Roque Lozano - Academia.edu (original) (raw)

Papers by Roque Lozano

Uptake and transporting pattern of toxic ions to the shoot is a crucial response by plant under s... more Uptake and transporting pattern of toxic ions to the shoot is a crucial response by plant under saline conditions affecting metabolic activities and thereby determines salt sensitivity/tolerance in rice. Experiments were conducted to compare the rate of transpiration and its effect on sodium accumulation in shoot of two inbred rice lines (IR55178 – 163 tolerant and IR55178-104 sensitive differing in salt tolerance along with a salt tolerant check Shua-92) under different levels of salinity (0, 50 and 75 mM). The parameters studied indicated that transpiration rates were sharply decreased in response to salinity in both genotypes. While, sodium uptake continued to increase however, the tolerant genotype maintained transpiration rate quite satisfactorily and also exhibited ability to maintain higher K: Na ratio and low Na concentration in the xylem than the sensitive genotype. It is concluded that transport of sodium ions in the present study was negatively correlated with transpiration (r =-0.806).

In order to evaluate the nutritional value

The objective of the study was to evaluate the influence of two shrub leaves on digestion, nitrog... more The objective of the study was to evaluate the influence of two shrub leaves on digestion, nitrogen retention and ruminal digestion characteristics of sheep. Twelve rumen-fistulated castrated male sheep (Pelibuey x Rambouillet) of 32.0 ± 2.3 kg live weight were randomly assigned to three diets (four sheep/diet): diet 1 or control, consisted of 49.2% Medicago sativa hay and 50.8% of Cynodon plectostachyus straw dry matter basis (DM), diet 2 consisted of 36.2% Celtis pallida leaves and 63.8% Cynodon plectostachyus straw, diet 3 consisted of 43.9% Ziziphus obtusifolia leaves and 56.1% Cynodon plectostachyus straw. The diets were added with 0.5% of a mineral premix and 5.0% molasses. Medicago sativa hay was used as control feed of good nutritional quality. Sheep intakes of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose and hemicellulose were not significantly different among treatment diets. However, the digestion coefficients of DM, OM, CP, NDF, ADF, cellulose and hemicellulose resulted similar (P>0.05) between sheep fed the M. sativa hay and the C. pallida diets, but both were higher (P<0.05) than sheep consuming the Z. obtusifolia diet. The N intake, fecal N and urinary N were not different (P>0.05) among the three diets, but numerically sheep fed C. pallida, excreted more N in urine than the sheep on the other diets. Leaves of evaluated shrubs may have potential to be used as alternative browse supplement for sheep fed diets based on roughages of low nutritional quality.

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SUMMARY The extent of vegetation used by free browsing goats on a rangeland is a practical measur... more SUMMARY The extent of vegetation used by free browsing goats on a rangeland is a practical measure to determine rangeland productivity and may be measured by the similarity indices between the botanical composition of diet and the rangeland. The aims of this study were to evaluate and compare, seasonally the similarity indices of forage species and goats diets under the Sonorant desert conditions. Samplings were carried out in summer and autumn of 2006, and winter 2007 in a 200-ha rangeland with an animal density of 0.13 to 0.36 individuals/ha. Twenty two fixed transects (30 m long) distributed randomly were used to measure the botanical composition and importance value (IV) for plant types by the line-intercept method. Identified species were classified as non legumes trees and shrubs (NLTS), legumes trees and shrubs (LTS), cacti, forbs, agaves and grasses. Five castrated Creole-Nubio goats (29 kg of BW) provided with esophageal fistula were used to obtain diet samples and determine botanical composition of diets by microhistological analyses. Botanical composition of diet (A) and IV values (B) were used to calculate the similarity indices (SI) according to S = 2(W)(100)/A+B, being W the lower value between A and B. Sixty plant species were founded in the study area, but only 23 species were in diet of goats. Similarity indices indicated that NLTS were more utilized in all seasons than other plant types. The SI between seasons indicated a gradient of forage utilization in the following order (P<.05): In summer; forbs (87.3) > NLTS (70.2) > LTS (39.1) > cactus (0.0) = grasses (0.0), in autumn; cactus (85.9) > NLTS (85.6) > forbs (77.1) > LTS (73.3) > grasses (6.9) and in winter LNTS (88.8) > LTS (88.0) > grasses (87.4) > forbs (70.8) > cactus (53.3). Goats utilized only 30% of the vegetation on rangeland in all seasons and showed light change in their forage utilization pattern because of the opportunistic feeding behavior of these animals; however they maintain a high utilization on shrubs and trees.

The production of milk from goats managed under extensive range grazing conditions can be affecte... more The production of milk from goats managed under extensive range grazing conditions can be affected in quantity and quality by the nutrient and especially by the mineral content of the forages on the rangeland, which in turn reflects soil and precipitation conditions. Mexico with its large dairy dual-purpose goat population and vast expanses of arid rangelands is a good model for many other countries with similar conditions. In several studies on the semiarid rangeland of northeastern Mexico the voluntary selection of brush browse, forbs and grasses by goats, and in comparison by sheep and deer was determined from observations, collections, samples from esophageally fistulated goats and sheep, and microhistological analyses of deer feces monthly for several years. The area had low annual rain precipitation often less than 400 mm and dry season from November to July. Blackbrush (Acacia sp.), Mesquite (Prosopis sp.), Palo verde (Cercidium macrum), Jujube (Ziziphus sp.), Hackberry (Celtis sp.), Pricklypear (Opuntia sp.), Cenizo (Leucophyllum sp.), Soapbrush (Porlieria sp.) were dominant brush species. Goats selected 81 ± 1.4% brush browse, 12 ± 1.2% forbs, and 7 ± 1.0% grasses throughout the year for their diet, while the botanical composition of the rangeland was 41% brush, 19% forbs, and 40% grasses. Goats preferred Acacia, Cercidium, Porlieria, and Celtis. Significant undersupplies of Mg, Cu, Mn, and Zn in the naturally selected diets of goats in relation to requirements in most months was determined. Contrary to the behavior of goats, sheep selected 95–63% grasses, 1–36% browse, and 0.1–2.2% forbs in different months of the year. Sheep had deficient diets in Ca, Mg, K, Cu, and Mn during several months. Deer appeared to select like goats 94% browse, 5% forbs, and 1% grasses. Deer had deficient diets apparently only in Zn during the 6 months of summer and autumn. Several brush browse and grass species with relatively high mineral contents during some seasons were identified as possibly helpful to alleviate mineral deficiencies, such as Hackberry (Celtis sp.), Soapbrush (Porlieria sp.), Jujube (Ziziphus sp.), Desmanthus sp., Cenizo (Leucophyllum sp.), and Huisache (Acacia sp.) brush; Hall's Panicum (Panicum sp.), and Buffelgrass (Cenchrus sp.). Published by Elsevier B.V.

