Ruminant Health Research Articles

Effects of lactic acid bacteria on the quality of silage and health of ruminants

Silage is an essential part of the rations for ruminants. Preparation and production of high-quality silage is vital to improving the quality and efficiency of animal husbandry. The nutritive value and fermentation quality of silage is dependent on not only the type and quality of the forage crop, but also the ensiling technique and epiphytic microbiota. Lactic acid bacteria (LAB), as an important silage additive and feed probiotics, play an important role in improving the quality of silage forage and regulating the growth performance and health of ruminants. LAB offer various advantages for ruminants as potential probiotics and are able to improve nutrient acquisition, growth performance and immune function stimulation in ruminants. In this paper, we review the current knowledge on the effects of LAB on silage quality and ruminant health. The comprehensive and in-depth understanding of the biological functions of important microorganisms, like LAB, in the silage fermentation process, the mechanisms of action, and the physiological effects on ruminant health is useful for developing highly effective compound silage inoculants, and for providing a scientific basis for improving physiological health of ruminants.

Dietary Supplementation with Sugar Beet Fructooligosaccharides and Garlic Residues Promotes Growth of Beneficial Bacteria and Increases Weight Gain in Neonatal Lambs.

The proper development of the early gastrointestinal tract (GIT) microbiota is critical for newborn ruminants. This microbiota is susceptible to modification by diverse external factors (such as diet) that can lead to long-lasting results when occurring in young ruminants. Dietary supplementation with prebiotics, ingredients nondigestible and nonabsorbable by the host that stimulate the growth of beneficial GIT bacteria, has been applied worldwide as a potential approach in order to improve ruminant health and production yields. However, how prebiotics affect the GIT microbiota during ruminants’ early life is still poorly understood. We investigated the effect of milk supplementation with a combination of two well-known prebiotics, fructooligosaccharides (FOS) from sugar beet and garlic residues (all together named as “additive”), exerted on preweaned lamb growth and the composition of their fecal microbiota, by using 16S rRNA gene amplicon high-throughput sequencing. The results showed a significant increase in the mean daily weight gain of lambs fed with the additive. Lamb fecal microbiota was also influenced by the additive intake, as additive-diet lambs showed lower bacterial diversity and were significantly more abundant in Bifidobacterium, Enterococcus, Lactobacillus and Veillonella. These bacteria have been previously reported to confer beneficial properties to the ruminant, including promotion of growth and health status, and our results showed that they were strongly linked to the additive intake and the increased weight gain of lambs. This study points out the combination of FOS from sugar beet and garlic residues as a potential prebiotic to be used in young ruminants’ nutrition in order to improve production yields.

The first report of multidrug resistance in gastrointestinal nematodes in goat population in Poland

BackgroundProphylactic anthelmintic treatment with one of three basic classes of anthelmintics (benzimidazoles, macrocyclic lactones and imidazothiazoles) is still the mainstay of control of gastrointestinal nematode infections in small ruminants worldwide. As a consequence, anthelmintic resistance is a serious threat to small ruminant health and production. While the resistance to one class of anthelmintics has already been reported in most of countries, the newly-emerging problem is the resistance to two or even all of classes referred to as multidrug resistance. This study aimed to evidence the presence of multidrug resistance of gastrointestinal nematodes in goats in Poland.ResultsThe combination of one in vivo method (fecal egg count reduction test) and two in vitro methods (egg hatch test and larval development test) performed in two goat herds in the southern Poland showed the presence of gastrointestinal nematodes resistant to fenbendazole and ivermectin in both herds. Moreover, in one herd it revealed the development of resistance to the last effective anthelmintic, levamisole, in response to one-year intensive use. Haemonchus contortus was the most prevalent gastrointestinal nematode in samples in which resistance to benzimidazoles and ivermectin was found, whereas Trichostrongylus colubriformis predominated when resistance to levamisole was observed.ConclusionThis study shows for the first time that multidrug resistance of gastrointestinal nematodes to three basic classes of anthelmintics is already present in goat population in Poland. Moreover, it may indicate that different species or genera of gastrointestinal nematodes are responsible for the resistance to specific anthelmintics.

Sensing solutions for improving the performance, health and wellbeing of small ruminants.

