Rotational Grazing Modifies Rhipicephalus microplus Infestation in Cattle in the Humid Tropics.

Rotational grazing has been mentioned as a potential tool to reduce losses caused by high tick loads. This study aimed: (1) to evaluate the effect of three grazing modalities (rotational grazing with 30- and 45-day pasture rest and continuous grazing) on Rhipicephalus microplus infestation in cattle, (2) to determine population dynamics of R. microplus in cattle under the three grazing modalities mentioned in the humid tropics. The experiment was carried out from April 2021 to March 2022 and consisted of 3 treatments of grazing with pastures of African Stargrass of 2 ha each. T1 was continuous grazing (CG00), and T2 and T3 were rotational grazing with 30 (RG30) and 45 d of recovery (RG45), respectively. Thirty calves of 8-12 months of age were distributed to each treatment (n = 10). Every 14 days, ticks larger than 4.5 mm were counted on the animals. Concomitantly, temperature (°C), relative humidity (RH), and rainfall (RNFL) were recorded. Animals in the RG45 group had the lowest count of R. microplus compared to the RG30 and CG00 groups; these results suggest that RG45 days of rest could be a potential tool to control R. microplus in cattle. Yet, we also observed the highest population of ticks on the animals under rotational grazing with a 30-day pasture rest. A low tick infestation characterized rotational grazing at 45 days of rest throughout the experiment. The association between the degree of tick infestation by R. microplus and the climatic variables was nil (p > 0.05).

Prevalence and risk factors of coccidiosis in calves from Veracruz, México.

The objectives of the present study were: (1) to determine the prevalence of Eimeria spp. sporulated oocysts in calves from 26 Municipalities in the Central Zone of the State of Veracruz, Mexico, (2) to identify the Eimeria spp. infecting calves, and (3) to identify the risk factors associated with the presence of Eimeria spp. in tropical cattle. A total of 930 individual fecal samples were analyzed by using the McMaster technique; then, oocysts were maintained in 2.5% potassium dichromate to allow sporulation. The general prevalence of calves with Eimeria spp. oocysts was 39.7% (370/930). Of a total of 10 identified species, Eimeria canadensis was the most observed, followed by Eimeria bovis and Eimeria zuernii. The statistical analysis showed an association between the age of the calves (5 to 9 months), the presence of other animals, the physiographic regions and the restricted type of husbandry with the presence of Eimeria spp. in calves (P<0.05). Protective risk factors, such as: routine coprological analysis was also associated with a decrease in infection. These data demonstrate the presence of coccidia in cattle from the State of Veracruz, additionally to the necessary measures that must be taken to control this parasitosis.

Maternal supply of a source of omega-3 fatty acids and methionine during late gestation on the offspring's growth, metabolism, carcass characteristic, and liver's mRNA expression in sheep.