This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/authorsrights

Microhistological analysis of feces was used to estimate the selection of white-tailed deer (Odoc... more Microhistological analysis of feces was used to estimate the selection of white-tailed deer (Odocoileus uirginianus, Tex.) in the state of Nuevo Leon in northeastern Mexico. Browse was the main component of deer diets (94% annual mean). Major species were blackbrush acacia (Acacia rigid& Benth), guajillo (Acacia berlandieri Benth) soapbrush (Porlieria angustifolia Englem), cenizo (Leucophylium texanus Benth), huisache (Acacia farnesiana L), popotillo (Ephedra aspera Englem), palo Verde (Cercidium macrum I.M. Johnst) and honey mesquite (Prosopis glandulosa Torr). These species represented about 82% the total plant composition of deer diets on an annual basis. Forbs were numerous (23 species in deer diets), but represented only about 5% of the total annual diet. Major forbs in deer diets were Hibiscus spp., Zephyranthes arenicofu Hansel, Agrythamnia neomexicana Muell and Dyssodiu acerosa DC. Grasses were selected by deer in very low amounts; buffelgrass (Cenchrus ciliaris L.) was the major grass in the annual diets of deer. Because of the nature of deer diets, it is concluded that browse should be considered an important part of the deer habitat, and that those shrub species that are used by deer for food and refuge should be preserved. 0 1997 Elsevier Science B.V.

Foliage from 15 shrub species was used to estimate the extent and rate of cell wall (CW) degradat... more Foliage from 15 shrub species was used to estimate the extent and rate of cell wall (CW) degradation in the rumen of ®stulated Pelibuey sheep. Branches from the browse species: Acacia

Leaves and twigs from shrub species consumed by range goats: Acacia obtusifolia were evaluated fo... more Leaves and twigs from shrub species consumed by range goats: Acacia obtusifolia were evaluated for comparative seasonal contents of Ca, P, Mg K, Zn, Mn, Cu and Fe. Plants were collected in summer (September 12, 1992), fall (November 20, 1992), winter (February 20, 1993) and spring (May 22, 1993) in Marõ Ân, County, Nuevo Leon, Mexico. During spring and summer mineral concentrations were higher in general. Only Ca, Mg, K, and Fe were in substantial amounts in all seasons to meet adult goat requirements. With the exception of spring, shrubs had extremely low P concentrations. Manganese, Cu and Zn in most plants had low marginal levels to meet adult goat requirements. Moreover, potential intake of P, Mn, Cu and Zn in shrub species by goats weighing 50 kg BW consuming 2.0 kg per day DM was low. However, plants such as D. virgathus, L. texanum, P. glandulosa, L. leucocephala and C. macrum can be considered prominent components in diets of range goats because of their high mineral concentrations. It appears that ration formulations for range goats in northeastern Mexico should include P, Mn, Cu and Zn in all seasons of the year.

Native grasses from northeastern Mexico, such as Aristida spp., Bouteloua gracilis (Thurb), Cench... more Native grasses from northeastern Mexico, such as Aristida spp., Bouteloua gracilis (Thurb), Cenchrus incertus (M.A. Curtis), Hilaria berlangeri (Steud. Nash), Panicum hallii (Varsey), Setaria macrostachya (H.B.K.), and Cenchrus ciliaris (L.), an introduced grass, that are consumed by range goats were evaluated to estimate seasonal CP, lignin, Ca, P, K, Mg, Na, Cu, Fe, Zn, Mn contents, and the rate and extent of DM digestion. The in situ nylon bag technique was used to estimate effective digestibility/degradability of DM (EDDM). Potential mineral intake by an adult range goat consuming these grasses was also estimated. The CP content in all grasses was significantly different between seasons. P. hallii had high annual mean CP contents (12%) and Aristida spp. (6%) was low. The native grasses B. gracilis (9%, annual mean), S. macrostachya (10%) and C. incertus (8%) had CP values comparable to the introduced grass C. ciliaris (9%). Lignin contents in all grasses were also significantly different between seasons. Aristida spp. had high annual means (10%) and H. berlangeri was low (6%). With the exception of H. berlangeri, all grasses had higher lignin contents (annual means) than C. ciliaris (6%). The EDDM in all grasses was significantly different between seasons. C. incertus (45%, annual mean) had the highest EDDM, while Aristida spp. (26%) was lowest. During spring and autumn, EDDM in all grasses was higher than in the other seasons. P. hallii, H. berlangeri and C. incertus had comparable EDDM values to C. ciliaris (40%) in all seasons. It was estimated that an adult range goat consuming the studied grasses, could eat sufficient amounts of Ca, Fe, and K (except for K from Aristida spp. in winter and summer), but of Na, Zn and Mn only in spring and autumn, and of Cu only in autumn. The P and Mg contents were marginally deficient in most grasses and in all seasons. The native grasses P. hallii, S. macrostachya, B. gracilis can be considered valuable grasses for goats on the range, because of their relatively high CP contents, and C. incertus, P. hallii and H. berlangeri because of their relatively high EDDM values, comparable to C. ciliaris. However, range goats consuming these grasses need to be supplemented with P and Mg in all seasons, with Na, Zn and Mn in winter and summer, and Cu in winter, spring and summer seasons.

