Re-identifying beef cattle using improved AlignedReID++

Accurate and continuous identification of individual cattle is crucial to precision farming in recent years.It is also the prerequisite to monitor the individual feed intake and feeding time of beef cattle at medium to long distances over different cameras.However,beef cattle can tend to frequently move and change their feeding position during feeding.Furthermore,the great variations in their head direction and complex environments(light,occlusion,and background)can also lead to some difficulties in the recognition,particularly for the bio-similarities among individual cattle.Among them,AlignedReID++model is characterized by both global and local information for image matching.In particular,the dynamically matching local information(DMLI)algorithm has been introduced into the local branch to automatically align the horizontal local information.In this research,the AlignedReID++model was utilized and improved to achieve the better performance in cattle re-identification(ReID).Initially,triplet attention(TA)modules were integrated into the BottleNecks of ResNet50 Backbone.The feature extraction was then enhanced through cross-dimensional interactions with the minimal computational overhead.Since the TA modules in AlignedReID++baseline model increased the model size and floating point operations(FLOPs)by 0.005 M and 0.05 G,the rank-1 accuracy and mean average precision(mAP)were improved by 1.0 percentage points and 2.94 percentage points,respectively.Specifically,the rank-1 accuracies were outperformed by 0.86 percentage points and 0.12 percentage points,respectively,compared with the convolution block attention module(CBAM)and efficient channel attention(ECA)modules,although 0.94 percentage points were lower than that of squeeze-and-excitation(SE)modules.The mAP metric values were exceeded by 0.22,0.86 and 0.12 percentage points,respectively,compared with the SE,CBAM,and ECA modules.Additionally,the Cross-Entropy Loss function was replaced with the CosFace Loss function in the global branch of baseline model.CosFace Loss and Hard Triplet Loss were jointly employed to train the baseline model for the better identification on the similar individuals.AlignedReID++with CosFace Loss was outperformed the baseline model by 0.24 and 0.92 percentage points in the rank-1 accuracy and mAP,respectively,whereas,AlignedReID++with ArcFace Loss was exceeded by 0.36 and 0.56 percentage points,respectively.The improved model with the TA modules and CosFace Loss was achieved in a rank-1 accuracy of 94.42%,rank-5 accuracy of 98.78%,rank-10 accuracy of 99.34%,mAP of 63.90%,FLOPs of 5.45 G,frames per second(FPS)of 5.64,and model size of 23.78 M.The rank-1 accuracies were exceeded by 1.84,4.72,0.76 and 5.36 percentage points,respectively,compared with the baseline model,part-based convolutional baseline(PCB),multiple granularity network(MGN),and relation-aware global attention(RGA),while the mAP metrics were surpassed 6.42,5.86,4.30 and 7.38 percentage points,respectively.Meanwhile,the rank-1 accuracy was 0.98 percentage points lower than TransReID,but the mAP metric was exceeded by 3.90 percentage points.Moreover,the FLOPs of improved model were only 0.05 G larger than that of baseline model,while smaller than those of PCB,MGN,RGA,and TransReID by 0.68,6.51,25.4,and 16.55 G,respectively.The model size of improved model was 23.78 M,which was smaller than those of the baseline model,PCB,MGN,RGA,and TransReID by 0.03,2.33,45.06,14.53 and 62.85 M,respectively.The inference speed of improved model on a CPU was lower than those of PCB,MGN,and baseline model,but higher than TransReID and RGA.The t-SNE feature embedding visualization demonstrated that the global and local features were achieve in the better intra-class compactness and inter-class variability.Therefore,the improved model can be expected to effectively re-identify the beef cattle in natural environments of breeding farm,in order to monitor the individual feed intake and feeding time.

