Finishing of grazing crossbred steers supplemented with detoxified castor bean meal (Ricinus communis L.) in the rainy-dry transition period.

This study evaluated levels of replacement of soybean meal by castor bean meal in the finishing crossbred steers on Brachiaria brizantha cv. Marandu pasture during the rainy-dry transition period. Forty Holstein-Zebu crossbred steers with an average initial weight of 395.93 ± 10 kg were randomly allocated to four treatment groups that were supplemented with concentrate levels of replacing (0, 290, 613, and 903 g/kg DM of the supplement; at 0.4% body weight [BW]). The experimental period was 120 days. A completely randomized experimental design was adopted; with regression analysis using the computational software package (SAS 9.2, USA). Intake and digestibility of dry matter (DM) and nutrients and animal performance were evaluated. The replacement levels did not influence (P > 0.05) the intakes of DM (kg/day), organic matter (OM, kg/day), neutral detergent fiber (NDF, kg/day and %BW), non-fibrous carbohydrates (NFC, kg/day), or total digestible nutrients (kg/day). However, the intake of crude protein (CP) and ether extract (EE, kg/day) decreased as the replacement levels were increased (P < 0.05). The digestibility of DM, OM, NDF, and EE did not change, whereas CP digestibility decreased linearly and NFC digestibility increased linearly (P < 0.05). The replacement levels did not affect (P > 0.05) final body weight, average daily gain, feed conversion, and carcass yield. Castor bean meal can replace up to 903 g/kg DM of soybean meal in the composition of the supplement without compromising the performance of steers on Marandu pasture during the rainy-dry transition period.

Metabolic profile of goats fed diets containing crude glycerin from biodiesel production.

Feedlot finishing of goats is a growing practice, but the economic viability of this technology is compromised by the inclusion of ingredients such as corn and soybean. An alternative to minimize this barrier is the use of agroindustry coproducts as substitutes for those ingredients, such as crude glycerol. This study aimed to evaluated the metabolism of crossbred Boer finishing goats fed diets containing crude glycerin from biodiesel production. Thirty-two crossbred, castrated goat of age were distributed in a fully randomized experimental design with four treatments and eight replicates. The experiment lasted 69 days, and goats were fed sorghum silage and concentrate, with the inclusion of crude glycerin in the diet at levels of 0, 50, 100, and 150 g/kg on a dry matter basis. The diets did not have an effect (p > 0.05) on the serum urea levels. Increasing dietary crude glycerin levels did not the influence the metabolic or urinary profiles (p > 0.05). The liver tissue of the goats fed diets containing the highest crude glycerin inclusion levels showed deleterious effects. The inclusion of crude glycerin with approximately 6.6 g/kg methanol caused deleterious effects to the liver tissue of Boer crossbred goats as the glycerin concentrations increased. However, glycerin levels did not cause deleterious effects on the liver tissue or on the serum or urinary profiles. The use of crude glycerin with lower methanol content is recommended for goat diets.

Inclusion of calcium oxide in sugarcane silage under different particle sizes on performance of dairy cows.

Our objective was to evaluate voluntary intake, apparent digestibility, performance, and nitrogen balance of dairy cows fed sugarcane silage under different particle sizes treated or not with calcium oxide (CaO). Eight F1 Holstein/Zebu cows, with body weight of 521.5 ± 55.17 kg, and 60 ± 10 days in milk were used, distributed into two simultaneous 4 × 4 Latin squares. The treatments were composed of sugarcane into two particle sizes (15 and 30 mm) with and without the addition of CaO (10 g/kg of natural matter), being the treatments compared according to a 2 × 2 factorial arrangement. Data were analyzed by the MIXED procedure of SAS. The intake of dry matter (13.05 kg/day), crude protein, non-fibrous carbohydrates, and neutral detergent fiber was not modified (P > 0.05) by the inclusion of the calcium oxide, nor by particles size and interaction among both. However, there was interaction between CaO and particle size on dry matter digestibility (P = 0.002), being that the CaO was effective in promoting greater DM digestibility in silages with larger particle size. The milk yield and composition were also not affected by the diets (P > 0.05), similarly for nitrogen balance (P > 0.05). The addition of CaO to sugarcane silage with different particle sizes (15 and 30 mm) does not affect the milk yield and composition of dairy cows, nor the nitrogen balance. However, when CaO is added to the sugarcane silage under larger particle sizes, there are benefits in DM digestibility.