Diversity of production systems and specific socio-economic barriers are key reasons explaining why the implementation of new technologies in small ruminants, despite being needed and beneficial for farmers, is harder than in other livestock species. There are, however, helpful peculiarities where small ruminants are concerned: the compulsory use of electronic identification created a unique scenario in Europe in which all small ruminant breeding stock became searchable by appropriate sensing solutions, and the largest small ruminant population in the world is located in Asia, close to the areas producing new technologies. Notwithstanding, only a few research initiatives and literature reviews have addressed the development of new technologies in small ruminants. This Research Reflection focuses on small ruminants (with emphasis on dairy goats and sheep) and reviews in a non-exhaustive way the basic concepts, the currently available sensor solutions and the structure and elements needed for the implementation of sensor-based husbandry decision support. Finally, some examples of results obtained using several sensor solutions adapted from large animals or newly developed for small ruminants are discussed. Significant room for improvement is recognized and a large number of multiple-sensor solutions are expected to be developed in the relatively near future.

Perceptions and practices among Zambian sheep and goat traders concerning small ruminant health and disease.

Trade in animals and animal products is a key factor in the transmission of infectious diseases. Livestock traders play an important role in this process, yet there is little knowledge of traders’ perceptions of animal disease or their associated actions. The aim of this study was to investigate perceptions and practices of Zambian small ruminant traders with regard to sheep and goat health and disease. It also analysed how existing perceptions and practices might affect risks of disease transmission through trade. A case study was performed at the two largest small livestock markets in Zambia: the Lusaka market in the capital and the Kasumbalesa market near the border with the Democratic Republic of Congo. Semi-structured interviews with 47 traders performed in April-May and September 2018 represent the core material. Zambian small ruminant traders frequently trade animals that have clinical signs of disease, either because they appear unaware or indifferent to the associated risks, experience financial constraints or assign responsibility for disease prevention to other value chain actors. In their decision about whether or not to sell a visibly sick small ruminant, traders appear to consider whether the clinical sign is perceived as ‘natural’ or the result of an illness, whether the buyer is aware of the animal’s health condition, and whether the animal is sold for consumption or breeding purposes. Traders appear to regard the veterinary certificate required to transport small ruminants in Zambia as proof of health, placing the responsibility for potential disease in traded animals on the veterinary authorities. In their description of a model trader, taking good care of and being sensitive to customer needs was emphasized, indicating that an efficient way to encourage traders to change their behaviour is to influence customer demands. In contrast to the focus in previous studies on identifying and filling knowledge gaps, the present study show that lack of knowledge is not central to why traders engage in disease-transmitting behaviour. Greater awareness of other reasons for certain perceptions and practices could lead to the formulation of risk communication strategies and mitigation measures that are relevant for the local context, as well as alternative strategies for changing trader behaviour.

Effects of supplementation containing rumen by-pass protein on parasitism in grazing lambs

Abstract Parasitic gastro-intestinal nematodes (GIN) are a serious challenge to sustainable small ruminant health and performance on pasture. Management practices including protein supplementation can help mitigate the deleterious effects of GIN and sustain livestock performance. We postulated that a combination of protein supplementation and grazing management would suppress GIN infection and contribute to marketable lamb gain in organic and conventional production systems. Objectives were to determine if performance and GIN infection of weaned lambs on pasture were influenced by 1) protein supplementation; 2) protein supplement source that included rumen undegradable protein (RUP) with the addition of a fish oil treatment to address energy concentration in the feed supplement; and 3) protein supplementation with RUP based on body mass and grazing interval duration. We found that lambs supplemented with RUP had increased BW and PCV, and reduced FEC and FAMACHA© scores. Body weight gains increased as the corn-fishmeal supplement was increased from 1 % to 2 % BW. Parasitized lambs may have increased dietary protein requirements that can be met in part by provision of RUP in the form of fish meal. Our work demonstrates the practical success of improved animal performance with protein supplementation based on body weight, and the importance of protein supplement source. The RUP supplement, such as fish meal, appears to have significant bearing on immunological responses as inferred from observed changes in FEC associated with the target GIN, H. contortus.

The effect of chromium on ruminant health

The effect of chromium on ruminant health

Increasing the content of physically effective fiber in high-concentrate diets fed to beef heifers affects intake, sorting behavior, time spent ruminating, and rumen pH.