Diet and monensin influence the temporal dynamics of the rumen microbiome in stocker and finishing cattle

Background Stocker cattle diet and management influence beef cattle performance during the finishing stage,but knowledge of the dynamics of the rumen microbiome associated with the host are lacking.A longitudinal study was conducted to determine how the feeding strategy from the stocker to the finishing stages of production affects the temporal dynamics of rumen microbiota.During the stocker phase,either dry hay or wheat pasture were provided,and three levels of monensin were administrated.All calves were then transported to a feedlot and received similar finishing diets with or without monensin.Rumen microbial samples were collected on d 0,28,85 during the stocker stage(S0,S28 and S85)and d 0,14,28,56,30 d before slaughter and the end of the trial during the finishing stage(F0,F14,F28,F56,Pre-Ba,and Final).The V4 region of the bacterial 16S rRNA gene of 263 rumen samples was sequenced.Results Higher alpha diversity,including the number of observed bacterial features and the Shannon index,was observed in the stocker phase compared to the finishing phase.The bacterial amplicon sequence variants(ASVs)differentiating different sampling time points were identified.Dietary treatments during the stocker stage temporally impact the dynamics of rumen microbiota.For example,shared bacteria,including Bacteroidales(ASV19)and Streptococcus infantarius(ASV94),were significantly higher in hay rumen on S28,S85,and F0,while Bacteroidaceae(ASV11)and Limivicinus(ASV15)were more abundant in wheat.Monensin affected rumen microbial composition at a specific time.Transportation to feedlot significantly influenced microbiome structure and diversity in hay-fed calves.Bacterial taxa associated with body weight were classified,and core microbiotas interacted with each other during the trial.Conclusions In summary,the temporal dynamics of the rumen microbiome in cattle at the stocker and finishing stage are influenced by multiple factors of the feeding strategy.Diet at the stocker phase may temporarily affect the microbial composition during this stage.Modulating the rumen microbiome in the steers at the stocker stage affects the microbial interactions and performance in the finishing stage.

Effects of Maize Silage Harvest Stage on Growth Performance and Economic Benefits of Beef Cattle

[Objectives]This study aimed to investigate the effects of whole-crop maize silage harvested at different stages on growth and economic benefits of beef cattle.[Methods]A total of 30 Simmental crossbred cattle weighing about 378 kg were randomly divided into three groups,respectively fed for 70 days with whole-crop maize silage harvested at milk stage(GroupⅠ),dough stage(GroupⅡ)and physiological maturity stage(GroupⅢ).Moreover,the cattle in all groups were given the same concentrate diet.[Results]There were significant differences in dry matter,crude protein and neutral detergent fiber between whole-crop maize silages harvested at different stages(P<0.05).The dry matter in GroupⅡandⅢwas significantly higher than that in GroupⅠ(P<0.05).The crude protein content peaked in GroupⅡ,up to 6.37%,which was significantly higher than that in GroupⅠ(by 12.74%,P<0.05)and GroupⅢ(by 9.26%,P<0.05).Starch content significantly increased with the postponing of maize harvest(P<0.05).The content of neutral detergent fiber in Group I was significantly higher than that in GroupⅡ(P<0.05)and GroupⅢ(P<0.05).The average daily weight gain in GroupⅡwas 8.53%higher than that in GroupⅠ(P<0.05)and 3.70%higher than that in GroupⅢ(P>0.05).The dry matter intake in GroupⅡwas significantly higher than that in GroupⅠ(P<0.05)and GroupⅢ(P<0.05).There was no significant difference in feed/gain ratio between the groups(P>0.05).The economic benefit in GroupⅡwas the highest,up to 9.99 yuan/day per capita.,followed by that in GroupⅢ,9.79 yuan/day per capita,and that in GroupⅠwas the lowest,only 8.03 yuan/day per capita.[Conclusions]The whole-crop maize silage harvested at dough stage has the best quality and produces the highest economic returns for beef cattle.

Improvement Effect of Beef Cattle Frozen Semen of Different Varieties for Local Yellow Cattle

In the improvement process of local yellow cattle with frozen semen of beef cattle, the cows were grouped according to different cross combinations. Then, the conception rate, dystocia rate and reproductive survival rate of the cows in each group, as well as the body size and body weight of new-born calves, were ana- lyzed. The results showed that no significant differences were found in conception rate among different groups （P〉0.05）; there was no significant difference in dystocia rate between the A and C groups （P〉0.05）, but the dystocia rate in the B group was significantly different from those in the A and C groups （P〈0.05）. There were positive correlations between calf forehead width, chest circumference and the dys- tocia rate.