During a period of 15 weeks (July through November 1989), 40 lambs (Rambouillet XPelibuey; 25 cas... more During a period of 15 weeks (July through November 1989), 40 lambs (Rambouillet XPelibuey; 25 castrated males and 15 females) were randomly grouped among five energy treatment levels (five males and three females per treatment level). The energy supplement ranged from 0.8% to 2.0% of body weight (BW), adjusted weekly. After the morning supplement feeding, lambs were allowed to graze freely for 7-9 h in a buffelgrass (Cenchrus ciliuris) pasture. Male lambs were harnessed for total collection of feces, during the last 10 days of the study. Total organic matter and crude protein intakes increased (PC 0.05) with an increase in energy supplementation. Average daily gain of lambs also increased (P<O.O5) with an increase in the level of energy in the diet. The regression of metalizable energy (ME) intake (kcal per kgo.75 per day) on BW gain resulted in an estimated daily ME requirement for maintenance of 85.9 kcal per kg " .75, and for gain was 0.54 kcal ME per g gain per kg " .75. Maximum growth of lambs was 147 g per day with a level of energy supplementation of 2.0% of BW. Even though there was a linear response in BW gain of lambs due to energy supplementation, the economics of supplementation response were worthy for the level of supplementation of 0.8% BW, with the type of supplement used in this study. Thus, to reduce the cost of supplementation of grazing lambs in a buffelgrass pasture it is recommended to include sources of high energy in the supplements such as fats or oil.

This study was conducted to estimate and compare the organic matter (OM), energy and mineral inta... more This study was conducted to estimate and compare the organic matter (OM), energy and mineral intakes of grazing lambs in a buffelgrass pasture during 1 year. Vegetation in the study area (10 ha) consisted mainly of buffelgrass (70% of covered area) and shrubs such as blackbrush (Acacia rigidula), palo Verde (Cercidium macrum) and cenizo (Leucophyllum texanurn). Shrubs comprised about 27% of the covered area. From January through December 1989, five 3-year-old castrated male lambs (Peli-buey X Rambouillet), weighing about 39 kg, were used to determine monthly total fecal output. Feces were collected during 4 days, after a 5 day adjustment period. The in vitro organic matter digestibility (IVOMD) was determined using esophageal extrusa samples collected from six esophageally fistulated male lambs. Differences (P < 0.05) were found in OM intake (OMI) among months (annual mean, 818.6 g day). In general, lambs consumed more OM during May, June and July. Digestible energy (DE) intake was different (P<O.O5) among months. Annual mean was 1436 kcal DE per day. Lambs consumed more DE during May, and least during February. Crude protein intake was highest (P<O.O5) during July (189.7 g day) and lowest in January (90.1 g day). Neutral detergent fiber intake (NDFI) was also dissimilar (P < 0.05) among sampling periods, the highest NDFI being in July (974.3 g per day) and the lowest in the winter months. Acid detergent fiber intake of lambs followed a similar pattern to that of NDFI. Macro minerals consumed by lambs (K, Ca, Mg and Na) were in general higher (P < 0.05) during the summer months compared with other months. Trace minerals (especially Cu and Fe, Zn and Mn) consumed by lambs also varied seasonally. In general, the results of this study indicate that only during the summer months do lambs consume nutrients that meet or exceed their requirements.

An in vivo digestibility trial was conducted to evaluate the influence of shrub leaves on digesti... more An in vivo digestibility trial was conducted to evaluate the influence of shrub leaves on digestion and N retention by Ž. goats. Twelve male castrated Spanish goats 33.1 " 2.4 kg BW were randomly placed in metabolism stalls and assigned to Ž .Ž. Ž .Ž. Ž. three diets four goatsrdiet : 1 control 23% alfalfa hay plus 77% bean straw BS , 2 22% hackberry Celtis pallida plus Ž. Ž. Ž. 78% BS and 3 18% ceniso Leucophyllum texanum plus 18% soapbrush Porlieria angustifolia plus 64% BS. All diets Ž. contained 1.5% N. Diets were offered in two equal portions daily. The DM and CP intakes of goats were similar P) 0.05 Ž. among diets. However, NDF and ADF intakes were lower P-0.05 in goats fed diets with hackberry and ceniso plus Ž. soapbrush than goats fed alfalfa hay. Digestibilities of DM and CP were similar P) 0.05 among goats. Cell wall and its Ž. fractions were digested less efficiently P-0.05 when goats were fed the hackberry and ceniso plus soapbrush diets Ž. instead the alfalfa hay diet. Goats retained N in a manner similar P) 0.05 among diets. Differences on fiber digestion between diets containing alfalfa hay and browse species may be related to the chemical or physical nature of the cell wall. q 1998 Elsevier Science B.V.

The aim of this study was to determine seasonally the nutritive value and fermentability of diets... more The aim of this study was to determine seasonally the nutritive value and fermentability of diets selected by range goats in a thorn shrubland of North México. Esophageal cannulated goats were used to obtain extrusa samples. Samples were collected monthly from February 1999 to December 2000. Intact males fitted with harnesses were utilized for total fecal collection and DM intake determinations. Crude protein, ash and cell wall contents were determined. Macro (Na, Ca, P, Mg, K) and trace elements (Cu, Mn, Zn and Fe) were also estimated. In vitro gas production was performed to estimate rumen kinetics of goat diets. Statistical comparisons were made between seasons. The OM (mean = 84.3%), CP (13.5%), NDF (49.6%), ADF (37.5%) and lignin (12.0%) contents were different (P < 0.05) between periods. Dry matter intake ranged from 58.6 (summer) to 91.7 g kg 0.75 (winter). With exception of P, all minerals were different (P < 0.05) between seasons. Moreover, during all seasons, goats selected diets with sustained amounts of Na, Ca, Mg, K, Co, Zn and Fe. However, Cu and Mn appeared to be insufficient. Significant differences between seasons were obtained in the gas production parameters. Mean values for the gas produced from the insoluble but fermentable fraction b and the constant rate of gas production c were 33.0 ml/200 mg OM and 5.6% h −1 , respectively. Dietary CP was adequate to meet goat requirements in all seasons. However, a regime of Cu and Mn supplementation must be considered. Negative correlations between cell wall constituents and in vitro gas parameters may indicate the detrimental effect such compounds exert on gas production. Differences registered in cumulative gas production and fraction c permit to identify the differences of nutritive value of the diets selected by animals throughout seasons.

