Saúl Rojas-Hernández

The chemical composition and in vitro digestibility evaluation of almond tree ( Prunus dulcis D. A. Webb syn. Prunus amygdalus ; var. Shokoufeh) leaves versus hulls and green versus dry leaves as feed for ruminants

The current study aimed to evaluate the chemical composition and in vitro digestibility of almond tree (Prunus dulcis D. A. Webb syn. Prunus amygdalus; var. Shokoufeh) leaves versus hulls, and green versus dry leaves as feed for ruminants. The fresh green almond hulls (GAH) and leaves (GAL) were harvested and spread under a shade to dry. Dry almond leaves (DAL) were collected from under the trees where as dry almond hulls (DAH) were collected 4xa0weeks after harvesting the fresh samples. The chemical composition of substrates was determined using standard approaches and the metabolisable energy (ME), in vitro dry matter (DMD) and in vitro organic matter (OMD) digestibility were measured using the in vitro gas production (GP) technique. The GAL contained 81xa0gxa0crude protein (CP)xa0kg−1 DM while DAH contained 103xa0gxa0CPxa0kg−1 DM. The CP was higher (Pxa0=xa00.0003) in dry (leaves and hulls) than in green (leaves and hulls) samples. The ash content ranged from 99.2 to 181.5xa0gxa0kg−1 DM in DAH and DAL, respectively, (Pxa0=xa00.0041). The ether extract content ranged from 27 for DAH to 65xa0gxa0kg−1 for DAL (Pxa0=xa00.0018). The acid detergent fibre and neutral detergent fibre content ranged from 185 to 304 and 444 to 620xa0gxa0kg−1 DM (Pxa0=xa00.04), for GAL and DAH, respectively. The DAH had the highest (Pxa0=xa00.0001) GP24 and GP96. The DAH had the highest (Pxa0=xa00.0001) potential GP (i.e., b), while the GP rate was highest for GAL and GAH (Pxa0=xa00.034), ME was highest for DAH (Pxa0=xa00.0001), and in vitro OMD was highest for DAH (Pxa0=xa00.0001). The highest DMD (Pxa0=xa00.0001) values were obtained with DAH followed by GAL, DAL and GAH, respectively. It can be concluded that almond hulls and leaves have a good nutritional potential to cover the maintenance nutrient requirements of small ruminants. Almond hulls and leaves can also be used as supplement to low quality mature pasture and/or crop residues. However, more studies are warranted to better characterize these feeds in in vivo animal feeding trials.

Productive response of lambs fed Crescentia alata and Guazuma ulmifolia fruits in a tropical region of Mexico

In vitro gas production with and without polyethylene glycol (PEG) of the fruits of Crescentia alata and Guazuma ulmifolia was evaluated, the degradation kinetics of lamb diets with added fruit of the tree was determined, and the ration intake and growth rate of lambs fed these diets were measured. Twenty-five entire male lambs of 23.5u2009±u20090.44xa0kg body weight were used and distributed in treatments: T0 (control without fruit); T1 and T2, 15 and 30xa0% of the fruit of C. alata; and T3 and T4, 15 and 30xa0% of the fruit of G. ulmifolia. Data variables chemical composition, fermentation kinetic, and digestibility in vitro were analyzed by a completely randomized design and data production response factorials design of five treatments by three evaluation periods. The total phenolic content (TP) (23.0xa0g/kg DM) was higher (Pu2009<u20090.01) in the fruits of G. ulmifolia. The addition of PEG increased (Pu2009<u20090.05) in vitro gas production (156.6xa0mL/g DM) in fruits of G. ulmifolia. In the fermentation kinetics, the total gas volume was higher (Pu2009<u20090.01) at T0 (bu2009=u2009293xa0mL/g DM), and the rate of degradation (c) but Lag time (tlag) was not different. In animal response, total dry matter intake was higher in lambs that received T4 (1.35xa0kg), and the daily weight gain and feed conversion did not differ (Pu2009>u20090.05) among lambs receiving the treatments. Thirty percent G. ulmifolia fruit added in the diet increased dry matter intake and improved feed conversion but did not increase weight gain.

Prevalence of bovine subclinical mastitis, its etiology and diagnosis of antibiotic resistance of dairy farms in four municipalities of a tropical region of Mexico

