Kappa-casein genotyping in tropical milking Criollo and its association to milk production and composition.

Caseins are abundant proteins in milk and found in four types (αS1, αS2, ß, and κ). There is substantial variation in the allelic and genotypic frequencies of the κ-casein gene in different cattle breeds, although the tropical milking Criollo (TMC) has not yet been investigated. The aim was to determine the allelic and genotypic frequencies in the κ-casein gene for two alleles (A and B) in TMC and further investigate its association to milk production and composition. A total of 180 TMC females were genotyped from blood samples. κ-Casein genotyping was performed using restriction fragment length polymorphism (RFLP) after polymerase chain reaction (PCR)-based amplification of genomic DNA. Allele frequencies were 0.39 for A-allele and 0.61 for B-allele (P < 0.05). Genotype frequencies were 0.09 (AA), 0.60 (AB), and 0.31 (BB) (P < 0.05). The κ-casein genotype in TMC cows did not affect milk yield or composition. In sum, the TMC has high frequencies of the B-allele and AB/BB genotypes, although there are no association of such genotypes and milk traits.

A multi-criteria approach to identify favorable areas for goat production systems in Veracruz, México.

This research identifies favorable areas for goat production systems in the state of Veracruz, Mexico. Through the use of the analytic hierarchy process, layers of biophysical and soil information were combined to generate a model of favorability. Model validation was performed by calculating the area under the curve, the true skill statistic, and a qualitative comparison with census records. The results showed the existence of regions with high (4494.3 km2) and moderate (2985.8 km2) favorability, and these areas correspond to 6.25 and 4.15%, respectively, of the state territory and are located in the regions of Sierra de Huayacocotla, Perote, and Orizaba. These regions are characterized as mountainous and having predominantly temperate-wet or cold climates, and having montane mesophilic forests, containing pine, fir, and desert scrub. The reliability of the distribution model was supported by the area under the curve value (0.96), the true skill statistic (0.86), and consistency with census records.

Effect of selective anthelmintic treatments on health and production parameters in Pelibuey ewes during lactation.

A study was conducted from December to April 2013, with the aim of evaluating a system of selective antiparasitic treatments using the FAMACHA© color chart compared with a conventional suppressive deworming system every 30 days in Pelibuey ewes during lactation. For the study, 54 ewes were used. They were randomly divided into two groups: FAMACHA and chemical treatments. The ewes in the first group received selective treatment depending on the ocular mucosa coloration (FAMACHA) and body condition score (BCS), while in the second group (chemical) all the animals remained under routine deworming every 30 days. Fecal nematode egg counts, proportion of third-stage trichostrongylid larvae, body condition, coloration of the ocular mucosa, and packed cell volume in the ewes were determined, while in lambs only body weight (BW) was recorded. No significant differences (p > 0.05) were observed in any of the studied variables between groups; however, the use of antiparasitic drugs was reduced during the experimental period in the FAMACHA group and no deaths of lambs or ewes were recorded. The results indicate that during the lactation of ewes, a strategy of selective treatments can be implemented without showing deterioration in major health and productive parameters of these animals.

Anthelmintic resistance in gastrointestinal nematodes from grazing beef cattle in Campeche State, Mexico.

Production of beef cattle is one of the most important economic activities in Mexico. However, anthelmintic resistance (AR) has affected animal productivity. The aim of this study was to determine the presence of AR in gastrointestinal nematodes (GIN) of beef cattle in Candelaria Municipality of Campeche State, Mexico. Sixty-five-month-old beef calves were selected for the faecal egg count reduction test (FECRT) and the inhibition of egg hatch (IEH) assay. These parameters were determined using albendazole (benzimidazole, BZ), ivermectin (IVM, Macrocyclic lactone, ML) and levamisole (LEV, imidazothiazole, IMZ). Allele-specific PCR (AS-PCR) confirmed polymorphisms at codon 200 of isotype 1 of the ß-tubulin gene of Haemonchus placei. The results showed 32 % IVM toxicity by FECRT, indicating problems of AR in the GIN population. In contrast, BZ and LEV showed 95 and 100 % toxicity, respectively, against GIN from infected beef calves. The infective larvae (L3) of Cooperia, Haemonchus and Oesophagostomum were identified before anthelmintic treatment, and Cooperia L3 larvae were identified after treatment with IVM. The IEH assays had lethal dose 50 (LD50) of 187 nM to BZ, confirming the ovicidal effect of BZ. In contrast, the LD50 for LEV and IVM were 3.3 and 0.4 mM, respectively. The results obtained by AS-PCR confirmed two DNA fragments of 250 and 550 bp, corresponding to the resistant and susceptible alleles in the H. placei population. The nematode Cooperia showed AR against IVM, while the toxicity effect of BZ against GIN with both FECRT and IEH was confirmed.

Coat Color in Local Goats: Influence on Environmental Adaptation and Productivity, and Use as a Selection Criterion.

This paper aims to review, systematically synthesize, and analyze fragmented information about the importance of coat color in local goats and its relationship with productivity and other important traits. Topics on current research on color expression are addressed, the relationship that has as a mechanism of environmental adaptation, its relationship with the production of meat, milk, and derivates, and the economic value of this characteristic. The use of this attribute as a tool to establish selection criteria in breeding programs based on results reported in the scientific literature is significant, particularly for low-income production systems, where the implementation of classic genetic improvement schemes is limited due to the lack of productive information, which is distinctive of extensive marginal or low scaled production systems around the world.