AbstractThe importance of fiber particle size in ruminal health is well known, but there are fewer studies to assess the requirements of physically effective NDF (peNDF) in beef cattle than in dairy cattle. The objective of this study was to establish the optimal peNDF proportion in high-concentrate diets fed to beef cattle, to reduce the risk of subacute ruminal acidosis. The experimental design was a replicated Latin Square 4 × 4, with four periods of 21 d. Treatments consisted of four diets with different peNDF proportions: 6.4%, 10.4%, 13.6%, and 15.4%, offered ad libitum as total mixed ration, and containing 15% barley straw and 85% concentrate. Diets, which differed in proportions of straw > 4 mm (considered peNDF) and straw < 4 mm, were manually mixed with concentrate. This concentrate was the same for all diets. A ruminal bolus was orally administered to each heifer for pH measurement. Intake, water consumption, intake by particle size, feed sorting, feeding behavior, behavioral activities, and rumen pH were recorded. Chemical composition and particle sizes of diets offered were assessed in the last week of each period. Data were analyzed using the MIXED procedure of SAS. Orthogonal contrasts determined the linear and quadratic effects of increasing peNDF proportion. T-test procedure determined whether heifers carried out sorting behavior. Particles >4 mm linearly increased (P = 0.001), and particles <4 mm linearly decreased (P = 0.001) as peNDF increased. Water consumption and feeding behavior were unaffected by treatment. As peNDF increased, intakes of DM and NDF linearly decreased (P = 0.001), whereas peNDF intake increased (P = 0.001). Intake of particles > 4 mm linearly increased, whereas intake of particles < 4 mm linearly decreased (P = 0.001) as peNDF increased. Diet 6.4% performed sorting for particles > 4 mm (P < 0.01), and diets 13.6% and 15.4% against particles > 4 mm (P < 0.01). Diet 10.4% tended to sort against particles > 4 mm (P < 0.10). Time spent ruminating linearly increased (P = 0.001) as peNDF increased. Diets did not differ in mean and minimum rumen pH, but time under rumen pH thresholds (5.8, 5.7, 5.6, and 5.5) linearly decreased as peNDF increased (P < 0.05). The results suggested that the diet that best met the requirements of not compromising intake, limiting sorting behavior, and promoting time spent ruminating to reduce the number of hours under rumen pH thresholds, was the 10.4% diet.

Microscopical and molecular diagnosis of gastrointestinal nematodes infecting small ruminants in Menofia governorate

Gastrointestinal nematodes are the most common problems affecting the health and productivity of small ruminants. The study was carried out on 45 slaughtered small ruminants (19 sheep and 26 goats) for microscopical and molecular diagnosis of recovered nematodes. The gastrointestinal tracts of slaughtered animals were examined by sieving method for nematode recovery. The recovered nematodes were washed, cleared, mounted and identified. RAPD-PCR was carried out on 10 samples (adults and larvae) by using 3 primers. The results revealed that the infection rate of nematodes was higher in sheep than goats. The recovered nematodes were Haemonchus contortus, Trichostrongylus axei, Cooperia sp, Ostertagia ostertagi and Trichuris ovis. The infection rate of different nematodes was recorded. Comparison between Trichuris ovis from sheep and goats revealed genetic polymorphism and genetic variability in DNA amplification using three primers. Overall, RAPD-PCR indicated genetic polymorphism and genetic variability between different nematodes and within the same species.

Effect of carbohydrate source on productive performance, ruminal and systemic health of grazing cows

Background: The nutritional limitations of Cenchrus clandestinus –i.e., high protein and low energy concentrations- make it necessary to supplement cows with non-fibrous carbohydrate (NFC) sources to improve productive performance. Nevertheless, such supplementation can lead to ruminal acidosis. Objective: To evaluate partial replacement of corn grain (Zea mays, ZM) with sorghum grain (Sorghum vulgare, SV), cassava root (Manihot esculenta, MES) or citrus pulp (Citrus sp., C) on milk yield and quality, ruminal pH and health of grazing cows. Methods: Eight Holstein cows were evaluated in a 4 x 4 Latin square design during the first 60 days of lactation. Treatments (isoenergetic rations, 1.45 ± 0.003 Mcal NEL/kg DM) consisted of a mixture of grass and four concentrates with different NFC sources. Results: No differences in dry matter intake, feed efficiency, ruminal pH, hematological and metabolic profile were observed between treatments. Rumen pH was higher than 6.0, confirming the absence of ruminal acidosis. Milk yield (energy-corrected), protein, and total solids were higher for MES vs. C. Conclusions: None of the NFC sources tested compromised the ruminal or systemic health of the cows, while MES improved milk yield and quality.

