Effect of feeding wheat middlings and calcium lignosulfonate as pellet binders on pellet quality growth performance and lipid peroxidation in broiler chickens.

Basal diets supplemented with 4 kg Ca-LS/ton of diet. Pellet quality characteristics (per cent fines, the present study was conducted to evaluate the influence of wheat middlings (WM) and calcium lignosulfonate (Ca-LS) as pellet binders on the pellet quality characteristics, growth performance, blood parameters, nutrients digestibilities, lipid peroxidation and muscle fatty acids profile in Egyptian broiler strain. A total of 3,120 broiler chicks at 1-day of age were divided randomly into three experimental treatments with eight replicates (130 each). The first treatment was fed the basal pelleted diets without any additives, the second treatment was fed diets including 50 kg WM/ton of diet and the third treatment was fed per cent pellets, and pellet durability index) were significantly improved in WM and Ca-LS treatments compared with the control. Body weight gain was significantly increased, while feed intake was significantly decreased resulting in improving of feed conversion ratio significantly in WM group in comparison with control and Ca-LS groups (p < .05). Nutrients apparent digestibility (dry matter, crude protein and crude fibre) were significantly improved by inclusion of WM compared with control and Ca-LS. Plasma total cholesterol, and uric acid concentrations were significantly decreased by dietary WM in comparison with control and Ca-LS experimental groups. Furthermore, linoleic, alpha-linolenic and arachidonic acids contents in breast muscle were significantly increased by WM and Ca-LS, while, muscle malondialdehyde concentration was significantly decreased. It could be concluded that inclusion of WM and Ca-LS can improve pellet quality characteristics, and WM (at a level of 50 kg/ton) had positive effects on growth performance, nutrients digestibilities, lipid peroxidation and fatty acids profile in Egyptian broiler strain.

The effects of lignocellulose supplementation on laying performance, egg quality parameters, aerobic bacterial load of eggshell, serum biochemical parameters, and jejunal histomorphological traits of laying hens.

This study was performed to investigate the effects of lignocellulose supplementation (LS) on performance parameters, egg quality, aerobic bacterial load of eggshell, serum biochemical parameters, and jejunal histomorphological traits of laying hens between 18 and 38 wk of age. A total of 640 pullets at 16 wk of age were allotted to 4 treatment groups as 0 kg (control, CONT), 0.5 kg, 1 kg, and 2 kg LS per ton of feed. Body weight (BW), daily feed intake, egg production (EP), egg weight (EW), and efficiency of feed utilization (EF) were determined as the mean of each 3-wk period between 18 and 38 wk of age. Laying hens in the 1 kg LS group had a higher BW mean (1632.1 g, P < 0.001). The highest mean value of EP and EW were observed in 1 kg LS group (81.8% and 57.3 g, respectively), whereas the lowest values were found in the 2 kg LS group (78.6% and 54.4 g, respectively, P < 0.001). The mean of EF was the lowest in the 1 kg LS group (2.72, P < 0.001). There was a decline in eggshell breaking strength and eggshell thickness in the 2 kg LS, when compared with the 0.5 and 1 kg LS groups (P < 0.001). The total aerobic bacterial load of the eggshell was the lowest in the 1 kg LS group (4.7 log10 cfu/mL). The level of aspartate amino transferase and alanine amino transferase showed an increment in both the CONT and 2 kg LS groups (P < 0.001). The high level of LS (2 kg per ton of feed) caused a decline in the levels of IgY, IgA and IgM, when compared to the 0.5 and 1 kg LS groups (P < 0.001). Laying hens in 0.5 and 1 kg LS groups had longer villus height (1335.9 µm) in the jejunum than the others (P < 0.001). These findings showed that the 1 kg LS per ton of feed improved EP and EW, eggshell quality, immunoglobulin levels and intestinal morphology, and decreased the total aerobic bacterial load.