Status quo of genetic improvement in local goats: a review.

This review aims to summarize and synthesize the fragmented information available on the genetic improvement of local goats (criollo, indigenous, native) on the American and other continents, where populations with these goats have an important role in food security and the economy of rural communities, as well as in conservation of biodiversity and productivity improvement. Topics such as the current state of goat production globally, conservation programs, resistance to parasites and diseases, use of phenotypical characteristics and genomic information, and molecular markers for genetic improvement are addressed. The main challenges, opportunities, and limitations described in recent literature concerning local goats in the immediate future are discussed.

Protein Supplementation as a Nutritional Strategy to Reduce Gastrointestinal Nematodiasis in Periparturient and Lactating Pelibuey Ewes in a Tropical Environment.

The study was carried out to evaluate the effect of energy and protein supplementation on parasitological and hematological response during peripartum and lactation of productive and non-productive Pelibuey ewes in a tropical environment. Forty-eight Pelibuey ewes aged 3-5 years and with a body weight of 31 ± 5 kg were used. Four groups of 12 ewes, including non-pregnant and productive ewes, were formed. A factorial treatment design was formulated, where two levels of energy (low, 9.6 MJ/kg, n = 24; and high, 10.1 MJ/kg, n = 24) and two levels of protein (high, 15% crude protein in diet, n = 24; and low, 8% crude protein in diet, n = 24) were studied. Fecal and blood samples were collected to determine the fecal egg count (FEC) of gastrointestinal nematodes (GIN), packed cell volume (PCV) and peripheral eosinophil (EOS) count. These variables were rearranged with respect to the lambing date in a retrospective study. The high dietary protein level had a significant effect on reducing the FEC and increasing the PCV of ewes during lactation, in comparison with animals fed with the low protein level. Differences in the study variables were attributed to physiological stage. Lactating ewes showed the highest FEC values (2709 ± 359 EPG), the lowest PCV values (21.9 ± 0.7%) and the lowest EOS (0.59 ± 0.6 Cells × 103 µL). It is concluded that high levels of dietary protein improve the hematological response and reduce the FEC in Pelibuey ewes under grazing conditions. The non-pregnant ewes maintained some resilience and resistance to GIN infection compared to productive ewes.

Haemonchus contortus infection induces a variable immune response in resistant and susceptible Pelibuey sheep.

The immune response and phenotypic characteristics of Pelibuey lambs were analysed after the induction of a Haemonchus contortus trickle infection. Male lambs (n = 29; 20 kg live weight) were infected with 100 H. contortus infective larvae per kg of live weight on day 3, 5 and 7 of the experiment. The number of eggs per gram (epg), seven haematological parameters and the immunoglobulin A (IgA) level were analysed for 56 experimental days. In addition, histopathological samples from the fundic abomasal region and the relative expression of 10 immune-related genes from 15 infected and three non-infected lambs were analysed at day 0 and 49 of the experiment. The epg count and some haematological parameters (leucocytes, red blood cells, haemoglobin and total protein) with statistically significant differences (P < 0.01) were used to identify nine resistant and 20 susceptible lambs (1166 ±â€¯1071 and 3171 ±â€¯1463 epg, respectively). Moreover, acute infiltration of immune cells and parasitic granuloma formation were observed in susceptible lambs; the resistant group had moderate inflammatory cell infiltration. With respect to relative gene expression, resistant lambs showed upregulation (P < 0.001) of 10 genes, from 2.2 to 15.99 fold. Moreover, there was a strong indirect correlation (P < 0.05) between the epg count and interleukin 5 (IL5) gene expression. By contrast, there was an average 0.34 fold downregulation in nine of the immune-related genes (P ≤ 0.05) in susceptible lambs (the only exception was Fc fragment of IgE receptor Ia [FCER1A] upregulation). In addition, there was a direct correlation (P ≤ 0.05) between the epg count and the expression of IL8, which encodes an inflammatory chemokine. In conclusion, this study showed differential IL5 and IL8 gene expression during haemonchosis in resistant and susceptible Pelibuey lambs, respectively, together with a variable immune response based on histopathological and haematological parameters.

Effect of an Arthrobotrys musiformis (Fungi: Orbiliales) culture filtrate on the population of gastrointestinal parasitic nematode eggs in faeces of grazing lambs.

This study assessed the anthelmintic activity of the oral administration of a free-spore culture filtrate of the nematophagous fungus (NF) Arthrobotrys musiformis (M-10) on gastrointestinal parasitic nematodes (GIN) in naturally infected lambs. The fungus was grown on potato-dextrose agar plates (PDA) and transferred to a fermented rice medium (FRM). After 40-day incubation the total amount of FRM with the growing fungi was transferred to a flask shaker with distilled water for a 24 h period. The fungus was centrifuged and filtered. Three groups of six naturally-infected lambs (>1000 epg) each were treated once as follows: Group 1) 63.8 mg/kg A. musiformis culture filtrate (CF) (per os); Group 2) Levamisole 7.5 mg/ml (intramuscularly), Group 3) 15 ml of distilled water (per os). Faecal samples were individually collected on days -2, 0, 2, 4, 6, 8 and 10 after treatment. For each experimental group, mean egg shedding was calculated and transformed (log 10 [epg + 1]). Means between the fungal filtrate group and the negative control were analysed using a T-Student Test. The faecal egg count reduction test (FECRT) was performed in groups treated with CF and Levamisole in relation to the control group (water) were 36.8-57.4% and 89-95.4%, respectively., although due to the difference between groups, no statistical significance was found (p > 0.05). The use of A. musiformis CF appears to be a good alternative treatment, although, more studies should be performed to establish the use of these fungal products as potential tools for GIN control.

