Effects of vegetable oil supplementation on rumen fermentation and microbial population in ruminant: a review.

Understanding the nature of ruminant nutrition and digestion is essential to improve feeding management and animal production. Among many approaches, manipulating ruminant nutrition and fermentation through feed supplementation is being practised and researched. Over the last decade, the utilization of vegetable oils in feed formulation and their effects on various aspects of ruminants have been reported by many researchers. It is important to understand the lipid metabolism in ruminants by microorganisms because it affects the quality of ruminant-derived products such as meat and milk. Majority of vegetable oil supplementation could reduce rumen protozoa population in ruminants due to the effects of medium-chain fatty acids (FAs). However, vegetable oil also contains unsaturated FAs that are known to have a negative effect on cellulolytic bacteria which could show inhibitory effects of the fibre digestion. In this paper, the physiology of nutrient digestion of ruminants is described. This paper also provides a current review of studies done on improvement and modification of rumen fermentation and microbial population through vegetable oil supplementation.

Effects of naturally-produced lovastatin on carcass characteristics, muscle physico-chemical properties and lipid oxidation and cholesterol content in goats.

This study investigated the carcass characteristics, physico-chemical properties, storage stability and cholesterol content of meat from goats fed with different levels of naturally-produced lovastatin used to mitigate enteric methane production. Twenty intact Saanen male goats of 5-6 months old with initial live weight of 25.8 ±â€¯4.0 kg were randomly allotted into four dietary treatments containing 0 (Control), 2 (Low), 4 (Medium) and 6 mg (High) per kg live weight (LW) of naturally-produced lovastatin for 12 consecutive weeks. No differences were found in all the parameters measured except for full LW, hot and cold carcass weight, shear force, color and cholesterol content among the treatment groups. Aging had significant effects on all the parameters measured in this study except a* (redness) of meat. Meat samples in the Medium and High treatments were of higher lightness and yellowness, more tender and lower cholesterol levels. We conclude that, in addition to mitigate enteric methane emissions, dietary supplementation of naturally-produced lovastatin at 4 mg/kg LW could be a feasible feeding strategy to produce tender meat containing lower cholesterol.

Naturally Produced Lovastatin Modifies the Histology and Proteome Profile of Goat Skeletal Muscle.

This study was conducted to examine the effects of different levels of lovastatin on the histological and sarcoplasmic proteome profile of goat skeletal muscle. A total of 20 intact male Saanen goats were randomly assigned in equal numbers to four groups and fed a total mixed ration containing 50% rice straw, 22.8% concentrates and 27.2% of various proportions of untreated or treated palm kernel cake (PKC) to achieve the target daily intake levels of 0 (Control), 2 (Low), 4 (Medium) or 6 (High) mg lovastatin/kg BW. A histological examination discovered that the longissimus thoracis et lumborum muscle of animals from the Medium and High treatment groups showed abnormalities in terms of necrosis, degeneration, interstitial space and vacuolization. Our preliminary label-free proteomics analysis demonstrates that lovastatin supplementation induced complex modifications to the protein expression patterns of the skeletal muscle of the goat which were associated with the metabolism of carbohydrate and creatine, cell growth and development processes and other metabolic processes. The changes in these biochemical processes indicate perturbations in energy metabolism, which could play a major role in the development of myopathy. In conclusion, the present study suggests that supplementation of naturally produced lovastatin above 4 mg/kg BW could adversely affecting the health and wellbeing of treated animals.

Metagenomics analysis reveals significant modulation of cecal microbiota of broilers fed palm kernel expeller diets.

The potential use of palm kernel expeller (PKE) as an alternative energy source in broiler diets is limited by the high fiber content. Although enzymatic treatment could alleviate the fiber component and increase the nutritive value of PKE, this apparent improvement is not reflected in the growth response of birds fed with the treated-PKE. As chicken's ceca are the most heavily populated with microflora within their gastrointestinal tract, it was hypothesized that any modulation of the intestinal environment by dietary treatments should be reflected by the composition and activities of the cecal microflora. There is a correlation between cecal microbiota composition and the efficiency of the host to extract energy from the diet and to deposit that energy into improved feed conversion ratio. At present, little is known about the changes on cecal microflora of broilers fed with PKE diets. Hence, this study was designed to assess the effects of feeding different forms of PKE; namely untreated PKE (UPKE), enzyme-treated PKE (EPKE), and oligosaccharides extracted from PKE (OligoPKE), on the cecal microbiota of broiler chickens at 14 d old (day 14) and 28 d old (day 28) using 16S rRNA gene high-throughput next-generation sequencing method. The results showed that temporal changes in cecal microbiota of broiler chickens were evident on day 14 and day 28. The relative abundance of phylum Firmicutes, known to be involved in nutrient uptake and absorption in both age groups was higher in the UPKE as compared to EPKE group. In addition, supplementation of OligoPKE increased (P < 0.05) the relative abundance of Lactobacillus on both D14 and D28, signifying its effect as prebiotics in enhancing growth of indigenous Lactobacillus. Our results showed that cecal microbiota was significantly modulated by dietary treatments and that the lower relative abundance of phylum Firmicutes in chickens fed with EPKE could be a reason why broiler chickens fed with EPKE of higher metabolizable energy (ME) content did not show improvement in their growth performance.

