Effect of different blend levels of spineless cactus and Mombasa hay as roughage on intake, digestibility, ingestive behavior, and performance of lambs.

This study aimed to determine the best level of the blend of spineless cactus (Nopalea cochenillifera) and Mombasa (Panicum maximum) hay as roughage in the diet of lambs based on intake, digestibility, ingestive behavior, and lamb performance. Forty-eight uncastrated crossbred Santa Ines breed lambs with an average age of 4 months old and an average initial BW of 20.5 kg ± 2.8 kg were distributed in two experiments using a completely randomized design: experiment 1: 16 lambs (four treatments and four replicates) for in vivo digestibility trial in metabolic cage; experiment 2: 32 lambs (four treatments and eight replicates) in feedlot to determine intake, ingestive behavior, and performance. As the amount of cactus in the roughage increased, there was a linear reduction (P <0.001) on intake (g/day) of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), non-fibrous carbohydrates (NFC) digestibility, time spent ruminating, feeding efficiency of NDF (P = 0.0153), NDF rumination efficiency rate (P = 0.032), final BW, TWG, and ADG of lamb. However, there was a linear increase (P <0.001) on the intake of the NFC and TDN, digestibility coefficient of DM, CP, total carbohydrates (TC) and NDF gross energy, metabolizable energy, and time spent idling when spineless cactus increased in the roughage blend. The least amount of cactus in the roughage (112-637 g/kg DM) promoted higher intake of DM and CP, improving lamb performance. However, the blend up to 450-300 g/kg DM improved digestibility and energy production as well as it did not affect the feed efficiency.

Fatty acid, chemical, and tissue composition of meat comparing Santa Inês breed sheep and Boer crossbreed goats submitted to different supplementation strategies.

To compare the fatty acid (FA) composition, and chemical and tissue composition of meat, 24 uncastrated males, 12 sheep of the Santa Inês breed, and 12 crossbred goats (F1 Boer × undefined breed) with the weight of 24.3 ± 2.38 kg. The animals were distributed in a randomized block design and treatments were arranged in a 2 × 2 factorial design, two small ruminant species/breed (Boer crossbreed goat × Santa Inês breed sheep), and two supplementation strategies (energy × protein energy). There was not an interaction between the small ruminant species and the supplementation on average daily gain, tissue composition, chemical composition, or FA profile of the longissimus lumborum muscle. Sheep presented greater weight and yield of fat in the subcutaneous, intermuscular, and total depots than goats, which results in better finishing of the sheep for slaughter. Goat meat presented a lower lipid concentration than sheep meat. The protein-energy supplementation increased oleic acid, ΣUFA, ΣMUFA, hypocholesterolemic/ Hypercholesterolemic index, and enzymatic activity Δ9-desaturase C18 and decreased SFA capric acid in the muscle when compared with energetic supplementation. In Caatinga biome conditions, Boer crossbreed goats meat has a lower concentration of lipids and a healthier FA composition compared with Santa Inês breed sheep because it has a lower SFA and greater PUFA content, which are sources of n-3 and n-6, which may contribute to the reduction of blood cholesterol (LDL). In addition, protein-energy supplementation also improved the quality of animal fat compared with supplementation only with the energetic concentrate, regardless of species.

Performance and carcass characteristics of lambs fed diets with increasing levels of Mimosa tenuiflora (Willd.) hay replacing Buffel grass hay.

This study evaluated the performance and carcass characteristics of lambs fed diets with increasing levels of Mimosa tenuiflora (Willd.) hay replacing Buffel grass (Cenchrus ciliaris). Twenty-eight Santa Inês male lambs with an average body weight (BW) of 20.3 ± 1.49 kg(mean ± SD) were allocated in individual stalls and distributed in a completely random design with four treatments (0, 20, 40, and 60 g/100 g total DM M. tenuiflora hay replacing Buffel grass hay in diet) with seven replications. M. tenuiflora hay at the level of 20% dry matter (DM) total replacing Buffel grass hay increased final weight (P = 0.006), total weight gain (P < 0.001), average daily weight gain (ADWG; P < 0.001), DM intake (P < 0.001), and feed efficiency (P < 0.001). Intake of crude protein, NDFap, ADFap, ash, ether extract, total and non-fibrous carbohydrates, and total digestible nutrients presented a positive quadratic effect with M. tenuiflora hay replacing Buffel grass hay and 40 g/100 g total DM level presented greater intake. There were positive quadratic effects by M. tenuiflora hay inclusion at 20 g/100 g total DM level on slaughtering weight (P = 0.005), hot carcass weight (P = 0.002), cold carcass weight (P = 0.002), empty body weight (P = 0.001), hot carcass yield (P = 0.002), cold carcass yield (P = 0.003), and increase linear on biological yield (P = 0.003). There was no influence on cooling weight loss (P = 0.284). M. tenuiflora hay may be included in lamb diets at amounts up to 20 g/100 g total DM substitution of Buffel grass hay because increase in the nutrients intake, growth performance, and carcass characteristics.