Butlerius butleri (Nematoda: Diplogasteridae) Feeds on Haemonchus contortus (Nematoda: Trichostrongylidae) Infective Larvae and Free-Living Nematodes in Sheep Faecal Cultures Under Laboratory Conditions: Preliminary Report.

AIM: This study assessed the feeding activity of the predatory nematode Butlerius butleri on the infective larvae of the sheep parasitic nematode Haemonchus contortus (Hc-L3) and on two free-living nematodes Panagrellus redivivus (Pr) and Rhabditis sp. (R) in sterile sheep faecal cultures. MATERIALS AND METHODS: A bioassay was carried out in sheep faecal cultures, where predatory and prey nematodes were put together to assess the predatory behaviour on the different nematodes. Faecal cultures (n = 9) were set up in different treatments as follows: Treatments 1, 2 and 3 contained 20 specimens of B. butleri and 2000 Hc-L3, Pr and R, respectively; treatments 4, 5 and 6, contained only 2000 Hc-L3, Pr and R, respectively, as control groups. Treatment 7 contained 20 B. butleri as control. All treatments were incubated at room temperature for 30 days. The average number of nematodes recovered from each treatment was obtained and the reduction rate with respect to their corresponding control was estimated. Data were analysed using an ANOVA test using a completely randomised design in the SAS programme. RESULTS: Butlerius butleri reduced the Hc-L3, population by 91.8%, whereas its population increased 131.6 times. The interactions between B. butleri and Pr and R resulted in 80.9% and 62.5% nematode reduction and B. butleri increased its populations 268.3 and 82.7 times, respectively. This experiment was performed only once, so this can be considered a preliminary report at this time. CONCLUSION: This study provides evidence for the first time that B. butleri feeds on one of the most economically important nematodes of small ruminants, Hc-L3.

High energy levels in the diet reduce the parasitic effect of Haemonchus contortus in Pelibuey sheep.

Nutritional aspects modulate the parasitological and immune response in infected sheep. The aim of the present study was to evaluate the parasitological and humoral immune response of Pelibuey sheep experimentally infected with Haemonchus contortus that were fed diets with two different energy (n = 12) and protein (n = 12) levels. Twenty-four Pelibuey lambs infected with H. contortus were evaluated over 12 weeks. An additional six animals were considered as a control group. Fecal egg count (FEC) was determined, in addition to packed cell volume (PCV), total plasma protein (TPP), and immunoglobulin levels (IgA, IgG, and IgM) by indirect enzyme-linked immunosorbent assay (iELISA). Data were analyzed by repeated measures over time. The lambs that received a high-energy (HighE) diet had the lowest FEC (P < 0.01) regardless of whether they received a high (HighP) or low (LowP) level of protein. The effect of energy level was also observed over time: FEC values decreased and PCV and TPP values increased. Higher immunoglobulin levels were obtained for females (P < 0.05) than males yet, overall, the energy and protein levels of the diets did not affect the response of the immunoglobulins. Over time, however, an increase in IgG and IgM was observed, whereas the IgA level remained basal.

Comparison of four nonlinear growth models in Creole chickens of Mexico.

Animal growth is a complex and dynamic process that involves physiological and morphological changes from hatching to maturity. It is defined as the increase in body size per time unit. Mathematical functions, called growth models, have been used to explain growth patterns. The aim of this study was to compare the Gompertz-Laird, logistic, Richards, and Von Bertalanffy growth models to determine which best fits the data of the Creole chickens (CC). Three hundred forty-seven CC were individually weighed from hatching until 177 D of age. Birds were fed a starter diet (0-18 D of age; 19% crude protein (CP) and 3,000 kcal of ME/kg) and grower diet (19-177 D of age; 18% CP and 2,800 kcal of ME/kg). Data were analyzed using PROC NLIN to fit the nonlinear growth curve. The coefficient of determination (R2), Akaike information criteria (AIC), and Bayesian information criteria (BIC) were used to compare the goodness of fit of the models. The Von Bertalanffy (R2: 0.9382, 0.9415; AIC: 2,224.1, 2,424.8; BIC: 2,233.5, 2,434.3, for females and males, respectively) was the model that best explained growth of the birds. On the other hand, both the Gompertz-Laird and logistic models overestimated hatching BW and underestimated the final BW of CC. Females reached age of maximum growth faster than males. The asymptotic weight was higher in males (3,011 g) than in females (2,011 g). Body weight at inflection point was 892 g at 64 D of age for males and 596 g at 54 D for females. In conclusion, the best fit of the data was obtained with the Von Bertalanffy growth model; the information is intended to serve as the basis for utilizing CC.

