The effect of periodic energy restriction on growth performance, serum biochemical indices, and meat quality in sheep

Effects of Different Dietary Energy Levels on Development, Quality of Carcass and Meat, and Fatty Acid Profile in Male Lambs

This experiment was conducted to study the effects of dietary energy level on the growth performance and meat quality of weaned Alpine Merino lambs. The study ran for a total of 104 days (20-day pretrial, 84-day trial). From three groups of test lambs, we randomly selected ten lambs per group to determine slaughter performance, meat quality characteristics, and organ indexes. The slaughter performances of the lambs improved as the dietary energy level increased. The live weight before the slaughter of the lambs was significantly higher in the high group than in the low and medium groups. The carcass weight was significantly higher in the high group than in the low group. Dietary energy level had little effect on the organ weight of lambs. Meat quality differed among the three dietary energy levels. The muscle yellowness and redness scores decreased significantly as the energy levels increased. The C18:0, C21:0, C20:1, C18:2n6c, and C20:2 contents in the muscle were significantly higher in the high group than in the medium and low groups. The C18:3n6 content in the muscle was significantly higher in the low group than in the medium group. The C20:5n3 content in the longissimus dorsi was significantly higher in the high group than in the medium and low groups. The monounsaturated and unsaturated fatty acid contents in the muscle were significantly higher in the high group than in the low group. A dietary energy level of 10.5 MJ/kg is suitable for fattening weaned male Alpine Merino lambs.

Relationship between feed efficiency and resilience in dairy ewes subjected to acute underfeeding

Selection of dairy sheep based on production levels has caused a loss of rusticity, which might compromise their future resilience to nutritional challenges. Although refocusing breeding programs toward improved feed efficiency (FE) is expected, more-efficient ewes also seem to be more productive. As a first step to examine the relationship between FE and resilience in dairy sheep, in this study we explored the variation in the response to and the recovery from an acute nutritional challenge in high-yielding Assaf ewes phenotypically divergent for FE. First, feed intake, milk yield and composition, and body weight changes were recorded individually over a 3-wk period in a total of 40 sheep fed a total mixed ration (TMR) ad libitum. Data were used to calculate their FE index (FEI, defined as the difference between the actual and predicted intake estimated through net energy requirements for maintenance, production, and weight change). The highest and lowest FE ewes (H-FE and L-FE groups, respectively; 10 animals/group) were selected and then subjected to the nutritional challenge (i.e., withdrawing the TMR and limiting their diet only to the consumption of straw for 3 d). Afterward, sheep were fed again the TMR ad libitum. Temporal patterns of variation in performance traits, and ruminal fermentation and blood parameters were examined. A good consistency between FEI, residual feed intake, and feed conversion ratio was observed. Results supported that H-FE were more productive than L-FE sheep at similar intake level. Average time trends of milk yield generated by a piecewise model suggest that temporal patterns of variation in this trait would be related to prechallenge production level (i.e., H-FE presented quicker response and recovery than L-FE). Considering all studied traits, the overall response to and recovery from underfeeding was apparently similar or even better in H-FE than in L-FE. This would refute the initial hypothesis of a poorer resilience of more-efficient sheep to an acute underfeeding. However, the question remains whether a longer term feed restriction might impair the ability of H-FE ewes to maintain or revert to a high-production status, which would require further research.

Effect of dietary Agriophyllum squarrosum on average daily gain, meat quality and muscle fatty acids in growing Tan lambs

The herb A. squarrosum is reputed to possess medicinal properties for humans, and has the potential to be a feed resource for livestock. We hypothesized that this herb would improve the meat quality of lambs. To test this hypothesis, 24 Tan ewe-lambs (27.7 ± 0.45 kg) were offered diets containing 0 (CON), 100 (AS₁₀₀), 200 (AS₂₀₀) and 300 (AS₃₀₀) g A. squarrosum/kg DM, and average daily gain, carcass traits, blood metabolites, meat quality and fatty acid profiles were determined. Drip loss % and cooking loss % decreased with the AS₁₀₀ and AS₂₀₀ diets (P < 0.05). Dietary A. squarrosum reduced muscle fiber area and diameter and increased density of the meat (P < 0.05), which indicated that the meat was more tender. The concentrations of C10:0 and C18:1n-9 t were 1ower and of C17:0 and C18:3n-3 were greater in the AS₂₀₀ and AS₃₀₀ treatments than CON (P < 0.05). Our results suggest that feeding lambs up to 200 g/kg DM of A. squarrosum can increase the water-holding capacity and L* value of meat without compromising growth. Further research is needed to determine the optimal level.