Effects of repeated oral inoculation of artificially fed lambs with lyophilized rumen fluid on growth performance, rumen fermentation, microbial population and organ development

Early life development and growth are critical in determining the lifelong growth performance and health of ruminants, and weaning poses the greatest challenge to young animals and has the most profound consequence. In this study, we aimed to investigate the effects of microbial intervention on the growth and development of young lambs and their rumen microbiota as they went through weaning. Forty-eight lambs were allocated to two groups, with one group being orally inoculated with lyophilized rumen fluid, and the other receiving no inoculation served as the control. Growth performance, rumen fermentation characteristics, and carcass measurements were determined weekly one week before and two weeks after weaning. We also determined the population dynamics of total bacteria, protozoa, fungi, and select genera and species of known rumen bacteria and assessed the temporal changes in the activities of glucanase (both endo- and exo-), xylanase, β-glucosidase, and amylase in the rumen content. Our results showed that the early life inoculation significantly increased the apparent digestibility of feed dry matter and crude protein before weaning, and post-weaning crude protein digestibility remained elevated in the inoculated lambs compared to the control lambs. Starch digestibility tended to be higher in the inoculated lambs than in the control lambs two weeks after weaning. Molar proportion of ruminal propionate and amylolytic enzyme activity were higher in the inoculated lambs than in the control lambs after weaning. Different temporal fluctuation patterns of Megasphaera elsdenii and Selenomonas ruminantium, and a lower abundance of Ruminococcus flavefaciens were noted in the rumen of the inoculated lambs compared to the control lambs after weaning. The development of internal organs, including the lower gut and liver, was also stimulated by the inoculation. In conclusion, some rumen bacterial populations of young lambs were clearly affected by the inoculation with rumen microbiota, which could contribute to the digestion of the nonstructural carbohydrates available in the starter feed. Improved digestion of starter feed may enhance the energy and nutrient harvest and utilization in young ruminants during the critical weaning phase.

The role of micronutrients in high-yielding dairy ruminants: Choline and vitamin E

This review addresses the potential role of antioxidants and methyl-group sources in optimising the metabolic health of dairy ruminants. The productivity of high-yielding dairy cows has increased over the past 40 years and the milk yield has doubled. Such increases in milk production have been observed not only in dairy cows but also to some extent in other dairy ruminants such as ewes, goats and buffaloes (Bubalus bubalis). As a consequence, in all specialized dairy ruminants it is essential to optimize the macro and micro-nutrient supply, especially during the most critical period in the animals' production cycle i.e. from parturition until the peak of lactation. In this critical phase, an array of factors can enhance the balance between the intake and demand for nutrients, although the availability and supply of the selected micronutrients is also important. The supplementation of dietary antioxidants or boosting the endogenous methyl group status, via vitamin E, selenium and choline are proposed as possible strategies in maintaining stable metabolic health and optimising milk production.

Rumination recognition method of dairy cows based on the change of noseband pressure

Rumination is closely related to ruminant's health and welfare, so it is very important to monitor rumination. Rumination monitoring equipment based on chewing and swallowing audio is easy to be affected by ambient noise, equipment based on acceleration sensor is not easy to monitor number of cuds and other information, equipment based on video monitoring has high cost and is easy to be affected by weather and other cows, while equipment based on chewing pressure can accurately record the chewing pressure of dairy cows, and use related processing technology to obtain the number of cuds and other information. In the related research, the peak value and interval of masticatory pressure peak in time domain were used to identify rumination. In view of the problem that the standard of pressure peak was not well defined due to the different head size and masticatory strength of different age and different breed cows, this paper proposed a method to identify the number of rumination, duration of rumination and number of cuds of cows by using standard deviation and noseband pressure signal frequency spectrum. The accurate and stable frequency spectrum range of rumination noseband pressure signal was obtained by frequency spectrum analysis, and the interference of feeding noseband pressure signal to rumination noseband pressure signal was eliminated by using standard deviation. Compared with the direct observation, the results showed that the recognition accuracy of the method proposed in this paper were 100%, 94.2% and 94.45% for the number of rumination, duration of rumination and number of cuds respectively, and the average absolute errors were 0, 2.0029% and 2.5623% respectively, which showed that the method can accurately identify the rumination information of dairy cows.