The objective of the present experiment was to evaluate the effect of maternal supplementation with fatty acids (FAs) and methionine (Met) during late gestation on offspring growth, energy metabolism, plasma resolvin (RvD1) concentration, carcass characteristics, and hepatic mRNA expression. Ewes (5 pens/treatment; 3 ewes/pen) blocked by body weight (BW) were assigned to one of four treatments from day 100 of gestation until lambing. The treatments were: basal diet (NS) without FAs or Met supplementation; FA supplementation (FS; 1.01 % of Ca salts, containing n-3 FA); Met supplementation (MS; 0.1 % of rumen-protected methionine); and FS and MS (FS-MS). At birth (day 0), ewes and lambs were placed in a common pen. On day 60, lambs were weaned, sorted by sex, blocked by BW, and placed on a common finishing diet for 54 d (FP). A lamb per pen was used for a glucose tolerance test (GTT) after the FP. Carcass characteristics were recorded on day 56. Lamb data were analyzed as a randomized complete block design with a 2 × 2 × 2 factorial arrangement, with repeated measurements when needed (SAS 9.4). At weaning, lambs born to MS- or FS-fed ewes were heavier than lambs born from FS-MS ewes (FS × MS × Time; P = 0.02). A marginal significant FS × MS interaction (P = 0.09) was also observed on RvD1; lambs born to ewes in the NS and FS-MS treatments showed a lower RvD1 plasma concentration when compared with lambs born to FS- or MS-fed ewes. Lambs born to dams fed FA showed an increase (P = 0.05) in liver COX-2 mRNA relative expression. Lambs born to ewes supplemented with Met showed an increase (P = 0.03) in liver FABP4 mRNA expression. An FS × MS × Time interaction (P = 0.07) was observed in plasma glucose during the GTT; lambs born from FS-fed ewes showed lower plasma glucose concentration than lambs born to Met-supplemented ewes at 2 min after bolus administration. During the GTT, a marginal significant effect (P = 0.06) was observed for the lamb average insulin concentration due to maternal Met supplementation during late gestation, where these lambs had the lowest plasma concentration. Contrary to our hypothesis, the interaction of FA and Met supplementation during late gestation did not show a greater positive effect on offspring postnatal growth and metabolism. However, the individual supplementation of each nutrient has an effect on offspring development with a concomitant change in markers involved in the inflammatory response and energy metabolism.

Late gestation supplementation of omega-3 fatty acids (FAs) or methionine (Met) alters the offspring's development. However, the effect of both nutrients on the physiology and growth of the progeny has not been explored. The experiment's objective was to evaluate the effect of dam supplementation with a Met and the omega-3 FAs, such as eicosapentaenoic and docosahexaenoic acids, during late gestation on growth, energy metabolism, and inflammatory response markers of the lamb. Ewes received one of the four following treatments: basal diet without FA or Met, FA supplementation, Met supplementation, or FA and Met supplementation. Supplementation of omega-3 FAs and Met did not show a greater effect on postnatal growth and metabolism of the offspring compared with the supplementation of each nutrient individually. However, individual supplementation influences offspring development with a concomitant change in markers involved in the inflammatory response and energy metabolism. Results of the present experiment suggest that offspring born to mothers that were fed FAs or Met on late gestation could have the ability to better cope with inflammatory processes, which could improve their long-term growth performance. Moreover, maternal supplementation of Met during late gestation could modulate offspring's glucose­insulin system, which may also affect offspring's growth.

Effects of Dietary Calcium Propionate Supplementation on Hypothalamic Neuropeptide Messenger RNA Expression and Growth Performance in Finishing Rambouillet Lambs.

The objective of this experiment was to evaluate the effects of feeding different levels concentrations of dietary calcium propionate (CaPr) on lambs' growth performance; ruminal fermentation parameters; glucose-insulin concentration; and hypothalamic mRNA expression for neuropeptide Y (NPY), agouti-related peptide (AgRP), and proopiomelanocortin (POMC). Thirty-two individually fed lambs were randomly assigned to four treatments: (1) control diet (0 g/kg of CaPr), (2) low CaPr, (30 g/kg dry matter (DM)), (3) medium CaPr, (35 g/kg DM), and (4) high CaPr (40 g/kg DM). After 42 days of feeding, lambs were slaughtered for collecting samples of the hypothalamus. Data were analyzed as a complete randomized design, and means were separated using linear and quadratic polynomial contrast. Growth performance was not affected (p ≥ 0.11) by dietary CaPr inclusion. The ruminal concentration of total volatile fatty acids (VFA) increased linearly (p = 0.04) as dietary CaPr increased. Likewise, a linear increase in plasma insulin concentration (p = 0.03) as dietary CaPr concentration increased. The relative mRNA expression of NPY exhibited a quadratic effect (p < 0.01), but there were significant differences in the mRNA expression of AgRP and POMC (p ≥ 0.10). Dietary calcium propionate did not improve lamb growth performance in lambs feed with only forage diets. Intake was not correlated with feed intake with mRNA expression of neuropeptides.