Effects of soybean hulls and lignocellulose on performance, nutrient digestibility, microbial metabolites and immune response in piglets.

A feeding trial with 96 piglets was performed to investigate the effect of added soluble (SDF) and insoluble dietary fibre (IDF) sources on performance, apparent total tract digestibility (ATTD), concentration of microbial metabolites and pro-inflammatory marker genes as indicators for immune response. Piglets were allotted to four treatments (T): T1 control, T2 with soybean hulls (IDF/SDF: 8.35) and T3 and T4 with two different kinds of lignocellulose (IDF/SDF: >70). Diets were isofibrous for their value of total dietary fibre to underline the particular physicochemical properties of fibre sources. No differences were observed regarding average daily feed intake, average daily gain (ADG), feed conversion ratio and body weight, while T2 expressed higher ADG in the grower phase (day 14-54) vs. T3. Soybean hulls (T2) resulted in higher ATTD of dry matter and organic matter vs. T4; ether extract vs. T1 and neutral detergent fibre vs. T1, T2 and T3. The concentration of short chain fatty acids did not differ among treatments. Ileal digesta in T2 generated higher amounts of cadaverine vs. T3 and T4, likewise T1 vs. T4. Finally, no impact on immune response was detected. In conclusion, soybean hulls affected ATTD positively and lignocellulose prevented the formation of cadaverine, no overall direct response of SDF nor of IDF for the inclusion level  were observed.

Growth performance, pH value of gizzard, hepatic enzyme activity, immunologic indicators, intestinal histomorphology, and cecal microflora of broilers fed diets supplemented with processed lignocellulose.

This study was performed to investigate the hypothesis that supplementation of processed lignocellulose (PL) in the diets of broilers has a positive effect on growing performance, pH value of gizzard, hepatic enzyme activity, immunologic indicators, histomorphological character of small intestine, and cecal microflora populations. A total of 720 one-day-old Ross 308 broiler chicks were allotted to 4 treatment groups and fed maize-soybean meal based diets. The basal diet was supplemented with PL with an amount of 0 kg (control), 0.5 kg, 1 kg, and 2 kg per ton feed. Growing performance parameters, were determined weekly until 35 D of age. Blood samples for enzyme activities and immunoglobulins, jejunum and cecum samples for histomorphological characters for villus growth, and microbial population were collected from 12 broilers from each group. At 35 D of age, body weight of broilers supplemented with 1 kg of PL was found to be the highest with a value of 2305.0 g, when compared to the broilers supplemented with control, 0,5 and 2 kg of PL groups (2154.0, 2201.0, and 2141.7 g, respectively, P = 0.001). An increased activity of aspartate amino transferase (AST) was observed in the control and 1 kg PL supplementation groups (633.6 and 597.4 IU/L, respectively), whereas alkaline phosphatase (ALP) activity was the highest in the control group (5404 IU/L, P < 0.05). Broilers in the control group had the lowest level of IgY and IgA (122.2 and 25.8 mg/dL, respectively, P < 0.05). Villus height increased by 22.0%, 40.7%, and 34.8% in 0.5, 1, and 2 kg PL supplementation groups, respectively, when compared to the control (P < 0.001). The processed lignocellulose supplemented as 1 kg of PL decreased the average count of Staphylococcaceae, E. coli, and Enterobacteriaceae, whereas it increased the population of Lactobacillus spp. in the cecum (P < 0.05). These data indicate that the supplementation of processed lignocellulose had positive effects for performance via changes in hepatic enzyme activities, immunoglobulin levels, villus growth in jejunum, and microflora in cecum.

Effects of reducing growth rate via diet dilution on bone mineralization, performance and carcass yield of coccidia-infected broilers.