A region-wide survey was conducted in the tropical area of Tierra Caliente, State of Guerrero, Mexico to estimate the prevalence of subclinical bovine mastitis (SCM), distribution of mastitis pathogens, and in vitro antimicrobial susceptibility of different mastitis pathogens in dairy farms. In total, 1036 quarter milk samples were obtained from 259 cows at 87 different dairy farms. Collected quarter milk samples were submitted for California Mastitis Test (CMT), bacteriological examination, and testing for antimicrobial susceptibility. Overall prevalence of SCM in the studied area was 20.5xa0%. Prevalence in the different regions was as follows: 28xa0% in Arceliaxa0municipality, 21xa0% in Tlalchapaxa0municipality, 19.4xa0% in Pungarabatoxa0municipality, and 14.3xa0% in Finch Cutzamalaxa0municipality. Of all positive isolates, 97.5xa0% were Gram-negativexa0bacteria. Moreover, of all positive isolates, 37.5xa0% were Proteus vulgaris, 25xa0% Salmonella spp., 12.5xa0% Enterobacter aerogenes, and 10xa0% Escherichia coli. Klebsiella pneumonia and E. coli were sensitive for netilmicin antimicrobial. However, E. coli was sensitive for pefloxacin and gentamicin with a sensitivity for pefloxacin for E. aerogenes, while Staphylococci were sensitive for gentamicin and dicloxacillin. It could be concluded that practices such as the implementation of mastitis control programs, improved milking hygiene together with an intramammary treatment with netilmicin, pefloxacin, and gentamicin antimicrobials should be considered for mastitis prevention in the study area of Tierra Caliente, in the tropical area of Guerrero, Mexico.

Fruits chemical composition and potential ruminal digestion of nine tree species in dry tropic region of Mexico

Chemical composition, in vitro gas production (GP), in vitro dry matter (DMD) and organic matter (OMD) digestibility, metabolizable energy (ME), gas yield (GY24h), short chain fatty acids (SCFA) and microbial mass production (MMP) were measured in fruits of nine trees species, using in vitro gas technique with and without polyethylene glycol (PEG:MW-4000) as chelating tannins agent. The fruits with the highest protein content (Pxa0<xa00.001) (135.5–196.0xa0g/kg DM) were Leucaena esculenta, Pithecellobium acatlense, Acacia farnesiana and Enterolobium cyclocarpum, total phenols (Pxa0<xa00.001) (349.8–553.1xa0g/kg DM) Lysiloma divaricata, A. farnesiana and Caesalpinia coriaria and condensed tannins (Pxa0<xa00.001) L. divaricata and E. cyclocarpum with 95.7 and 71.7xa0g/kg DM, respectively. The highest DMD in fruits of C. coriaria, Pithecellobium dulce, A. farnesiana and L. esculenta (Pxa0<xa00.001). The GP, OMD, ME, GY24h, SCFA and MMP, was different (Pxa0<xa00.0001) between fruit trees. The PEG increased (Pxa0<xa00.0001) the GP, ME, GY24h and SCFA in the fruits of Gliricidia sepium, L. esculenta and C. coriaria. In conclusion, the nutritional composition and in vitro fermentation parameters differs between fruits. The increase in PEG increased the value of GP, ME, OMD, GY24hxa0and SCFA, indicating that the fruits contain phenolic compounds with biological activity that precipitate proteins.

Antibacterial activities of tannic acid against isolated ruminal bacteria from sheep

This present study was conducted to evaluate the antimicrobial effects of tannic acid (TA) against isolated ruminal bacteria from adult sheep. Rumen samples were collected from two (2) adults sheep, and a total of nine (9) ruminal bacteria were isolated from the sample. The sensitivity of the ruminal bacteria isolates to 0.63, 1.25, 2.50, 5.00 and 10.00u202fmgu202fTA/mL of growth medium was determined using clearance zone (CZ) of Kirby-Bauer disc diffusion susceptibility test. There was observable increase in the sensitivity of all bacterial isolates as the level of TA increases. Not all bacterial isolates have the capacity to tolerate more than 1.25u202fmgu202fTA/mL. The result shows that only 20% of the bacterial isolates had the capacity to tolerate 0.63 and 1.25u202fmg of tannic acid per liter. This concentration of tannic acid would be equivalent to 2% tannin in the diet of ruminant. Our findings shows that increase in concentration of tannic acid completely inhibited the ruminal bacteria from the sheep rumen.

Susceptibility of ruminal bacteria isolated from large and small ruminant to multiple conventional antibiotics

The pivotal aim of the present context was to isolate diversified group of bacteria from the ruminants and to evaluate their antibiogram pattern against 22 antibiotics of 14 different classes. The bacterial isolates from small and large ruminant (sheep, cattle and calves) were isolated from the rumen based on various colonies morphology, and subjected for preliminary antibiotics susceptibility assay using disc diffusion method. The most sensitive isolates (based on zone of inhibition) were selected for determining the minimum inhibitory concentration (MIC) of each antibiotic ranging from 1 to 256u202fμg/mL. Results revealed the concentration dependent growth inhibitory property of antibiotics a species-specific process. The maximum tolerable concentration (MTC) of each antibiotic was further determined using disc diffusion method, and results exhibited that the tolerance nature of ruminal isolates to antibiotics is a species-specific mechanism. Based on the MIC and MTC values of antibiotics, amikacin, ciprofloxacin, and amoxicilline were observed to be the most potent antibiotics in terms of inhibiting the growth of ruminal isolates. In brief, the findings of the current study showed that despite the overexploitation of antibiotics as additives in the animals feed, most of the ruminal isolates are sensitive to multiple conventional antibiotics tested. The growth inhibitory trait of antibiotics proves these antimicrobials a propitious agent against the pathogenesis of ruminal isolates in livestock.