Maternal Supply of Fatty Acids during Late Gestation on Offspring's Growth, Metabolism, and Carcass Characteristics in Sheep.

Lambs born from dams supplemented with different sources of fatty acids (FA) during late gestation have a different growth rate and plasma glucose concentration. The main objectives of this experiment were to evaluate the effect of supplementing different sources of FA during late gestation on offspring plasma metabolite concentrations, growth, and on a glucose tolerance test (GTT) during the finishing phase. Fifty-four lambs (18 pens, 3 lambs/pen) were born from ewes supplemented during late gestation with one of three treatments: (1) no FA (NF); (2) a source of monounsaturated FA (PDS, 1.01% of Ca salts); or (3) a source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (EDS, 1.01% of Ca salts containing). At birth (day 0), supplementation ceased, and all ewes and lambs were placed in a common pen. On day 60, lambs were weaned, grouped by sex, blocked by body weight (BW), and placed on a common finishing diet for 54 days (FP). One lamb per pen was used for the GTT after the FP. There was a tendency for FA × Sex × Day interaction (p = 0.08) on lamb growth during the finishing period, with PDS females being heavier than PDS males, while EDS males were heavier than EDS females at day 60. There was a tendency for FA × Sex interaction (p = 0.06) for plasma insulin concentration for the GTT. Plasma insulin concentration of wethers increased as FA unsaturation degree increased during the GTT; the opposite happened with the plasma insulin concentration of female lambs. In conclusion, FA supplementation during late gestation tended to modified growth and insulin response to a GTT; these changes differed with the degree of FA unsaturation of the supplement and lamb sex.

Role of Long Chain Fatty Acids in Developmental Programming in Ruminants.

Nutrition plays a critical role in developmental programs. These effects can be during gametogenesis, gestation, or early life. Omega-3 polyunsaturated fatty acids (PUFA) are essential for normal physiological functioning and for the health of humans and all domestic species. Recent studies have demonstrated the importance of n-3 PUFA in ruminant diets during gestation and its effects on pre-and postnatal offspring growth and health indices. In addition, different types of fatty acids have different metabolic functions, which affects the developmental program differently depending on when they are supplemented. This review provides a broad perspective of the effect of fatty acid supplementation on the developmental program in ruminants, highlighting the areas of a developmental program that are better known and the areas that more research may be needed.

Effects of maternal dietary omega-3 polyunsaturated fatty acids and methionine during late gestation on fetal growth, DNA methylation, and mRNA relative expression of genes associated with the inflammatory response, lipid metabolism and DNA methylation in placenta and offspring's liver in sheep.

BACKGROUND: Omega-3 PUFA or methionine (Met) supply during gestation alters offspring physiology. However, the effect of both nutrients on fetal development has not been explored. Our objective was to determine the effects of supplementation of these two nutrients during late gestation on fetal growth, DNA methylation, and mRNA expression of genes associated with the inflammatory response, and DNA methylation. Ewes (n = 5/treatment) were fed from day 100 to 145 of gestation one of the following treatments: 1) basal diet (NS) without fatty acids (FS) or methionine (MS) supplementation; 2) FS (10 g/kg Ca salts, source omega-3 PUFA); 3) MS (1 g/kg rumen protected methionine); and 4) FS and MS (FS-MS). On day 145, ewes were euthanized, and data from dams and fetus was recorded. Placenta (cotyledon), fetal liver, and blood samples were collected. RESULTS: A treatments interaction on fetal liver weight, ewe body weight and body condition score (BCS) was observed; FS-MS were heavier (P <  0.01) than FS and MS, and FS-MS ewes had a better (P = 0.02) BCS than NS. Methionine increased (P = 0.03) ewe plasma glucose concentration. Fetal liver global DNA methylation increased (P <  0.01) in FS and MS. Dietary treatments modify the mRNA relative expression on some of the genes evaluated. In the fetal liver, FS increased (P = 0.04) the mRNA relative expression of arachidonate-5-lipoxygenase-activating-protein and tended to decrease (P = 0.06) methionine-adenosyltransferase-1A. Moreover, MS decreased (P = 0.04) DNA-methyltransferase-1 and tended to decrease (P = 0.08) free-fatty-acid-receptor-1 mRNA relative expression. Furthermore, FS-MS decreased mRNA relative expression of tumor-necrosis-factor-alpha (P = 0.05), peroxisome-proliferator-activated-receptor-delta (P = 0.03) and gamma (P = 0.04), tended to decrease (P ≤ 0.09) interleukin-6, fatty-acid-transport-protein-1, and delta-5-desaturase, and increased adenosylhomocysteinase (P = 0.04) mRNA relative expression. In cotyledon, FS tended to decrease fatty acid binding protein 4 (P = 0.09) mRNA relative expression. CONCLUSION: Omega-3 PUFA and Met supplementation improves dam's performance in late gestation, which was positively correlated with an increase in offspring's liver development. Moreover, FS-MS decreased mRNA relative expression of proinflammatory cytokines, and lipogenic genes, and increased the expression on an enzyme that has an important role in methylation.