Zoometric measures and their utilization in prediction of live weight of local goats in southern México.

Objectives of this study were: (a) to compare live weight (LW) and zoometric measures (ZM) of local goats in two locations, (b) to fit the best regression equation for goat LW prediction using ZM. LW, body length (BL), trunk length (TL), withers height (WH), hearth girth (HG), rump width (RW), rump length (RL), head length (HL), head width (HW), and ear length (EL) were measured in 318 Local does in Amatepec and Tejupilco, State of Mexico. Statistical methods included student's "t" tests for comparison of means, and correlation, principal components (PC), and multiple linear regression analyses. To evaluate the goodness of fit for LW prediction models the R(2) value was used as a criterion. Differences (P ≤ 0.05) were found between does of Amatepec and Tejupilco in LW, BL, TL, HG, RL, HL, HW, and EL. In Amatepec, LW was correlated with HG, BL, and HW (P ≤ 0.01), whereas in Tejupilco LW was correlated with HG, BL, TL, and HW (P ≤ 0.01). From the Amatepec measures 5 PC were extracted, and which in a multiple regression analysis explained 83.3 % of the total variance, whereas from Tejupilco 4 PC were extracted, and which in a multiple regression analysis explained 82.4 % of the total variance. The best regression model to predict doe LW in Amatepec included TL, HG, RW, and HW, whereas for Tejupilco the best model included BL, HG, HW, and EL. It is concluded that: (1) Amatepec does surpass those of Tejupilco in LW and most ZM, (2) there are reliable ZM for predicting LW of local does in both locations, HG, and HW being common measures for both populations.

Evaluation of strategic and selective anthelmintic treatments on Pelibuey ewes in Cuba / Evaluación de tratamientos antihelmínticos estratégicos y selectivos en ovejas Pelibuey en Cuba / Avaliação de tratamentos anti-helmínticos estratégicos e seletivos em ovelhas Pelibuey em Cuba

Background: gastrointestinal parasitism is an important limitation for sheep production in Cuba. This situation is worsened by the lack of an effective parasite control strategy. Objective: to assess whether selective and strategic treatments could help achieve a level of control of nematodes similar to systematic drenchings. Methods: an experimental group of 73 Pelibuey ewes was divided into four groups: 1) the Epizoo group (Epizootiological drenching schedule) was dewormed at lambing in the middle of the dry season and at weaning; 2) the FAMACHA© group was treated according to the color of ocular mucosa as indicative of anemia (Categories 4 and 5 of the FAMACHA© color chart); 3) the Chemical group was drenched every three months; and 4) the control group, in which animals remained untreated unless fecal egg count (FEC) was higher than 1500 eggs per gram of feces or the packed cell volume (PCV) was lower than 15%. FECs, body scorings (BCS), hematocrits and color of ocular mucosa (COM) were evaluated monthly. Results: the control group showed the highest FEC and the lowest PCV. We also observed similar levels of FEC and body condition (BCS) in the Epizoo, FAMACHA© and Chemical groups. The PCV in FAMACHA© group was the highest, while no differences were found between the other two groups. Hematocrit had a strong negative correlation (-0.41) with FEC. The FAMACHA© method allowed a dramatic decrease in anthelmintic use. Conclusions: the obtained results suggest that FAMACHA© method could be incorporated as part of an effective parasite control strategy in sheep.

Antecedentes: el parasitismo gastrointestinal constituye una de las principales limitantes para producción de ovejas en Cuba. Esta situación es mucho más grave porque no existe un programa adecuado de control parasitario. Objetivo: evaluar si el uso de un tratamiento antihelmíntico estratégico o selectivo logra reducir los niveles de infestación parasitaria comparado con un sistema de tratamientos químicos sistemáticos. Métodos: se utilizó un rebaño experimental de 73 reproductoras Pelibuey que se dividió aleatoriamente en cuatro grupos: 1) El grupo epizootiológico (Epizoo) se trató al parto, a mediados del periodo seco y al destete, 2) el grupo FAMACHA© se desparasitó en función de la coloración de la mucosa ocular indicativa de anemia (categorías 4 y 5 de la carta de colores FAMACHA©), 3) el grupo Químico: se desparasitó cada tres meses, y 4) grupo control: no recibió tratamiento mientras su hematocrito (PCV) fuera inferior a 15% o la carga parasitaria (FEC) no superara los 1500 huevos por gramo de heces. Con frecuencia mensual se determinó a cada animal el conteo fecal de huevos (FEC), la condición corporal (BCS), el hematocrito (PCV) y la coloración de la mucosa ocular (COM). Resultados: se observaron valores similares para la BCS y el FEC en los grupos Epizoo, FAMACHA© y Químico. El PCV presentó los valores más altos en el grupo FAMACHA© y el grupo Control presentó los más bajos; no se apreciaron diferencias significativas entre los grupos Químico y Epizoo. El grupo control presentó los mayores FEC y los más bajos PCV. El hematocrito tuvo una relación fuerte y negativa (-0,41) con el FEC. El método FAMACHA© propició una disminución en el uso de fármacos antihelmínticos. Conclusiones: los resultados obtenidos sugieren que el método FAMACHA© podría ser incorporado como parte de una estrategia efectiva de control parasitario en ovinos.

