Effect of Crude Glycerin in the Feed of Lactating Goats on Concentrations of Essential and Toxic Metals in Serum, Urine, Milk, and Artisanal "Coalho" Cheese.

Goat farming is concentrated in semi-arid and tropical regions in Brazil. From 2006 to 2017, the number of goats sold in the country increased by 65.7%. The dairy products from these animals present higher digestibility, high vitamin A and B content, hypoallergenicity, and less lactose compared to dairy products from cows, in addition to having a higher sales value. Since corn and soybean meal generate an expense for feed management, crude glycerin, originating from the manufacture of biodiesel, has been studied as an energy substitute. However, this product contains heavy metals, posing risks to animal and human health. Few data are available on trace elements in biological samples and products derived from goats' milk with the dietary introduction of glycerin. The objective was to quantify aluminum (Al), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), and zinc (Zn) in the serum, urine, milk, and artisanal "coalho" cheese of dairy goats fed different levels of crude glycerin in feed management. In total, 16 Saanen goats were selected, lactating females, that were distributed in four Latin squares and randomly treated with different levels of crude glycerin (0, 5, 10, and 15%). After the end of each experiment cycle, serum, urine, milk, and artisanal "coalho" cheese samples were collected at the four moments. The samples were submitted to digestion assisted by microwave radiation. The multi-element analysis was carried out using inductively coupled plasma optical emission spectrometry (ICP OES). There was no influence of crude glycerin levels replacing corn in serum, milk, urine, and artisanal "coalho" cheese. The serum concentration of the metals Cu, Fe, Zn, and Mn; urine concentrations of Cu, Zn, Mn, Mo, and Cr; and milk and artisanal "coalho" cheese concentrations of Cu, Zn, and Mn remained within the standards found in the literature. The inclusion of 5 to 15% of crude glycerin, derived from cotton oil, in the diets of dairy goats in partial replacement of corn, does not alter the concentration of essential and toxic metals in serum, urine, milk, and artisanal "coalho" cheese and does not, therefore, present a risk factor for intoxication.

Palatability and nycterohemeral patterns of ingestive behavior of sheep fed different roughage sources.

The aim of this study was to evaluate the nycterohemeral patterns of ingestive behavior at 24, 48, and 72 h (Trial I) of sheep fed different roughages and the palatability index (Trial II) for sheep and goats fed different roughages used in a semiarid region. In the study, five sources of roughage were evaluated, namely: (1) Nopalea cochenillifera (L.) Salm-Dyck cladodes + urea + sugarcane bagasse (NUB); (2) Opuntia stricta (Haw.) Haw cladodes + urea + sugarcane bagasse (OUB); (3) Tifton hay; (4) corn silage; and (5) sorghum silage. Five Soinga sheep were used and arranged in a 5 × 5 Latin square design in Trial I. Six female Santa Ines sheep and six female Saanen goats were used to study the preferences for different roughages in Trial II, and three tests were carried out to determine the palatability index, comparing two roughage types at a time: test 1 - corn silage versus Nopalea cladodes + urea + sugarcane bagasse (NUB); test 2 - corn silage versus Opuntia cladodes + urea + sugarcane bagasse (OUB); and test 3 - NUB versus OUB. The highest dry matter (DM) intake was for diets composed by NUB. Feeding time (min/d) was higher for sorghum silage (291 min d-1), while rumination time was higher (P < 0.05) for corn silage (604.0 min d-1), sorghum silage (561.7 min d-1), and Tifton hay (529.7 min d-1). No difference (P > 0.05) was observed for feeding, rumination, and idleness time between species (sheep and goats), and there was no roughage × species interaction (P > 0.05). The palatability indexes were 76 and 77% (tests 1 and 2) for NUB and OUB, respectively. Sheep fed with roughage containing cactus cladodes associated with urea and sugarcane bagasse spent less time on ingestion and rumination activities. The ingestive behavior can be evaluated in a period of 48 h, using instantaneous scanning.

Cactus cladodes associated with urea and sugarcane bagasse: an alternative to conserved feed in semi-arid regions.

The objective of this study was to evaluate the nutritional value of different roughage sources as an exclusive feed for goats and sheep from the determination of nutrient intake and digestibility. Five goats and five sheep were used and arranged in a double 5 × 5 Latin square design. Treatments consisted of cactus Nopalea cochenillifera (L.) Salm-Dyck cladodes (Nopalea) + urea + sugarcane bagasse (NUB), cactus Opuntia stricta (Haw.) Haw cladodes (Opuntia) + urea + sugarcane bagasse (OUB), Tifton hay (TH), maize silage (MS), and forage sorghum silage (SS). Dry matter (DM) and crude protein (CP) intakes of NUB were greater than SS (0.620 and 0.058 versus 0.416 and 0.040 kg/day). Metabolizable energy (ME) intake was higher for NUB (1.52 Mcal/day). The DM digestibility did not change between the roughages (59%). The NUB, OUB, and MS organic matter digestibility (OMD; 62.4%) were greater than that of SS (57.4%). The roughage consisting of cactus cladodes associated with urea and sugarcane bagasse presented a greater nutritional value, similar to MS and TH, and higher than SS. Cactus cladodes associated with urea and sugarcane bagasse are recommended as an alternative to conserved feed.