Vitamin A administration at birth promotes calf growth and intramuscular fat development in Angus beef cattle

Background: Marbling, or intramuscular fat, is an important factor contributing to the palatability of beef. Vitamin A, through its active metabolite, retinoic acid, promotes the formation of new fat cells(adipogenesis). As intramuscular adipogenesis is active during the neonatal stage, we hypothesized that vitamin A administration during the neonatal stage would enhance intramuscular adipogenesis and marbling.Methods: Angus steer calves(n = 30), in a completely randomized design, were randomly allotted to three treatment groups at birth, receiving 0, 150,000, or 300,000 IU of vitamin A at both birth and one month of age.A biopsy of the biceps femoris muscle was collected at two months of age. After weaning at 210 d of age, steers were fed a backgrounding diet in a feedlot until 308 d of age, when they were transitioned to a high concentrate finishing diet and implanted with trenbolone/estradiol/tylosin mixture. Steers were harvested at an average of 438 d of age. All diets were formulated to meet nutrient requirements.Results: Weaning weight and weight during the backgrounding phase were linearly increased(P < 0.05) by vitamin A level, though no difference in body weight was observed at harvest. Intramuscular fat of steers at 308 d of age, measured by ultrasound, quadratically increased(P < 0.05) with vitamin A level from 4.0±0.26 % to 4.9±0.26 %.Similarly, carcass marbling score in the ribeye quadratically increased(P < 0.05).Conclusion: Administration of vitamin A at birth increased weaning weight and enhanced marbling fat development.Thus, vitamin A administration provides a practical method for increasing marbling and early growth of beef cattle.

Residual feed intake in beef cattle and its association with carcass traits, ruminal solid-fraction bacteria, and epithelium gene expression

Background: Residual feed intake(RFI) describes an animal’s feed efficiency independent of growth performance.The objective of this study was to determine differences in growth performance, carcass traits, major bacteria attached to ruminal solids-fraction, and ruminal epithelium gene expression between the most-efficient and the least-efficient beef cattle. One-hundred and forty-nine Red Angus cattle were allocated to three contemporary groups according to sex and herd origin. Animals were fed a finishing diet in confinement for 70 d to determine the RFI category for each. Within each group, the two most-efficient(n = 6; RFI coefficient =-2.69 ± 0.58 kg dry matter intake(DMI)/d) and the two least-efficient animals(n = 6; RFI coefficient = 3.08 ± 0.55 kg DMI/d) were selected. Immediately after slaughter, ruminal solids-fraction and ruminal epithelium were collected for bacteria relative abundance and epithelial gene expression analyses, respectively, using real-time PCR.Results: The most-efficient animals consumed less feed(P = 0.01; 5.03 kg less DMI/d) compared with the leastefficient animals. No differences(P > 0.10) in initial body weight(BW), final BW, and average daily gain(ADG) were observed between the two RFI classes. There were no significant RFI × sex effects(P > 0.10) on growth performance.Compared with the least-efficient group, hot carcass weight(HCW), ribeye area(REA), and kidney, pelvic, and heart fat(KPH) were greater(P ≤ 0.05) in the most-efficient cattle. No RFI × sex effect(P > 0.10) for carcass traits was detected between RFI groups. Of the 10 bacterial species evaluated, the most-efficient compared with least efficient cattle had greater(P ≤ 0.05) relative abundance of Eubacterium ruminantium, Fibrobacter succinogenes, and Megasphaera elsdenii, and lower(P ≤ 0.05) Succinimonas amylolytica and total bacterial density. No RFI × sex effect on ruminal bacteria was detected between RFI groups. Of the 34 genes evaluated in ruminal epithelium, the mostefficient cattle had greater(P ≤ 0.05) abundance of genes involved in VFA absorption, metabolism, ketogenesis, and immune/inflammation-response. The RFI × sex interactions indicated that responses in gene expression between RFI groups were due to differences in sex. Steers in the most-efficient compared with least-efficient group had greater(P ≤ 0.05) expression of SLC9 A1, HIF1 A, and ACO2. The most-efficient compared with least-efficient heifers had greater(P ≤ 0.05) m RNA expression of BDH1 and lower expression(P ≤ 0.05) of SLC9 A2 and PDHA1.Conclusions: The present study revealed that greater feed efficiency in beef cattle is associated with differences in bacterial species and transcriptional adaptations in the ruminal epithelium that might enhance nutrient delivery and utilization by tissues. The lack of RFI × sex interaction for growth performance and carcass traits indicates that sex may not play a major role in improving these phenotypes in superior RFI beef cattle. However, it is important to note that this result should not be considered a solid biomarker of efficient beef cattle prior to further examination due to the limited number of heifers compared with steers used in the study.