Effects of Dietary Non-Fibrous Carbohydrate (NFC) to Neutral Detergent Fiber (NDF) Ratio Change on Rumen Bacteria in Sheep Based on Three Generations of Full-Length Amplifiers Sequencing.

Simple SummaryRumen microbes play an important role in the health and production of ruminants, and they are influenced by dietary changes. In our study, we investigated the change of rumen bacteria under the four treatments of dietary non-fibrous carbohydrate (NFC) to neutral detergent fiber (NDF) ratios in sheep using three generations of full-length amplifiers sequencing. As rumen is a complex organ, and the effects of dietary NFC/NDF ratio change on ruminal bacteria might change over time, thus the study was conducted for four periods of 72 d in total. The results showed that the composition of rumen bacteria changed with different dietary NFC/NDF ratio during the experimental periods. Rumen bacterial diversity was decreased in dietary NFC/NDF ratio of 1.90 with the prolong of experimental periods. The main dominant phyla in Karakul sheep rumen didn’t change, while their relative abundance changed with dietary NFC/NDF ratio and experimental periods. The relative abundance of unidentified-Lachnospiraceae and main cellulose-degrading bacteria was higher in dietary NFC/NDF ratio of 1.37 than other groups (NFC/NDF ratio of 0.54, 0.96 and 1.90).The study was conducted to investigate the effects of dietary NFC/NDF ratio change on rumen bacteria in sheep. Twelve Karakul sheep were assigned randomly into four groups fed with four dietary NFC/NDF ratios of 0.54, 0.96, 1.37, and 1.90 and they were assigned into groups 1, 2, 3, and 4, respectively. The experiment was divided into four periods: I (1–18 d), II (19–36 d), III (37–54 d), and IV (55–72 d). In each period, the first 15 d were used for adaption, and then rumen fluid was collected for 3 d from each sheep before morning feeding. The fluid was analyzed with three generations of full-length amplifiers sequencing. Results showed that the bacterial diversity of group 4 was decreased in period III and IV. At the phylum level, Bacteroidetes (37–60%) and Firmicutes (26–51%) were the most dominant bacteria over the four periods. The relative abundance of Bacteroidetes, Firmicutes, Tenericutes, and Spirochaete changed with dietary NFC/NDF ratio change over the four periods, but there was no difference among groups over the four periods (p > 0.05). At the genus level, unidentified-Lachnospiraceae was the dominant genus, and its relative abundance in group 3 was high during the period I and III (p < 0.05). The relative abundance of Mycoplasma in group 4 was high in the period I and II (p < 0.05). The relative abundance of Succiniclasticum was high in group 2 of period II (p < 0.05). At the species level, the relative abundance of Butyrivibrio-fibrisolvens was found to be high in group 3 during periods I and III (p < 0.05). The main semi-cellulose-degrading bacteria and starch-degrading bacteria were low, and there was no significant difference among groups over four periods (p > 0.05). Taken together, the dietary NFC/NDF ratio of 1.90 decreased the diversity of bacteria as a period changed from I to IV. While the main phylum bacteria didn’t change, their relative abundance changed with the dietary NFC/NDF ratio change over the four periods. The most prevalent genus was unidentified-Lachnospiraceae, and its relative abundance was higher in dietary NFC/NDF ratio of 1.37 than other groups. Similarly, the main cellulose-degrading species was higher in the treatment of dietary NFC/NDF ratio of 1.37 than other groups.

Effect of ruminal administration of soy sauce oil on rumen fermentation, milk production and blood parameters in dairy cows.

ObjectiveTo evaluate soy sauce oil (a by-product of making whole soybean soy sauce) as a new dietary lipid source, a large amount of soy sauce oil was administered into the rumen of dairy cows.MethodsFour Holstein dairy cows fitted with rumen cannulae were used in a 56-day experiment. Ruminal administration of soy sauce oil (1 kg/d) was carried out for 42 days from day 8 to day 49 to monitor nutritional, physiological and production responses.ResultsDry matter intake and milk yield were not affected by soy sauce oil administration, whereas 4% fat-corrected milk yield and the percentage of milk fat decreased. Although ruminal concentration of total volatile fatty acids (VFA) and the proportion of individual VFA were partially affected by administration of soy sauce oil, values were within normal ranges, showing no apparent inhibition in rumen fermentation. Administration of soy sauce oil decreased the proportions of milk fatty acids with a carbon chain length of less than 18, and increased the proportions of stearic, oleic, vaccenic and conjugated linoleic acids. Conjugated linoleic acid content in milk became 5.9 to 8.8 times higher with soy sauce oil administration. Blood serum concentrations of non-esterified fatty acid, 3-hydroxybutyric acid, total cholesterol, free cholesterol, esterified cholesterol, triglyceride and phospholipid increased with administration of soy sauce oil, suggesting a higher energy status of the experimental cows.ConclusionThe results suggest that soy sauce oil could be a useful supplement to potentially improve milk functionality without adverse effects on ruminal fermentation and animal health. More detailed analysis is necessary to optimize the supplementation level of this new lipid source in feeding trials.