Supplemental Herbal Choline Increases 5-hmC DNA on Whole Blood from Pregnant Ewes and Offspring.

Herbal formulas during pregnancy have been used in developing countries. Despite that, the potential effects on the mother and offspring and whether those supplements elicit epigenetic modifications is still unknown. Therefore, our objectives were to determine the effects of supplemental herbal choline source (BCho) on the percentage of 5-hmC in whole blood from gestating ewes and their offspring, as well as determining the milk quality and growth of the offspring. Thirty-five gestating Rambouillet ewes were randomly assigned to five treatments: T1, supplementation of 4 g per day (gd-1) of BCho during the first third of gestation; T2, supplementation of 4 gd-1 of BCho during the second third of gestation; T3, supplementation of 4 gd-1 of BCho during the last third of gestation; T4, supplementation of 4 gd-1 of BCho throughout gestation; and T5, no BCho supplementation (control). For the 5-hmC DNA analysis, whole blood from ewes was sampled before pregnancy and at each third of gestation (50 days). Whole blood from lambs was sampled five weeks after birth. The evaluation of the nutritional programming effects was conducted through the percentages of 5-hmC in the lambs. Compared with other treatments, the whole blood from ewes supplemented during T1 and T4 had the greatest 5-hmC percentages (p < 0.05). However, only ewes fed BCho throughout gestation (T4) maintained the greatest percentages of 5-hmC (p < 0.05). The lamb growth performance indicated that the BCho maternal supplementation did not affect the nutritional programming. However, the lambs born from ewes supplemented during T2 had the greatest 5-hmC percentages (p < 0.05). Our data suggest that ewes supplemented during T4 with BCho increase and maintain the percentages of 5-hmC in whole blood, and the offspring born from ewes supplemented with BCho during T2 maintained the greatest percentages of 5-hmC 35 d after they were born.

Nutritional value of sugarcane silage enriched with corn grain, urea, and minerals as feed supplement on growth performance of beef steers grazing stargrass.

The objectives were to evaluate the silage quality of sugarcane silage enriched (as fed) with corn grain ground (10%), urea (1.5%), and mineral premix (0.5%) and its effects as a feed supplement on growth performance of beef steers grazing stargrass. Firstly, in micro-silages, whole sugarcane enriched with corn grain, urea, and minerals (WSCE) were ensilaged by 0, 20, 40, and 60 days. Crude protein (CP) and lactic acid (LA) increased linearly (P < 0.05) and true protein decreased linearly (P < 0.05) as fermentation time increased. The pH values in silages were affected quadratically by fermentation time. Thus, after a 20-day fermentation, the pH values were below 4.5. Secondly, in micro-silos WSCE and stem sugarcane enriched with corn grain, urea, and minerals (SSCE) with and without calcium propionate were ensilaged by 30 days, but it did not affect any chemical composition trait in the silage. The SCCE silages had higher CP and LA and lower pH than WSCE silages. Finally, for 120 days, 20 beef steers (378 ± 33 kg initial BW) grazing stargrass were supplemented (daily by 1-h free access) with WSCE silage. Supplemental silage increased total dry matter intake, total gain, and the average daily gain, without any affectation on feed conversion and total tract digestion of dry matter. It is concluded that whole sugarcane silage is an alternative feed supplement to improve growth performance in beef steers grazing stargrass.

