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This experiment was conducted to investigate the effects of dietary energy on antioxidant capacity, liver glucose-lipid-related gene expressions and meat fatty acid of Holstein bulls. Thirty-six Holstein bulls (age, 17.0 ± 0.49 months; body weight, 493.3 ± 39.7 kg) were randomly allocated to three dietary treatments. The metabolizable energy of diets was 10.12, 10.90 and 11.68 MJ/kg. Bulls in each dietary treatment were sampled at the age of 20, 23 or 26 months. Results showed that serum glutathione peroxidase and superoxide dismutase decreased with the increasing age. Dietary energy and age had interaction effects on the expressions of fatty acid synthase, peroxisome proliferator-activated receptor alpha, acyl coenzyme A oxidase 1 and carnitine palmitoyl-transferase 1 alpha. Besides, the increase of age and dietary energy increased the expression of liver phosphoenolpyruvate carboxykinase 1. The expressions of liver glucose-6-phosphatase, tumour necrosis factor alpha and sterol regulatory element binding protein 1 increased with the increasing age. The increase of age and dietary energy increased the proportions of C18:1cis-9, C18:2n-6trans and monounsaturated fatty acid. In summary, the increase of age and dietary energy enhanced the intensity of metabolic changes and inflammatory responses. Dietary energy and age affected the expressions of liver lipid metabolism-related genes, further affected meat fatty acid composition of Holstein bulls.

The objective of this study was to evaluate the effect of different dietary densities on growth performance, carcass characteristics, meat quality, serum metabolism, ruminal papillae morphology and liver injuries of steers. For this purpose, a total of eighteen Holstein steers were randomly fed one of the three diets: high energy and protein diet (H), standard energy and protein diet (C), and low energy and protein diet (L) for 11 months fattening with three-step finishing strategy. Steers fed with H diet had higher (p .05) average daily gain, feed efficiency, hot carcass weight, serum aspartate aminotransferase to alanine aminotransferase ratio, and monounsaturated fatty acids along with continuous low ruminal pH value, severer hepatic steatosis and ruminal papillae parakeratosis. Meanwhile, steers fed L diet increased the proportion of C20:0, C22:6n-3, saturated fatty acids and n-3 polyunsaturated fatty acids along with lower n-6 to n-3 ratio in longissimus dorsi muscle as compared to that of steers fed H diet. Dietary densities did not influence (p .10) proximate nutrients and sensory characteristics of beef. The present study indicates that Holstein steers could achieve better growth and carcass performance under high-density diet, whereas they are under threat of visceral injuries and metabolic disorders. This study gives comprehensive relationship between productivity and animal health and suggests that a proper diet should be adopted for fattening Holstein steers in consideration of both beef quality and quantity and animal health.

Intramuscular fat (IMF) content is critical for the eating quality of beef, but mechanisms regulating IMF deposition remain unsystematically defined. Myogenic and adipogenic cells come from a similar pool of progenitor cells. We hypothesized that adipogenic differentiation was primed in high marbling cattle. To test, two groups of cattle with high and low marbling levels were selected from a uniform group of cattle with the same genetic background and management. By RNA-sequencing, differentially expressed genes were identified. Myogenic genes (eg. MyoG) were up-regulated in the low marbling group, while apolipoprotein E genes (eg. APOE) were down-regulated. Meanwhile, the expression of fibrogenic genes was mixed, with collagen isoforms, COL11A2 and COL22A1 more highly expressed in the high marbling group, and COL14A1, COL16A1, COL1A1 and COL1A2 more lowly expressed. In summary, our data show that adipogenesis was elevated in high marbling cattle accompanied by weakened myogenesis, pointing to the developmental origins of differences in beef marbling.

