Evaluation of internal markers in digestibility estimation for sheep and goats.

The objective of this study was to compare the indirect methods of obtaining digestibility with the direct method of total fecal collection to estimate the apparent digestibility of nutrients in sheep and goats supplemented with non-protein nitrogen. Five goats and five sheep with no defined racial pattern were used, distributed in two 5 × 5 Latin squares, with split plots, considering the diets as plots and the apparent digestibility determination methodologies as subplots. The diets were composed of buffelgrass hay and the addition, via ruminal infusion, of increasing amounts of nitrogen supplementation in order to gradually raise the CP level of the basal diet in intervals of 2% points, that is, + 2, +4, + 6 and + 8%. Samples of the feeds offered, and the leftovers were collected daily during the five days of collection to determine the nutrient intake, as well as the total collection of feces to determine the apparent digestibility of the nutrients. The amount of fecal dry matter excreted was estimated by the concentration of Indigestible Acid Detergent Fiber (ADFi), Indigestible Neutral Detergent Fiber (NDFi), Indigestible Dry Matter at 244 h (DMi 244 h) and Indigestible Dry Matter at 264 h (DMi 264 h). Among the evaluated markers, DMi 264 h had the lowest accuracy in estimating fecal excretion and nutrient digestibility. For the goat species, the markers ADFi and DMi 244 h proved to be able to adequately predict fecal excretion and digestibility indices, while NDFi stood out for both species. Among the evaluated markers, NDFi is the one that most accurately estimates the nutrient digestibility of the diet for goats and sheep.

Forage cactus as an additive in corn without the cob silages of feedlot sheep diets.

This study aimed to assess the impact of adding forage cactus as an additive to the production of corn silage without the cob on the performance of feedlot sheep and subsequent silage losses. The experimental design was completely randomized, consisting of three treatments: corn silage without cob; 0% = 100% corn plant without the cob; 10% = 90% corn plant without cob + 10% forage cactus; 20% = 80% corn plant without cob + 20% forage cactus. Significant effects were observed for dry matter intake (P = 0.0201), organic matter (P = 0.0152), ether extract (P = 0.0001), non-fiber carbohydrates (P = 0.0007). Notably, nutrient digestibility showed significant differences in organic matter (P = 0.0187), ether extract (P = 0.0095), neutral detergent fiber (P = 0.0005), non-fiber carbohydrates (P = 0.0001), and metabolizable energy (P = 0.0001). Performance variables, including total weight gain (P = 0.0148), average daily weight gain (P = 0.0148), feeding efficiency, and rumination efficiency of dry matter (P = 0.0113), also exhibited significant effects. Consequently, it is recommended to include 20% forage cactus in corn silage, which, based on natural matter, helps meet animals' water needs through feed. This inclusion is especially vital in semi-arid regions and aids in reducing silage losses during post-opening silo disposal.

Chemical Properties, Ruminal Fermentation, Gas Production and Digestibility of Silages Composed of Spineless Cactus and Tropical Forage Plants for Sheep Feeding.

