Blood parameter of Nellore steers submitted to different levels of feed intake

Abstract

Blood parameters of 18 Nellore steers submitted to high concentrate diet in two sequential feeding regimes (phase 1: restriction and phase 2: ad libitum feeding) were evaluated. In the first phase, steers were fed for 56 days three intake levels of dry matter (ad libitum, 75 g dry matter (DM)/kg metabolic body weight (BW 0.75) or 60 g DM/kg BW 0.75. In the second phase, from the 57 th day on feed, animals fed 60 g DM/kg BW 0.75 and 75 g DM/kg BW 0.75 were fed ad libitum until the 136 th day. In the 8 th , 27 th , 55 th (first phase), 71 st , 84 th , 112 th and 132 nd (second phase) day of experimental period, blood samples were collected and insulin-like growth factor I (IGF-I), triiodothyronine (T3), thyroxine (T4), glucose, plasma ureic nitrogen (PUN) and total protein (TP) were determined. In the first phase IGF-I, T4, glucose and total protein concentration was not different among treatments (P>0.05) and there was no interaction between treatment and time (P>0.05). There was an interaction among treatments and time on T3 and plasma ureic nitrogen (P<0.01). In the second phase IGF-I, T3, T4, glucose and total protein concentration was not different among treatments and there was no interaction between treatment and time (P>0.05). For plasma ureic nitrogen concentration there was an interaction among treatments and time (P=0.02). Lower levels of diet intake can be used to improve animal performance in feedlot.

Assessing the impact of essential oil blends as antibiotic alternatives on nutritional and metabolic parameters in non-forage-based diet-fed Nellore steers

“…However, when fed a high-concentrate diet, values can exceed 70 mg dL −1 . For example, Aferri et al (2019) found 129.23 mg dL −1 of blood glucose in Nellore cattle confined with 800 g kg DM −1 of concentrate in the diet. Furthermore, glycemia in cattle is higher in the presence of additives that modulate ruminal fermentation, which increases propionate production, the primary glucose precursor in the liver (Duffield, Merrill & Bagg, 2012).…”

Estratégias de suplementação de fêmeas Nelore primíparas e pluríparas no pós-parto e de bezerros lactentes em pastagem tropical

“…O pós-parto de primíparas pode ser bastante desafiador, uma vez que, além das exigências de mantença, gestação e lactação, necessitam de nutrientes para seu próprio crescimento; assim, não atendidas estas exigências, podem não demonstrar cio fértil durante a lactação (NOGUEIRA et al, 2014) Diversos estudos avaliaram os efeitos da nutrição e metabolismo pós-parto em vacas leiteiras de diferentes ordens de parto (NASROLLAHI et al, 2017;NEAVE et al, 2017;TIENKEN et al, 2015;SAQIB et al, 2018), no entanto, a respeito de vacas de corte em condição de pastejo, ainda são escassos os trabalhos que avaliaram os efeitos da suplementação no pós-parto no metabolismo de diferentes ordens de parto.…”