Hybridization in bovines is practiced with the main aim of improving production performance, which may imply the microbial variations in the rumen from the parental breed cross to their progeny. Besides, the interactions of offspring breed with sex in terms of rumen bacteria are not clear. This study aims to evaluate the variations in rumen bacterial communities in different breeds and sexes, and the correlations among fattening performance, serum biochemical parameters, and rumen fermentation. Forty-two 19.2 ± 0.67-month-old beef cattle (390 ± 95 kg of initial body weight) comprising two genetic lines (Yiling and Angus × Yiling) and two sexes (heifers and steers) were raised under the same high-grain diet for 120 d. On the last two days, blood samples were collected from each animal via the jugular vein before morning feeding for analyzing serum biochemical parameters; rumen fluid samples were obtained via esophageal intubation 2 h after morning feeding for analyzing rumen fermentation parameters and bacterial communities. The results show that both breed and sex had a certain impact on fattening performance, serum biochemical parameters, and rumen fermentation. No differences in the diversity and structure of rumen bacterial communities were observed. Significant interactions (p < 0.05) of breed and sex were observed for Succinivibrionaceae UCG-002 and Prevotellaceae UCG-001. The relative abundances of the Rikenellaceae RC9 gut group, Prevotellaceae UCG-003, and Succinivibrio were different (p < 0.05) between breeds. Heifers had a higher (p = 0.008) relative abundance of the Rikenellaceae RC9 gut group than steers. Correlation analysis showed a significant relationship (p < 0.05) of rumen bacteria with serum biochemical parameters, rumen pH, and rumen fermentation patterns. Additionally, only two genera, Prevotellaceae UCG-003 and Prevotellaceae UCG-001, had positive correlations with feed efficiency. In conclusion, serum biochemical parameters, rumen fermentation, and rumen bacterial communities are partly driven by the breed and sex of cattle fed a high-grain diet.

The objectives of this study were to investigate the effects of age and dietary straw levels on growth performance, carcass and meat traits, as well as tissue antioxidant status of Yiling cull cows. Twenty-four Yiling cull cows were arranged in a 2 × 2 factorial design: two age classes consisting of younger cull cows (YCC, appearing with three or four pairs of permanent teeth) and older cull cows (OCC, worn out teeth), two dietary treatments consisting of lower and higher rice straw levels (LRS and HRS, providing 0.7 kg/d and 1.2 kg/d rice straw per head based on air-dry basis, respectively). Cows were fed twice a day. Straw was offered at half of the predetermined weight each meal, concentrate was separately supplied ad libitum. After 300 d of feeding, final body weight (BW), total BW gain, average daily gain and gain:feed intake were higher (p &lt, 0.01) in the YCC group than in the OCC group. Total dry matter intake was higher (p = 0.03) in the HRS group than in the LRS group, but neutral detergent fiber apparent digestibility was negatively affected (p = 0.01) by increased straw levels. Decreased C15:0, C17:0, C20:5n3c, and saturated fatty acids (SFAs) proportion as well as increased C18:1n9c and monounsaturated fatty acids (MUFAs) proportion in meat from YCC with HRS diet were observed as compared to that in meat from YCC with LRS diet (p &lt, 0.05). Meat from HRS group had higher (p = 0.04) C18:3n3c proportion than meat from LRS group. No significant differences (p &gt, 0.05) were found for meat quality attributes except for cooking loss, which was higher (p = 0.02) in the HRS group than in the LRS group. Both YCC group and HRS group had higher (p &lt, 0.05) cold carcass weight compared to OCC group and LRS group. Moreover, catalase activity of liver tissue was higher (p = 0.045) in YCC than in OCC, while superoxide dismutase activity of muscle tissue was higher (p = 0.01) in LRS than in HRS. Based on results, we concluded that younger age and feeding high-level straw can improve the finishing performance of Yiling cull cows.

This study aimed to investigate the effects of compound probiotics (consisting of 10

Twenty-eight bulls weighing 227 ± 6.8 (SD) kg were randomly assigned to four concentrate levels (1-1.5 kg [low level of concentrate {LC}], 1.5-2 kg [medium level of concentrate], 2-2.5 kg [high level of concentrate {HC}], and 2.5-3 kg [highest level of concentrate {H+C}]) and fed corn stover silage ad libitum. At the beginning of the experiment, the bulls in each treatment were fed 1, 1.5, 2, and 2.5 kg of concentrate, respectively, and these levels were increased by 0.25 kg at the end of each month to compensate for the growth requirements of the bulls. After three months, increases in the concentrate level from LC to HC resulted in increased (P