Impact of environmental contaminants on reproductive health of male domestic ruminants: a review.

Environmental contaminants are gaining more attention in the livestock sector lately due to their harmful effects on productivity and fertility of livestock. Recent research indicates that many domestic ruminants are becoming subfertile/infertile due to confounding reasons associated with management. Contaminants like metals, metalloids, herbicides, pesticides, insecticides, chemicals, or natural contaminants are present everywhere in day to day life and are becoming a threat to the livestock. Studies on a broad-spectrum of animals suggest that high doses of acute or low doses of chronic exposure to the contaminants lead to disruption of multi-organs/systems including reproductive function. The lowered reproductive efficiency in animals is attributed to the endocrine disruptor activities of the environmental contaminants on the gonads, affecting gametogenesis and steroidogenesis. In vitro studies on testicular cells and the semen suggest that spermatozoa are more susceptible to damage by environmental contaminants. The quality of the semen happens to be a critical factor in the livestock industry. Contaminants affecting gametogenesis and steroidogenesis may lead to devastating consequences to the livestock reproduction, and thus the production. However, there is a lack of collective data on the effect of such environmental contaminants on the fertility of male domestic ruminants. This review discusses the studies related to the impact of environmental contaminants on male fertility in large (bull and buffalo) and small (sheep and goat) ruminants by focusing on the underlying molecular interactions between the contaminants and gonads.

Identification of rotavirus A strains in small ruminants: first detection of G8P[1] genotypes in sheep in Turkey.

Although members of rotavirus group A (RVA) are major enteric pathogens of humans and animals of many species, their impact on the health of small ruminants is not well documented. In this study, we conducted a molecular analysis of VP4, VP7, VP6 and NSP4 genes of RVAs detected using a commercial antigen ELISA in small ruminants with or without diarrhea in Turkey. Of the RVAs detected in sheep, one strain (Kutahya) was characterized as genotype G8P[1]-I2-E2. Two others (Ankara-1 and Ankara-2) were identified as NSP4 E2 and VP6 I2 genotypes, although they were untyped for the VP4 and VP7 genes. The RVAs from two goats were characterized as genotype G6P [1]-I2-E2. This is the first detection of in goats RVA genotypes G6P [1], which had previously only been found in cattle in Turkey, and of RVA in sheep. The study extends our current knowledge about the circulation of two RVA G genotypes, G6 and G8, in goat herds, and the detection of the G8 genotype in sheep in Turkey. This provides further information about the molecular epidemiology of RVAs in different animal species and indicates that additional surveillance programs are needed to determine the epidemiology of RVA in small ruminants and other species.

PSX-37 Effect of forage neutral detergent fiber level for feedlot lambs: Digestibility

Abstract Fiber plays an important role to maintain the normal functioning of the rumen in cattle fed with high-concentrate diets. However, the optimal incorporation of fiber in the finishing diets should counteract the two main limitations of this ingredient in fattening due to the limitation in the ingestion of the diet and the dilution of diet energy as result to its low energy content. Therefore, efforts have been made to determine the optimal level of NDF in the finishing diets where the negative associative effects of the NDF are avoided without undermining its role as a functional feed in fattening. For the above, eight lambs (30.50± 4.44 kg initial weight) were used in a replicated 4 × 4 Latin square design in order to evaluate effective neutral detergent fiber (eNDF) levels (4, 8, 12, and 16% diet DM) on growing-finishing diets in lambs. Experiment had 4 period of 21 days each (17-d to diet adaptation and 4-d to sampling). Dietary treatments consisted of a cracked corn-based diet in which the eNDF concentration of diet was manipulated by replacing cracked corn grain by corn stubble. As the level of eNDF increased, intake of DM, MO, NDF, and GE were linearly increased (P &amp;lt; 0.01), but starch intake was decreased. The apparent digestible energy (Mcal/kg) showed a quadratic effect (P &amp;lt; 0.01) being maximal at 8% eNDF level increased. Ruminal pH increased (P &amp;lt; 0.01) from 5.77 to 6.70 as the level of eNDF increased. It is concluded that 4% of eNDF level in corn-cracked based finishing diet is enough so as not affect ruminal health in lambs. Digestible energy was optimized at 8% of eNDF level.