Coccidiosis and rapid growth rate (GR) compromise bone mineralization in modern broilers. We tested the hypothesis that reducing GR via diet dilution during peak bone development will improve bone mineralization in both infected and uninfected broilers. A total of 384 male Ross 308 chicks were allocated to a basal grower diet (3,107 kcal/kg ME and 19.4% CP) diluted with 0, 5, 10, or 15% lignocellulose (n = 12 pens/treatment, 8 birds/pen) at day 10 of age. Prior to this, birds in each group received half the intended diet-dilution levels (day 8 to 10 of age) and a common starter diet (day 1 to 7 of age). At day 13 of age (day 0 post-infection, pi), birds were orally inoculated with either 7,000 sporulated Eimeria maxima oocysts (I) or water (C), forming a 4 diet-dilution level × 2 infection status factorial experiment. Performance was measured over 12 days pi and scaled to BW at infection (day 0 pi) to account for a priori BW differences. At day 12 pi (day 25 of age), 1 bird/pen (a total of 6 birds/treatment) was sampled to assess tibia and femur mineralization relative to BW, and carcass yield. There was no interaction (P > 0.05) between infection status and diet-dilution level on ADFI/BW measured over day 1 to 12 pi, or on any bone variable. ADG/BW pi decreased (P < 0.01) with diet dilution amongst C birds, but was statistically similar (P > 0.05) amongst I birds. I compared to C birds had reduced breast meat (P < 0.05) and eviscerated carcass yield (P < 0.01), femur (P < 0.05) and tibia (P < 0.01) breaking strength (BS), and femur ash weight (AW) (P < 0.05). Diet dilution did not affect carcass yield, but improved femur BS (P < 0.001), and tended to improve (P < 0.1) femur and tibia AW. Overall, diet dilution significantly affected femur, more than tibia, variables: relative BS, robusticity index, and ash percentage. Reducing GR affected broiler long bone mineralization to a similar degree in the presence or absence of coccidiosis.

Effect of calcium lignosulfonate supplementation on metabolic profiles of confined lambs.

This study aimed to evaluate the effect of calcium lignosulfonate associated with whole cottonseed in high-concentrate diets for sheep. Eight Dorper crossbred sheep with an average live weight of 42.5 ± 1.70 kg were assigned to two 4 × 4 Latin squares. The following experimental diets were evaluated: control diet (without calcium lignosulfonate) and diets with inclusion of 50, 100, and 150 g of calcium lignosulfonate/kg fresh matter. Diets were composed of soybean meal, ground corn, and whole cottonseed. Feed intake, digestibility, metabolic characteristics, and feeding behavior were evaluated. The intake of nutritional components did not show significant differences as a function of the lignosulfonate levels in the diet; however, the increase in calcium lignosulfonate levels linearly decreased the dry matter digestibility. Rumen ammonia nitrogen concentrations decreased linearly as the lignosulfonate levels in the diets were increased. There was no effect of lignosulfonate levels on blood parameters or feeding behavior of the animals. The use of lignosulfonate associated with cottonseed decreases the digestibility of dry matter and the concentration of rumen ammonia nitrogen, but does not change the intake of nutritional components, the blood parameters, or the feeding behavior of sheep.

Coarse particle inclusion and lignocellulose-rich fiber addition in feed benefit performance and health of broiler chickens.