Antecedentes: o parasitismo gastrointestinal é uma limitação para a produção de ovinos em Cuba. Esta situação é agravada pela falta de uma estratégia eficaz de controle parasitário. Objetivo: avaliar se os tratamentos seletivos podem ajudar a alcançar um nível de controle de nematóides semelhante a dois tratamentos sistemáticos. Métodos: um rebanho experimental de 73 ovelhas foi dividido em quatro grupos: 1) o grupo Epizoo (Esquema de tratamento epizootiológico) foi tratado no parto, no meio da estação seca e ao desmame, 2) o grupo FAMACHA© foi tratado de acordo com a cor da mucosa ocular (categorias 4 e 5 na cartela de cores FAMACHA©), 3) o grupo químico são vermifugados a cada três meses, e 4) o grupo controle não recebeu tratamento, enquanto seu hematócrito (PCV) fosse inferior a 15% ou a carga parasitária (FEC) não ultrapassasse 1.500 ovos por grama de fezes. A contagem de ovos por grama (FEC) de fezes, o escore da condição corporal (BCS), hematócrito (PCV) e a coloração da mucosa ocular (COM) foram avaliados mensalmente. Resultados: um nível similar de FEC e BCS foram observados nos grupos Epizoo, FAMACHA© y Químico. O PCV apresentou-se maior no grupo FAMACHA© e o grupo Controle teve os valores mais baixos; enquanto nenhuma diferença foi estimada entre os outros dois grupos. O grupo controle apresentou o maior FEC e o menor PVC. O hematócrito teve uma forte correlação negativa (-0,41) com o FEC. O método FAMACHA© permitiu uma diminuição drástica do uso de anti-helmíntico. Conclusões: os resultados sugerem que o método FAMACHA© pode ser incorporado como parte de uma estratégia para o controle de parasitas gastrintestinais em ovelhas.

Variability in the fecal egg count and the parasitic burden of hair sheep after grazing in nematode infected paddocks

This study aimed to evaluate the variability in the fecal egg count (FEC) and the parasitic burden of naive hair sheep after grazing in nematode infected paddocks. The research was carried out in Tabasco, Mexico, during two periods (August and December). In each period 32 lambs were grazed for one month on African star grass (Cynodon plectostachyus) contaminated with gastrointestinal parasitic nematodes. FEC, packed cell volume (PCV) and body weight (BW) were recorded. Gastrointestinal worms were recovered at necropsy. Data were analyzed with the MIXED procedure of SAS using a model of repeated measurements over time. A higher number of Haemonchus contortus worms was found in December (2814±838) than in August (1166±305). The opposite occurred with Cooperia curticei (2167±393 and 3638±441, respectively). The FEC and correlation coefficient in respect to the worm burden were higher in December (6516 ± 1599, r=0.83, respectively) than in August (4364±771, r=0.44, respectively). A high variability in resistance-susceptibility to gastrointestinal nematodes (GIN) occurred in Katahdin × Pelibuey lambs after grazing.

Prevalencia de parásitos gastrointestinales en ovinos sacrificados en un rastro de Tabasco, México / Prevalence of gastrointestinal parasites in slaughtered sheep at a slaughterhouse in Tabasco, Mexico

The objective of this study was to determine the prevalence of gastrointestinal parasitic nematodes in sheep at necropsy at a slaughterhouse in Tabasco, Mexico. Adult parasites from gastrointestinal tract were recovered and preserved in formaldehyde for their later counting and identification. Adult nematodes were separated by species and the final count was transformed to Log + 1 to decrease the variance. GLM procedure using SAS statistic program was performed for data analysis. Provenance, sex, physiological status, and sampling month were considered as the variation sources. From a total sample of 242 slaughtered animals necropsied for monitoring gastrointestinal parasites, 57.4% including Nematoda, Trematoda or Cestoda classes. The main identified species corresponded to Haemonchus contortus in the abomasum. Cooperia curticei, Trichostongylus colubriformis, Strongyloides papillosus and Bunostomum trigonocephalum were found in the small intestine and Oesophagostomum columbianum, and Trichuris ovis in the large intestine. Fasciola hepatica and Moniezia expansa were the Trematoda and Cestoda parasites found in liver and small intestine, respectively with prevalence lower than 7%. The average of the total count of adult nematodes in the gastrointestinal tract of the infested animals was 2175 ± 445. Among the factors studied, the slaughter month and the provenance of the animals affected the prevalence of parasite infestation in sheep at slaughter. The main adult parasites found were H. contortus, C. curticei and T. colubriformis with average counts higher than 1009, 813 and 335, respectively.