Effect of the Replacement of Maize Silage and Soyabean Meal with Mulberry Silage in the Diet of Hu Lambs on Growth Performance, Serum Biochemical Indices, Slaughter Performance, and Meat Quality

Maize silage has a high demand for fertilizer and water. As an unconventional feed resource, mulberry silage has the potential to replace most maize silage and to alleviate the shortage of roughage in the mutton sheep industry in China. The purpose of this experiment was to study the effect of the replacement of maize silage and soyabean meal with mulberry silage in the diet of Hu lambs on growth performance, serum biochemical indices, slaughter performance, and meat quality. Ninety-six healthy Hu lambs were randomly divided into four groups with six replicates per group and four lambs per replicate. The amounts of 0, 20, 40, and 60% of maize silage were replaced by mulberry silage in each group (denoted as CON, L, M, and H, respectively). The results showed that replacing maize silage with mulberry silage had no significant effect on the growth performance or the slaughter performance of Hu lambs (p > 0.05). Feeding Hu lambs with mulberry silage significantly reduced serum glucose (GLU) and the blood urea nitrogen (BUN) content (p < 0.05), and it increased the content of ether extract (EE) in the longissimus dorsi muscle (p < 0.05). Meanwhile, the percentage of EAA in the M and H groups was significantly lower than that in the CON and L groups (p < 0.05). In addition, in the fatty acid profile, the percentage of C16:1 in the M group was significantly increased, while the percentage of C18:0 and C20:0 were significantly decreased (p < 0.05). Based on these findings, it was recommended that 20−40% of maize silage be replaced by mulberry silage in the diet of Hu lambs.

Glutamate Supplementation Improves Growth Performance, Rumen Fermentation, and Serum Metabolites in Heat-Stressed Hu Sheep

This study evaluated the effect of glutamate supplementation on the physiological parameters of heat-stressed Hu sheep. Forty-eight male Hu sheep with an average initial body weight of 17.74 ± 0.17 kg were randomly divided into two groups: The control group (CON) was fed a basal diet and a treatment group (GLU) was fed a basal diet + 3 g/head/day of L-glutamate. There were six replications in each group with four sheep in each replication for a 90 days feeding test. Growth performance, serum biochemistry, and serum hormones were measured during phase 1 (1–30 days), phase 2 (31–60 days), and phase 3 (61–90 days) of the experiment; rumen fermentation characteristics, nutrient digestibility, and slaughter performance were measured at the end of the experimental periods. There were no differences in growth performance, serum biochemical indices, and immune indices between CON and GLU during phases 1 and 2. However, a higher average daily gain (ADG), a lower average daily feed intake (ADFI), and a lower F:G ratio (ADFI/ADG) were observed in GLU during phase 3 (p < 0.05). Serum levels of glutamate, globulin, immunoglobulin A, immunoglobulin G, immunoglobulin M, and growth hormone in GLU were higher than those in CON only on day 90 (p < 0.05). Serum levels of heat shock protein 70, adrenocorticotrophic hormone, corticosterone, triiodothyronine, and tetraiodothyronine in GLU were lower than those in CON on day 90 (p < 0.05). At the end of the experiment, ruminal pH, microbial crude protein, ammonia nitrogen, and isovalerate concentrations in GLU were higher than those in CON (p < 0.05). The apparent digestibility of dry matter, organic matter, and crude protein in GLU was higher than those in CON (p < 0.05). There were no differences in carcass traits and organ indices but spleen weight and spleen index tended to be higher in GLU. In conclusion, dietary glutamate supplementation improved rumen fermentation, increased nutrition digestibility and metabolism, enhanced immunity, and promoted growth performance of heat-stressed Hu sheep. This suggests that a longer period of glutamate supplementation (not less than 60 days) at a level of 3 g/head/day is beneficial to Hu sheep under heat stress.

Replacing cottonseed meal and sorghum with dried distillers` grains with solubles enhances the growth performance, carcass traits, and meat quality of feedlot lambs