Inclusion of palm kernel cake in the supplement reduces nutrient digestibility but does not interfere with the performance of steers finished on tropical pasture.

The aim of this study was to evaluate the effect of increasing inclusion levels of palm kernel cake (PKC) in the supplement of steers finished on a Urochloa brizantha cv. Marandu pasture on intake, digestibility, feeding behavior, weight gain, and carcass traits. Forty 1/2 Holstein × 1/2 Zebu crossbred steers with an average body weight of 352.80 ± 3.32 kg, at 36 months of age, were supplemented with concentrate at 0.4% of their body weight. Four treatments were formulated (supplement containing 0, 15, 30, or 45% PKC, dry matter [DM] basis) and the animals were monitored for 240 days, weighed, and slaughtered. The inclusion of PKC in the supplement did not influence the intakes of total DM, crude protein, or neutral detergent fiber, but increased (P < 0.05) ether extract intake and reduced (P < 0.05) non-fibrous carbohydrate intake. The apparent digestibility of DM, crude protein, and neutral detergent fiber decreased (P < 0.05), whereas intake and rumination efficiencies by the dietary treatments. Average daily gain, carcass weight, and backfat thickness did not change in response to the inclusion of PKC in the supplement. We recommend the inclusion of 45% palm kernel cake in the concentrate of steers supplemented at 0.4% of their body weight and finished on Urochloa brizantha cv. Marandu pasture.

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.

Effect of dietary inclusion of licuri cake on intake, feeding behavior, and performance of feedlot cull cows.

Licuri cake (LC) is an interesting alternative nutritional component for high-grain diets for ruminants due to its high protein (21.6% CP), fat (12.0% EE), and fiber (62.8% NDF) contents. We investigated the effect of increasing levels of LC inclusion on the intake, digestibility, feeding behavior, performance, and carcass traits of cull cows fed high-grain diets. Forty Zebu cows with an initial weight of 318 ± 38.1 kg, at 105 months of age, were confined in collective stalls and fed (ad libitum) a diet containing 0, 50, 100, or 150 g/kg LC on a diet dry matter (DM) basis. Licuri cake inclusion induced quadratic responses (P < 0.05) in the intakes of DM (9.57 kg/day at 97.8 g/kg LC), crude protein (CP; 1.02 kg/day at 91.7 g/kg LC), and total digestible nutrients (6.68 kg/day at 75.2 g/kg LC). The digestibility of DM, CP, and non-fibrous carbohydrates decreased linearly (P < 0.05). Neutral detergent fiber (NDF) intake and rumination efficiencies increased linearly (P < 0.05) with the inclusion of LC in the diet. The inclusion of LC did not influence (P > 0.05) on daily weight gain, hot carcass weight, or back fat thickness in the carcass. Therefore, we recommend the inclusion of up to 150 g/kg LC in high-grain diets for feedlot cull cows.

Effect of crude glycerin levels on meat quality and carcass characteristics of crossbred Boer goats.

This study assessed the effects of four levels of crude glycerin (0, 50, 100, and 150 g/kg dry matter (DM) basis) in the diet of Boer crossbred goat kids on the qualitative and quantitative carcass characteristics as well as meat quality. Thirty-two crossbred, castrated Boer x undefined breed goat kids with an initial average weight of 17.8 ± 2.2 kg between 3 and 4 months of age were distributed across a complete randomized experiment with four treatments and eight replicates. The DM intake linearly decreased (p < .05) as the crude glycerin inclusion level in the diet increased. Crude glycerin levels decreased (linear effect, p < .05) empty body weight, hot dressing percentage, and cold dressing percentage. Conformation and subcutaneous fat thickness were not affected (p > .05) by dietary crude glycerin. Crude glycerin levels decreased (linear effect, p = .03) rib eye area of the Longissimus dorsi muscle, however, did not affect color, cooking loss, and shear force. The crude glycerin can be included up to 50 g/kg DM in the diet of crossbred Boer goats without negatively affecting carcass characteristics and meat quality. It can be recommended as an energy source in finishing diets.

Feeding behavior of post-weaned crossbred steers supplemented in the dry season of the year.