Measures to improve gut health and nutrient digestibility have been sought due to in-feed antibiotics being phased out in poultry. The appropriate physical structure of feed ingredients and addition of dietary fiber may be beneficial in enhancing gut health in poultry. In this study, the effect of a lignocellulose-rich fiber source and corn particle size on broiler performance, gizzard development, nutrient digestibility, cecal microflora, and litter quality was evaluated. A total of 684 day-old male Ross 308 chicks were randomly allocated to 6 treatments with 6 replicate pens, each housing 19 birds. A 2 × 3 factorial arrangement of treatments was applied with the factors of: corn particle size (coarse: 2,982 µm or fine: 941 µm geometric mean diameter), and 3 levels of lignocellulose (0%, 1% or 2%). Significant particle size × fiber interaction was observed for feed conversion ratio (FCR) at d 10 (P < 0.05). The birds fed coarsely ground corn (CGC) had lower FCR than those fed finely ground corn (FGC) only at 2% of lignocellulose but not at 1% or no lignocellulose addition. Birds fed FGC were heavier (P < 0.001) at d 10. In contrast, at d 24 and 35, birds fed CGC had lower FCR than those fed FGC (P < 0.05). Ileal gross energy and protein digestibility increased in birds fed CGC compared with those fed FGC at d 24 (P < 0.05). Relative gizzard weight was higher (P < 0.05) on d 24 and 35 in birds fed CGC as compared to those fed FGC. Birds consumed 2% dietary lignocellulose had decreased counts of cecal Clostridium spp. compared to those with 1% lignocellulose (P < 0.05) at d 24. On d 35, both levels of lignocellulose had significantly decreased (P < 0.05) litter moisture content compared to the control. In conclusion, birds fed pelleted diets containing CGC exhibited improved FCR, and increased nutrient digestibility, which may have been caused by larger gizzards. Furthermore, dietary lignocellulose addition is beneficial to litter quality.

Supplementing the feeds of layer pullets, at different ages with two different fiber sources improves immune function.

Two experiments were conducted to study the effects of lignocellulose supplementation on immune function in layer pullets at different stages of growth. Four-wk-old pullets (Experiment 1) were fed a control, diet (Diet C); Diet C plus 1% mixed soluble/insoluble fiber (Diet MF), or plus 1% insoluble fiber (Diet IF). At 7.5 wk-of-age, heterophil phagocytosis, and oxidative burst in Groups MF (328.5 beads/100 cells; 4,330.0 ΔRFU; relative fluorescent units) and IF (350.3; 5,264.4) were greater (P < 0.05) than Controls (303.4; 3,509.0). At 8 wk-of-age, Group MF and IF relative weights of bursa of Fabricius (0.57 g/100 g BW; 0.58 g /100 g BW), thymus glands (0.77; 0.78), and areas of Peyer's patches (PP) (2.7 cm2; 2.9 cm2) were higher (P < 0.05) than Controls (bursa, 0.50 g; thymus, 0.70 g; PP area, 1.8 cm2). In Experiment 2, 10-wk-old pullets were fed a control diet or diets containing 1.5% MF or IF for 8 wk. At 14 wk-of-age IF pullets had higher (P < 0.05) heterophil phagocytosis efficiency (447.9 beads/100 cells) than Controls (376.4) and MF and IF had greater (P < 0.05) oxidative burst (1,302.9 and 1,857.7 ΔRFU) than Controls (744.1). At 17 wk-of-age MF and IF had increased (P < 0.05) proliferation of T-lymphocytes (ConcanavalinA-stimulated) (100.4 and 103.1% of unstimulated cells) and B-lymphocytes (lipopolysaccharide-stimulated) (122.4 and 129.0) than Controls (ConA, 79.4; lipopolysaccharide, 106.6). At 18 wk-of-age, IF pullets were heavier (1,607.5 g, P < 0.05) than Controls (1,506.5 g), had heavier (P < 0.05) bursa of Fabricius (1.12 g) than MF and Control groups (0.98 g; 0.92 g) and cecal tonsils of MF (0.38 g) and IF (0.39 g) weighted more (P < 0.05) than Controls (0.33 g). Number of jejunal and ileal PP (10.0) in IF pullets was higher (P < 0.05) than Controls (7.1). These results indicate that both MF and IF can improve development of the immune system of young and grower pullets during periods of maturation and involution of lymphoid organs.

Model-based characterisation of growth performance and l-lactic acid production with high optical purity by thermophilic Bacillus coagulans in a lignin-supplemented mixed substrate medium.