The dietary energy level can affect ruminal microbiota, and further can affect rumen fermentation and fatty acid (FA) synthesis. In this study, we investigated the correlations between rumen bacteria and rumen fermentation parameters and intramuscular fat (IMF) FA profiles of Holstein bulls fed different energy diets via using 16S rRNA high-throughput sequencing and gas chromatography. The results showed that the improved dietary energy increased propionate, isobutyrate and isovalerate concentrations, and decreased acetate concentration and the acetate/propionate ratio. Increased dietary energy improved beef IMF content and had no effects on cooking loss, Warner-Bratzler shear force, water holding capacity, or drip loss. Increase dietary energy also decreased C18:0, C18:1 trans, C22:0, C20:3n-3, C22:6n-3, and saturated fatty acids, and increased C18:1 cis-9, C18:2n-6 trans, and monounsaturated fatty acids. 16S rRNA high-throughput sequencing analysis revealed that dietary energy had no impact on alpha diversity or the relative abundance of most of the major phyla and genera in rumen. In all dietary treatment groups, the dominant microbial phyla were Bacteroidetes (54.91%) and Firmicutes (33.60%), and the major microbial genus was Prevotella_1 (21.75%). Improved dietary energy decreased the abundances of Firmicutes and Tenericutes and increased that of Proteobacteria at the phylum level, while decreasing those of RC9_gut_group, and increased Prevotellaceae_UCG-004, Phocaeicola, Acetitomaculum, Lachnoclostridium_1, Prevotellaceae_UCG-003, and Anaerovibrio at the genus level. Spearman correlation analysis showed high correlations between rumen bacteria and fermentation parameters/IMF FA profiles. Collectively, our data indicated that dietary energy affects the ruminal microbiota, and further affects ruminal fermentation and IMF FA composition.

The aim of this study was to investigate the impact of dietary crude protein (CP) levels and calcium salts of long-chain fatty acids (CSFA) on the nutrient intake and digestibility, nitrogen deposition, rumen fermentation characteristic and microbiota, plasma biochemical indexes and fatty acid composition in the Holstein bulls. Eight Holstein bulls was used in a 4 × 4 Latin Square design with 2 × 2 factorial diets, including two levels of CP (133 or 112 g/kg dry matter), and with or without 2.32 g/kg CSFA. The high CP level diets increased the CP intake and the CP apparent digestibility and the urinary nitrogen excretion (P = 0.001). Dietary supplementation with CSFA promoted the apparent digestibility of organic matter (P = 0.012). The diets of CSFA and high CP level raised the rumen ammonia nitrogen concentration (P = 0.009), and enhanced the isovalerate and valerate concentrations, respectively. The high CP diets improved the abundance of Butyrivibrio fibrisolvens (P = 0.037) and Megasphaera elsdenii (P = 0.023), while the CSFA reduced the abundance of methanogens (P = 0.047). High CP increased urea concentration (P = 0.008). Dietary supplementation with CSFA increased the cholesterol and the low-density lipoprotein cholesterol concentration in the plasma, and the proportion of C16:0, C18:1n9c and Δ9 desaturase C18, while it reduced the ratio of C21:1 and C22:0. The low CP diets reduced the protein waste and environmental pollution in the final stage of fattening Holstein bulls. Further study needs to be done to investigate the effect of CSFA on the CH4 emission in terms of microbial mechanism in the rumen.

The rumen anaerobic fermentation has been exploited as a molecular platform for producing fermentative biogas and organic acids. The aim of this study was to select more efficient rumen fermentation bacteria by comparing the nutrient degradation rate, rumen fermentation characteristics and bacterial flora between the bulls and heifers. The rumen fluid from bulls and heifers was inoculated to wheat straw for anaerobic fermentation to produce organic acids and biogas. The results showed that the bulls had higher degradation rate of dietary total solids and acid detergent fiber, and had higher concentration of acetate, butyrate, ammoniacal nitrogen, total volatile fatty acids and total fungi in rumen compared with the heifers (P

Roughage particle size can influence rumen development, which is also determined by rumen microorganisms and their metabolic end-products. Therefore, the aim of this study was to evaluate the comprehensive effects of roughage length and rumen bacterial community on the rumen development of weaned calves. A total of thirty-six weaned Angus female calves (125 &plusmn, 3 d, 161.2 &plusmn, 13.0 kg) were randomly assigned to three diets differing in roughage particle size: 4 cm (short length), 24 cm (medium length), and 44 cm (long length). Results showed that chopping roughage increased dry matter intake and organic matter apparent digestibility, altered rumen fermentation indicated by the increased rumen butyrate and valerate concentrations, and increased plasma glucose, cholesterol, and total protein. Chopping roughage affected rumen bacterial community, as indicated by altering the diversity indices, by increasing ruminal bacteria Papillibacter and Eubacterium_hallii_group, which are involved in butyrate production, and by increasing Synergistetes and Mogibacterium, which are involved in bacterial colonization. In conclusion, chopping roughage at 4 cm was shown to improve the rumen bacterial community, alter rumen fermentation, eventually promote the development of rumen.