The aim was to evaluate the chemical composition, carbohydrates, protein fractionation and in vitro gas production of silages composed of spineless cactus and tropical forages and their effect on sheep performance. Treatments consisted of silages: corn silage (CS), spineless cactus silage (SCS), spineless cactus + gliricidia (SCG), spineless cactus + buffel grass silage (SCBG) and spineless cactus + pornunça (SCP). Silos were opened 60 days after ensiling, and analyses were carried out. The digestibility test lasted for 36 days, with eight animals per treatment. A completely randomized design was adopted. Considering carbohydrate fractionation, CS, SCS and SCBG silages had higher total carbohydrate content (p = 0.001). The SCS silage presented a higher A + B1 fraction (p = 0.001). The SCBG and SCG silages showed a higher B2 fraction (p < 0.0001) compared to the CS and SCS silages. The SCBG and SCP silages presented a higher C fraction (p = 0.001). For protein fractionation, the SCP and SCG silages showed higher crude protein contents (p = 0.001). The CS and SCS silages showed a higher A fraction (p = 0.001). The SCBG silage presented a higher B1 + B2 fraction (p = 0.001). The SCG silage showed a higher B3 fraction (p = 0.006) compared to SCBG silage. The SCS and SCP silages showed a higher C fraction (p = 0.001). Exclusive SCS silage showed higher in vitro dry matter digestibility (p = 0.001), dry matter degradability (p = 0.001) and total gas production (p = 0.001). The use of the SCBG, SCP and SCG silages to feed sheep increased the dry matter intake (p < 0.001). Sheep fed the SCG silage showed greater dry matter and crude protein digestibility compared to the sheep fed the CS, SCS and SCP silages (p = 0.002). There was a higher water intake (p < 0.001) with the use of the SCS and SCG silages to feed the sheep. The SCP and SCG silages provided a greater intake (p < 0.001) and excretion (p < 0.001) of nitrogen by the animals. Although there were no differences between the treatments for daily gains, lambs that received the spineless cactus-based silage associated with tropical forages showed higher gains (160-190 g/day) than lambs that received CS silage (130 g/day). Thus, the use of spineless cactus associated with buffelgrass, pornunça and gliricidia to prepare mixed silages (60:40) to feed sheep has potential use to feed sheep, with positive effects on nutrient degradation and increases in dry matter intake. Under experimental conditions, we recommend the exclusive use of spineless cactus silage associated with buffel grass, pornunça and gliricidia in feeding sheep in semi-arid regions, as it provides nutrients, water and greater daily gains compared to corn silage.

Fermentation Profile, Aerobic Stability, and Chemical and Mineral Composition of Cactus Pear Silages with Different Inclusion Levels of Gliricidia Hay.

Cactus pear is used in large proportions in diets for small ruminants in semiarid regions. However, its exclusive use is not recommended due to the low fiber and crude protein content and the high water and mineral content, leading to metabolic disorders, low dry matter intake, and weight loss. The use of mixed cactus silage associated with protein and fibrous sources seeks to overcome the deficits in dry matter, fiber and crude protein, aiming to improve the nutritional quality of the diets that will be offered to ruminants. Thus, the use of gliricidia hay in cactus pear silages could represent an important alternative to improve the nutritional and fermentative characteristics of the ensiled material. Therefore, our aim was to evaluate the fermentation dynamics, nutritional characteristics, and aerobic stability of mixed silages of cactus pear combined with different levels of gliricidia hay. This was a completely randomized experimental design with five treatments and five repetitions. The treatments consisted of different levels of inclusion of gliricidia hay (0, 10, 20, 30, and 40% on a dry matter basis) in the composition of mixed cactus pear silages. The inclusion of gliricidia hay in the composition of mixed silages of cactus pear resulted in a quadratic effect for dry matter recovery, pH, NH3-N, buffering capacity, aerobic stability, ether extract, P, K, Na, and Zn (p < 0.05). There was a reduction in density, effluent losses, maximum pH, mineral matter, non-fiber carbohydrates, Ca, Mg, Fe, and Mn (p < 0.05), and an increase in the time to reach maximum pH as well as an upward trend in pH, dry matter, organic matter, crude protein, neutral detergent fiber, acid detergent fiber, and B (p < 0.05). Under experimental conditions, the inclusion of gliricidia hay between 20 and 30% in cactus pear-based silage provided an improvement to the chemical composition and fermentation parameters of the silages.

Thermoregulatory responses and ingestive behavior of sheep subjected to water restriction and high- and low-energy diets in a semi-arid environment.

The aim of the study was to evaluate the effect of water restriction and low- and high-energy diets on sheep's thermoregulatory responses and ingestive behavior. Forty sheep, non-castrated, with an average body weight of 18.85 kg (SD = 2.80 kg) and an average age of 5 months were assigned to a 2 × 2 factorial arrangement, comprising 2 diets (high- and low-energy) and 2 water offers (ad libitum and 50% water restriction), with 10 replicates. Thermoregulatory responses were evaluated in two periods (morning and afternoon). There was an interaction effect of Diet x Water supply x Periods on respiratory rate (P < 0.05). High-energy diets resulted in increased heart rate, idleness, dry matter feeding and rumination efficiency, and water intake. Low-energy diets increased feeding time, rumination time, the number of ruminal cuds, chews per day, total chewing time, neutral detergent fiber intake and rumination efficiency, number of ruminations per day, average duration of rumination, and defecation frequency. Water supply affected heart rate and idleness (P < 0.05). Sheep had higher values of heart rate and rectal and surface temperatures during the afternoon (P < 0.05). Water restriction combined with a low-energy diet and high environmental temperature leads to a reduction in the respiratory rate of Santa Inês crossbred sheep. Regardless of the dietary energy value, water restriction by 50% of the daily requirement of sheep reduces dry matter intake and increases idleness.