Sequence Variations in the Bovine IGF-I and IGFBP3 Genes and Their Association with Growth and Development Traits in Chinese Beef Cattle

The objective of this study was to determine the genotype effects of the bovine insulin-like growth factor Ⅰ （IGF-Ⅰ） and its binding protein 3 （IGFBP3） genes on growth and development traits in beef cows, including 130 Chinese Simmental, 42 Nanyang, and 47 Luxi Yellow cattle. Sequence variations in the bovine IGF-Ⅰ and IGFBP3 genes were investigated by single strand conformation polymorphism （SSCP）. SSCPs were detected in 6 fragments, which is the 5＇-flanking region, the 2nd exon, the 5th exon, and the 5th intron of the IGF-1 gene, and the 2nd exon, the 3rd exon of the 1GFBP3 gene. Two polymorphisms, an A-to-G transition in the 2rid exon of the IGF-Ⅰ gene and a T-to-C transition in the 2rid exon of IGFBP3 gene were detected in 3 breeds. The allele frequencies of 2 polymorphisms were 0.0411 （A）, 0.9589 （B）, and 0.7237 （A）, 0.2763 （B）, respectively. These 2 loci were analyzed to associate with body weight, height at withers, body length, heart girth, rump width, and beef production index （BPI） at 0, 6, 12, 24, and 36-month old. The IGFBP3 locus was shown to be associated with rump width, heart girth at 24-month and 36-month. Animals with BB genotype had higher rump width （24.86 ± 0.47） cm at 24-month and （27.50 ± 0.63） em at 36-month. The heart girth was highest for the individuals with BB genotype （171.33 ± 1.84） cm and higher than those with AB genotype （166.68 ± 1.13） cm （P〈 0.05） at 36-month.

Effects of marker density and minor allele frequency on genomic prediction for growth traits in Chinese Simmental beef cattle

Genomic selection has been demonstrated as a powerful technology to revolutionize animal breeding. However, marker density and minor allele frequency can affect the predictive ability of genomic estimated breeding values （GEBVs）. To investigate the impact of marker density and minor allele frequency on predictive ability, we estimated GEBVs by constructing the different subsets of single nucleotide polymorphisms （SNPs） based on varying markers densities and minor allele frequency （MAF） for average daily gain （ADG）, live weight （LW） and carcass weight （CW） in 1 059 Chinese Simmental beef cattle. Two strategies were proposed for SNP selection to construct different marker densities： 1） select evenly-spaced SNPs （Strategy 1 ）, and 2） select SNPs with large effects estimated from BayesB （Strategy 2）. Furthermore, predictive ability was assessed in terms of the correlation between predicted genomic values and corrected phenotypes from 10-fold cross-validation. Predictive ability for ADG, LW and CW using autosomal SNPs were 0.13＋0.002, 0.21＋0.003 and 0.25＋0.003, respectively. In our study, the predictive ability increased dramatically as more SNPs were included in analysis until 200K for Strategy 1. Under Strategy 2, we found the predictive ability slightly increased when marker densities increased from 5K to 20K, which indicated the predictive ability of 20K （3% of 770K） SNPs with large effects was equal to the predictive ability of using all SNPs. For different MAF bins, we obtained the highest predictive ability for three traits with MAF bin 0.01-0.1. Our result suggested that designing a low-density chip by selecting low frequency markers with large SNP effects sizes should be helpful for commercial application in Chinese Simmental cattle.