Oil supplementation improved growth and diet digestibility in goats and sheep fed fattening diet.

OBJECTIVE: This study evaluated the growth, digestibility and rumen fermentation between goats and sheep fed a fattening diet fortified with linseed oil. METHODS: Twelve 3 to 4 months old male goats and sheep were randomly allocated into two dietary treatment groups in a 2 (species)×2 (oil levels) factorial experiment. The treatments were: i) goats fed basal diet, ii) goats fed oil-supplemented diet, iii) sheep fed basal diet, and iv) sheep fed oil-supplemented diet. Each treatment group consisted of six animals. Animals in the basal diet group were fed with 30% alfalfa hay and 70% concentrates at a rate equivalent to 4% of their body weight. For the oil treatment group, linseed oil was added at 4% level (w:w) to the concentrate portion of the basal diet. Growth performance of the animals was determined fortnightly. Digestibility study was conducted during the final week of the feeding trial before the animals were slaughtered to obtain rumen fluid for rumen fermentation characteristics study. RESULTS: Sheep had higher (p<0.01) average daily weight gain (ADG) and better feed conversion ratio (FCR) than goats. Oil supplementation did not affect rumen fermentation in both species and improved ADG by about 29% and FCR by about 18% in both goats and sheep. The above enhancement is consistent with the higher dry matter and energy digestibility (p<0.05), as well as organic matter and neutral detergent fiber digestibility (p<0.01) in animals fed oil- supplemented diet. Sheep had higher total volatile fatty acid production and acetic acid proportion compared to goat. CONCLUSION: The findings of this study suggested that sheep performed better than goats when fed a fattening diet and oil supplementation at the inclusion rate of 4% provides a viable option to significantly enhance growth performance and FCR in fattening sheep and goats.

Effects of naturally-produced lovastatin on feed digestibility, rumen fermentation, microbiota and methane emissions in goats over a 12-week treatment period.

Twenty male Saanen goats were randomly assigned to four levels of lovastatin supplementation and used to determine the optimal dosage and sustainability of naturally produced lovastatin from fermentation of palm kernel cake (PKC) with Aspergillus terreus on enteric methane (CH4) mitigation. The effects on ruminal microbiota, rumen fermentation, feed digestibility and health of animal were determined over three measuring periods (4-, 8- and 12-weeks) and the accumulation of lovastatin in tissues was determined at the end of the experiment. The diets contained 50% rice straw, 22.8% concentrates and 27.2% of various proportions of untreated or treated PKC to achieve the target daily intake level of 0 (Control), 2, 4 or 6 mg lovastatin/kg body weight (BW). Enteric CH4 emissions per dry matter intake (DMI), decreased significantly (P<0.05) and equivalent to 11% and 20.4%, respectively, for the 2 and 4 mg/kg BW groups as compared to the Control. No further decrease in CH4 emission thereafter with higher lovastatin supplementation. Lovastatin had no effect on feed digestibility and minor effect on rumen microbiota, and specifically did not reduce the populations of total methanogens and Methanobacteriales (responsible for CH4 production). Similarly, lovastatin had little effect on rumen fermentation characteristics except that the proportion of propionate increased, which led to a decreasing trend (P<0.08) in acetic: propionate ratio with increasing dosage of lovastatin. This suggests a shift in rumen fermentation pathway to favor propionate production which serves as H+ sink, partly explaining the observed CH4 reduction. No adverse physiological effects were noted in the animals except that treated PKC (containing lovastatin) was less palatable at the highest inclusion level. Lovastatin residues were detected in tissues of goats fed 6 mg lovastatin/kg BW at between 0.01 to 0.03 µg/g, which are very low.