Carcass traits and meat quality of goats fed with cactus pear (Opuntia ficus-indica Mill) silage subjected to an intermittent water supply.

The effect of different proportions of cactus pear (Opuntia ficus-indica Mill) silage (CPS) and intermittent water supply (IWS) to crossbreed goats' diets on carcass traits and meat quality were evaluated. The IWS caused a reduction (p = 0.03) in the percentage of leg fat in the animals. The rib eye area, carcass weight, and physical-chemical characteristics were not affected (p > 0.05) by the CPS or IWS. The IWS reduced (p = 0.04) the elongase enzyme activity. The CPS inclusion in the diet reduced C22:0 (p = 0.01), some branched-chain fatty acid (BCFA), C20:1 (p = 0.03), c13-C18:1 (p = 0.01) fatty acids. Therefore, in situations of water scarcity, an intermittent water supply of up to 48 h and diets with up to 42% cactus pear silage, can be adopted in goat feedlot, without affecting carcass traits and meat quality.

Proportions of concentrate and rehydrated ground grain corn silage at different storage times for better use of starch by lambs.

This study aimed to evaluate the nutritional and bioeconomic potential of rehydrated ground grain corn silage (RGGCS), at different storage times associated with proportions of concentrates for better starch utilization by lambs. Forty Dorper-Santa Inês crossbred lambs were used, with an average body weight of 24 ± 3.9 kg, and an average age of 90 days. The lambs were feedlot for 63 days in experiment design completely randomized, with eight repetitions and five experimental diets: Diet 1: 850 g/kg concentrate including dry ground corn; diet 2: 850 g/kg concentrate including RGGCS ensiled for 45 days; diet 3: 650 g/kg concentrate including RGGCS ensiled for 90 days; diet 4: 650 g/kg concentrate including RGGCS ensiled for 45 days; diet 5: 850 g/kg concentrate including RGGCS ensiled for 45 days. As roughage, silage corn whole plant. Starch intake was higher (P < 0.05) with the dry ground corn diet; however, digestibility was lower (P < 0.05) for most nutrients compared to the RGGCS diet. A smaller amount of starch in the feces of animals that received the RGGCS diet was found. A diet with 850 g/kg of concentrate, including RGGCS ensiled for 45 days, generates higher net income, increases nutrient intake, and could be an alternative during the fluctuation of corn prices.

Histological and physical-mechanical characteristics of the skin of Dorper sheep related to residual feed intake and the confinement environment.

The aim was to evaluate the effect of residual feed intake (RFI) on the histological, physical and mechanical characteristics of the sheep skin confined in full sun or shade. Dorper sheep (n = 64), male, with an initial bodyweight of 17.8 ± 2.43 kg was confined for 40 days to determine the RFI. After classification, 30 animals with positive RFI and 30 animals with negative RFI were selected, which were distributed in 2 confinement environments. This was a factorial arrangement of 2 (groups of animals-positive RFI and negative RFI) × 2 (environments-full sun and shade), with 15 animals for each combination of factors. The sheep remained in confinement for 60 days. After slaughter, skins were divided in half, and fragments were collected from the right portion for histological sections. The left part of each skin was subjected to tanning. Interaction effect RFI × environment was found in the evaluation of leather fragments in the horizontal direction on elongation at break, leather thickness and tear strength (p < 0.05). An isolated effect of the environment was found on elongation at break of leather fragments in the evaluation on the vertical direction (p = 0.01) and on the number of secondary follicles during the histological evaluation of the dorsal and lateral regions of the skin (p < 0.05). An effect of the interaction RFI × environment was observed for the thermostatic layer of the hip region (p = 0.03). Sheep with positive RFI and kept in confinement in full sun have a leather with greater elongation at break and tear strength, important aspects in determining the quality of the product by the leather industry.

Effect of Increased Salt Water Intake on the Production and Composition of Dairy Goat Milk.