The aim of this study is to track the dynamic alterations in nutrient intake and digestion, rumen fermentation and plasma metabolic characteristics, and rumen bacterial community of Holstein finishing steers in response to three nutrient density diets as fattening phases advanced. A total of eighteen Holstein steers were randomly allocated into three nutrient density groups and steers in each group were fed under a three-phase fattening strategy, with nutrient density increased in each group when fattening phase advanced. Results showed that both fattening phase and dietary nutrient density significantly influenced the nutrient digestion, most of the rumen fermentation parameters, and part of bacteria at phylum and genus levels. Individually, dietary nutrient density affected the concentrations of plasma alanine aminotransferase and urea N, bacterial richness and evenness. All determined nutrient intake and plasma biochemical parameters, except for alanine aminotransferase and triglyceride, differed among fattening phases. Spearman correlation analysis revealed strong correlations between fiber intake and bacterial richness and evenness, rumen fermentation characteristics and certain bacteria. Moreover, Patescibacteria abundance was positively correlated with ambient temperature and plasma total protein. These results indicate that rumen fermentation and nutrient digestion were influenced by both dietary nutrient density and fattening phase, and these influences were regulated by certain rumen bacterial community and ruminal bacteria may be affected simultaneously by ambient temperature. This study may provide insights into diet optimization and potentially adaptive mechanism of rumen bacterial community in response to fattening phases and gradually climatic change.

The objective of this study was to explore whether collecting rumen samples of finishing steers at monthly intervals differed, and whether this difference or similarity varied with diets. For these purposes, 12 Chinese Holstein steers were equally divided into two groups. The dietary treatments were either standard energy and standard protein (C) or low energy and low protein (L). Rumen samples were obtained on day 30, day 60 and day 90 from both dietary treatments and were analyzed by using 16S rRNA gene sequencing. The results showed that monthly intervals had no effect on the richness and evenness of the rumen bacterial community in the two diets. However, taxonomic difference analysis (relative abundance &gt, 0.5%) revealed that the relative abundance of three phyla (Proteobacteria, Fibrobacteres and Cyanobacteria) and six genera (Rikenellaceae_RC9_gut_group, Ruminococcaceae_NK4A214_group, Fibrobacter, Eubacterium_coprostanoligenes_group, Ruminococcaceae_UCG-010 and Ruminobacter) were significantly different between monthly sampling intervals, and the difference was prominent between sampling in the first month and the subsequent two months. Moreover, the differences in abundances of phyla and genera between monthly sampling intervals were affected by diets. Analysis of similarity (ANOSIM) showed no significant differences between monthly sampling intervals in the C diet. However, ANOSIM results revealed that significant differences between the first month and second month and between the first month and third month were present in the L diet. These results indicated that temporal dynamics in rumen bacterial community composition did occur even after an adaptation period of three months. This study tracked the changes in rumen bacterial populations of finishing cattle after a shift in diet with the passage of time. This study may provide insight into bacterial adaptation time to dietary transition in finishing steers.

Twenty-eight male, weaned Chinese Holstein calves ((156.8±33.4) kg) were used to investigate the effects of dietary forage to concentrate ratio (F:C) and forage length on nutrient digestibility, plasma metabolites, ruminal fermentation, and fecal microflora. Animals were randomly allocated to four treatments in a 2×2 factorial arrangement: whole-length forage (WL) with low F:C (50:50); WL with high F:C (65:35); short-length forage (SL) with high F:C (65:35); and SL with low F:C (50:50). Chinese wildrye was used as the only forage source in this trial. The grass in the SL treatments was chopped using a chaff cutter to achieve small particle size (∼50% particles >19 mm). Dry matter intake (DMI) and organic matter (OM) intake was increased by increasing both F:C (P0.05). Microflora similarity was 50–73% among the different treatments. It is concluded that the WL with high F:C (65:35) diet is suitable for weaned calves.

This study investigated the replacement of Leymus chinensis (LC) with whole-crop wheat hay (WCWH) in the diets of Holstein bulls in the fattening stage and examined the potential effects on blood parameters, fatty acids in rumen fluid and serum, and the rumen microbiomes. In this study, 12 Holstein bulls in the fattening period (body weight=485.0 ± 40.8 kg) were assigned to 1 of 4 dietary treatments using a 4 × 4 Latin square design. Each experimental period consisted of a 17-d adaptation period and a 5-d collection period. The dietary treatments consisted of 4 proportions of WCWH (0, 33, 67, and 100%) as a substitute for LC (designated as WCWH0, WCWH33, WCWH67, and WCWH100, respectively). On d 18 and 22 of each experiment period, blood and rumen content samples were collected for analysis, respectively. Real-time quantitative PCR was used to analyze the rumen microbiomes. The results from this study revealed no differences in the saturated, monounsaturated, and polyunsaturated long-chain fatty acid proportions of rumen liquid among the treatments. It was observed in the present trial that rumen microbiotal flora were not significantly different in the bulls fed LC compared with the bulls fed WCWH. Additionally, blood sample analysis demonstrated that the concentration of urea nitrogen in the WCWH100 group was higher than that observed in the other groups. Meanwhile, no differences were detected for other serum parameters. There were no differences in the proportions of serum saturated, monounsaturated, and polyunsaturated long-chain fatty acids among the treatments. In conclusion, our data revealed that LC can be replaced with WCWH in the diet of Holstein bulls in the fattening stage with no negative effects on the blood indicators, fatty acids, and microbiomes.