The objective of this study was to evaluate the feeding behavior of grazing steers supplemented in the dry season of the year. Thirty-two castrated crossbred (½ Holstein-Zebu) steers with an average initial weight of 378 ± 7.54 kg, aged 14 months, were distributed into four treatment groups in a completely randomized design with eight replicates. The animals were managed in an area covered with a pasture of Brachiaria brizantha cv. Marandu, in a rotational grazing system. The supplement was formulated so that the animals in the different treatment groups would ingest the same amount of crude protein (CP) daily. Thus, the treatments consisted of increasing levels of supplementation, based on the animals' body weight (BW), as the protein content of the supplement was reduced. The following treatments (dry matter basis) were tested: T2, supplement at 0.2% BW, with 50% CP; T4, supplement at 0.4% BW, with 25% CP; T6, supplement at 0.6% BW, with 16.67% CP; and T8, supplement at 0.8% BW, with 12.5% CP. Forage dry matter intake decreased linearly (P < 0.05), characterizing a substitution effect. The increasing supplementation levels influenced the animals' feeding behavior, especially grazing time, total feeding time, number of grazing bouts, and number of bites per day, which showed a positive quadratic response (P < 0.05), and rumination time, number of rumination bouts, number of cuds ruminated per day, and number of chews per ruminated cud, which exhibited a negative quadratic behavior (P < 0.05). Dry matter and neutral detergent fiber (NDF) feed efficiencies and dry matter and NDF rumination efficiencies responded quadratically (P < 0.05). In conclusion, concentrate supplementation at up to 0.8% BW improves the feeding behavior of grazing steers in terms of the intake of concentrate supplement and forage as well as the feed and rumination efficiencies.

Ingestive behavior of Girolando steers supplemented on tropical pastures.

In this study, we evaluated the feeding behavior of Girolando steers on Brachiaria brizantha cultivar Marandu pastures. Twenty-two animals with an average initial weight of 209.09 ± 8.18 kg were distributed in a completely randomized design in a 3 × 2 factorial arrangement (three seasons and two nutritional plans (NP)) with 11 replicates, as follows: rainy season 1 (NP1, mineral mixture ad libitum, and NP2, nitrogen/energy supplement [2 g.kg‒1 body weight [BW]]); dry season (NP1, nitrogen/energy supplement [1 g.kg‒1 BW], and NP2, nitrogen/energy supplement [2 g.kg‒1 BW]); and rainy season 2 (NP1, mineral mixture ad libitum, and NP2, nitrogen/energy supplement ([1 g.kg‒1 BW]). Total chewing time was longer in NP1 (566.44 vs 528.33 min.day‒1 in NP2) (p < 0.05). The grazing, idle, trough, and total chewing times were affected by the interaction between nutritional plans and seasons. The period expended grazing was longer for the NP1. The idle time was affected by the nutritional plans and was lower for the NP1. Feeding at the trough was not affected by the nutritional plans. The animals of the NP2 showed the highest feed efficiencies in DM and NDF (0.91 and 0.52 vs 0.75 and 0.45 in NP1, respectively). Rainy season 2 had the highest efficiencies. The feeding behavior changes according to the supplementation level. Nutritional plan 2 in the second rainy season presented the best results.

Nutrient intake, digestibility, feeding behavior, nitrogen balance, and performance of feedlot goat kids fed high-concentrate diets containing licury cake (Syagrus coronata).

The current trial was carried out to evaluate the impacts of adding licury cake (Syagrus coronata) in high-concentrate diets for goat kids feedlot-finished on growth performance and metabolic parameters. Forty crossbred non-castrated Boer goat kids with approximately four months and similar initial live weights (20.15 ± 2.79 kg). The experimental design used in this study was a completely randomized, with four diets (0, 10, 20, and 30% of licury cake inclusion in a dry matter basis (DM)). Licury cake inclusion decreased nutrient intake and digestibility (P < 0.05). Times spent in feeding (P < 0.001) and rumination (P = 0.003) activities, number of events in feeding (P < 0.001) and idling (P = 0.015) increased, whereas a linear reduction occurred in feeding and rumination efficiencies of DM and neutral detergent fiber (P < 0.001). Nitrogen (N) intake, retained N (P < 0.001), triglycerides concentrations (P = 0.002), aspartate-aminotransferase, alanine-aminotransferase, and gamma-glutamyltransferase decreased with the licury cake inclusion (P < 0.05). Final body weight (P = 0.008), average daily gain (P = 0.001), and total weight gain (P = 0.001) decreased linearly when licury cake was included in diets. High-concentrate diets containing increasing levels of licury cake decrease intake and apparent digestibility of nutrients and performance when supplied for goat kids feedlot-finished. Therefore, the inclusion of the studied levels of licury cake in goat kids fed high-concentrate diets is not recommended for feedlot-finished systems.