Due to its necessity and magnitude, water is essential for animal nutrition. This study aimed to evaluate the effects of increasing levels of water salinity on the quality of goat milk in the Brazilian semiarid region. Twenty-four multiparous Alpine goats, with an average live weight of 38.0 ± 4.0 kg and an average lactation period of 30 days, distributed entirely at random, were used. The experiment lasted 64 days including an initial period of 14 days of adaption to the diet. The experimental treatments consisted of water with different levels of total dissolved solids (TDS): 640, 3188, 5740, and 8326 mg L-1, obtained using sodium chloride (NaCl). Increasing the levels of TDS in drinking water from 640 to 8326 mg L-1 did not significantly (p > 0.05) affect the production and the physicochemical composition of the milk. There was a linear increase (p < 0.05) in the water consumption and acidity variables as a function of the total dissolved solid levels. The mineral composition of the milk was not altered with increasing levels of TDS in water from 640 to 8326 mg L-1. There was no negative effect (p > 0.05) for any of the sensorial attributes analyzed in relation to the treatments. Therefore, as a general conclusion, based on the analyses carried out in this experiment, it was found that water with total dissolved solids, when supplied for short periods of up to 48 days, does not alter the production, physicochemical characteristics, or the organoleptic properties of goat's milk.

Intake, digestibility, nitrogen balance and performance of crossbreed Boer goats fed with diets containing saltbush (Atriplex nummularia L.) and spineless cactus (Opuntia ficus-indica).

Saltbush and spineless cactus are adapted to arid and semiarid regions and used as an important forage resource in ruminants' diet. However, spineless cactus restricts production due to its low crude protein and NDF levels and high salt and oxalate contents, which can limit the digestibility and intake of dietary nutrients. Therefore, this experiment was conducted to evaluate the best ratio levels of saltbush associated with spineless cactus in diets for crossbreed Boer goats through ingestion, water balance, digestibility, nitrogen balance, growth and carcass weight. Twenty-four castrated crossbred Boer (Boer × Brazilian native) goats 6 months of age and average body weight of 20.28 kg were utilized. The animals were weighed and distributed in randomized blocks in four experimental diets with saltbush of 8.4, 18.8, 31.2 and 48.3%. The addition of saltbush hay promoted quadratic behaviour (P < 0.05) in intake of dry matter and nutrients. There was no effect (P < 0.05) from the addition of saltbush hay on the digestibility of organic matter, total carbohydrates, non-fibrous carbohydrates and neutral detergent fibre, whereas there was an increase in dry matter. The crude protein digestibility behaved quadratically (P = 0.06), where the maximum digestibility was obtained with the addition of 31.2% of hay. The balance and net nitrogen utilization presented a quadratic effect (P < 0.01). Saltbush in rations for goats presented promising results, the growth rate (0.15 kg/day) obtained in diet with a lower proportion of saltbush, would satisfy smallholders when considering that this species, associated with spineless cactus, may reduce the use of concentrate feeds; however, the diet with 31.2% of saltbush hay provided the biggest gain in body and carcass weight of the goats.

Water intake and ingestive behavior of sheep fed diets based on silages of cactus pear and tropical forages.

The objective was to evaluate the water intake and ingestive behavior of sheep fed diets containing silages of cactus pear combined with tropical forages. Forty sheep without defined breed, intact, with initial average weight of 22.65 ± 1.01 kg were distributed in a completely randomized design with 5 treatments and 8 replications. The experimental diets consisted of cactus pear silage (CPS), cactus pear + buffel grass silage (CPBS), cactus pear + gliricidia silage (CPGS), cactus pear + pornunça silage (CPPS), and corn silage (CS). CPGS provided higher water intake via food, total water intake, metabolic water, and excretion via feces and urine (P < 0.05). Animals that received diets containing CS showed higher water intake via drinking fountain, less efficient feeding and rumination of dry matter, less efficient rumination of neutral detergent fiber, grams of dry matter per cud, grams of neutral detergent fiber per cud, and the shortest average time spent in chewing per cud (P < 0.05). CPGS, CPPS, and CS provided longer times for rumination and numbers of cuds per day (P < 0.05). CPS showed animals spending more time in idleness, lower quantity of cuds per minute, higher concentration of crystals in urine, with a higher frequency of ammonia-magnesium phosphate and calcium oxalate. Silages based on cactus pear are an alternative to the supply of water via food for sheep in semi-arid.