Rumen Degradation Characteristics of Six Types of Common Roughage in Khorchin Beef Cattle in Tongliao City

[Objective] The paper was to study the degradation characteristics of different types of roughage in Khorchin beef cattle. [Method] The nylon bag method was used to determine the rumen degradability of six types of roughage： dry matter （DM）, crude protein （CP）, neutral detergent fiber （NDF） and acid detergent fiber （ADF）. [Result] Among the six types of roughage, alfalfa hay had the highest effective degradability of DM and CP in rumen; followed by alfalfa block, corn silage, leymus chinensis and corn stover, and the effective degradability of rice straw was lowest. In terms of effective degradability of NDF and ADF, alfalfa hay was the most effective, while leymus chinensis was the least effective. [Conclusion] Considering degradation characteristics of six types of roughage in Khorchin beef cattle, alfalfa hay possesses the highest nutritional value, while rice straw has the lowest value.

Distribution of Selenium and Mercury in Heilongjiang Province and Its Effect on Body of Beef Cattle

The aim of this study was to study the distribution of Selenium （Se） and Mercury （Hg） in feed and drinking water in Heilongjiang Province and the effect on body of beef cattle. The experiment selected four areas of Qiqihar, Harbin, Jixi and Hegang Cities in Heilongjiang Province. In each area, a pasture was selected. Five beef cattle from each ranch were collected. At the same time, blood, liver, muscle, kidney, urine and faece of the cattle were collected, as well as drinking water, feed and formula feed from the ranch. The contents of Se and Hg in the collected samples were detected by inductively coupled plasma mass spectrometry. The results showed that the contents of Se in liver, kidney, urine and blood of beef cattle were increased with the increase of Se contents in drinking water, while the contents of Se in muscle tissue and manure were decreased. When the contents of Se in feed increased, the contents of them in muscle, manure and liver of beef cattle were increased frst and then decreased, while the contents of Se in kidney, urine and blood were decreased frst and then increased. When Hg contents in drinking water were increased, the contents of them in beef cattle tissue, blood and manure were increased frst and then decreased, and the contents of Se in urine were increased frst and them decreased. And when Hg contents in feed increased, the contents of Se and Me were also increased. In conclusion, Se and Hg contents in these areas were within the safety standards, meanwhile, the contents of Se and Hg in body tissues of beef cattle were affected to varying degrees by the contents of selenium and mercury in feed.

Assessing the Environmental Impact of Extensive Beef Production in Grazing Lands of Argentina

Because of environmental constraints,beef cattle was for more than a century the only viable farming option in the extensive semiarid and subhumid lands of Argentina and the main source of nutrients for humans as well.However,a growing concern and criticism have risen today about its possible negative impact on the climate and the environment.These worries tend to affect current public opinions,national policies,and international trade.Based on 40 beef cattle farms scattered across different semiarid and subhumid regions of Argentina,here we evaluated the impact of extensive cattle production on carbon,water,and nutrient pollution.Life-Cycle Assessment(LCA)and Land-Based Assessment(LBA)were the two approaches we used here to compare the environmental impact of beef production.While the environmental footprint(EF)resulting from LCA expresses the impact per unit of food,the environmental balance(EB),derived from LBA,aims at quantifying the impact per unit of land.As such,the EB considers both negative and positive impacts on the farm as an integrated system.Following standardized procedures,we evaluated EF and EB up to the farm gate,leaving aside delocalized post-farm impacts such as those of processing,packaging,and transportation that occur beyond the farm gate.In agreement with previous evidence,our results show that the EF tends to decrease as per-head production increases.Correlation coefficients and statistical significance were the following for carbon(R=−0.574;p<0.01),water(R=−0.561;p<0.01),and N(R=−0.704;p<0.01)and Phosphorus(P)pollution(R=−0.802;p<0.01)footprints.On the contrary,the EB seems to be highly sensitive,and as per-hectare beef production increases.Correlations were the following for carbon emissions(CE:R=0.955;p<0.01),water consumption(WC:R=0.822;p<0.01),nitrogen excretion(NE:R=0.948;p<0.01)and phosphorus excretion(PE:R=0.945;p<0.01).What our results suggest is that the notion of EF is useful to evaluate the environmental impact in intensive beef production systems,and the EB is suitable to assess the impact of the extensive ones.In practice,both approaches provide different perspectives on the environmental-impact problem and they should be complementary used.We concluded that the methodological rigidity of EF does not allow proper discrimination among farms in the extensive systems.On the contrary,the EB approach tended to be highly sensitive to detecting differences between individual farms and farmers,thus allowing the identification of successful options for extensive beef production in terms of public image,policy-making,and commercial opportunities.