Three Bacillus coagulans strains were characterised in terms of their ability to grow in lignin-containing fermentation media and to consume the lignocellulose-related sugars glucose, xylose, and arabinose. An optical-density high-throughput screening was used for precharacterisation by means of different mathematical models for comparison (Logistic, Gompertz, Baranyi, Richards & Stannard, and Schnute). The growth response was characterised by the maximum growth rate and lag time. For a comparison of the screening and fermentation results, an unstructured mathematical model was proposed to characterise the lactate production, bacterial growth and substrate consumption. The growth model was then applied to fermentation procedures using wheat straw hydrolysates. The results indicated that the unstructured growth model can be used to evaluate lactate producing fermentation. Under the experimental fermentation conditions, one strain showed the ability to tolerate a high lignin concentration (2.5g/L) but lacked the capacity for sufficient pentose uptake. The lactate yield of the strains that were able to consume all sugar fractions of glucose, xylose and arabinose was ∼83.4%. A photometric measurement at 280nm revealed a dynamic change in alkali-lignin concentrations during lactate producing fermentation. A test of decolourisation of vanillin, ferulic acid, and alkali-lignin samples also showed the decolourisation performance of the B. coagulans strains under study.

Lignin nanotubes as vehicles for gene delivery into human cells.

Lignin nanotubes (LNTs) synthesized from the aromatic plant cell wall polymer lignin in a sacrificial alumina membrane template have as useful features their flexibility, ease of functionalization due to the availability of many functional groups, label-free detection by autofluorescence, and customizable optical properties. In this report we show that the physicochemical properties of LNTs can be varied over a wide range to match requirements for specific applications by using lignin with different subunit composition, a function of plant species and genotype, and by choosing the lignin isolation method (thioglycolic acid, phosphoric acid, sulfuric acid (Klason), sodium hydroxide lignin), which influences the size and reactivity of the lignin fragments. Cytotoxicity studies with human HeLa cells showed that concentrations of up to 90 mg/mL are tolerated, which is a 10-fold higher concentration than observed for single- or multiwalled carbon nanotubes (CNTs). Confocal microscopy imaging revealed that all LNT formulations enter HeLa cells without auxiliary agents and that LNTs made from NaOH-lignin penetrate the cell nucleus. We further show that DNA can adsorb to LNTs. Consequently, exposure of HeLa cells to LNTs coated with DNA encoding the green fluorescent protein (GFP) leads to transfection and expression of GFP. The highest transfection efficiency was obtained with LNTs made from NaOH-lignin due to a combination of high DNA binding capacity and DNA delivery directly into the nucleus. These combined features of LNTs make LNTs attractive as smart delivery vehicles of DNA without the cytotoxicity associated with CNTs or the immunogenicity of viral vectors.

Use of the stable isotope (57) Fe to track the efficacy of the foliar application of lignosulfonate/Fe(3+) complexes to correct Fe deficiencies in cucumber plants.

BACKGROUND: During the last decade, environmental concerns regarding the use of recalcitrant synthetic chelates to overcome iron chlorosis has increased and new ligands such as lignosulfonates (LS) have been evaluated. However, the efficacy of these products is variable. In this work a hardwood (eucalyptus) and softwood (spruce) LS were compared to try to relate their physico-chemical characteristics and their efficacy. Also two more products derived from the eucalyptus lignosulfonate were tested. RESULTS: All the LS tested presented a good ability to complex Fe, but only the spruce LS was capable to maintain significant amounts of soluble Fe above pH 8. According to the FTIR data, structural changes related to the Fe source (Fe(2+) or Fe(3+) ) used to form the complex occurred in the LS molecule and might influence their efficacy. Cucumber (Cucumis sativus L. cv Ashley) chlorotic plants were used to test lignosulfonate efficacy when applied through foliar sprays in comparison with FeSO(4) and EDTA/(57) Fe(3+) . The (57) Fe content of plants sprayed with LS was very low in respect to the EDTA treatment, but this was not reflected in the biomass and re-greening rates. Eucalyptus LS modifications improve its efficacy for iron chlorosis recovery to levels similar to those found for the spruce LS. Two applications of the LS are recommended. CONCLUSIONS: Lignosulfonates did not require surfactants for their application; they did not burn the leaves, and had a stimulating effect on the vegetative growth of the plants. So these by-products could be a good alternative when applied through foliar sprays for cucumber plants.