The study was conducted to estimate and to compare the monthly variation of nutrient content of d... more The study was conducted to estimate and to compare the monthly variation of nutrient content of diets of deer. During 1989, samples of plant species were collected and pooled, according to the botanical composition of feces to simulate the monthly diet of deer. Collections were carried out in four ranches (about 12 000 ha) located in the state of Nuevo Le6n. Two diets in each ranch were evaluated for CP, neutral detergent fiber (NDF), acid detergent fiber (ADF), insoluble nitrogen in acid detergent fibre (INADF), in vitro dry matter digestibility (IVDMD), macro and trace minerals. Deer consumed diets with a high content of browse species (annual mean 94.2%). Forbs represented 5.2% and grasses 0.6% of the total composition. The crude protein (CP) in diets varied (P < 0.01) throughout the year (annual mean 15.1%). The IVDMD was low during all months (annual mean 39.9%). High levels of the shrub Acacia rigidula (about 50.0%) which had high levels of condensed tannins (about 15.0%) may negatively influence the in vitro digestion of DM. Calcium, Mg, Na and K concentrations in deer diets were in adequate amounts to satisfy ruminant requirements. Phosphorus levels in diets were extremely low during all months. Conversely, higher concentrations of P in feces may indicate that deer had consumed more forbs than those determined by microhistology in feces. Although deer requirements of trace elements are unknown, they selected diets with concentrations of Fe, Mn and Cu to cover beef cattle requirements. However, Zn was the most limiting trace element appearing at marginal levels in diets during 6 months (summer and fall). It is recommended to managers and owners to open forest canopy in the range to allow an increase of forbs and native grass diversity and density with its associated increased nutritional value.

The legumes Acacia peninsularis (Brit. L. Rose) Standley; Cercidium floridium Benth; Mimosa xanti... more The legumes Acacia peninsularis (Brit. L. Rose) Standley; Cercidium floridium Benth; Mimosa xantii, Gray; Pithecellobium confine Standley and Prosopis sp. Torr. and non-legumes Bursera microphylla Gray (Burceraceae); Cyrtocarpa edulis (Brand) Stand (Anacordiaceae); Lippia palmeri, S. Wats (Verbenaceae); Opuntia cholla, Weber (Cactaceae) and Turnera diffusa Wild (Turneraceae) were evaluated in their mineral content. Shrubs were collected from 16 linear transects of 30 m. Collections were carried out in each season during three consecutive years. Potential mineral intake of range goats consuming these shrubs was also estimated. Non-legumes were highest in Na content than legumes in all seasons. Both legumes and non-legumes were lower in K and Cu, whereas Na and Fe were highest during spring than in other seasons. In summer, Ca was lower and P was highest in all plants. Levels of Ca were nine times higher than requirements for range ruminants. Potential intake of Ca, Mg, K, Na, Mn and Fe by range goats consuming these shrubs was sufficient to satisfy their requirements. However, consumption of P, Cu, Zn was low. It is concluded that range goats grazing these shrub species must be supplemented with P, Cu and Zn throughout the year in order to sustain goat productivity.

Ž. Ž. Ž Leaves from the shrubs blackbrush acacia Acacia rigidula , palo verde Cercidium macrum , ... more Ž. Ž. Ž Leaves from the shrubs blackbrush acacia Acacia rigidula , palo verde Cercidium macrum , and huisache Acacia. Ž. farnesiana were evaluated as protein supplements in low-quality buffelgrass Cenchrus ciliaris straw-based diets for sheep Ž. Ž. using in vivo Trial 1 and in situ Trial 2 digestibility trials. Leaves were collected in Marin, Nuevo Leon, Mexico. In Triaí Ž. 1, the four diets that contained approximately 1.5% N consisted of: 1 control—26% alfalfa hay plus 74% buffelgrass straw Ž. Ž. Ž. Ž. BS ; 2 30% blackbrush acacia plus 70% BS; 3 16% palo verde plus 84% BS; and 4 21% huisache plus 79% BS. Ž. Ž. Twelve sheep Pelibuey= Rambouillet, average 37.5 kg BW were fed the four diets three sheep per diet in two equal Ž. Ž. portions daily 0800 and 1600 in addition to approximately 400 g of a sorghum grain-based supplement 11%, CP at 0800 Ž. h. In Trial 2 the rate and extent of dry matter DM and N loss from nylon bags for alfalfa hay, blackbrush acacia, palo verde, and huisache was evaluated using four ruminally cannulated sheep in a 4 = 4 Latin square experiment. In Trial 1, nutrient digestibilities were low in sheep fed the blackbrush diet compared with the other three diets. Moreover, sheep fed the blackbrush diet retained less N than sheep fed the other diets. Results of Trial 2 indicated large differences in the ruminal degradability among the four species. Alfalfa hay, palo verde and huisache exhibited rapid rumen digestibility of DM and CP compared with blackbrush. Tannins from blackbrush may have negative effects on N and fiber digestibility and N retention by sheep. However, low tannin shrubs such as palo verde and huisache consumed at low levels, influenced nutrient digestibility and N retention of sheep in a manner similar to alfalfa hay. q 1998 Elsevier Science B.V.

