<p>  </p> <p>There is a clear need for more research detailing how to manage birds in cage-free housing systems. Although management guides for birds in cage-free systems focus on adult hens, previous research has established that the pullet phase is important to success later in life. Past research regarding the effects of stocking density on behavior has focused on caged adult hens, and often deals with confounding factors such as group size, limiting its interpretation. The goal of this project was to investigate the impacts of stocking density on behaviors of pullets in cage-free housing systems. </p> <p>A 2x2 randomized complete block design with two strains (Lohmann LB-Lite (Brown) and Lohmann LSL-Lite (White)) and two stocking densities (619.1 (high stocking density; HSD) and 1,248.9 (low stocking density, LSD) cm2/bird) was utilized. Videos of 6 pens for each strain by stocking density combination (59 birds/pen, n = 1416) were recorded for 2 consecutive days at 12 and 16 weeks of age (WOA). Behaviors of interest were recorded every 10 minutes for 1 hour in the morning, afternoon, and evening. Most behavior data were analyzed using a mixed model, PROC GLIMMIX, in SAS 9.4 with main effects of stocking density (SD), strain, age and time of day (TOD). Behaviors that were infrequent or that could not be transformed to meet normality assumptions were analyzed as binomial data (occurred or did not occur) and odds ratios were calculated using PROC LOGISTIC.</p> <p>Stocking density influenced every behavior examined. The LSD had fewer birds that performed eating and drinking behaviors, but more birds performed inactive, locomotion, exploratory and comfort behaviors compared to the HSD. Additionally, birds in the HSD were more likely to participate in pecking and piling behaviors compared to LSD. These results suggest that LSD may provide welfare benefits to the pullets. However, producers may face economic barriers when attempting to decrease stocking densities. Further research is needed in this area, but these results could help to achieve a stocking density that maximizes the range of behaviors pullets are able to perform within the scope of a producer’s resources. Future directions may consider collecting behavior data across the life cycle in addition to examining the relationships among behavior and welfare parameters such as feather quality, foot condition and keel bone fractures.</p>

Broilers are nearing their genetic potential and nutritional strategies are the primary means to improve their performance. Improving raw material quality, especially soybean meal, could improve broiler performance, health and welfare. Inadequate processing of soybean meal leads to high residual anti-nutritional factors (ANF) which has a negative influence on broiler performance. High trypsin inhibitor content in low- quality soybean meal causes decreased protein digestion and absorption. The main aim of this study was to evaluate the optimal quality of soybean meal for commercial use to promote performance and welfare parameters of broiler chickens. Ten dietary treatments were formulated to the same nutritional specifications, but with different soybean meals that ranged from very high-quality (Treatment 1) to the lowest quality (Treatment 10). The quality of soybean meal was determined using Table 2.1 as target values for each soybean meal quality parameter. Soybean meal quality was evaluated using urease levels (pH change), TIA (trypsin inhibitor activity), Evonik TIA, KOH (potassium hydroxide solubility), Evonik KOH, Evonik PDI (protein dispersibility index) and Evonik PCI (processing conditions indicator). The treatment diets were fed to 4800 broilers that were randomly allocated to 80 pens, each with 60 birds and eight replicates. Over a 35-day growth trial, broiler performance, welfare and physiological traits were measured on a weekly basis. Overall, improved performance was observed with higher-quality soybean meal outperforming the lower-quality soybean meal. High-quality soybean meal showed significantly better feed conversion ratio’s (FCR) and European performance efficiency factor (PEF) throughout the 35-day period, and significantly higher average daily gain (ADG) up until day 21. Bodyweight (BW), feed intake (FI) and mortality showed no significant differences irrespective of soybean meal quality. No significant differences were found in physiological traits namely: pancreas weight as a percentage of bodyweight, pancreas length to bodyweight ratio, gizzard and proventriculus weight as a percentage of bodyweight and gizzard erosion score, (PW%BW, PL:BW, GPV%BW, GE score) irrespective of soybean meal quality. High quality soybean meal showed lower incidence and lower severity of rapid feed passage (RFP) and foot pad dermatitis (FPD). Evonik PCI and urease levels (pH change) showed the strongest correlation to broiler performance, health and welfare. This study suggests using soybean meal with the following quality parameters: urease levels of around 0.05, TIA levels of below 4mg/g, KOH levels of 78-80%, PDI levels of around 15 and PCI levels of around 11. The Evonik PCI and urease (pH change) analyses for soybean meal quality was found to be the easiest and cheapest method and can be recommended as the primary quality assays for commercial feed companies in the future. / Dissertation (BSc (Agric) Animal Science)--University of Pretoria, 2020. / AFGRI / Animal and Wildlife Sciences / BSc (Agric) Animal Science / Restricted