Flaxseed added to the diet of Alpine goats affects the nutrients intake and blood parameters.

The flaxseed is a nutraceutical food used as a source of α-linolenic acid, which can bring benefits to the health of mammals. This study was carried out to examine the effect of flaxseed inclusion in the diets on the intake of nutrients, body weight, and blood parameters of Alpine goats. Twenty-one adult females with an initial average weight of 41.06 ± 1.84 kg were used in a completely randomized design, with four experimental treatments (0, 5, 10, and 15% of flaxseed in the total diet) and five replications per treatment. The intake of the dry matter presented a decreasing linear effect (P < 0.001), with a reduction of 53.5% between the control diet (0% of flaxseed) and 15% of flaxseed, but no effect was observed on weight gain (P > 0.05). Inclusion of flaxseed from 0 to 15% linearly decreased the intakes of organic matter, crude protein, non-fibrous carbohydrates, and neutral detergent fiber, but increased the ether extract intake (P < 0.001). Regarding plasma concentration traits, increasing the flaxseed levels from 0 to 15% had linear positive effect on LDL, VLDL, and triglycerides (P < 0.05), but no effect on cholesterol, HDL, glucose, creatinine, and urea (P > 0.05). The inclusion of flaxseed in the diet for 80 days changes the nutrients intake and blood parameters but shows no impact on body weight. However, further studies are required to determine the impact of flaxseed on the goat's health in the long term since there has been an increase in the concentration of triglycerides, LDL, and VLDL.

Effects of replacing ground corn with Nopalea cochenillifera meal on the intake, performance, and economic viability of grazing steers.

The objective of this study was to evaluate the effects of replacing different levels of spineless-cactus meal instead of ground corn on supplements for crossbred steers grazing in Urochloa brizantha cv. Marandú pastures. Forty crossbred steers with an average body weight (BW) of 261 ± 7.46 kg were distributed in a completely randomized design. In supplements, the ground corn grain was substituted with 0%, 30%, 60%, and 90% spineless-cactus meal. The substitution of spineless-cactus meal instead ground corn promoted a linear decrease in the ether extract (EE; P = 0.03) and non-fibrous carbohydrates (NFC; P < 0.01) intakes. The apparent digestibility of EE was influenced (P < 0.05) showing a linear decrease. The apparent digestibility of NFC had a quadratic effect (P = 0.03). For the neutral detergent fiber corrected for ash and protein, the apparent digestibility increased linearly (P = 0.01). The average daily gain showed a quadratic effect (P < 0.01), with a maximum response estimated at 44.94% (1055.52 g/day) substitution with spineless-cactus meal for ground corn. The cost per animal per period and the cost per hectare decreased linearly (P < 0.01). The revenue, net revenue, exchange rate, and monthly revenue of the activity showed quadratic responses to the spineless-cactus meal supplements (P < 0.01), with maximum effects at 44.99%, 47.46%, 61.25%, and 57.35%, respectively. The substitution with up to 44.94% of spineless-cactus meal for ground corn provided daily gains, increased the feed conversion, and was favorable as a cost to the production system. Moreover, the profitability increased with maximum animal performance and improved use of fiber from pastures.

Productive characteristics of feedlot Santa Inês and Dorper lambs: intake, digestibility, feeding behavior, performance, carcass traits, and meat quality.

This study aimed to evaluate the intake, digestibility, feeding behavior, performance, carcass traits, and meat quality of feedlot Santa Inês (locally adapted breed) and Dorper (transboundary breed) lambs. Twenty non-castrated lambs were used (10 from the Santa Inês genetic group and 10 Dorper), with approximately 3 months of age and an initial body weight of 22.95 ± 2.1 kg (mean ± standard deviation), distributed in a completely randomized design. Nutrient intake and digestibility, feeding behavior, and liver metabolism enzymes were similar (P > 0.05) between genetic groups. Dry matter (DM) feeding and ruminating efficiency were higher (P < 0.05) in the Santa Inês genetic group. There was also no difference (P > 0.05) in the subjective evaluation and morphometric measurements. Genetic groups showed differences and trend to differences (P < 0.05) in performance and commercial cuts. The physicochemical characteristics, centesimal composition, and sensory attributes of the Longissimus lumborum muscle did not differ between the genetic groups (P > 0.05). The Santa Inês genetic group showed higher feeding efficiency and productive parameters when compared to Dorper lambs. Therefore, Santa Inês lambs have greater potential for meat production than Dorper lambs, when kept in the same breeding system as the feedlot.

