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Simple Summary: Enhancing the energy density of lamb diets is a proven method to improve their productivity. While using carbohydrates for this purpose may seem intuitive, it can lead to undesirable shifts in ruminal metabolism, potentially triggering metabolic diseases. Hence, substituting carbohydrates with lipids is favored. Nevertheless, lipids, though effective, can also disrupt ruminal fermentation parameters. Among these lipids, soybean oil stands out for its positive impact on both beef and dairy cattle, leading to improved performance. In our study, we sought to assess the effects of soybean oil supplementation on performance, digestibility, feeding behaviour, and blood metabolites of feedlot lambs. Our findings indicate that the inclusion of soybean oil resulted in a linear reduction in nutrient intake, consequently lowering the average daily gain of the lambs. Additionally, soybean oil supplementation induced selective feeding behaviour among the lambs. Based on our observations, we recommend incorporating soybean oil into lamb diets at a maximum inclusion rate of 41 g/kg DM to optimize production parameters. The strategy implemented to adapt lambs to increasing levels of high-fat diet mitigated the detrimental effects of lipids on the rumen, with high-density energy intake being the constraining factor on performance. The objective of the current study was to evaluate the effects of soybean oil inclusion in diets on feeding behaviour, digestibility, performance, and blood metabolites of feedlot lambs. Forty non-castrated Santa Inês lambs with a mean age of 5 months and initial body weight of 34.88 ± 3.19 kg were used in a 40-day feeding trial. The lambs were distributed in five experimental diets with the inclusion of increasing soybean oil (SO) levels: 0, 30, 60, 90, and 120 g/kg DM. The SO inclusion promoted a linear reduction in DM intake (p < 0.001), crude protein (CP, p < 0.001), non-fibrous carbohydrates (NFC, p < 0.001), and total digestible nutrients (TDN, p = 0.004). There was an increasing quadratic effect on the intake of ether extract (EE; p = 0.002) and decreasing for neutral detergent fiber (p = 0.005). The soybean oil inclusion promoted the greater apparent digestibility of CP (p = 0.016), EE (p = 0.005), NDFom (p < 0.001), and TDN (p < 0.001); on the other hand, the apparent digestibility of NFC (p = 0.005) was decreased. The average daily gain decreased (p < 0.001) with SO inclusion. The SO inclusion increased feeding time (p = 0.004), reduced the efficiency of DM rumination (p = 0.001), and reduced the concentration of blood N-ureic (p < 0.001). Considering the productive parameters, SO can be included in diets and it is recommended that we include SO of up to 41 g/kg DM in diets for fattening lambs as the ideal maximum level. The strategy implemented to adapt lambs to increasing levels of high-fat diet mitigated the detrimental effects of lipids on the rumen, with high-density energy intake being the constraining factor on performance. [ABSTRACT FROM AUTHOR]

The study was conducted to evaluate the effects of feeding frequencies (one, two, three, and four times per day) on the performance of male feedlot lambs. Forty Santa Inês male lambs were used with an average age of 120 days approximately and initial body weight of 24.90 ± 1.8 kg (mean ± S.D.). The lambs were distributed to treatment groups in a completely randomized experimental design, with 10 animals per treatment, placed in individual pens. A standard diet consisted of Tifton-85 hay and concentrate with a ratio of 60:40, respectively. The different feeding frequencies did not influence (p > 0.05) the intake of nutritional components, blood parameters, weight gain, ingestive behavior, carcass characteristics, or meat quality of male feedlot lambs. The feeding frequency of 3 and 4 times per day promoted the highest digestibility of neutral detergent fiber (NDF; p = 0.008) and total digestible nutrients (TDN; p = 0.002). The feeding frequency of 3 times per day promoted the highest digestibility of crude protein (CP; p = 0.005). The time devoted to rumination (min/kg DM) was increased (p = 0.029) when the diet was supplied once a day compared to the other feeding frequencies. Based on these results, the recommended feeding frequency for male feedlot lambs is once a day. When feeding at this frequency, the ingestive behavior, productivity, carcass characteristics, and meat quality of male feedlot lambs will not be compromised. [ABSTRACT FROM AUTHOR]