El objetivo de esta investigación fue conocer la prevalencia de parásitos en ovinos sacrificados en un rastro en el estado de Tabasco. Se realizó la recuperación y conservación en formol de parásitos adultos presentes en el tracto gastrointestinal, para su posterior conteo e identificación. Los conteos de nematodos adultos por especie se transformaron a Log + 1 para disminuir la varianza, y se realizó el análisis con el procedimiento GLM del SAS en el cual se incluyeron como fuentes de variación: origen, sexo, estado fisiológico y mes de muestreo. De una muestra total de 242 animales sacrificados, se observó que 57.4% se encontraban parasitados con alguna especie de las clases Nematoda, Trematoda o Cestoda. Las principales especies identificadas correspondieron a Haemonchus contortus en abomaso. Cooperia curticei, Trichostongylus colubriformis, Strongyloides papillosus y Bunostomum trigonocephallum en intestino delgado. Oesophagostomum columbianum, y Trichuris ovis en intestino grueso. De los trematodos se encontró Fasciola hepatica en hígado y de los cestodos Moniezia expansa se localizó en intestino delgado con prevalencia menor a 7%. El conteo total de los nematodos adultos en el tracto gastrointestinal de los animales parasitados fue, en promedio, 2175 ± 445. De los factores estudiados, el mes de sacrificio y el origen de los animales afectaron la prevalencia de parasitosis en los ovinos al sacrificio. Los tres principales parásitos fueron: H. contortus, C. curticei y T. colubriformis, con conteos promedio de adultos, superiores a 1009, 813 y 335, respectivamente.

Características físico-químicas de la leche de ovejas Rambouillet bajo manejo intensivo / Physicochemical characteriztics of Rambouillet ewes's milk under intensive management

El propósito de este trabajo fue determinar la composición fisicoquímica de la leche de ovejas Rambouillet manejadas en estabulación. Para tal efecto se utilizaron durante un periodo de lactancia de 12 semanas, 36 ovejas Rambouillet entre 2 y 5 años de edad con un peso promedio de 60 ± 5 kg, que habían parido solamente una cría. Se tomaron muestras de la leche en las semanas 1, 3, 6, 8 y 12, y el análisis físicoquímico se realizó utilizando métodos tradicionales de laboratorio. El análisis estadístico se efectuó utilizando el paquete “R” y teniendo como variables dependientes sólidos totales, grasa, proteína, lactosa, cenizas, acidez real, densidad y pH, mientras que laúnica variable independiente fue etapa de lactancia. Los promedios generales de la composición de la leche fueron: sólidos totales 16,89 ± 2,14; grasa 5,78 ± 2,09; proteína 5,26 ± 0,49; lactosa 4,54 ± 0,35; cenizas 0,92 ± 0,07; acidez real 2,05 ± 0,30; densidad 1,036 ± 2,9 x 10 –3; y pH 6,68 ± 0,17. Se presentaron diferencias significativas (P<0,05) de los componentes de la leche durante el transcurso de la lactancia, excepto en el pH (P>0,05). En sólidos totales, grasa, proteína y densidad hubo un incremento a partir de la semana 6; la lactosa y cenizas tuvieron un decremento en las semanas 12 y 8, respectivamente, mientras que la acidez real aumentó a partir delinicio de la lactancia. Las características fisicoquímicas de la leche de ovejas Rambouillet son semejantes a las que se encuentran en otras razas, por lo que es posible utilizar su leche durante periodos cortos y procesarla con fines industriales, principalmente en quesos.

The aim of this work was to determine the physicochemical composition of Rambouillet ewe’s milk in intensive management for this, 36 Rambouillet ewes, 2-5 years old, with an average body weight of 60 kg, that had given birth to a single lamb, were utilized during 12-week lactation period. Milk simples were taken in weeks 1, 3, 6, 8 and 12 and the physicochemical analysis was performed utilizing traditional laboratory methods. The statistical analysis was carried out utilizing the “R” statistical package with total solids, fat, protein, lactose, ashes, real acidity, density, and pH as dependent variables, and lactation stage as the only independent variable. Overall means for the milk composition were: total solids 16.89 ± 2.14%, fat 5.78 ± 2.09 percent, protein 5.26 ± 0.49 percent, lactose 4.54 ± 0.35 percent, ashes 0.92 ± 0.07 percent, real acidity 2.05 ± 0.30 percent, density 1.036 ± 2.9 x 10 –3 and pH 6.68 ± 0.17. There were significant differences (P<0.05) of the milk components during lactation. except in pH (P>0.05). From week 6 on there was an increase in total solids, fat, protein, and density; lactose and ashes had a decrease in weeks 12 and 8, respectively, whereas real acidity had an increase from week 1 on. Physicochemical characteristics of Rambouilet ewes’s milk are not very different from those found in other breeds, for which it is possible to utilize the milk of these ewes for short periods and process it with industrial purposes, mainly in cheese.

Efecto del tipo de amamantamiento en la actividad ovárica postparto de ovejas pelibuey y tasas de crecimiento de corderos en los primeros 90 días de edad / Effect of Suckling Type on Ovarian Activity of Postpartum Pelibuey Ewes, and Lamb Growing Rate During the First 90 Days After Birth