Quantitative characterization of nonstructural carbohydrates of mezcal Agave (Agave salmiana Otto ex Salm-Dick).

Fructans are the reserve carbohydrates in Agave spp. plants. In mezcal factories, fructans undergoes thermal hydrolysis to release fructose and glucose, which are the basis to produce this spirit. Carbohydrate content determines the yield of the final product, which depends on plant organ, ripeness stage, and thermal hydrolysis. Thus, a qualitative and quantitative characterization of nonstructural carbohydrates was conducted in raw and hydrolyzed juices extracted from Agave salmiana stems and leaves under three ripeness stages. By high-performance liquid chromatography (HPLC), fructose, glucose, sucrose, xylose, and maltose were identified in agave juice. Only the plant fraction with hydrolysis interaction was found to be significant in the glucose concentration plant. Interactions of the fraction with hydrolysis and ripeness with hydrolysis were statistically significant in fructose concentration. Fructose concentration rose considerably with hydrolysis, but only in juice extracted from ripe agave stems (early mature and castrated). This increase was statistically significant only with acid hydrolysis.

Efecto de enzimas fibrolíticas exógenas en la degradación ruminal in vitro de dietas para vacas lecheras / Effect of exogenous fibrolytyc enzime on in vitro ruminal degradation of rations for dairy cows

Para determinar el efecto in vitro de enzimas fibrolíticas exógenas en la degradación ruminal de la materia seca (DIVMS) y de la fibra detergente neutro (DIVFDN) se incubaron de 3 a 72h en licor ruminal, tres dietas con 40:60, 50:50 y 60:40 relación forraje:concentrado (F:C), con o sin enzimas fibrolíticas. Se usó un diseño de bloques completos al azar con un arreglo factorial 3×2×6 (ración F:C de 40:60, 50:50, 60:40; enzima, 0 o 2g·kg-1 MS; tiempo de incubación de 3, 6, 12, 24, 48 y 72h). La DIVMS de dieta 60:40 F:C fue mayor (P±0,05) que la de 50:50 o 40:60. Por su parte, la DIVFDN de la dieta 50:50 F:C fue mayor que la de 40:60 o 60:40. La interacción entre F:C de la dieta, enzima y el tiempo de incubación indicó que las enzimas fibrolíticas exógenas tuvieron mayor impacto en la DIVMS y en la DIVFDN en las primeras 12h de incubación en la dieta con mayor contenido de fibra.

Efecto de enzimas fibrolíticas exógenas en la degeneración in vitro de ingredientes alimenticios: y en la producción de leche de vacas holsten / Effect of exogenous fibrolytic enzymes on in vitro dry matter disapperance of foodstuffs: and on milk yield of Holstein cows