Diurnal variations and time to reach steady state of external markers used to estimate fecal excretion in sheep.

We executed two studies to investigate time to reach steady state (EXP1) and diurnal variations (EXP 2) of markers, in order to recommend spot fecal sampling in sheep. Eight lambs were used in EXP 1. Each animal has received titanium dioxide (TDOX) and chromium oxide (COX) together during two periods of 15 days. Thirty sheep of the Santa Ines breed were used in EXP 2. Fecal samples were taken with 2-h intervals in the last 5 days of each period, simultaneously to total feces collection. A sine-cosine model was used to evaluate EXP 2, and broken-line model for EXP 1. TDOX could complete its recovery after 2.3 days, and it could accurately promote fecal estimates after 3 days of marker infusion. COX could stabilize after 4.1 days, and it could promote fecal estimates after 5 days. However, estimated fecal excretion became similar to total feces output after 3 days for TDOX and after 6 days for COX. For both markers, a total 6 days of adaptation period could be summed to a 3-day collection period. Spot sampling was similar to total fecal output at 6:00 to 8:00 on morning and between 5:00 and 7:00 on afternoon for TDOX. Also, COX could be sampled at 6:00 to 8:00 on morning and between 5:00 and 7:00 on afternoon. External markers could be evaluated from 3-day fecal spot collection. Fecal collections could be made before the morning feeding, and around 6 p.m. for both markers.

Carcass and meat traits of goats fed diets containing cottonseed cake.

The cottonseed cake has the necessary nutritional characteristics to be able to substitute the traditional ingredients (such as soybean meal) and reduce the costs of the diet. However, it is necessary to determine the best level of inclusion of cottonseed cake in the diets of fattening goats to improve meat production and quality. The objective of this study was to evaluate carcass and meat traits of feedlot goats fed diets containing cottonseed cake replacing soybean meal (33 %, 66 % and 100 %). Thirty-two uncastrated Boer crossbred goats (4 months old, 16  ±  2 kg initial body weight) were used in a completely randomized experimental design. Replacing soybean meal with cottonseed did not compromise ( P > 0.05 ) slaughter weight, carcass traits (dressing percentage, loin-eye area and back-fat thickness), primal cuts or carcass morphometric measurements; moisture, protein, or total lipid contents of meat; or the physicochemical traits of color ( L * , a * and b * coordinates), pH, shear force, and cooking loss. However, there was a reduction ( P = 0.001 ) in the mineral matter content (from 1.08 % to 0.97 %) and an increase ( P = 0.006 ) in the cholesterol content (from 50.85 to 70.55 mg/100 g of meat) of the meat as the dietary levels of cottonseed cake were increased. Based on the results of production and meat quality, we recommend using cottonseed cake as an alternative protein source to replace up to 100 % of soybean meal in feedlot goat diets.

Effect of high-concentrate diets with calcium lignosulfonate and cottonseed processing method on quantitative traits and non-carcass components of feedlot cull ewes.

This study examined the effects of cottonseed processing form and the inclusion of calcium lignosulfonate in high-concentrate diets for feedlot cull ewes on carcass traits and non-carcass components. Thirty Santa Inês cull ewes with an average body weight of 44.2  ±  5.2 kg and an average age of 50 months were distributed into collective stalls in a completely randomized design. The treatments consisted of diets including whole cottonseed, crushed cottonseed, whole cottonseed treated with lignosulfonate (100 g/kg, as fed), crushed cottonseed treated with lignosulfonate (100 g/kg, as fed), and a control diet without cottonseed. The experimental diets did not influence ( P > 0.05 ) average daily weight gain (0.195 kg/day), slaughter weight (51.74 kg), or in vivo biometric and on-carcass measurements. There was no difference ( P > 0.05 ) in loin-eye area or subcutaneous fat thickness as evaluated in vivo by ultrasound. There was no diet effect on hot carcass weight and yield (24.8 kg and 47.8 %), cold carcass weight and yield (24.2 kg and 46.8 %), or chilling loss (2.1 %). Non-carcass components did not differ in response to the diets ( P > 0.05 ). Dietary inclusion of calcium lignosulfonate increases the proportions of udder and liver relative to empty body weight ( P < 0.05 ). Neither the cottonseed processing method nor the inclusion of calcium lignosulfonate in high-concentrate diets for cull ewes affects their performance, biometric or morphometric measurements, non-carcass components, or qualitative traits of their carcass.