La finalidad del presente estudio fue determinar el efecto del amamantamiento en la duración del intervalo parto-primera ovulación (IPPO), los cambios de peso corporal (CPC) posparto de las hembras y la ganancia diaria de peso (GDP) y mortalidad (M) de los corderos durante los primeros 90 d posparto en la raza Pelibuey. Cuarenta y dos ovejas multíparas con sus crías se asignaron al azar a uno de tres tratamientos: amamantamiento continuo (AC; n=16), amamantamiento restringido (AR; n= 16) y destete precoz (DP; n= 10). Los corderos en AC permanecieron con sus madres las 24 h del día con amamantamiento ad libitum; en AR, los corderos amamantaron durante 30 min al día (08:00 a 08:30); y en DP, las crías se separaron de sus madres desde los 7 d de nacidos sustituyéndose la alimentación con sustituto de leche. Para eliminar el efecto confundido de la época del año en los resultados obtenidos en el manejo del amamantamiento, se integró un grupo testigo con ovejas no gestantes (OV; n= 15). La eliminación del amamantamiento con el destete total (DP) de los corderos a los 7 d de edad aumentó el número de ovejas que ovularon antes de los 56 d posparto, disminuyó el IPPO y la pérdida de peso de las ovejas (P<0,05), disminuyó la GDP de las crías y aumentó la M de los corderos respecto a AC y AR (P<0,05). El AR disminuyó el IPPO con respecto a AC, mejoró la GDP y disminuyó la M de los corderos con respecto a DP (P<0,05). El AR parece ser el mejor sistema de manejo para un adecuado desarrollo del cordero y reiniciar la actividad reproductiva de las ovejas durante los primeros tres meses posparto.

It was studied the effects of suckling on ewe parturition-first ovulation period (IPPO), changes in post-parturition body weight (CPC), and lamb daily weight gain (GDP) and mortality (M) during the first 90 d postpartum. Forty-two multiparous Pelibuey ewes with lambs were randomly assigned to one of three suckling treatments: continuous suckling (AC; n=16), restricted suckling (AR; n=16) and early weaning (DP; n=10). Ewes and lambs in AC stayed together 24 h a day nursing ad-libitum, ewes and lambs in AR stayed together for only 30 min a day (from 08:00 to 08:30) to nurse, and lambs in DP were permanently separated from their mothers at day 7 after lambing and fed with a milk formula. A blank treatment consisting of non-pregnant ewes (OV; n=15) was included to remove the effect of season on treatments. Early weaning at day 7 after birth increased the number of ewes ovulating during the first 56 days postpartum, decreased the IPPO and weight lost of ewes (P<0.05), decreased lamb GDP and increased M relative to AC and AR (P<0.05). AR decreased the IPPO compared to AC, improved lamb GDP and decreased M compared to DP (P<0.05). Restricted suckling appears to be a better system for raising lambs and restore reproductive activity of ewes during the 3 month postpartum period.

Efectos de la inclusión de un concentrado de proteína de soya y dos fuentes de energía en el substituto de leche en el comportamiento productivo de cabritos nubios / Effect of a soy protein concetrate and two energy sources as milk substitutes on productive performance nubian kids

El objetivo de este trabajo fue evaluar la inclusión de un concentrado de proteína de soya y dos fuentes de energía en el substituto de leche sobre el comportamiento productivo de cabritos Nubios desde el nacimiento hasta el destete, manejados en la Unidad Caprina de la Facultad de Agronomía, Universidad Autónoma de San Luis Potosí, México. Se utilizaron sesenta y ocho cabritos (35 hembras y 33 machos) asignados de manera aleatoria a los tratamientos: T1: proteína láctea + sebo de res, T1: 20,0 por ciento de concentrado de proteína de soya + sebo de res, T1: 40,0 por ciento de concentrado de proteína de soya + sebo de res, T1: proteína láctea + sebo de puerco, T1: 20,0 por ciento de concentrado de proteína de soya + sebo de puerco y, T1: 40,0 por ciento de concentrado de proteína de soya + sebo de puerco. El concentrado de proteína de soya no afectó (P>0,05) el consumo de dieta líquida ni la ganancia diaria de peso promedio, pero afectó significativamente (P<0,05) el consumo de concentrado de iniciación (95;95 y 97 g d-¹ animal-¹). Las fuentes de energía no afectaron (P>0,05) el consumo de la dieta líquida ni la ganancia diaria de peso promedio, pero afectaron (P<0,05) el consumo de concentrado de iniciación (97 vs 95 g d-¹ animal-¹). El sexo de los cabritosno afectó (P>0,05) el consumo del substituto de leche ni la ganancia diaria de peso promedio, pero si afectó (P<0,05) el consumo de concentrado de iniciación (100 vs. 92 g d-1animal-1para machos y hembras, respectivamente). El periodo experimental (semanas) afectó significativamente (P<0,05) todas las variables. Los niveles de concentrado de proteína de soya, fuentes de energía y sexo de la cría no afectaron (P>0,05) la conversión de alimento en base a sólidos totales de la leche. Se presentaron algunas interacciones significativas (P<0,05) en el consumo de substituto de leche y concentrado de iniciación.