Mixed silages of cactus pear and gliricidia: chemical composition, fermentation characteristics, microbial population and aerobic stability.

The present study aimed to evaluate the chemical composition, profile and fermentative losses, microbial population and the aerobic stability of mixed silages of cactus pear and gliricidia. The treatments corresponded to the addition levels of gliricidia (Gliricidia sepium (Jacq.) Steud), in the silages of cactus pear (Opuntia ficus indica Mill.), at ratios 0%, 25%, 50%, 75% and 100% gliricidia. The data were subjected to analysis of variance and regression to evaluate the effect of the addition levels of gliricidia. The average related to the opening days were compared by the Tukey's test and the average hours of exposure to air were compared by the Student's t-test. The addition of gliricidia in cactus pear silage provided a linear increasing effect for pH, crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL), neutral detergent insoluble protein (NDIP), and increased aerobic stability (AS). The highest dry matter recovery was estimated in the silages with 58% gliricidia. Based on the fermentative, chemical composition and silage losses, all the silages tested were adequate. However, considering aerobic stability, the addition of at least 25% gliricidia is recommended to provide the animal a feed with important quality and high nutritional value.

Impact of water restriction periods on carcass traits and meat quality of feedlot lambs in the Brazilian semi-arid region.

Water restriction periods were evaluated in crossbred lambs (n = 32) distributed in one of four treatments: without water restriction, water restriction for 24, 48 and 72 h. The water restriction for 72 h reduced the water and dry matter intakes, body weight at slaughter and hot and cold carcass yields. Water restriction did not affect the weight of the carcass cuts and the chemical composition of the meat. The fatty acid EPA increased and DHA reduced with increasing water restriction period. There was an increasing linear effect for meat shear force, with less force (30.5 N/cm2) for sheep meat without water restriction and higher force (45.8 N/cm2) for those with water restriction for 72 h. The period of 24 h of water restriction was the one that promoted the highest similarities in the characteristics assessed to those in animals receiving water ad libitum. Therefore, water restriction periods should not exceed 24 h for feedlot animals in situations of severe water shortage.

In vitro screening of plants from the Brazilian Caatinga biome for methanogenic potential in ruminant nutrition.

Thirty-nine plants naturally found in Brazilian Caatinga semiarid biome were screened using an in vitro fermentability testing focused in apparent organic matter digestibility (aOMD), gas, methane (CH4), and short-chain fatty acid (SCFA) production. Three independent in vitro runs were carried out and plants were classified by CH4 concentration as proportion of gas and per unit of apparent digested organic matter (aDOM). According to its CH4 concentration on produced gas (mL/L), the plants were classified as low (> 110), medium (from 60 to 110), and high (< 60) anti-methanogenic potential. From evaluated plants, 3, 24, and 12 were classified as high, medium, and low anti-methanogenic potential. High anti-methanogenic potential plants Cnidoscolus phillacanthus (CnPh), Chloroleucon foliolosum (ChFo), and Anadenanthera macrocarpa (AnMa) produced 21.3, 34.3, and 35.9 mL CH4/L of gas. Methane concentration for Myracrodruon urundeuva (MyUr) was 61.1 mL/L and classified as medium potential. However, CH4 production per unit of aDOM was similar between MyUr and AnMa (3.35 and 2.68 mL/g, respectively). Molar proportions of acetate and propionate in SCFA produced by ChFo fermentation were 0.02 and 0.78 mmol/mol. Acetate to propionate ratios were 0.79, 0.03, 1.39, and 1.36 for CnPh, ChFo, AnMa, and MyUr, respectively. Greater aOMD were observed for Opuntia sp. and Calotropis procera (632 and 601 g/kg, respectively), which were classified as medium mitigating potential plants. AnMa, ChFo, CnPh, and MyUr are promising anti-methanogenic plants for ruminants. Selecting forages to feed ruminants in Caatinga is a potential strategy for enteric CH4 emission reduction, and our in vitro results can support future research by indicating species to be evaluated in in vivo studies integrating mixed diets with performance, digestibility, and CH4 production, yield, and intensity. Graphical abstract ᅟ.