Efficiency of a NPK fertilizer with adhered zinc lignosulfonate as a zinc source for maize (Zea mays L.).

The aim of this work was to evaluate the efficiency of a NPK fertilizer (8:15:15) with a Zn lignosulfonate (ZnLS) adhered as Zn source for maize plants. This product was compared in three experimental designs with the same NPK fertilizer with ZnSO(4) adhered and with no Zn adhered. The first and the second assays were carried out in a growth chamber by using perlite and a calcareous soil as substrate and the third experiment was raised in two calcareous fields. In general, growth chamber experiments showed that plants treated with NPK + ZnLS presented the highest dry weight and Zn concentrations in shoots. Also at field experiments, the Zn concentration in shoots was significantly high in plants treated with NPK + ZnLS. The grain harvested showed that this treatment gave the highest values in one location, but in the other no significant differences were observed. Although further research is required, we can conclude that NPK + ZnLS product could be a suitable source of Zn for maize crops.

Dietary lignins are precursors of mammalian lignans in rats.

The mammalian lignans enterolactone (ENL) and enterodiol, commonly found in human plasma and urine, are phytoestrogens that may contribute to the prevention of breast cancer and coronary heart disease. They are formed by the conversion of dietary precursors such as secoisolariciresinol and matairesinol lignans by the colonic microflora. The identification of lignins, cell-wall polymers structurally related to lignans, as precursors of mammalian lignans is reported here for the first time. In study 1, rats were fed rye or wheat bran (15% diet) for 5 d. Untreated brans and brans extracted with solvents to remove lignans were compared. ENL was estimated in urine samples collected for 24 h by time-resolved fluoroimmunoassay. ENL urinary excretion was reduced from 18.6 to 5.3 nmol/d (n=8; P<0.001) when lignans were removed from rye bran and from 30.5 to 6.2 nmol/d (P<0.001) when they were removed from wheat bran. These results suggest that lignins, embedded in the cell wall and retained in the bran during solvent extraction, account for 26-32% of the ENL formed from cereal brans. In study 2, rats were fed a deuterated synthetic lignin (0.2% diet) together with wheat bran (15%) for 3 d. The detection of deuterated ENL by LC-tandem MS in urine (20 nmol/d) clearly confirms the conversion of lignin into mammalian lignans. More research is warranted to determine the bioavailability of lignins in the human diet.

Estrogenic activity of phenylpropanoids from Sarcomelicope megistophylla and structure determination of a new norneolignan.

Bioassay-guided fractionation of the neutral extract of the bark of Sarcomelicope megistophylla resulted in the isolation of the new nor-neolignan sarcomeginal ( 1), together with the known ailanthoidol ( 2) and (+/-)-seco-isolariciresinol ( 3). The structure of 1 was determined by spectroscopic means. Estrogenic activity of the isolated compounds was tested using estrogen receptor-positive MCF7 and estrogen receptor-negative MDA-MB-231 human mammary adenocarcinoma cell lines. Compound 3 displayed significant estrogenic activity.

Effect of different sources of dietary fibre on growth performance, intestinal morphology and caecal carbohydrases of domestic geese.