Uptake and transporting pattern of toxic ions to the shoot is a crucial response by plant under s... more Uptake and transporting pattern of toxic ions to the shoot is a crucial response by plant under saline conditions affecting metabolic activities and thereby determines salt sensitivity/tolerance in rice. Experiments were conducted to compare the rate of transpiration and its effect on sodium accumulation in shoot of two inbred rice lines (IR55178 – 163 tolerant and IR55178-104 sensitive differing in salt tolerance along with a salt tolerant check Shua-92) under different levels of salinity (0, 50 and 75 mM). The parameters studied indicated that transpiration rates were sharply decreased in response to salinity in both genotypes. While, sodium uptake continued to increase however, the tolerant genotype maintained transpiration rate quite satisfactorily and also exhibited ability to maintain higher K: Na ratio and low Na concentration in the xylem than the sensitive genotype. It is concluded that transport of sodium ions in the present study was negatively correlated with transpiration (r =-0.806).

In order to evaluate the nutritional value

The objective of the study was to evaluate the influence of two shrub leaves on digestion, nitrog... more The objective of the study was to evaluate the influence of two shrub leaves on digestion, nitrogen retention and ruminal digestion characteristics of sheep. Twelve rumen-fistulated castrated male sheep (Pelibuey x Rambouillet) of 32.0 ± 2.3 kg live weight were randomly assigned to three diets (four sheep/diet): diet 1 or control, consisted of 49.2% Medicago sativa hay and 50.8% of Cynodon plectostachyus straw dry matter basis (DM), diet 2 consisted of 36.2% Celtis pallida leaves and 63.8% Cynodon plectostachyus straw, diet 3 consisted of 43.9% Ziziphus obtusifolia leaves and 56.1% Cynodon plectostachyus straw. The diets were added with 0.5% of a mineral premix and 5.0% molasses. Medicago sativa hay was used as control feed of good nutritional quality. Sheep intakes of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose and hemicellulose were not significantly different among treatment diets. However, the digestion coefficients of DM, OM, CP, NDF, ADF, cellulose and hemicellulose resulted similar (P>0.05) between sheep fed the M. sativa hay and the C. pallida diets, but both were higher (P<0.05) than sheep consuming the Z. obtusifolia diet. The N intake, fecal N and urinary N were not different (P>0.05) among the three diets, but numerically sheep fed C. pallida, excreted more N in urine than the sheep on the other diets. Leaves of evaluated shrubs may have potential to be used as alternative browse supplement for sheep fed diets based on roughages of low nutritional quality.

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SUMMARY The extent of vegetation used by free browsing goats on a rangeland is a practical measur... more SUMMARY The extent of vegetation used by free browsing goats on a rangeland is a practical measure to determine rangeland productivity and may be measured by the similarity indices between the botanical composition of diet and the rangeland. The aims of this study were to evaluate and compare, seasonally the similarity indices of forage species and goats diets under the Sonorant desert conditions. Samplings were carried out in summer and autumn of 2006, and winter 2007 in a 200-ha rangeland with an animal density of 0.13 to 0.36 individuals/ha. Twenty two fixed transects (30 m long) distributed randomly were used to measure the botanical composition and importance value (IV) for plant types by the line-intercept method. Identified species were classified as non legumes trees and shrubs (NLTS), legumes trees and shrubs (LTS), cacti, forbs, agaves and grasses. Five castrated Creole-Nubio goats (29 kg of BW) provided with esophageal fistula were used to obtain diet samples and determine botanical composition of diets by microhistological analyses. Botanical composition of diet (A) and IV values (B) were used to calculate the similarity indices (SI) according to S = 2(W)(100)/A+B, being W the lower value between A and B. Sixty plant species were founded in the study area, but only 23 species were in diet of goats. Similarity indices indicated that NLTS were more utilized in all seasons than other plant types. The SI between seasons indicated a gradient of forage utilization in the following order (P<.05): In summer; forbs (87.3) > NLTS (70.2) > LTS (39.1) > cactus (0.0) = grasses (0.0), in autumn; cactus (85.9) > NLTS (85.6) > forbs (77.1) > LTS (73.3) > grasses (6.9) and in winter LNTS (88.8) > LTS (88.0) > grasses (87.4) > forbs (70.8) > cactus (53.3). Goats utilized only 30% of the vegetation on rangeland in all seasons and showed light change in their forage utilization pattern because of the opportunistic feeding behavior of these animals; however they maintain a high utilization on shrubs and trees.

The production of milk from goats managed under extensive range grazing conditions can be affecte... more The production of milk from goats managed under extensive range grazing conditions can be affected in quantity and quality by the nutrient and especially by the mineral content of the forages on the rangeland, which in turn reflects soil and precipitation conditions. Mexico with its large dairy dual-purpose goat population and vast expanses of arid rangelands is a good model for many other countries with similar conditions. In several studies on the semiarid rangeland of northeastern Mexico the voluntary selection of brush browse, forbs and grasses by goats, and in comparison by sheep and deer was determined from observations, collections, samples from esophageally fistulated goats and sheep, and microhistological analyses of deer feces monthly for several years. The area had low annual rain precipitation often less than 400 mm and dry season from November to July. Blackbrush (Acacia sp.), Mesquite (Prosopis sp.), Palo verde (Cercidium macrum), Jujube (Ziziphus sp.), Hackberry (Celtis sp.), Pricklypear (Opuntia sp.), Cenizo (Leucophyllum sp.), Soapbrush (Porlieria sp.) were dominant brush species. Goats selected 81 ± 1.4% brush browse, 12 ± 1.2% forbs, and 7 ± 1.0% grasses throughout the year for their diet, while the botanical composition of the rangeland was 41% brush, 19% forbs, and 40% grasses. Goats preferred Acacia, Cercidium, Porlieria, and Celtis. Significant undersupplies of Mg, Cu, Mn, and Zn in the naturally selected diets of goats in relation to requirements in most months was determined. Contrary to the behavior of goats, sheep selected 95–63% grasses, 1–36% browse, and 0.1–2.2% forbs in different months of the year. Sheep had deficient diets in Ca, Mg, K, Cu, and Mn during several months. Deer appeared to select like goats 94% browse, 5% forbs, and 1% grasses. Deer had deficient diets apparently only in Zn during the 6 months of summer and autumn. Several brush browse and grass species with relatively high mineral contents during some seasons were identified as possibly helpful to alleviate mineral deficiencies, such as Hackberry (Celtis sp.), Soapbrush (Porlieria sp.), Jujube (Ziziphus sp.), Desmanthus sp., Cenizo (Leucophyllum sp.), and Huisache (Acacia sp.) brush; Hall's Panicum (Panicum sp.), and Buffelgrass (Cenchrus sp.). Published by Elsevier B.V.