Effects of Plant Oil Mixture on Production Performance,Carcass and Beef Quality in Beef Cattle

[Objective] To study the effects of plant oil mixture on production performance, carcass and beef quality in beef cattle. [Method] Single-factor randomized blocks design was used. Sixteen healthy Yanbian yellow bulls having close body weight were selected and randomly divided into four groups, four cattle per group. Been oil, safflower oil and sunflower oil were mixed respectively at a volume ratio of 11：5：4. The oil blend was added to the daily diets of beef cattle respectively at a proportion of 4%, 5% and 6%. The effects of the plant oil mixture on production performance, carcass and beef quality were investigated. [ Result.] Compared with the control cattle, the experimental cattle had significantly lower feed intake （P 〈 0.05）, non-significantly higher efficiency of feed utilization, and significantly lower digestibility of crude fiber and calcium （P 〈 0.05）. With the increasing level of plant oil, the digestibility of dry matter showed a decreasing trend. The digestibility of dry matter was significantly lower in the cattle fed on the plant oil mixture at a level of 6% than in the control （ P 〈 0.05）. The plant oil mixture had no effect on the digestibility of crude protein, ether extract, crude ash, nitrogen-free extract and phosphorus. With the increasing level of plant oil, the serum content of high-density lipoprotein showed an increasing trend. The serum content of high-density lipoprotein was significantly higher in the cattle fed on the plant oil mixture at a level of 6% than in the control （ P 〈 0.05）. With the increasing level of plant oil, the content of total cholesterol showed an increasing trend, whereas the content of low-density lipoprotein showed a decreasing trend. Moreover, other indicators did not change significantly. The experimental cattle had larger eye muscle area and better beef quality than the control group. The content of crude protein and ether extract in beef increased with the increasing level of plant oil. [ Conclusion] The plant oil mixture added to the daily feed decreases intake and digestibility of crude fiber and calcium but has no remarkable effect on production performance of beef cattle. The addition also increases eye muscle area and improves beef quality, thereby improving quality of carcass and beef. The proportion of the plant oil mixture should be added at a proportion lower than 5%.

Effects of Different Compound Trace Element Premixed Materials on Beef Cattle Production Performance and Anti-oxidation Capacity

In this study,the effects of two types of premixed materials with different combinations of trace elements on the production performance and antioxidant capacity of simmental beef cattle were examined.Fifteen healthy simmental beef cattle of similar weight(approximately 330 kg),the same age(12 months),without castration,and a good physique were divided into three groups,with five beef cattle in each group.Food of Group Ⅰ beef cattle was supplemented with a commercially marketed 5% compound trace element premixture for fine beef cattle.Food of Group Ⅱ beef cattle was supplemented with a 5% compound microelement premixture for beef cattle that was designed to address local nutrient deficiencies and surpluses.In the blank control group,the beef cattle were not fed a premixture.The pretest period was 15 days,and the test period was divided into prefattening(45 days)and postfattening(45 days)stages.Body weight and body size indices were recorded at 1,2 and 3 months,and blood samples were collected regularly.In Group Ⅰ,the daily weight gain increased significantly by 15.7% compared with that of the control group.The largest daily weight gain was in Group Ⅱ,which increased by 31.6% compared with that in the control.During the test period of 90 days,the body size indices of the three different groups increased in different months,with significant increases in the indices for both test groups compared with those of the control.In Group Ⅰ,the activity of CP,the total activity of SOD and Cu-Zn-SOD increased significantly(p<0.05)compared with those in the control group,with a highly significant increase observed in GSH-PX activity(p<0.01).In Group Ⅱ,the increases in the activity of CP and the total activity of SOD and Cu-Zn-SOD were highly significant compared with those in the control group(p<0.01).In addition,a significant increase was observed in GSH-PX activity(p<0.05).Based on pretest results,the concentrations of Cu,Zn,Mo,Mn,Se and Co in the blood of experimental beef cattle were lower than those of the normal range.After feeding for 90 days,the concentrations of Cu,Zn,Mo,Mn,Se and Co in the blood of Groups Ⅰ and Ⅱ were significantly higher than those in the control group(p<0.05).The concentrations of elements in the blood of Group Ⅱ were close to the appropriate levels.Thus,the effects of the specifically designed compound microelement premixture on the prevention of nutrient imbalances and control of beef cattle nutrition metabolism and the production of fattened beef cattle were significant.

