Replacement of Tifton hay by spineless cactus in Girolando post-weaned heifers´ diets.

This study aims to evaluate the effect of the Tifton 85 hay (Cynodon dactylon L. Pers) replacement by Orelha de Elefante Mexicana spineless cactus (Opuntia stricta [Haw.] Haw) on the nutrient intake and digestibility, growth performance, microbial protein synthesis, and efficiency of dietary nitrogen compound utilization in the diets of Girolando heifers. Twenty-four (3.5 months and 100 kg ± 3.5 kg) Girolando heifers (5/8 Holstein x Gyr) were used and arranged in a completely randomized design. Dry matter, organic matter, crude protein, and neutral detergent fiber decreased linearly as a function of the levels of Tifton hay (TH) replacement by Orelha de Elefante Mexicana spineless cactus (OEM). The non-fiber carbohydrate intake and coefficient of dry matter digestibility increased, while the neutral detergent fiber (NDF) digestibility decreased linearly with the OEM inclusion. After evaluating the growth performance by observing weight gain and morphometric measurements, there were no significant alterations. The urinary volume, nitrogen balance as well as the efficiency of nitrogen retention had increased, while the urinary and plasma urea concentrations had decreased linearly with the OEM inclusion. The results obtained in this study show that Orelha de Elefante Mexicana spineless cactus should replace Tifton hay in post-weaned heifer diets.

Sugarcane bagasse as exclusive roughage for dairy cows in smallholder livestock system.

OBJECTIVE: The study aimed to evaluate sugarcane bagasse as roughage in lactating cow on feed intake, digestibility, ingestive behavior, milk production and composition, and microbial protein synthesis. METHODS: Ten Girolando cows at initial body weight of 450±25.6 kg and at 143.7±30.7 days in milk were assigned in two 5×5 Latin square designs. Five 21-day experimental periods were adopted (1° to 14-day: diets adaptation period; 15° to 21-day: data collection and sampling period). The diets consisted of four different levels of sugarcane bagasse (45%, 50%, 55%, and 60%) and a control diet, commonly adopted in the region, based on spineless cactus (25% sugarcane bagasse), formulated to meet 12 kg/d milk yield. RESULTS: The dry matter (DM), organic matter (OM), and total digestible nutrients intakes and DM and OM digestibilities observed for 45% and 50% bagasse inclusion were similar to control diet, while that 55% and 60% bagasse inclusion were lower. Cows fed control diet, and bagasse diets of 45%, and 50% levels had the nutritional requirements attended, that guaranteed 12 kg/d of milk yield. The crude protein intake and digestibility of cows fed 45%, 50%, and 55% of bagasse inclusion were similar to control diet. The neutral detergent fiber (NDF) intake and digestibility differ for all bagasse diets related to control diet, while the non-fiber carbohydrates intake and digestibility for cows fed 45% of bagasse were similar for control diet. The intakes and digestibilities of nutrients decreased linearly in function of bagasse inclusion; NDF and indigestible NDF intakes did not vary. The ruminating time, feeding and rumination efficiency, microbial protein synthesis and milk yield decreased linearly with sugarcane bagasse inclusion. CONCLUSION: Sugarcane bagasse decreases milk production; however, its inclusion level in between 45% to 50% associated to concentrate could replace diets based on spineless cactus for crossbred dairy cow's producing 12 kg/d of milk.

Carcass characteristics of lambs fed spineless cactus as a replacement for sugarcane.

OBJECTIVE: Fresh sugarcane has been a new roughage source for ruminant's in semiarid regions, a function of the decline of sugar and alcohol industry in recent years. However, there is little data published regarding lambs fed sugarcane associated with spineless cactus. This study evaluated the effect of sugarcane replacement with spineless cactus (0%, 33%, 66%, and 100%) in the diet of Santa Inês lambs on carcass characteristics. METHODS: Thirty-six non-castrated Santa Ines lambs at four months of age and an initial body weight of 22±2.3 kg were assigned in a randomized block design and slaughtered after 70 days of confinement. The effects of spineless cactus as a replacement for sugarcane in the diet of the lambs on the carcass characteristics, commercial cut weight and yield, leg tissue composition, and carcass measurements were studied. RESULTS: The study revealed quadratic behavior in slaughter body weight, and hot and cold carcass weight, with maximum values of 38.60, 18.60, and 18.11 kg and replacement levels of 40.18%, 44.42%, and 43.14%, respectively. The cold carcass yield presented an increasing linear behavior. The compactness index of carcass and leg presented a quadratic effect, with estimated maximal values of 0.28 and 0.57 kg/cm and replacement levels of 43.37% and 45.5%, respectively. The weights of commercial cuts of leg, loin, shoulder, and breast showed quadratic behavior, with maximum values of 2.79, 0.852, 1.46, and 1.30 kg and replacement levels of 49.5, 45.32, 39.0, and 40.7, respectively. For tissue composition, quadratic behavior was verified for leg weight, subcutaneous fat, and total fat. CONCLUSION: The replacement of sugarcane by spineless cactus at level 44% is recommended for finishing lambs considering that this level improved most of the carcass characteristics, weights, and yields of commercial cuts and leg tissue composition.

Spineless cactus as a replacement for sugarcane in the diets of finishing lambs.

The effects of replacement of sugarcane by spineless cactus (0, 33, 66, and 100 % on dry matter (DM) basis) were evaluated on intake, digestibility of nutrients, ingestive behavior, and performance of finishing lambs. Thirty-six non-castrated Santa Ines lambs at 4 months of age and an initial body weight of 22 ± 2.3 kg were assigned in a randomized block design. A quadratic effect was found for intake of DM, organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), and digestible organic matter (DOM), with maximum values of 1.31, 1.19, 0.219, 0.358, and 0.845 g/day estimated with 42.5, 38.5, 38.8, 21.3, and 44.9 % replacement level, respectively. The digestibility of DM, OM, CP, and EE increased linearly; however, there was a quadratic effect on NDF digestibility with maximum value estimated of 500 g/kg with 64.2 % replacement level. Rumination time, total chewing, and rumination efficiency decreased linearly with the replacement levels; however, idle time increased linearly. A quadratic effect was found for final weight, body weight gain, and total weight gain with maximum values estimated of 38.6 kg, 0.232 kg/day, and 16.2 kg with 39.1, 38.2, and 40.4 % replacing levels. The replacement of 49.5 % sugarcane by spineless cactus can be recommended as optimal level, and problems related to intake, digestibility, and performance are concentrated outside that level.