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Microhistological analysis of feces was used to estimate the selection of white-tailed deer (Odoc... more Microhistological analysis of feces was used to estimate the selection of white-tailed deer (Odocoileus uirginianus, Tex.) in the state of Nuevo Leon in northeastern Mexico. Browse was the main component of deer diets (94% annual mean). Major species were blackbrush acacia (Acacia rigid& Benth), guajillo (Acacia berlandieri Benth) soapbrush (Porlieria angustifolia Englem), cenizo (Leucophylium texanus Benth), huisache (Acacia farnesiana L), popotillo (Ephedra aspera Englem), palo Verde (Cercidium macrum I.M. Johnst) and honey mesquite (Prosopis glandulosa Torr). These species represented about 82% the total plant composition of deer diets on an annual basis. Forbs were numerous (23 species in deer diets), but represented only about 5% of the total annual diet. Major forbs in deer diets were Hibiscus spp., Zephyranthes arenicofu Hansel, Agrythamnia neomexicana Muell and Dyssodiu acerosa DC. Grasses were selected by deer in very low amounts; buffelgrass (Cenchrus ciliaris L.) was the major grass in the annual diets of deer. Because of the nature of deer diets, it is concluded that browse should be considered an important part of the deer habitat, and that those shrub species that are used by deer for food and refuge should be preserved. 0 1997 Elsevier Science B.V.

Foliage from 15 shrub species was used to estimate the extent and rate of cell wall (CW) degradat... more Foliage from 15 shrub species was used to estimate the extent and rate of cell wall (CW) degradation in the rumen of ®stulated Pelibuey sheep. Branches from the browse species: Acacia

Leaves and twigs from shrub species consumed by range goats: Acacia obtusifolia were evaluated fo... more Leaves and twigs from shrub species consumed by range goats: Acacia obtusifolia were evaluated for comparative seasonal contents of Ca, P, Mg K, Zn, Mn, Cu and Fe. Plants were collected in summer (September 12, 1992), fall (November 20, 1992), winter (February 20, 1993) and spring (May 22, 1993) in Marõ Ân, County, Nuevo Leon, Mexico. During spring and summer mineral concentrations were higher in general. Only Ca, Mg, K, and Fe were in substantial amounts in all seasons to meet adult goat requirements. With the exception of spring, shrubs had extremely low P concentrations. Manganese, Cu and Zn in most plants had low marginal levels to meet adult goat requirements. Moreover, potential intake of P, Mn, Cu and Zn in shrub species by goats weighing 50 kg BW consuming 2.0 kg per day DM was low. However, plants such as D. virgathus, L. texanum, P. glandulosa, L. leucocephala and C. macrum can be considered prominent components in diets of range goats because of their high mineral concentrations. It appears that ration formulations for range goats in northeastern Mexico should include P, Mn, Cu and Zn in all seasons of the year.

Native grasses from northeastern Mexico, such as Aristida spp., Bouteloua gracilis (Thurb), Cench... more Native grasses from northeastern Mexico, such as Aristida spp., Bouteloua gracilis (Thurb), Cenchrus incertus (M.A. Curtis), Hilaria berlangeri (Steud. Nash), Panicum hallii (Varsey), Setaria macrostachya (H.B.K.), and Cenchrus ciliaris (L.), an introduced grass, that are consumed by range goats were evaluated to estimate seasonal CP, lignin, Ca, P, K, Mg, Na, Cu, Fe, Zn, Mn contents, and the rate and extent of DM digestion. The in situ nylon bag technique was used to estimate effective digestibility/degradability of DM (EDDM). Potential mineral intake by an adult range goat consuming these grasses was also estimated. The CP content in all grasses was significantly different between seasons. P. hallii had high annual mean CP contents (12%) and Aristida spp. (6%) was low. The native grasses B. gracilis (9%, annual mean), S. macrostachya (10%) and C. incertus (8%) had CP values comparable to the introduced grass C. ciliaris (9%). Lignin contents in all grasses were also significantly different between seasons. Aristida spp. had high annual means (10%) and H. berlangeri was low (6%). With the exception of H. berlangeri, all grasses had higher lignin contents (annual means) than C. ciliaris (6%). The EDDM in all grasses was significantly different between seasons. C. incertus (45%, annual mean) had the highest EDDM, while Aristida spp. (26%) was lowest. During spring and autumn, EDDM in all grasses was higher than in the other seasons. P. hallii, H. berlangeri and C. incertus had comparable EDDM values to C. ciliaris (40%) in all seasons. It was estimated that an adult range goat consuming the studied grasses, could eat sufficient amounts of Ca, Fe, and K (except for K from Aristida spp. in winter and summer), but of Na, Zn and Mn only in spring and autumn, and of Cu only in autumn. The P and Mg contents were marginally deficient in most grasses and in all seasons. The native grasses P. hallii, S. macrostachya, B. gracilis can be considered valuable grasses for goats on the range, because of their relatively high CP contents, and C. incertus, P. hallii and H. berlangeri because of their relatively high EDDM values, comparable to C. ciliaris. However, range goats consuming these grasses need to be supplemented with P and Mg in all seasons, with Na, Zn and Mn in winter and summer, and Cu in winter, spring and summer seasons.