The purpose of this study was to assess the effects of calcium salt of long-chain fatty acids (CSFA) and alfalfa on beef cattle in the late fattening. 48 Holstein bulls were selected and randomly divided into 4 groups, feeding four dietary that Leymus chinensis with (LC) or with no (LN) 2.4% CSFA, and alfalfa replaced 50% Leymus chinensis with (AC) or with no (AN) 2.4% CSFA. The results indicated that alfalfa improved the feed conversion rate (P < 0.05). CSFA increased serum low density lipoprotein cholesterol, and reduced the cooking loss of Longissimus muscle (P < 0.05). CSFA and alfalfa reduced Acetate/Propionate. Alfalfa and CASF had significant additive effects on the apparent digestibility of dry matter, crude protein, neutral detergent fiber, acid detergent fiber, organic matter and rumen fermentation for acetate, isobutyrate, butyrate, isovalerate, total volatile fatty acids (P < 0.05). CSFA increased microbial diversity index when compared with alfalfa (P < 0.05), but no significant differences were detected in bacterial genera abundances among diets. The relative abundances of rumen bacterial genera have significant correlation with apparent digestibility of nutrients, rumen fermentation characteristics and serum biochemical parameters (P < 0.05). These results comprehensively evaluated the additive effects of alfalfa and CSFA on the application in Holstein bulls.

Objective Wheat is an alternative to corn silage for ruminant feeding in northern China. This study examined the effects of harvest time and added molasses on nutritional content, ensiling characteristics and in vitro degradation of whole crop wheat (WCW). Methods Fresh WCW at the milk-ripe stage was harvested at 0700 h (i.e., in the morning [Mo]) and 1700 h (i.e., in the afternoon [Af]), and then immediately used to prepare silage and make hay. Commercial molasses was added to Af WCW at 0%, 2%, 4%, and 6% (fresh weight) proportions. The WCW treated with molasses was mixed thoroughly prior to ensiling. Results Dry matter (DM), neutral detergent fiber, water soluble carbohydrate (WSC) content (p

Traditionally, Chinese indigenous cattle is geographically widespread. The present study analyzed based on genome-wide variants to evaluate the genetic background among 157 individuals from four representative indigenous cattle breeds of Hubei Province of China: Yiling yellow cattle (YL), Bashan cattle (BS), Wuling cattle (WL), Zaobei cattle (ZB), and 21 individuals of Qinchuan cattle (QC) from the nearby Shanxi Province of China. Linkage disequilibrium (LD) analysis showed the LD of YL was the lowest (r2=0.32) when the distance between markers was approximately 2 kb. Principle component analysis (PCA), and neighbor-joining (NJ)-tree revealed a separation of Yiling yellow cattle from other geographic nearby local cattle breeds. In PCA plot, the YL and QC groups were segregated as expected; moreover, YL individuals clustered together more obviously. In the NJ-tree, the YL group formed an independent branch and BS, WL, ZB groups were mixed. We then used the FST statistic approach to reveal long-term selection sweep of YL and other 4 cattle breeds. According to the selective sweep, we identified the unique pathways of YL, associated with production traits. Based on the results, it can be proposed that YL has its unique genetic characteristics of excellence resource, and it is an indispensable cattle breed in China.