Detoxified castor meal in substitution of soybean meal in sheep diet: growth performance, carcass characteristics and meat yield.

The aim of this study was to evaluate the intake, digestibility, performance, and carcass characteristics of lambs fed different levels of replacement (0, 15, 30, and 45 % based on dry matter, DM) of soybean meal (SM) by detoxified castor meal (DCM). Twenty-four and 32 intact hair lambs of nondescript breed (21.7 ± 2.6 kg of initial average body weight and approximately 10 months old) were used, respectively, in the intake and digestibility and performance experiments. The diets were composed of buffel grass hay, ground corn grain, and different levels of SM, DCM, and urea, in a roughage-to-concentrate ratio of 40:60. There was no effect of treatments on DM intake. However, crude protein (CP) and neutral detergent fiber (NDF) intakes were higher at 30 and 45 % than at 0 and 15 % of DCM, which in turn showed higher intake of non-fiber carbohydrates (NFC) (P < 0.05). The organic matter, CP, and NDF digestibilities were not affected, but the digestibility of NFC was lower at 30 and 45 % than at 0 % of DCM (P < 0.05). The average daily gain, feed conversion, slaughter and carcass weights, chilling losses, ribeye area, and absolute values and yields of neck, ribs, loin, and leg were not affected. However, the carcass yield was lower at 45 % of DCM and the absolute value of shoulder was lower at 30 and 45 % of DCM (P < 0.05). The replacement of SM by DCM up to 45 % in the feed of lambs did not negatively affect the intake, digestibility, performance, and main carcass features.

Silage or fresh by-product of peach palm as roughage in the feeding of lambs.

The objective of this study was to evaluate intake and apparent digestibility of agro-industrial by-product of peach palm in diets for lambs. Twenty castrated, crossbred Santa Ines lambs, with average age of 150 days and body weight of 22.4 ± 3.4 kg, were distributed in a completely randomized design with four experimental diets composed of the following: fresh by-product of peach palm enriched with urea + ammonia sulfate (FU); fresh peach palm by-product + concentrate (FP); silage of peach palm by-product + concentrate (SP); and silage of peach palm by-product enriched with 15% of cornmeal + concentrate (SPC). Intake was recorded daily, and the digestibility coefficients were estimated with the internal marker indigestible acid detergent fiber (iADF). Diet FU resulted in the lowest intake and digestibility of the nutrients evaluated. Animals receiving diet FP showed higher intakes of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), total digestible nutrients (TDN), and digestible energy (DE) in relation to animals fed diets SP and SPC. Diets SP and SPC showed higher coefficients of digestibility of DM, OM, CP, and NDF than diet FP. Diet SP reduced the intakes of DM, OM, ether extract (EE), non-fibrous carbohydrate (NFC), TDN, and DE and the digestibility coefficients of DM, OM, and NFC as compared with diet SPC. Feedlot lambs fed a diet with fresh peach palm by-product + concentrate (diet FP) have higher nutrient intake.

Performance and characteristics of carcass and non-carcass components of lambs fed peach-palm by-product.

The objective of this study was to evaluate the effects of supplying the by-product of peach-palm (Bactris gasipaes) on performance and characteristics of carcass and non-carcass components of feedlot lambs. Twenty Santa Ines lambs of 150 days average age and 22.4 ± 3.4 kg body weight were confined in individual pens. A completely randomized design was utilized with four experimental diets composed of: fresh peach-palm by-product enriched with urea, fresh peach-palm by-product + concentrate, silage of peach-palm by-product + concentrate, and silage of peach-palm by-product enriched with 15 % corn meal + concentrate. Intake was evaluated daily, and at the end of 42 days of experiments, lambs were slaughtered and the characteristics of carcass and non-carcass parts were evaluated. Performance and carcass characteristics showed differences between the animals' intake of total mixed rations (TMR) and only the diet with roughage. For the lambs that intaked TMR, the form of utilization of roughage (fresh or as silage) affected animal performance but did not change the carcass characteristics. Dry matter intake and feed conversion were influenced by the form of utilization of the silage (with and without additive). Providing fresh by-product plus concentrate improves lamb performance but does not interfere in the carcass characteristics, compared with the use of by-product in the form of silage.