During a period of 15 weeks (July through November 1989), 40 lambs (Rambouillet XPelibuey; 25 cas... more During a period of 15 weeks (July through November 1989), 40 lambs (Rambouillet XPelibuey; 25 castrated males and 15 females) were randomly grouped among five energy treatment levels (five males and three females per treatment level). The energy supplement ranged from 0.8% to 2.0% of body weight (BW), adjusted weekly. After the morning supplement feeding, lambs were allowed to graze freely for 7-9 h in a buffelgrass (Cenchrus ciliuris) pasture. Male lambs were harnessed for total collection of feces, during the last 10 days of the study. Total organic matter and crude protein intakes increased (PC 0.05) with an increase in energy supplementation. Average daily gain of lambs also increased (P<O.O5) with an increase in the level of energy in the diet. The regression of metalizable energy (ME) intake (kcal per kgo.75 per day) on BW gain resulted in an estimated daily ME requirement for maintenance of 85.9 kcal per kg " .75, and for gain was 0.54 kcal ME per g gain per kg " .75. Maximum growth of lambs was 147 g per day with a level of energy supplementation of 2.0% of BW. Even though there was a linear response in BW gain of lambs due to energy supplementation, the economics of supplementation response were worthy for the level of supplementation of 0.8% BW, with the type of supplement used in this study. Thus, to reduce the cost of supplementation of grazing lambs in a buffelgrass pasture it is recommended to include sources of high energy in the supplements such as fats or oil.

This study was conducted to estimate and compare the organic matter (OM), energy and mineral inta... more This study was conducted to estimate and compare the organic matter (OM), energy and mineral intakes of grazing lambs in a buffelgrass pasture during 1 year. Vegetation in the study area (10 ha) consisted mainly of buffelgrass (70% of covered area) and shrubs such as blackbrush (Acacia rigidula), palo Verde (Cercidium macrum) and cenizo (Leucophyllum texanurn). Shrubs comprised about 27% of the covered area. From January through December 1989, five 3-year-old castrated male lambs (Peli-buey X Rambouillet), weighing about 39 kg, were used to determine monthly total fecal output. Feces were collected during 4 days, after a 5 day adjustment period. The in vitro organic matter digestibility (IVOMD) was determined using esophageal extrusa samples collected from six esophageally fistulated male lambs. Differences (P < 0.05) were found in OM intake (OMI) among months (annual mean, 818.6 g day). In general, lambs consumed more OM during May, June and July. Digestible energy (DE) intake was different (P<O.O5) among months. Annual mean was 1436 kcal DE per day. Lambs consumed more DE during May, and least during February. Crude protein intake was highest (P<O.O5) during July (189.7 g day) and lowest in January (90.1 g day). Neutral detergent fiber intake (NDFI) was also dissimilar (P < 0.05) among sampling periods, the highest NDFI being in July (974.3 g per day) and the lowest in the winter months. Acid detergent fiber intake of lambs followed a similar pattern to that of NDFI. Macro minerals consumed by lambs (K, Ca, Mg and Na) were in general higher (P < 0.05) during the summer months compared with other months. Trace minerals (especially Cu and Fe, Zn and Mn) consumed by lambs also varied seasonally. In general, the results of this study indicate that only during the summer months do lambs consume nutrients that meet or exceed their requirements.

An in vivo digestibility trial was conducted to evaluate the influence of shrub leaves on digesti... more An in vivo digestibility trial was conducted to evaluate the influence of shrub leaves on digestion and N retention by Ž. goats. Twelve male castrated Spanish goats 33.1 " 2.4 kg BW were randomly placed in metabolism stalls and assigned to Ž .Ž. Ž .Ž. Ž. three diets four goatsrdiet : 1 control 23% alfalfa hay plus 77% bean straw BS , 2 22% hackberry Celtis pallida plus Ž. Ž. Ž. 78% BS and 3 18% ceniso Leucophyllum texanum plus 18% soapbrush Porlieria angustifolia plus 64% BS. All diets Ž. contained 1.5% N. Diets were offered in two equal portions daily. The DM and CP intakes of goats were similar P) 0.05 Ž. among diets. However, NDF and ADF intakes were lower P-0.05 in goats fed diets with hackberry and ceniso plus Ž. soapbrush than goats fed alfalfa hay. Digestibilities of DM and CP were similar P) 0.05 among goats. Cell wall and its Ž. fractions were digested less efficiently P-0.05 when goats were fed the hackberry and ceniso plus soapbrush diets Ž. instead the alfalfa hay diet. Goats retained N in a manner similar P) 0.05 among diets. Differences on fiber digestion between diets containing alfalfa hay and browse species may be related to the chemical or physical nature of the cell wall. q 1998 Elsevier Science B.V.

The aim of this study was to determine seasonally the nutritive value and fermentability of diets... more The aim of this study was to determine seasonally the nutritive value and fermentability of diets selected by range goats in a thorn shrubland of North México. Esophageal cannulated goats were used to obtain extrusa samples. Samples were collected monthly from February 1999 to December 2000. Intact males fitted with harnesses were utilized for total fecal collection and DM intake determinations. Crude protein, ash and cell wall contents were determined. Macro (Na, Ca, P, Mg, K) and trace elements (Cu, Mn, Zn and Fe) were also estimated. In vitro gas production was performed to estimate rumen kinetics of goat diets. Statistical comparisons were made between seasons. The OM (mean = 84.3%), CP (13.5%), NDF (49.6%), ADF (37.5%) and lignin (12.0%) contents were different (P < 0.05) between periods. Dry matter intake ranged from 58.6 (summer) to 91.7 g kg 0.75 (winter). With exception of P, all minerals were different (P < 0.05) between seasons. Moreover, during all seasons, goats selected diets with sustained amounts of Na, Ca, Mg, K, Co, Zn and Fe. However, Cu and Mn appeared to be insufficient. Significant differences between seasons were obtained in the gas production parameters. Mean values for the gas produced from the insoluble but fermentable fraction b and the constant rate of gas production c were 33.0 ml/200 mg OM and 5.6% h −1 , respectively. Dietary CP was adequate to meet goat requirements in all seasons. However, a regime of Cu and Mn supplementation must be considered. Negative correlations between cell wall constituents and in vitro gas parameters may indicate the detrimental effect such compounds exert on gas production. Differences registered in cumulative gas production and fraction c permit to identify the differences of nutritive value of the diets selected by animals throughout seasons.

