Preliminary exploration of the effects of extended colostrum feeding on calf lying behavior and factors associated with student success in an introductory level animal science course

Abstract

This thesis consists of two projects: assessing the effects of supplementing colostrum in the diet of preweaned non-replacement dairy calves beyond the first 24 hours of age on lying behavior (Project 1) and assessing factors associated with student final grades in an introductory animal science course (Project 2).The objective of Project 1 was to determine if extended colostrum feeding (ECF) from 0-14 d was associated with preweaned dairy calf behavior. Feeding colostrum beyond 24 h of age has been seen to improve calf health and growth, yet the behavioral impacts are unknown. Neonatal Holstein and Holstein-Limousin calves (n = 26) were enrolled after they received 4L of maternal colostrum at birth and 4L 8 hours later, according to the dairy's existing protocol. Calves were transported 40km to a university teaching and research facility at 1 d of age. Calves were randomly assigned to treatment (COL; fed milk replacer + 44g colostrum replacer for the first 14 days, average Brix value = 14.5%) or control (CON; fed only milk replacer, average Brix value = 12.2%) upon arrival and blocked by breed and sex (n = 15 females, n = 11 males). Electronic loggers were attached to the hind leg of each calf for 4 d to record lying time, number of lying bouts, and lying bout duration during weeks 1, 2, 3, and 8 of life. Calves were weighed and average daily gain (ADG) was calculated at the end of each week. Health and fecal scores were assigned to each calf using a 0-3 scale twice weekly; clinical respiratory disease was defined as a sum of scores ≥ 5 or two or more scores ≥ 2 and diarrhea was defined as a fecal score ≥ 2. Thoracic ultrasounds were performed weekly, and scores were assigned to each calf using a 0-3 scale; pneumonia was defined as a score ≥ 2. Lying behavior and diarrhea were analyzed using multivariable logistic regressions; ADG and feed-to-gain ratios were analyzed using multivariable linear regression. All models controlled for breed and sex with week as a repeated measure. Other health measures were reported via summary statistics. Treatment was not associated with proportion of time spent lying (CON: 78.8 ± 1.5%; COL: 79.5 ± 2.5%; P = 0.0.63), number of daily lying bouts (CON: 23.8 ± 1.1; COL: 23.7 ± 1.1; P = 0.96), or average lying bout duration (CON: 48.5 ± 3.3 min; COL: 49.6 ± 3.3 min; P = 0.71). Treatment was not associated with ADG within the first two weeks of life (P = 0.39) or throughout the preweaned period (P = 0.88), nor was it associated with feed-to-gain ratios for milk (P = 0.24) or for grain (P = 0.74). Ninety-two percent (12/13) of COL calves and 100% of CON calves had diarrhea at least once during the study period (P = 0.18). Eight percent (1/13) of COL calves and 15% (2/13) of CON had clinical and/or subclinical respiratory disease at least once during the study period (P = 0.0.34). Treatment was not associated with incidence of scours (P = 0.18) or incidence of respiratory disease (P = 0.57). This pilot study did not find associations between ECF and lying behavior, growth, or health during the preweaned dairy calves. However, this information can be used to refine sample sizes and measurements in future studies. The objective of Project 2 was to determine if demographic factors and academic behaviors such as involvement in extracurricular activities, study strategies, notetaking habits, and attendance patterns were associated with students' final grade in a 100-level Introductory Food Animal Science course at Colorado State University (CSU). The impact of demographic factors and student academic behaviors or habits on student success are well-documented in many science disciplines, yet little data exists for animal science programs. Students enrolled in the course at CSU during the fall 2021, 2022, and 2023 semesters (n = 556) were asked to complete an anonymous survey at semester's end regarding their final grade, academic behaviors, and demographics. Survey question types included multiple choice, Likert-scale, and short answer. Multivariable logistic regressions assessed associations between final course grade (pass: 'A', 'B', or 'C'; fail: 'D', or 'F'; outcome) and involvement in departmental extracurriculars (yes/no), perceived adequacy of study skills and notetaking strategies (Likert), attendance patterns (Attended 100%/Attended 80-90%/Attended < 70%), self-reported high school GPA (HSGPA; ≥ 4.00, 3.00-3.99, < 3.00), race (white/racially minoritized), number of times enrolled in the course (1/ >1), and first-generation (FG) status (yes/no). Students that had meaningful connections with faculty and those that were involved in clubs, research, and/or voluntary animal feeding were associated with a lower predicted probability of earning a failing grade compared to those who were not involved (P = 0.0060, P = 0.0027, P = 0.0125, P = 0.0013, respectively). Students with perceived inadequacies in study skills and notetaking strategies were associated with a lower predicted probability of passing compared to those who felt their skills were adequate (P = 0.0018 and P < 0.0001, respectively), yet no differences of probability of earning a failing grade were seen between students with different notetaking strategies (P = 0.6616) or quantities of time spent studying for quizzes or exams (P = 0.4353 and P = 0.3703, respectively). Students who attended class 80-90% of the time or less than 70% of the time were associated with lower odds of passing, compared to those who attended 100% of class periods (P = 0.0099 and P = 0.0045, respectively), but no differences were seen between those attending 10% of the time and those attending 90-100% of the time (P = 0.1854), nor was there a difference seen between those attending 80-90% and those attending less than 70% of the time (P = 0.2032). An interaction occurred between FG and HSGPA (P = 0.0397), which showed lower probabilities of earning a failing grade for non-FG students compared to FG students at each of the three levels of HSGPA (≥ 4.00: P = 0.0158; 3.00-3.99: P = 0.0184; < 3.00: P = 0.0341). Racially minoritized students and students retaking the course had a higher probability of earning a failing grade in the course than their respective counterparts (P < 0.0001 and P = 0.0030, respectively). This study highlights the roles of involvement, attendance, perceived inadequacies in learning behaviors, and various demographics in academic performance and can be used to inform future student support programs in animal science disciplines.