We evaluated the impacts of substituting cottonseed meal (CSM) and sorghum grain (SG) with dried distillers` grains with solubles (DDGS) in lamb feedlot diets on the dry matter intake (DMI), the growth performance, blood serum analysis, feces phosphorus (P) and nitrogen (N), wool production and quality, carcass traits, adipose tissue fatty acid (FA) profiles, and sensory panel tests. For 72 d, Rambouillet wether lambs (n = 44, initial body weight, BW = 28.8 ± 3.3 kg) were individually fed ad libitum pelleted diets containing DDGS that replaced 0% (0DDGS), 25% (25DDGS), 50% (50DDGS), or 75% (75DDGS) of the CSM and SG in a completely randomized design trial. Linear and quadratic effects of DDGS levels on the response variables were analyzed. Treatment × day interactions (P < 0.001) were observed for BW and DMI. As the DDGS level was increased, DMI (from days 21 to 70), lamb BW (from days 56 to 70), average daily gain, blood urea nitrogen and P, and fecal P linearly increased (P ≤ 0.05). Fecal N quadratically increased (P = 0.01), but no effects were found for gain:feed, blood insulin-like growth factor-1, or calcium. No differences in wool production or most of the wool quality parameters were detected. Adipose tissue stearic acid linearly increased (P = 0.02), linoleic acid quadratically increased (P = 0.01), and oleic acid tended to quadratically decrease (P = 0.08) as the DDGS increased in the diets. Increasing the DDGS level in the diets quadratically increased the hot carcass weight (P = 0.02), backfat thickness (P = 0.04), and body wall thickness (P < 0.001) while having no impact on the longissimus muscle area. As the DDGS increased in the diet, juiciness, tenderness, and overall acceptability linearly increased (P ≤ 0.05), while having no effect on the cook-loss, flavor intensity, or off-flavor detectability. Replacing 50% of CSM and SG with DDGS improved growth performance and enhanced the carcass and meat quality.

Effects of Phragmites australis Shoot Remainder Silage on Growth Performance, Blood Biochemical Parameters, and Rumen Microbiota of Beef Cattle

The objective of the present study was to assess the effects of replacing corn silage with Phragmites australis shoot remainder (PSR) silage on intake, growth performance, serum biochemical parameters, and rumen microbial diversity of growing-finishing beef. Fifteen Angus beef cattle with an average body weight of 253 ± 2.94 kg were randomly divided into three groups (five replicas vs. each group vs. Angus beef cattle). The three treatments were group A fed 60% PSR silage + 40% concentrate, group B fed 30% PSR silage + 30% corn silage + 40% concentrate, and group C fed 60% corn silage + 40% concentrate. The adaptation period was 15 days, and the trial period lasted for 45 days. Results showed that the ADG was significantly higher, and FCR was significantly lower both in groups A and B compared with group C. The results of serum biochemical parameters showed that the concentration of GLU was significantly lower in group B than both groups A and C. Microbial diversity results showed that the OTUs, Shannon, Chao1, and ACE indices were significantly lower in group A compared with groups B and C. At the phyla level, the relative abundances of Tenericutes and Melainabacteria had significant differences among the three groups, and the relative abundances of Papillibacter, Anaeroplasma, and Anaerovorax had significant differences among the three groups at the genus level. Additionally, Rikenellaceae was the unique biomarker among the three groups. Furthermore, the results of function prediction showed that the gene families associated with metabolism of cofactors and vitamins, cellular processes and signaling, metabolism, biosynthesis of other secondary metabolites, infectious diseases, signaling molecules and interaction, nervous system, and digestive system were significantly decreased, while lipid metabolism was dramatically increased from groups A to C at KEGG level 2. At KEGG level 3, 11 metabolic pathways were significantly influenced among the three groups. In summary, these findings indicated that PSR silage substituted the corn silage totally or partially improved the growth performance, and altered the rumen microbial composition and diversity and the corresponding change in prediction function of rumen bacteria in Angus beef cattle.

Growth performance, nutrient digestibility, blood parameters, and carcass characteristics by lambs fed an oregano and cobalt blend