Los complejos enzimáticos exógenos se han usado para incrementar la digestibilidad de la fibra contenida en los forrajes; sin embargo, no se conoce su efecto sobre otros ingredientes alimenticios que componen las raciones integrales para rumiantes. Por ello, en un primer experimento se evaluó el efecto de enzimas fibrolíticas en la degradación ruminal in vitro de la materia seca (DIVMS) de ingredientes alimenticios energéticos (granos de maíz y sorgo), fibrosos (cascarilla de soya y ensilado maíz), proteínicos (pasta de soya y semilla de algodón), heno de alfalfa (7, 12, 21 y 28 días de rebrote) y de un concentrado, a las 3, 6, 12, 24, 48 y 72h de incubación. Las enzimas fibrolíticas mejoraron (P<0,10) principalmente la DIVMS de los ingredientes fibrosos. En un segundo experimento se evaluó el efecto de las enzimas fibrolíticas en la producción de leche de vacas Holstein alimentadas con dietas integrales elaboradas con los ingredientes evaluados en el primer experimento. La producción de leche en la semana experimental 3, 4 y 8 (P<0,10), y 5 y 16 (P<0,05) fue incrementada por las enzimas fibrolíticas exógenas

Análisis estadpistico de experimentos de digestibilidad in vitro con forrajes / Statistical analysis of in vitro digestibility experiments with forages

Se usaron cuatro modelos estadísticos para analizar un experimento de degradación in vitro de la MS de heno de alfalfa y de ballico utilizando la primera fase de Tilley y Terry a las 48h, por duplicado (incubaciones) y con tres tubos (repetición) por incubación/forraje (seis tubos por forraje). Se aplicaron los siguientes modelos: 1) medias de cada incubación, con dos repeticiones por forraje; 2) cada tubo fue una repetición, con seis repeticiones por forraje; 3)como el modelo 2, pero con el término incubación en el modelo que no se usó como un término de error; 4) cada tubo fue una submuestra y con incubación x forraje como criterio de error en el modelo. Con los tres primeros modelos hubo diferencias (P<0,05) en la digestibilidad de los fo0rrajes; el modelo 1 tiene 2 grados de libertad para el error, pero en los modelos 2 y 3 hay 10 y 8 grados de libertad, respectivamente, Los modelos 2 y 3 no consideran la variabilidad de condiciones experimentales de la digestibilidad in vitro, y hay una probabilidad mayor de obtener resultados no repetibles. El análisis de la varianza con el modelo 4 (la interacción incubación x forraje como término de error experimental) no muestra diferencias (P>0,05) para forraje. Al repetir el experimento, la probabilidad de que los resultados puedan repetirse es menor. Según estos resultados, el modelo 4 sería más apropiado para analizar los estudios de digestibilidad in vitro, porque considera la variabilidad de condiciones experimentales in vitro y determinar la repetibilidad de los resultados

Efecto de enzimas fibrolíticas exógenas en la digestibilidad in vitro de la pared celular de heno de alfalfa (medicago sativa) o de ballico (lolium perenne) / Effect of exogenous fibrolytic enzymes on in vitro digestibility of cell wall of alfalfa (medicago sativa) or rye-grass (lolium ferenne)

Se midió la degradación in vitro de enzimas fibrolíticas exógenas y su efecto en la degradación in vitro de FDN y FDA de heno de alfalfa o ballico. Se usó la primera fase de Tilley y Terry (0,3,6,12,24,48 y 72h) con saliva McDougall (S) sola o con líquido ruminal (LR). La desaparición de la enzima (E) fue constante de 0 a 6h, y aumentó de 12 a 72h. La concentración de N-NH4 fue constante de 0 a 24h y su mayor valor fue a las 72h. La desaparición de FDN de los forrajes se incrementó de 6 a 72h con la E y de 24 a 72h con E + LR. Además, E aumentó la desaparición de FDA de alfalfa de 3 a 72h y la del ballico de 3 a 12h; pero E + LR no cambio la desaparición de FDA. La E con LR aumentó la desaparición neta de FDN de ambos forrajes a las 48 y 72h, pero redujo la desaparición neta de FDA del ballico a las 12h, en tanto que no hubo diferencias para la FDA de la alfalfa. En las primeras 12h no se dirigieron las enzimas del producto enzimático, el cual tiene un efecto positivo importante en la digestibilidad in vitro de la pared celular del heno de alfalfa y de ballico, aún en presencia de microorganismos ruminales