Simple Summary The gastrointestinal microbial ecosystem of cattle impacts their health and productivity. Collection of fecal samples provides a non-invasive and practicable way to explore the relationships between fecal microbiota and host productivity or health. Fecal bacteria are influenced by diet, feeding regime, animal age, and health status. However, dynamic variations in the fecal fermentation profile and microbiota composition of finishing steers in response to variable diets are limited. In the current study, we conducted an 11-month tracking investigation to uncover the dynamic variations in fecal fermentation profile and bacterial community in steers fed three stepwise density diets. We found that fecal bacterial diversity decreased as dietary density increased and as the fattening phase continued. Our results revealed that fecal organic acids and bacterial composition were influenced by diet and fattening period. Our results also indicated that time-dependent variations of fecal fermentation profile and microbiota composition exist in the long-term fattening of steers in addition to diet stimulation. This study will be beneficial to reducing fecal contamination from the origin by optimizing diet and fattening time. Abstract The objective of this study was to track the dynamic variations in fecal bacterial composition and fermentation profile of finishing steers in response to three stepwise diets varied in energy and protein density. A total of 18 Holstein steers were divided into three groups in such a way that each group contained six animals and received one of three stepwise dietary treatments. Dietary treatments were C = standard energy and protein diet, H = high energy and protein diet, and L = low energy and protein diet. Animals were fattened for 11 months with a three-phase fattening strategy. Fecal samples were collected to evaluate the dynamics of fecal fermentation and bacterial composition in response to dietary treatments and fattening phases using 16S rRNA gene sequencing. Fecal acetate, propionate, and butyrate increased with increasing density of diet and as the fattening phase continued. The relative abundances of Firmicutes and Bacteroidetes dominated and showed 56.19% and 33.58%, respectively. Higher dietary density decreased the fecal bacterial diversity, Firmicutes to Bacteroidetes ratio, and the relative abundances of Ruminococcaceae_UCG-005, Rikenellaceae_RC9_gut_group, and Bacteroides, whereas higher dietary density increased the abundance of Prevotella_9. Our results indicated that both fecal fermentation profile and bacterial composition share a time-dependent variation in response to different dietary densities. This knowledge highlights that both diet and fattening phase impact fecal fermentation profile and bacterial composition, and may provide insight into strategies to reduce fecal contamination from the origin by optimizing diet and fattening time.

The objective of this study was to evaluate the effects of dietary energy levels on growth performance, rumen fermentation and bacterial community, and meat quality of Holstein-Friesians bulls slaughtered at different ages. Thirty-six Holstein-Friesians bulls (17 months of age) were divided into a 3 &times, 3 factorial experiment with three energy levels (LE, ME and HE, metabolizable energy is 10.12, 10.90 and 11.68 MJ/kg, respectively) of diets, and three slaughter ages (20, 23 and 26 months). Results indicated that bulls fed with ME and HE diets had higher dry matter intake, average daily gain, and dressing percentage at 23 or 26 months of age. The ME and HE diets also reduced bacterial diversity, altered relative abundances of bacteria and produced lower concentrations of acetate, but higher butyrate and valerate concentrations in rumen fluid. Increasing in dietary energy and slaughter age increased the intramuscular fat (IMF) and water holding capacity. In summary, Holstein-Friesians bulls fed with ME and HE diets, slaughtered at 23 and 26 months of age could be a good choice to produce beef with high IMF. Slaughter age may have less influence than dietary energy in altering fermentation by increasing amylolytic bacteria and decreasing cellulolytic bacteria, and thus, further affecting meat quality.

OBJECTIVE This study investigated the effect of dietary crude protein (CP) supplementation on nutrient intake, nitrogen (N) utilisation, blood metabolites, ruminal fermentation and growth performance of young Holstein bulls. METHODS Twenty-one young bulls weighing 277±11.2 kg were equally divided into three groups and were offered diets formulated with low CP (LCP; 10.21% CP and 4.22% rumen degradable protein [RDP]), medium CP (MCP; 12.35% CP and 5.17% RDP) and high CP (HCP; 14.24% CP and 6.03% RDP). Yellow corn silage was used as a unique forage source and was mixed with concentrate. This mixed feed was given ad libitum to the young bulls included in the study. RESULTS Results showed that CP intake, blood urea nitrogen, N intake, total N excretion and N balance increased linearly with an increase in dietary CP level (p