Shifting ruminal fermentation via feeding a blend of oregano (Organum vulgare L.) essential oils and Co-lactate (EOC; Rum-A-Fresh, Ralco, Inc. Marshall, MN) could improve lamb growth and carcass performance. Eighteen Suffolk × Little Han Tail F1 male lambs (20.3 ± 0.23 kg BW and approximately 3 months old) were randomly assigned using a completely random design to one of three treatments. Treatments were (1) EOC0: basal ration without EOC, (2) EOC4: basal ration plus 4 g/d EOC, and (3) EOC7: basal ration plus 7 g/d EOC. Initial and 24 d BW was similar (P > 0.10), but at 48 and 72 d, lambs fed EOC7 demonstrated greater (P = 0.01) BW compared with EOC0 fed lambs, while lambs fed EOC4 were intermediate and similar (P > 0.05). Average daily gains (ADGs) for 0-24 and 0-72 d were greater (P < 0.05) for lambs fed EOC4 and EOC7 compared with lambs fed EOC0, while DM intake was similar (P > 0.10). Feed conversions for 0-24 d were improved (P < 0.02) for lambs fed EOC4 and EOC7 compared with lambs fed EOC0. However, 0-72-d feed conversions were greater (P < 0.01) for lambs fed EOC7 compared to lambs fed EOC0, with lambs fed EOC4 being intermediate and similar (P > 0.05). DM, NDF, and ADF digestibilities were similar (P > 0.10) among treatments, while CP digestibility was greater (P < 0.01) for lambs fed EOC4 and EOC7 compared with lambs fed EOC0. Carcass weight and dressing percentages were improved (P < 0.01) for lambs fed EOC7 compared with lambs fed EOC0 and EOC4. Head width was greater (P > 0.01) for lambs fed EOC7 compared with lambs fed EOC0 and EOC4, while rump width was greater (P > 0.01) for lambs fed EOC4 and EOC7 compared with lambs fed EOC0. Plasma triglyceride and cholesterol concentrations were lower (P < 0.05) for lambs fed EOC4 and EOC7 compared with lambs fed EOC0, while albumin, total serum protein, and glucose concentrations were greater (P < 0.05) for lambs fed EOC4 and EOC7 compared with lambs fed EOC0. Feeding an EOC blend as an alternative antibiotic growth promoter at 4 and 7 g/d linearly improved lamb growth performance, feed conversions, frame growth, carcass weights, dressing percentages, and immunity.

Flaxseed Oil and Heated Flaxseed Supplements Have Different Effects on Lipid Deposition and Ileal Microbiota in Albas Cashmere Goats

Simple Summary

With the grassland desertification intensified, pasture carrying capacity decreased, and grass seasonal changed, stall-feeding fattening has become an effective means to protect the natural environment. The stall-feeding fattening increased the cashmere goats’ weight but reduced the meat quality and increased the saturated fatty acids content in muscle and fat tissue of cashmere goats. Supplementing flaxseed and flaxseed oil rich-in linolenic acid (ALA) to diet to improve meat quality is an effective nutritional regulation means. Previous research results of our team showed that compared to diet supplemented with flaxseed oil, added flaxseed increased linoleic acid biohydrogenation by reducing the Ruminobacter relative abundance and increasing the relative abundance of Prevotellaceae_UCG-001 and Fretibacterium in rumen, protected ALA away from biohydrogenation, and more n-3 polyunsaturated fatty acids entered the post-intestinal tract. Based on the previous research, this study explored whether the ALA flowing into the posterior intestine can reduce fat deposition and blood lipid by affecting intestinal microbiota. The results showed that adding flaxseed grain to diet decreased the growth performance, lipid deposition, and blood lipid content of goats by regulating the blood lipid-related enzyme activity, which positively associated with [Eubacterium]_coprostanoligenes_group, but negatively associated with unclassified_f_Peptostreptococcaceae, Intestinibacter, and Ruminococcus_2.

Abstract

The present study investigated the effect of flaxseed grain or flaxseed oil on ileal microbiota and lipid deposition of cashmere goats. Sixty kid goats (average body weight 18.6 ± 0.1 kg) were allocated to three treatments, fed for 90 days, with control treatment: basal diet (CON, total-mixed ration), experimental treatment: basal diet with added flaxseed oil (LNO), experimental treatment: basal diet with added heated flaxseed grain (HLS). The final body weight, body weight gain, the weight of kidney fat, omental fat, tail fat, and fat tissue, the activity of fatty acid synthetase, acetyl-coa carboxylase, and malic dehydrogenase, and the relative abundance (RA) of unclassified_f_Peptostreptococcaceae and Intestinibacter were remarkably higher in the LNO treatment than in the HLS treatment, but the [Eubacterium]_coprostanoligenes_group RA showed the opposite result. The content of triglyceride, cholesterol, and low-density lipoprotein cholesterol were significantly higher in the CON and LNO treatments than in the HLS treatment, while the hormone-sensitive lipase activity and the non-esterified fatty acid content showed the opposite result. In conclusion, the flaxseed grain is more efficient than flaxseed oil in ameliorating the blood lipid profiles and it is a potential product for decreasing the lipid deposition of cashmere goats.