Palm kernel cake in high-concentrate diets for feedlot goat kids: nutrient intake, digestibility, feeding behavior, nitrogen balance, blood metabolites, and performance.

This study was conducted to evaluate the effects of including palm kernel cake (PKC) in high-concentrate diets for feedlot goat kids on nutrient intake, digestibility, feeding behavior, nitrogen balance, blood metabolites, and performance. Thirty-two castrated crossbred Boer × mixed breed goat kids with an average age of 4 months and an initial body weight of 19.65 ± 3.00 kg were distributed in a completely randomized design. The diets included one of four levels (0, 12, 24, and 36%) of PKC on a total dry matter basis. The PKC inclusion in the diets promoted quadratic effects in the nutrient intakes (P ≤ 0.05). The digestibility of ether extract increased (P = 0.010), whereas the digestibility of non-fibrous carbohydrates decreased (P = 0.017) with the inclusion of PKC. Palm kernel cake inclusion promoted a quadratic effect on the time spent per episode feeding and decreased the times spent idling and ruminated bolus per day (P ≤ 0.05). The ingested and retained nitrogen decreased with the inclusion of PKC (P ≤ 0.05). The inclusion of PKC in the diets had quadratic effects in the cholesterol concentrations, albumin (A), globulin (G), A:G ratio, and gamma-glutamyltransferase enzyme activity (P ≤ 0.05). The PKC inclusion promoted a quadratic increase in total weight gain (P = 0.026), with the highest value achieved at the inclusion level of 11.68%. The inclusion of up to 12% PKC in high-concentrate diets increases the intake and growth performance without compromising the digestibility of nutrients and feed efficiency.

Metabolizable Protein: 1. Predicting Equations to Estimate Microbial Crude Protein Synthesis in Small Ruminants.

Microbial crude protein (MCP) produced in rumen could be estimated by a variety of protocols of experimental sampling and analysis. However, a model to estimate this value is necessary when protein requirements are calculated for small ruminants. This model could be useful to calculate rumen degradable protein (RDP) requirements from metabolizable protein (MP). Then, our objective was to investigate if there is a difference in MCP efficiency between sheep and goats, and to fit equations to predict ruminal MCP production from dietary energy intake. The database consisted of 19 studies with goats (n = 176) and sheep (n = 316), and the variables MCP synthesis (g/day), total digestible nutrients (TDN), and organic matter (OM) intakes (g/day), and OM digestibility (g/kg DM) were registered for both species. The database was used for two different purposes, where 70% of the values were sorted to fit equations, and 30% for validation. A meta-analytical procedure was carried out using the MIXED procedure of SAS, specie was considered as the fixed dummy effect, and the intercept and slope nested in the study were considered random effects. No effect of specie was observed for the estimation of MCP from TDN, digestible Organic Matter (dOM), or metabolizable energy (ME) intakes (P > 0.05), considering an equation with or without an intercept. Therefore, single models including both species at the same fitting were validated. The following equations MCP (g/day) = 12.7311 + 59.2956 × TDN intake (AIC = 3,004.6); MCP (g/day) = 15.7764 + 62.2612 × dOM intake (AIC = 2,755.1); and MCP (g/day) = 12.7311 + 15.3000 × ME intake (AIC = 3,007.3) presented lower values for the mean square error of prediction (MSEP) and its decomposition, and similar values for the concordance correlation coefficient (CCC) and for the residual mean square error (RMSE) when compared with equations fitted without an intercept. The intercept and slope pooled test was significant for equations without an intercept (P < 0.05), indicating that observed and predicted data differed. In contrast, predicted and observed data for complete equations were similar (P > 0.05).

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.