Nutrition is one of the most important factors that affect animal performance, and it therefore also impacts on financial results in beef systems. In this way, finding the best strategy for feeding supplements is of paramount importance. Aiming to evaluate the effect of supplement feeding strategies for beef cows in the last third of gestation, two experiments were conducted. In Experiment 1, 35 pregnant Nellore cows were assigned to a completely randomized design with four treatments: control, which received no supplement; supplementation for the last 30 d of gestation (30-d; 3.0 kg/d); supplementation for the last 60 d of gestation (60-d; 1.5 kg/d); or supplementation for the last 90 d of gestation (90-d; 1.0 kg/d). All supplemented treatments received the same total amount of supplement throughout the experiment: 90 kg (20% of crude protein). A second experiment (Experiment 2) was delineated to evaluate the effects of the amounts offered in Experiment 1 on intake and metabolism. Four multiparous pregnant Nellore cows were assigned to a 4 × 4 Latin square design, with periods of 15 d each. There was a linear effect of the number of days of supplementation on calving body weight (BW; P < 0.05) and a quadratic effect on BW change from parturition to d 31 post-calving (P < 0.05), with cows on the 60-d strategy losing less BW post-calving. No difference was found in offspring birth BW (P > 0.10). A significant linear effect on interval from parturition to conception (P < 0.05) was observed, with the highest calving to conception interval being observed in the 90-d strategy. The level of supplementation did not affect forage intake or neutral detergent fiber digestibility (P > 0.10). Nitrogen excreted through urine tended to increase linearly with the level of supplementation (P < 0.10). Providing 1.5 kg of supplement during the last 60 d of gestation improves cow performance after calving, reducing the magnitude of BW lost, and reduces the number of days from calving to re-conception in the following breeding season compared to the usually recommended period of supplementation of 90 d pre-partum.

The objective of this work was to evaluate the effect of energy-protein supplementation in preand postpartum periods on the productive and metabolic responses of grazing beef cows on tropical pasture. A group of 48 multiparous Nellore cows, with an initial gestation period of 6.4 months, body weight (BW) of 514.9 kg, and body condition score (BCS) of 5.4, was distributed in a completely randomized design, in a 2×2 factorial arrangement. The evaluated treatments were: UNS-UNS, unsupplemented during prepartum and postpartum; UNS-SUP, unsupplemented during prepartum and supplemented during postpartum; SUP-UNS, supplemented during prepartum and unsupplemented during postpartum; and SUP-SUP, supplemented during preand postpartum. The energy-protein supplement was offered at an amount of 1.5 kg per animal per day. Prepartum supplementation increased average daily gain and BCS at calving. Prepartum supplementation reduced non-esterified fatty acids (NEFA) and increased serum concentrations of total proteins and globulins during postpartum. Postpartum supplementation increased the BCS of cows and BW of calves at the end of the experiment. Postpartum supplementation increased blood concentrations of progesterone, while NEFA decreased. Supplementation with 1.5 kg per day of the energy-protein supplement during the last 84 days of gestation improves productive performance and metabolic status during the preand postpartum periods of grazing cows.

The objective of this study was to evaluate the inclusion of coffee pulp silage (CPS) on the performance and profitability of crossbred cows in the middle tropics. The research took place at the Villa Marina Experimental Farm of the University of Pamplona, Pamplonita, Colombia. Four lactating multiparous bovines with a body weight of 380 ± 10 kg, 6 ± 0.03 years of age and a body condition of 3.8 on a scale of 1 to 5. The animals were distributed in a balanced 4 × 4 Latin square for residual effect. The experiment consisted of four subperiods of 21 days each, being the first 14 days of adaptation to the experimental diet and 7 days for taking samples. The base diet consisted ofPennisetumsp. forage, concentrated in a proportion of 0.2% of body weight, water, and mineralized salt at will. The inclusion of the CPS was included in levels of 4, 8, and 12% of the dry matter (DM) intake. DM intake parameters, nutrient digestibility, milk production and composition, blood parameters, and economic analysis were evaluated. Treatments were compared using orthogonal contrasts; contrasts were constructed in order to evaluate the effects of inclusion of CPS, and the linear and quadratic effects of level inclusion in the DM of the diet. For the variables which did not present inclusion of CPS effect but a linear or quadratic effect was significant, a Dunnett’s test was performed to identify whether a supplemented treatment differed from the control. Significance was considered atP < 0.05 and tendencies when 0.05 < P ≤ 0.10. The inclusion of CPS in the diet increases (P < 0.05) the voluntary intake in kg day⁻¹of DM, organic matter (OM), CP, ethereal extract (EE), non-fiber carbohydrates (NFC), digested OM (DM), neutral detergent fiber corrected for ash and protein (NDFap), DNDF and dietary NTD concentration, the total digestibility of DM and OM, and dietary DOM content. The production and chemical composition of milk was not affected (P > 0.10) by the inclusion of EPC in the diet. The inclusion of CPS increased (P < 0.05) the concentration of albumin and globulins in the blood. The inclusion of CPS in the diet improved the productive efficiency of dairy cattle. The inclusion of 4% CPS in the DM of the diet is a nutritional strategy, which improves the nutritional characteristics and the concentration of albumin and globulins in the blood of crossed dairy cows in the middle tropics and benefit: cost ratio without affecting milk production.