Changes in Rumen Microbiota Affect Metabolites, Immune Responses and Antioxidant Enzyme Activities of Sheep under Cold Stimulation

Simple Summary

Under a cold environment, the animal’s weight is reduced and even health is affected. As we all know, microbiota is beneficial to animal health. It can produce metabolites to improve animal immunity and avoid damage. Therefore, we aimed to understand the self-protection mechanisms of sheep under cold stress. To investigate this mechanism, we designed two experiments to explore the effects of low temperature and wind speed on sheep phenotypes, rumen microbes, immune cytokines and oxidative stress. Our results identified that the sheep remained healthy in a cold environment. This may be due to the enrichment of Lachnospiraceae in the rumen. A large amount of propionate may enter into the gluconeogenesis reaction, resulting in a decrease in the content of propionate in the rumen, thereby reducing animal’s immunity. In summary, the increase of Lachnospiraceae and propionate in the rumen may help sheep live in a cold environment. Our experiments provide some direction for the healthy feeding of animals in cold environments.

Abstract

Low-temperature environments can strongly affect the normal growth and health of livestock. In winter, cold weather can be accompanied by strong winds that aggravate the effects of cold on livestock. In this study, two experiments were conducted to investigate the effect of low temperature and/or wind speed on physiological indices, rumen microbiota, immune responses and oxidative stress in sheep. When sheep were exposed to cold temperature and/or stronger wind speeds, the average daily gain (ADG) decreased (p < 0.05), and the abundance of Lachnospiraceae was significantly higher (p < 0.05). The acetate and propionate contents and the proportion of propionate in the rumen also significantly reduced (p < 0.05). The immunoglobulin G (IgG) and TH1-related cytokines in the blood were significantly lower (p < 0.05). However, antioxidant enzyme contents were significantly increased and the concentration of malondialdehyde (MDA) was reduced (p < 0.05). In a cold environment, the abundance of Lachnospiraceae in the rumen of sheep was highly enriched, and the decreasing of propionate might be one of the factors affecting the immunity of the animals, the sheep did not suffer from oxidative damage during the experiment.

Effects of dietary energy level on growth performance, blood parameters and meat quality in fattening male Hu lambs

This experiment was conducted to investigate the effects of different dietary energy levels on growth performance, slaughter traits, meat quality and blood biochemical parameters in fattening male Hu lambs. Sixty lambs were fed five iso-protein diets which contained different levels of metabolizable energy in a completely randomized design for 70 days. At the end of study, fifteen lambs were harvested for further study. With the increase in dietary energy level, the daily weight gain and dry matter intake extremely increased (p < .001), and feed conversion ratio decreased significantly (p < .01). The live weight before slaughter (LWBS) and carcass weight had a significant increase (p < .05), non-carcass fat ratio and routine indexes of meat quality had no significant difference. Almost no effect was observed for the amino acid profile except for glycine concentration decreased (p < .05) in longissimus dorsi (LD) muscle. The concentrations of C17:0, C18:3n-3 and n-3 PUFA (p < .01) significantly decreased with the increasing dietary energy levels, and the ratio of ∑n-6/∑n-3 (p < .01) increased, whereas the concentrations of C18:1n-9t (p < .05) decreased in LD muscle and C18:1 (p < .01) increased in biceps femoris (BF) muscle. There were no obviously differences for diameter, area and density of muscle fibres. The relative expression of MyHC-IIa and MyHC-IIx decreased significantly (p < .05) in BF muscle, and the relative expression of MyHC-IIa displayed an obviously decreasing trend (p < .10) in LD muscle. These results suggest that increasing the dietary energy level can improve the growth performance and slaughter traits, and influence meat quality and fatty acid profiles in different muscle tissues of fattening male Hu lambs. These results provide a theoretical basis for developing Hu sheep nutritional standards and designing feed formulations.

Effects of spirulina supplementation on lipid metabolism disorder, oxidative stress caused by high-energy dietary in Hu sheep

The aim of this study was to investigate the effect of spirulina supplementation in a high-energy (HE) diet on lipid metabolism, oxidative status and immunity in Hu lambs. The lambs were assigned to two groups receiving either a standard diet (ST) or a HE diet. Each group was divided into three subgroups: no spirulina supplementation (control), 1% spirulina supplementation, or 3% spirulina supplementation. The body fat, serum cholesterol, triacylglycerol and oxidative stress increased in lambs fed the HE diet. However, 3% spirulina supplementation in the HE diet reduced above parameters and enhanced antioxidant capacity, including increased SOD activity and T-AOC content in serum and Longissimus thoracis et lumborum (LTL). Additionally, lambs receiving 3% spirulina supplementation showed an improvement in immunity-related parameters, including increased IgG concentration in serum and red and white blood cell counts. In conclusion, 3% spirulina supplementation in HE diet ameliorated lipid metabolic disorder and oxidative stress caused by a HE diet.