Impact of purified lignin on performance, rumen health, oxidative stress control and meat quality of lambs fed a high-concentrate diet

This study aimed to evaluate the influence of purified lignin as an additive in high-concentrate diets on performance, ruminal health, meat traits, and oxidative stress control in lambs. Thirty-two crossbred Dorper x Santa Ines sheep with an initial live weight and age of 23±6.3 kg and 60 days, respectively, were kept in individual pens and fed a diet composed of Cynodon sp. hay (10%) and concentrate (90%). The experimental design was a randomized block with four treatments: control, no additives; MON, 15 mg/kg DM of monensin, a known ionophore; LKR, 12.5 g/kg DM of Kraft lignin; SeE, 0.33 mg/kg of selenium and 100 IU/kg DM of vitamin E, which are known antioxidants. Blood samples were collected at the beginning and after 29 and 54 days of feeding for the evaluation of antioxidant enzyme activity. After 55 days of feeding, the lambs were slaughtered and the incidence of rumenitis and papillary morphology were evaluated, as well as carcass and meat traits and shelf life. The data were analyzed using the MIXED model of the SAS 9.3 program at a 5% level of significance. The treatments exerted no effect on performance or carcass traits. Animals fed LKR showed a higher incidence of lesions on the rumen wall (P = 0.03). There was no interaction between time and treatment. The treatments exerted no effect on the activity of most enzymes evaluated, but higher peroxidase activity was observed after 29 days of feeding in LKR animals compared to the MON (P = 0.005) and SeE (P = 0.015) groups. After 29 days of feeding, lower catalase activity (P = 0.030) was observed in animals fed MON compared to control, and MON animals showed lower activity compared to SeE after 54 days (P = 0.042). The SeE treatment was effective in maintaining low lipid peroxidation since this treatment exhibited the lowest values throughout the period of simulated display (P = 0.005). Kraft lignin exerted no protective effect on the rumen wall mucosa nor a positive effect on performance but increased the activity of peroxidases, indicating antioxidant activity.

Dynamic role of single-celled fungi in ruminal microbial ecology and activities.

In ruminants, high fermentation capacity is necessary to develop more efficient ruminant production systems. Greater level of production depends on the ability of the microbial ecosystem to convert organic matter into precursors of milk and meat. This has led to increased interest by animal nutritionists, biochemists and microbiologists in evaluating different strategies to manipulate the rumen biota to improve animal performance, production efficiency and animal health. One of such strategies is the use of natural feed additives such as single-celled fungi yeast. The main objectives of using yeasts as natural additives in ruminant diets include; (i) to prevent rumen microflora disorders, (ii) to improve and sustain higher production of milk and meat, (iii) to reduce rumen acidosis and bloat which adversely affect animal health and performance, (iv) to decrease the risk of ruminant-associated human pathogens and (v) to reduce the excretion of nitrogenous-based compounds, carbon dioxide and methane. Yeast, a natural feed additive, has the potential to enhance feed degradation by increasing the concentration of volatile fatty acids during fermentation processes. In addition, microbial growth in the rumen is enhanced in the presence of yeast leading to the delivery of a greater amount of microbial protein to the duodenum and high nitrogen retention. Single-celled fungi yeast has demonstrated its ability to increase fibre digestibility and lower faecal output of organic matter due to improved digestion of organic matter, which subsequently improves animal productivity. Yeast also has the ability to alter the fermentation process in the rumen in a way that reduces methane formation. Furthermore, yeast inclusion in ruminant diets has been reported to decrease toxins absorption such as mycotoxins and promote epithelial cell integrity. This review article provides information on the impact of single-celled fungi yeast as a feed supplement on ruminal microbiota and its function to improve the health and productive longevity of ruminants.