospectively on parameters related to first calving on 18 farms located in Northeastern Pennsylvania. This project was designed to study possible residual effects of calf management practices and events occurring during the first 16 wk of life on age, BW, skeletal growth, and body condition score at first calving. Multiple imputation method for handling missing data was incorporated in these analyses. This method has the advantage over ad hoc single imputations because the appropriate error structure is maintained. Much similarity was found between the multiple imputation method and a traditional mixed model analysis, except that some estimates from the multiple imputation method seemed more logical in their effects on the parameter measured. Factors related to increased age at first calving were increased difficulty of delivery, antibiotic treatment of sick calves, increased amount of milk or milk replacer fed before weaning, reduced quality of forage fed to weaned calves, maximum humidity, mean daily temperature, and maximum ammonia levels in calf housing areas. Body weight at calving tended to increase with parity of the dam, increased amount of grain fed to calves, increased ammonia levels, and increased mean temperature of the calf housing area. Body condition score at calving tended to be positively influenced by delivery score at first calving, dam parity, and milk or milk replacer dry matter intake. Withers height at calving was positively affected by treatment of animals with antibiotics and increased mean temperature in the calf area. This study demonstrated that nutrition, housing, and management factors that affect health and growth of calves have long-term effects on the animal at least through first calving.

Seventy-two Holstein calves were used to study the effect of feeding antibiotics or mannan oligosaccharides (MOS) in milk replacer. Calves were fed a 20% protein, 20% fat milk replacer containing antibiotics (400 g/ton neomycin + 200 g/ton oxytetracycline), MOS (4 g of Bio-Mos/d), or no additive (control) for 5 wk. Milk replacer was reconstituted to 12.5% dry matter and fed at 12% of birth weight during wk 1 and 14% of birth weight in wk 2 to 5. Fecal scores were monitored 3 times per week; body weight, heart girth, withers height, hip height, and hip width were measured at birth and weekly to 6 wk of age. Addition of MOS or antibiotics increased the probability of normal scores for fecal fluidity, scours severity, and fecal consistency as compared to control calves during the course of the study. Consumption of calf starter increased at a faster rate in calves fed MOS, and these calves consumed more calf starter after weaning (wk 6), than those fed antibiotic. No treatment differences in growth measures, total blood protein, or blood urea nitrogen were detected during the trial. Addition of MOS or antibiotics to milk replacer improved fecal scores in calves. Feed intake was improved in MOS-fed calves compared to antibiotic-fed calves, but this difference did not result in growth differences during the experimental period. The results suggest that antibiotics in milk replacers can be replaced with compounds such as mannan oligosaccharides to obtain similar calf performance.

The need for manganese for normal skeletal development appears to be related to its role in proteoglycan biosynthesis. The purpose of this research was to characterize the proteoglycans synthesized under conditions of manganese deficiency. The proteoglycans were extracted from epiphyseal growth plate cartilage and the monomers separated by cesium chloride density gradient centrifugation followed by column chromatography. The proteoglycan monomers from normal cartilage contained primarily (92%) chondroitin sulfate side chains with keratan sulfate being a minor (8%) component. Manganese deficiency reduced the total amount of cartilage proteoglycans. Of the monomers present in deficient cartilage, the majority (75%) were similar to those found in normal cartilage. Cartilage from deficient chicks also contained a second monomer fraction (25%) characterized by a reduced carbohydrate content. Thus, in addition to a reduction in total proteoglycan content, manganese deficiency results in qualitative changes in the proteoglycans present in epiphyseal growth plate cartilage.

An experiment with a factorial arrangement of treatments was conducted using five levels of dietary calcium and two levels of zeolite A. When dietary calcium was deficient or marginal, zeolite A improved calcium utilization, as evidenced by improved growth rate and a reduction in rachitic lesions. There was little benefit from adding zeolite A to diets adequate in calcium. The effect of zeolite A on the incidence of tibial dyschondroplasia was inconsistent.

The influence of the sex-linked dwarfing gene (dw) on growth and skeletal development in young male broiler chicks was investigated. Chickens that were homozygous (dw/dw) for the dwarfing gene had significantly lower BW and tibiotarsus lengths when compared with the heterozygous (Dw/dw) or normal (Dw/Dw) genotypes. All genotypes exhibited similar incidences of tibial dyschondroplasia. In contrast to several other types of dwarfism, there was no effect of the dw gene on the width of the epiphyseal growth plate or the proteoglycan content of this tissue.

This study was performed to determine the long-term effects of dietary aluminum on egg production and reproductive parameters in the mature laying hen and on growth rate and feed efficiency in young chicks. The diets used in these studies were adequate in phosphorus and other essential nutrients. Aluminum added to constitute 0.30% of the diet severely depressed growth and reduced feed efficiency, bone ash and plasma phosphorus in male Ross x Leghorn chicks. At the same time, 0.15% added aluminum mildly depressed growth, feed efficiency and bone ash but had no effect on plasma phosphorus levels. The reduction in bone ash was relatively mild, and no clinical signs of rickets were observed. In laying hens, diets containing 0.15% added aluminum did not affect egg production, but 0.30% added aluminum reduced production significantly. Long-term exposure to aluminum increased percent shell in both groups receiving aluminum, whereas egg weight remained similar to that in controls. There were no changes in hatchability or bone ash associated with dietary aluminum. Although dietary aluminum influenced bone aluminum content, egg aluminum content was not affected. These studies indicate that dietary aluminum interferes with systems in addition to phosphorus metabolism.