1. The aim of this study was to examine the effects of dietary fibre sources on growth and on the development of the gastro-intestinal tract in growing geese. 2. Six-week-old female White Roman geese were divided at random into 6 groups with 6 dietary treatments. Diets were isoenergetic and isonitrogenous and contained alfalfa meal, barley bran, rice hulls, cellulose, pectin or lignin as the major dietary source of fibre. 3. Food intake was significantly higher in the barley bran group than in the other groups. Both daily weight gain and food conversion of the pectin and alfalfa meal groups were lower than those of the other groups. 4. In the 9-week-old geese, the relative weight and the length of the small intestine did not significantly differ among treatment groups. However, the relative weight was significantly lightest and the caecal length was significantly shortest (P < 0.05) in the pectin group. 5. Activities of amylase and cellulose hydrolases of the caecal contents were also highest in the pectin group. 6. From SEM micrographs, no morphological damage of the villi was observable in the different intestinal segments of the geese in any of the treatments.

Evaluation and application of the Cornell Net Carbohydrate and Protein System for dairy cows fed diets based on pasture.

This study evaluated the Cornell Net Carbohydrate and Protein System for dairy cows consuming diets based on pasture, assessed the sensitivity of the model to critical inputs, and demonstrated application opportunities. Data were obtained from four grazing experiments and four indoor pasture feeding experiments (25 dietary treatments) involving dairy cows in New Zealand and the US. The model provided a reasonably good estimate of changes in body condition score (r2 = 0.78; slope not significantly different from 1), estimated energy balance (r2 = 0.76; slope not significantly different from 1), blood urea N (r2 = 0.94; underprediction bias of 0.5%), microbial N flow (r2 = 0.88; slope not significantly different from 1), and milk production. The model underpredicted dry matter intake (r2 = 0.80; 13% bias) and overpredicted ruminal pH (r2 = 0.47; 1.7% bias). Predicted milk production was especially sensitive to changes in pasture lignin content, effective fiber, rate of fiber digestion, and amino acid composition of ruminal microbes. Milk production was first-limited by the supply of metabolizable energy when only high quality pasture was fed, but specific amino acids limited milk production when more than 20% of the diet consisted of a grain supplement. These results indicate that the Cornell Net Carbohydrate and Protein System can be used for dairy cows in a grazing system to make realistic predictions of performance.

Iron bioavailability from diets containing isolated or intact sources of lignin.

Experiments were conducted to determine effects of isolated lignin and intact lignin in foods on bioavailability of intrinsic iron in lignin-containing foods and of supplemental iron (FeSO4.H20). Standard curve and slope ratio methodology were employed to determine iron bioavailability to chicks. In one experiment, lignin content of foods ranged from 2 to 25% and iron bioavailability ranged from -20 to 140%, but no association between lignin content and bioavailability existed. In other experiments, increasing dietary lignin concentration from some natural sources reduced total iron availability, whereas increasing isolated lignin concentration had no effect. These results suggest that lignin structure or other unidentified factors determine intrinsic iron availability. No lignin source significantly decreased supplemental iron bioavailability.

Forage intake and nutrition of range goats in a shrubland in northeastern Mexico.

Voluntary intake and nutritive value of diets selected by goats grazing a shrubland at Marin county, N.L., Mexico were determined. Four esophageally cannulated Spanish female goats (average BW 35 kg), were used to collect extrusa samples monthly throughout 1 yr (June 1987 to May 1988). Organic matter intake (OMI) was estimated by total fecal collections from four castrated Spanish male goats (average BW 42 kg). Diets selected by goats were high in CP throughout the year (means = 18.9%). Available CP represented only about half the total CP. The ADF content of extrusa samples differed (P less than .05) among months, with high ADF values during winter months. Dietary lignin followed a similar pattern during the year. Goats consumed forage with sufficient amounts of Ca, Na, K, Mg, Cu, ZN, Mn, and Fe to meet requirements. The OMI of goats was different (P less than .05) among sampling periods. On the average, estimated OMI (means = 878.7 g/d) compared well with results of other studies in the area. Amounts of DE consumed by goats (1.1 Mcal DE/d) were not sufficient to meet requirements for maintenance plus low activity. High levels of browse in the diets presumably were responsible for low in vitro OM digestibility (means = 34.1%) throughout the year. Thus, productivity of range goats in these areas should be improved by supplementing with protein and energy.