Background Freemartinism generally occurs in female offspring of dizygotic twins in a mixed-sex pregnancy. Most bovine heterosexual twin females are freemartins. However, about 10% of bovine heterosexual twin females are fertile. Farmers mostly cull bovine fertile heterosexual twin females due to the lack of a practical diagnostic approach. Culling of such animals results in economic and genetic-material losses both for dairy and beef industry. Methods In this study, a comparative test, including qualitative detection of SRY gene by polymerase chain reaction (PCR), quantitative detection of relative content of SRY by real-time quantitative polymerase chain reaction (qPCR), and quantitative detection of H-Y antigen, was performed to establish the most accurate diagnosis for freemartin. Twelve Holstein heterosexual twin females were used in this study, while three normal Holstein bulls and three normal Holstein cows were used as a positive and negative control, respectively. Results Polymerase chain reaction results revealed that SRY gene were absent in three heterosexual twin females and only two of them were verified as fertile in later age. The qPCR results showed that relative content of SRY was more than 14.2% in freemartins and below 0.41% in fertile heterosexual twin females. The H-Y antigen test showed no significant numerical difference between freemartin and fertile heterosexual twin female. Discussion Our results show that relative content of SRY quantified by qPCR is a better detection method for diagnosis of freemartin in Holstein cattle as compare to qualitative detection of SRY gene by PCR or quantitative detection of H-Y antigen. To the authors’ knowledge, this is the first time we applied qPCR to diagnosing freemartin by quantifying SRY gene and got relative SRY content of each freemartin and fertile heterosexual twin female. We concluded that low-level of SRY would not influence fertility of bovine heterosexual twin female.

This study presented the effects of alfalfa and calcium salts of long-chain fatty acids (CSFA) on feed intake, apparent digestibility, rumen fermentation, microbial community, plasma biochemical parameters, and fatty acid profile in Holstein freemartin heifers. Eight Holstein freemartin heifers were randomly divided into a 4 × 4 Latin Square experiment with 2 × 2 factorial diets, with or without alfalfa or CSFA. Dietary supplementation of CSFA significantly increased the apparent digestibility of dry matter, crude protein, neutral detergent fiber, organic matter, and significantly reduced N retention (P < 0.05). CSFA increased the concentration of ammonia nitrogen in the ruminal fluid (P < 0.05), but alfalfa increased the concentration of valerate and isovalerate (P < 0.05). CSFA increased the concentration of ammonia nitrogen and the relative population of Streptococcus bovis in the rumen (P < 0.05) and inhibited the relative population of Ruminococcus flavefaciens, methanogens, and protozoa (P < 0.05). Alfalfa instead of Leymus chinensis increased the relative population of Butyrivibrio fibrisolvens and Ruminobacter amylophilus in the rumen (P < 0.05) and reduced the relative population of the Ruminococcus albus and Megasphaera elsdenii (P < 0.05). Supplemental CSFA increased the concentration of cholesterol and low-density lipoprotein cholesterol in the plasma (P < 0.05). And it also altered the composition of fatty acids in the plasma, which was expressed in reducing saturated fatty acid (ΣSFA) ratio and C14-C17 fatty acids proportion except C16:0 (P < 0.05) and increasing the proportion of polyunsaturated fatty acid (ΣPUFA) and unsaturated fatty acid (ΣUFA) (P < 0.05). The results showed that alfalfa and CSFA had interaction effect on the apparent digestibility of ether extracts, plasma triglyceride concentration, isobutyrate concentration, and Ruminococcus albus relative abundance in the rumen. It was concluded that alfalfa substituting Leymus chinensis did not change the apparent digestibility of nutrients in the final stage of fattening Holstein freemartin heifers, while CSFA increased the cholesterol and the proportion of unsaturated fatty acids in plasma. Alfalfa and CSFA had mutual interaction effect on fat digestion and plasma triglycerides.

Marbling is an important trait regarding the quality of beef. Analysis of beef cattle transcriptome and its expression profile data are essential to extend the genetic information resources and would support further studies on beef cattle. RNA sequencing was performed in beef cattle using the Illumina High-Seq2000 platform. Approximately 251.58 million clean reads were generated from a high marbling (H) group and low marbling (L) group. Approximately 80.12% of the 19,994 bovine genes (protein coding) were detected in all samples, and 749 genes exhibited differential expression between the H and L groups based on fold change (>1.5-fold, p

Twelve Holstein bulls were used in a 4 × 4 Latin square design to investigate the effects of using whole-crop wheat hay (WCWH) as a substitute for Leymus chinensis (LC) on apparent digestibility, plasma parameters, ruminal fermentation, and microbial communities. Experimental treatments were four proportions of WCWH, 0, 33, 67, and 100%, as a substitute for LC (WCWH0, WCWH33, WCWH67, and WCWH100, respectively). The WCWH100 group showed a higher nutritional intake of crude protein (CP) and higher apparent digestibility of organic matter (OM), CP, and ether extract (EE) than the WCWH0 group (P P