The objective of this work was to evaluate the inclusion of a concentrate of soy protein and two energy sources as milk substitutes on productive performance of Nubian kids from birth to weaning, managed at the Goat Unit of the Faculty of Agronomy, Universidad Autónoma de San Luis Potosí, México. Sixty eight kids (35 females and 33 males) were randomly assigned to the treatments: T1 : lactic protein + cow lard, T2 : 20.0% of concentrate of soy protein + cow lard, T3 : 40.0% of concentrate of soy protein + cow lard, T4 : lactic protein + pork lard, T5 : 20.0% concentrate of soy protein + pork lard and, T6 : 40.0% of concentrate of soy protein + pork lard. The concentrate of soy protein did not affect (P>0.05) neither the consumption of liquid diet nor average daily weight gain, but it affected (P<0.05) consumption of the starting concentrate (95; 95, and 97 g d-¹ animal-¹). The energy sources did not affect (P>0.05) neither consumption of the liquid diet nor average daily weight gain, but they affected (P<0.05) consumption of the starting concentrate (97 vs 95 g d-¹ animal-¹). Sex of kid did not affect (P>0.05) neither consumption of the milk substitute nor average daily weight gain, but it affected (P<0.05) consumption of the starting concentrate (100 vs 92 g d-¹ animal-¹ for males and females, respectively). The experimental period (weeks) affected (P<0.05) all variables. The levels of the concentrate of soy protein, energy sources, and sex of kids did not affect (P>0.05) feed conversion based on milk total solids. There were some significant interactions (P<0.05) on consumption of the milk substitute and starting concentrate. It is concluded that it is possible to raise kids with milk substitutes prepared with a concentrate of soy protein, cow and/or pork lard.

Comportamiento reproductivo de ovejas barbados barriga negra sincronizadas con mpa y diferentes tiempos de aplicación de ecg durante la epoca de baja fertilidad / Reproductive Performance in Blackbelly Ewes Synchronized With MPA and eCG During the Low Fertility Season

El experimento se llevó a cabo para evaluar el efecto de diferentes tiempos de aplicación de eCG sobre el comportamiento reproductivo en ovejas Barbados Barriga Negra de segundo parto con 24,2±2,7 meses de edad y 32,6±3,9 kg de peso corporal, sometidas a un protocolo de sincronización de estros con esponjas intravaginales impregnadas con 65 mg de acetato de medroxiprogesterona (MPA) durante 12 días en la época de baja fertilidad (marzo-abril) y bajo condiciones de clima tropical de México. Los animales fueron asignados a uno de cuatro tratamientos; T1 (n=15): Monta continua; T2 (n=15): 65 mg de MPA + 200 U.I. de eCG 48 h antes del retiro de las esponjas + monta controlada; T3 (n=15): 65 mg de MPA + 200 U.I. de eCG al retiro de las esponjas + monta controlada y T4 (n=15): 65 mg de MPA + 200 mg de eCG al momento de la monta controlada. Las variables continuas fueron evaluadas con el análisis de varianza bajo el procedimiento GLM del paquete estadístico SAS. Las variables de proporción se analizaron con la prueba de distribución libre ji cuadrado. La comparación de medias se realizó con la prueba honesta de Tukey. La presentación de estros fue 40; 100; 100 y 100% para T1, T2, T3 y T4 con diferencias significativas (P<0,05). El inicio del estro no presentó diferencias (P>0,05) y el intervalo fue más largo en T1 y T4 (51±28,5 y 42±10,8 h) que T2 y T3 (39,2±8,1 y 38,8±6,7 h). Diferencias significativas (P<0,05) fueron observadas en el porcentaje de gestación (40; 66,6; 80 y 60% para T1, T2, T3, y T4, respectivamente). La concentración promedio de progesterona (7,4±8,1 ng/mL) indicó que el 25% de las ovejas analizadas no estuvieron ciclando al inicio del experimento. Se concluye que el uso de 65 mg de MPA mas 200 U.I. de eCG 48 h antes del retiro de las esponjas, al momento del retiro de las esponjas y al momento de la monta controlada sincroniza eficientemente los estros en ovejas Barbados Barriga Negra durante la época de baja fertilidad en ...

The experiment was carried out to evaluate the effect of different time of eCG administration on the reproductive performance of Blackbelly ewes of second lambing and 24.2±2.7 months of age and 32.6±3.9 kg of body weight, which were subjected to estrus synchronization protocols with intravaginal sponges impregnated with 65 mg of medroxiprogesterone acetate (MPA) for 12 days in the non breeding season (March and April) under the humid tropical environment of Mexico. The animals were randomly assigned to one of four treatments; T1 (n=15): Continuous breeding; T2 (n=15): 65 mg MPA + 200 U.I. eCG 48 h before sponges withdrawal + Controlled breeding; T3 (n=15): 65 mg MPA + 200 U.I. eCG at sponges removal + Controlled breeding and T4 (n=15): 65 mg MPA + 200 U.I. eCG at the moment of controlled breeding. The continuous variables were evaluated with the variance analysis under GLM procedures of statistical package SAS. The proportion variables were analyzed with chi square free test. The comparison of means was carried out with the honest test of Tukey. The estrus response was 40; 100; 100 y 100% for T1, T2, T3 and T4, respectively (P<0.05). The onset of the synchronized estrus did not show differences (P>0.05) and the interval were longer in T1 and T4 (51±28.5 y 42±10.8 h) than T2 and T3 (39.2±8.1 y 38.8±6.7 h). Significant differences were observed in pregnancy rates (40; 66.6; 80 y 60% for T1, T2, T3 and T4, respectively). Mean progesterone concentration (7.4±8.1 ng/mL) indicated that 25% of ewes were cycling at the beginning of the experiment. The results of this study show that the use MPA and 200 U.I. of eCG 48 h before sponges removal, at sponges withdrawal and at controlled breeding are efficient in synchronizing estrus in Blackbelly ewes during the non breeding season in tropical environment conditions of México.