Comparative Advantages and Specialized Production of Beef Cattle Industry in Yanbian Region

[Objective] To provide theoretical guidance for development of beef cattle industry in Yanbian region. [Method] Aggregated compara- tive advantage index and concentration factor were used to compare beef industry in Yanbian region and Jilin Province. [ Result] Beef cattle industry in Yanbian region had aggregated comparative advantages, and its concentration factor tended to rise year by year. [ Conclusion] The beef cattle industry in Yanbian region has obvious comparative advantages and development potential.

Variations in Reproductive Hormones during Estrus Cycle in Local Beef Cattle from Jilin of China

[ Objective] To provide a theoretical basis for improving reproductive efficiency of domestic beef cattle in Jilin of China. [ Method] China Red Steppe cattle, Yanbian yellow cattle and Simmental cattle in Jilin Province were used for detection. The levels of progesterone （P4）, estradiol （ E2 ）, follicle-stimulating hormone （FSH） and luteinizing hormone （LH） in serum and urine during estrus cycle were determined. [ Result] The levels of P4 and E2 were significantly different between pregnant cattle and non-pregnant cattle on Day 21 post estrus （ P 〈 0.01 ）. The level of LH on estrus day was significantly different from that on the other days of estrus cycle （ P 〈 0.05）. [ Conclusion] It is feasible to detect P4 level for diagnosis of estrus and eady pregnancy in beef cattle.

Economics of early weaning in northern great plains beef cattle production system

Early removal of the calf from its dam reduces forage needs of the cow-calf enterprise and has been found to improve BW gain and pregnancy rates in the cow herd. However, early weaning may not always be economically viable for producers and the risk should be considered carefully. This study was conducted to evaluate the effect of early and normal weaning of steer and heifer calves on net income at weaning. Calves from Angus xHereforddams were randomly assigned to one of two weaning treatments. Calves were either early weaned (EW) at 80-d of age or remained with their dams until normal weaning (NW) at 213-d of age. Calves assigned to EW treatment received a 17.5% crude protein and 0.82 Mcal/kg net energy diet for approximately 130-d in a drylot. All economic analyses were conducted at normal weaning for both NW and EW calves. At normal weaning, price of steers ($US/kg) was lower (P = 0.003) and weaned steer value ($US/steer) was greater (P P = 0.18) was found in price of heifers ($US/kg) and weaned heifer value ($US/heifer) between NW and EW heifers. Feed cost was increased (P < 0.001) in EW steers and heifers compared to NW calves. Net revenue for both weaned steers and heifers was reduced (P < 0.001) in EW calves due to the feed cost of the growing diet. This study indicates that early weaning calves at 80-d of age decrease weaned calf value and net revenue for the cow-calf segment.

Implications of Land Use Land Cover Change and Climate Variability on Future Prospects of Beef Cattle Production in the Lake Victoria Basin

This paper presents the lessons learnt from a research project titled “Improving Beef Cattle Productivity for Enhanced Food Security and Efficient Utilization of Natural Resources in the Lake Victoria Basin” which includes Tanzania, Uganda and Rwanda. The key focus is on the implications of land use land cover change and climate variability on the future prospects of beef cattle production in this region. The study utilizes information and data from natural resources and climate components to deduce the impact of land use and land cover changes on climate variability. Additional analysis is conducted to summarize the land use and land cover data to carry out analysis on climate data using the Mann-Kendal test, linear regression and moving averages to reveal patterns of change and trends in annual and seasonal rainfall and temperature. The findings reveal that the study areas of Rwanda, Uganda and Tanzania in the Lake Victoria Basin (LVB) have changed over time following land cover manipulations and land use change, coupled with climate variability. The grazing land has been converted to agriculture and settlements, thereby reducing cattle grazing land which is the cheapest and major feed source for ruminant livestock production. Although the cattle population has been on the increase in the same period, it has been largely attributed to the fact that the carrying capacity of available grazing areas had not been attained. The current stocking rates in the LVB reveal that the rangelands are greatly overstocked and overgrazed with land degradation already evidenced in some areas. Climate variability coupled with a decrease in grazing resources is driving unprecedented forage scarcity which is now a major limiting factor to cattle production. Crop cultivation and settlement expansion are major land use types overtaking grazing lands;therefore the incorporation of crop residues into ruminant feeding systems could be a feasible way to curtail rangeland degradation and increase beef cattle production.