Twenty multiparous Chinese Holstein dairy cows calving in hot summer (S group), were compared with 20 similar control cows calving in cool autumn (C group). Diets were the same for both groups; prepartum diets had relatively low energy density. Average temperature-humidity index was 76.5 and 53.0 in summer and autumn, respectively. S group cows had significantly higher rectal temperatures (39.6 vs. 39.0 °C) and respiration rates (79.0 vs. 31.3 breaths/min) than C group, and consumed less feed (prepartum 8.0 vs. 12.3 kg/day, postpartum 16.3 vs. 21.2 kg/day). Calculated energy balance (EB) was -7.98 vs. -5.15 Mcal/day for S group prepartum and postpartum, respectively. In contrast, EB was 1.36 vs. -2.03 Mcal/day for C group prepartum and postpartum, respectively. S group produced significantly less milk than C group by 15.4 % (5.2 kg/day) and 26.8 % (10.2 kg/d) for milk yield and energy-corrected milk, respectively. Percentages of milk fat (3.28 vs. 4.29 %), protein (3.08 vs. 3.33 %), and solids-not-fat (8.46 vs. 8.78 %) were significantly lower for S group. Milk urea nitrogen (19.54 vs. 13.31 mg/dL) was significantly higher in S group. Significantly lower feed efficiency was observed in S group (1.56 vs. 1.66). During the entire transition period, S group had significantly lower circulating glucose levels. S group had significantly higher levels of nonesterified fatty acids (NEFA) prepartum, but after 14 days in milk, NEFA was significantly lower. We conclude that increasing dietary energy density during transition period (especially prepartum) is necessary to minimize adverse effects of hot season.

Background Freemartinism generally occurs in female offspring of dizygotic twins in a mixed-sex pregnancy. Most bovine heterosexual twin females are freemartins. However, about 10% of bovine heterosexual twin females are fertile. Farmers mostly cull bovine fertile heterosexual twin females due to the lack of a practical diagnostic approach. Culling of such animals results in economic and genetic-material losses both for dairy and beef industry. Methods In this study, a comparative test, including qualitative detection of SRY gene by polymerase chain reaction (PCR), quantitative detection of relative content of SRY by real-time quantitative polymerase chain reaction (qPCR), and quantitative detection of H-Y antigen, was performed to establish the most accurate diagnosis for freemartin. Twelve Holstein heterosexual twin females were used in this study, while three normal Holstein bulls and three normal Holstein cows were used as a positive and negative control, respectively. Results Polymerase chain reaction results revealed that SRY gene were absent in three heterosexual twin females and only two of them were verified as fertile in later age. The qPCR results showed that relative content of SRY was more than 14.2% in freemartins and below 0.41% in fertile heterosexual twin females. The H-Y antigen test showed no significant numerical difference between freemartin and fertile heterosexual twin female. Discussion Our results show that relative content of SRY quantified by qPCR is a better detection method for diagnosis of freemartin in Holstein cattle as compare to qualitative detection of SRY gene by PCR or quantitative detection of H-Y antigen. To the authors’ knowledge, this is the first time we applied qPCR to diagnosing freemartin by quantifying SRY gene and got relative SRY content of each freemartin and fertile heterosexual twin female. We concluded that low-level of SRY would not influence fertility of bovine heterosexual twin female.

It is well known that rapid gain of muscle mass in neonatal pigs is highly related to protein synthesis. However, the role of protein degradation in muscle gain of the neonatal period has not been well established. Calpains and their endogenous inhibitors, calpastatins, play a significant role in early-stage myofibrillar protein degradation. To investigate the role of calpain–calpastatin system in muscle protein accumulation, we studied the expressions of their mRNA in muscle tissue sampled at days 1, 4, 6, 12, 20 and 28 from a total of 36 neonatal pigs. The steady-state mRNA levels of calpains 1A, 2 and 3A, calpastatin types 1, 2 and 3, obtained by quantitative real-time PCR analysis, decreased by 2–4 folds at the age of 4 to 6 days compared to 1-day-old piglets. Then, the relatively low expression level was maintained through 28 days of age. Expressions of calpains 1A, 3A and calpastatin type 1 were significantly correlated with the measurements of muscle protein accumulations such as muscle protein content and RNA/protein ratio. Expressions of calpain 1A, calpastatin types 1 and 3 were negatively correlated with birth weight and fractional rate of growth. The levels of calpains 1A and 2 mRNA were correspondent to their protease activities. In conclusion, decreased levels of calpain and calpastatin expressions over development in neonatal pigs are associated with high protein accumulations, suggesting that dramatic muscle growth during the neonatal period may be partially controlled by down-regulated calpain–calpastatin system.