The study was conducted to estimate and to compare the monthly variation of nutrient content of d... more The study was conducted to estimate and to compare the monthly variation of nutrient content of diets of deer. During 1989, samples of plant species were collected and pooled, according to the botanical composition of feces to simulate the monthly diet of deer. Collections were carried out in four ranches (about 12 000 ha) located in the state of Nuevo Le6n. Two diets in each ranch were evaluated for CP, neutral detergent fiber (NDF), acid detergent fiber (ADF), insoluble nitrogen in acid detergent fibre (INADF), in vitro dry matter digestibility (IVDMD), macro and trace minerals. Deer consumed diets with a high content of browse species (annual mean 94.2%). Forbs represented 5.2% and grasses 0.6% of the total composition. The crude protein (CP) in diets varied (P < 0.01) throughout the year (annual mean 15.1%). The IVDMD was low during all months (annual mean 39.9%). High levels of the shrub Acacia rigidula (about 50.0%) which had high levels of condensed tannins (about 15.0%) may negatively influence the in vitro digestion of DM. Calcium, Mg, Na and K concentrations in deer diets were in adequate amounts to satisfy ruminant requirements. Phosphorus levels in diets were extremely low during all months. Conversely, higher concentrations of P in feces may indicate that deer had consumed more forbs than those determined by microhistology in feces. Although deer requirements of trace elements are unknown, they selected diets with concentrations of Fe, Mn and Cu to cover beef cattle requirements. However, Zn was the most limiting trace element appearing at marginal levels in diets during 6 months (summer and fall). It is recommended to managers and owners to open forest canopy in the range to allow an increase of forbs and native grass diversity and density with its associated increased nutritional value.

The legumes Acacia peninsularis (Brit. L. Rose) Standley; Cercidium floridium Benth; Mimosa xanti... more The legumes Acacia peninsularis (Brit. L. Rose) Standley; Cercidium floridium Benth; Mimosa xantii, Gray; Pithecellobium confine Standley and Prosopis sp. Torr. and non-legumes Bursera microphylla Gray (Burceraceae); Cyrtocarpa edulis (Brand) Stand (Anacordiaceae); Lippia palmeri, S. Wats (Verbenaceae); Opuntia cholla, Weber (Cactaceae) and Turnera diffusa Wild (Turneraceae) were evaluated in their mineral content. Shrubs were collected from 16 linear transects of 30 m. Collections were carried out in each season during three consecutive years. Potential mineral intake of range goats consuming these shrubs was also estimated. Non-legumes were highest in Na content than legumes in all seasons. Both legumes and non-legumes were lower in K and Cu, whereas Na and Fe were highest during spring than in other seasons. In summer, Ca was lower and P was highest in all plants. Levels of Ca were nine times higher than requirements for range ruminants. Potential intake of Ca, Mg, K, Na, Mn and Fe by range goats consuming these shrubs was sufficient to satisfy their requirements. However, consumption of P, Cu, Zn was low. It is concluded that range goats grazing these shrub species must be supplemented with P, Cu and Zn throughout the year in order to sustain goat productivity.

Ž. Ž. Ž Leaves from the shrubs blackbrush acacia Acacia rigidula , palo verde Cercidium macrum , ... more Ž. Ž. Ž Leaves from the shrubs blackbrush acacia Acacia rigidula , palo verde Cercidium macrum , and huisache Acacia. Ž. farnesiana were evaluated as protein supplements in low-quality buffelgrass Cenchrus ciliaris straw-based diets for sheep Ž. Ž. using in vivo Trial 1 and in situ Trial 2 digestibility trials. Leaves were collected in Marin, Nuevo Leon, Mexico. In Triaí Ž. 1, the four diets that contained approximately 1.5% N consisted of: 1 control—26% alfalfa hay plus 74% buffelgrass straw Ž. Ž. Ž. Ž. BS ; 2 30% blackbrush acacia plus 70% BS; 3 16% palo verde plus 84% BS; and 4 21% huisache plus 79% BS. Ž. Ž. Twelve sheep Pelibuey= Rambouillet, average 37.5 kg BW were fed the four diets three sheep per diet in two equal Ž. Ž. portions daily 0800 and 1600 in addition to approximately 400 g of a sorghum grain-based supplement 11%, CP at 0800 Ž. h. In Trial 2 the rate and extent of dry matter DM and N loss from nylon bags for alfalfa hay, blackbrush acacia, palo verde, and huisache was evaluated using four ruminally cannulated sheep in a 4 = 4 Latin square experiment. In Trial 1, nutrient digestibilities were low in sheep fed the blackbrush diet compared with the other three diets. Moreover, sheep fed the blackbrush diet retained less N than sheep fed the other diets. Results of Trial 2 indicated large differences in the ruminal degradability among the four species. Alfalfa hay, palo verde and huisache exhibited rapid rumen digestibility of DM and CP compared with blackbrush. Tannins from blackbrush may have negative effects on N and fiber digestibility and N retention by sheep. However, low tannin shrubs such as palo verde and huisache consumed at low levels, influenced nutrient digestibility and N retention of sheep in a manner similar to alfalfa hay. q 1998 Elsevier Science B.V.