Prevalence and fuoroquinolone resistance of Campylobacter spp.isolated from beef cattle in Japan

Beef is a source of human Campylobacter infections.Antimicrobial treatment is needed when patients are immuno‑compromised or have other comorbidities.Therefore,we investigated the prevalence and antimicrobial resistance of Campylobacter spp.in beef cattle in Japan.Rectal swab samples were collected from 164 beef cattle at an abattoir between March 2021 and August 2021,and Campylobacter spp.were isolated from 94(57.3%)cattle.C.jejuni and C.coli were isolated from 68 and 26 cattle,respectively.For Campylobacter jejuni,the resistant rates against ampicillin,tetracycline and ciprofoxacin were 20.6,75.0 and 64.7%,respectively.For C.coli,the resistant rates against ampicil‑lin,tetracycline and ciprofoxacin were 53.8,76.9 and 88.5%,respectively.No Campylobacter isolates were resistant to erythromycin.By multilocus sequence typing,C.jejuni and C.coli isolates were classifed into 22 and 2 sequence types(STs).The top three STs of C.jejuni were ST806(12 isolates),ST21(nine isolates),and ST459(eight isolates).The most frequent ST of C.coli was ST1068(23 isolates).The results suggest that Campylobacter spp.are prevalent in the gastrointestinal tract of beef cattle slaughtered at abattoirs.Furthermore,the administration of erythromycin is efec‑tive against human campylobacteriosis caused by beef consumption.Monitoring the prevalence and antimicrobial resistance of Campylobacter spp.in beef cattle could be useful for managing the risk of human campylobacteriosis.

Growth Modeling of Charolais and Serrana Soriana Native Spanish Beef Cattle

The alternative productions, increasingly importance, are based on the rational utilization of the resources, on agreement with the environment and the use of autochthonous breeds that many cases are found in danger of disappearance, due to the tact that their suckling is not economically profitable. A way of predicting and knowing the growth of the animals is using mathematical models. This work presented the results of the estimate of the growth according to the Gompertz-Laird model of males of the atttochthonous breed Serrana Soriana and Charolais. The weight to the birth of the breed calfs Charolais （45.14 kg）, was superior to those of Serrana Soriana （40.13 kg）, and presented a greater relative growth （9.9%） before the inflection point of the growth curve： furthermore it ~as also superior to the maximum decline relative after this point （6%）, Serrana Soriana reached 7 days after the maximum growth point but with a smaller weight （315.05 kg vs 384.76 kg）. It was calculated a weight to the maturity of 1 ,（176.91） kg for Charolais and 856.40 kg for Serrana Soriana.

Exploration of Urinary Creatinine to Determine the Carcass and Its Protein Weight in Beef Cattle

This study was aimed to explore the use of creatinine as indicator to predict carcass and its protein weight in beef cattle. Eight Ongole crossbred cattle with initial body weight ranged at 133.5-228 kg and age of 6-18 months were used in this study. The cattle were fed Napier grass ad libitum and concentrate feeding for three months prior to be slaughtered. Concentrate feeding was consisted of rice bran and soybean meal which was provided to fulfill dry matter requirement at 2.1% of body weight （BW）. The availability of creatinine for prediction indicator was done by evaluate the correlation between the amount of daily urinary creatinine and the carcass and its protein weight. Carcass and its protein weight were measured by slaughtering the cattle, and chemically analyzed for determining protein content of carcass. The results showed that creatinine excreted in urine have a strong correlation with the cattle body weight （r = 0.88）, carcass weight （r = 0.67）, body protein （r = 0.70） and carcass protein （r = 0.72）. The conclusion of this study is creatinine excreted in urine have a strong relationship with the carcass and its protein, and therefore could be used to predict the carcass and its protein weight of beef cattle.