Slaughter Day Research Articles

Modulation of microbial communities and mucosal gene expression in chicken intestines after galactooligosaccharides delivery In Ovo.

Intestinal mucosa is the interface between the microbial content of the gut and the host’s milieu. The goal of this study was to modulate chicken intestinal microflora by in ovo stimulation with galactooligosaccharides (GOS) prebiotic and to demonstrate the molecular responses of the host. The animal trial was performed on meat-type chickens (Ross 308). GOS was delivered by in ovo injection performed into the air cell on day 12 of egg incubation. Analysis of microbial communities and mucosal gene expression was performed at slaughter (day 42 post-hatching). Chyme (for DNA isolation) and intestinal mucosa (for RNA isolation) from four distinct intestinal segments (duodenum, jejunum, ileum, and caecum) was sampled. The relative abundance of Bifidobacterium spp. and Lactobacillus spp. in DNA isolated from chyme samples was determined using qPCR. On the host side, the mRNA expression of 13 genes grouped into two panels was analysed with RT-qPCR. Panel (1) included genes related to intestinal innate immune responses (IL-1β, IL-10 and IL-12p40, AvBD1 and CATHL2). Panel (2) contained genes involved in intestinal barrier function (MUC6, CLDN1 and TJAP1) and nutrients sensing (FFAR2 and FFAR4, GLUT1, GLUT2 and GLUT5). GOS increased the relative abundance of Bifidobacterium in caecum (from 1.3% to 3.9%). Distinct effects of GOS on gene expression were manifested in jejunum and caecum. Cytokine genes (IL-1β, IL-10 and IL-12p40) were up-regulated in the jejunum and caecum of the GOS-treated group. Host defence peptides (AvBD1 and CATHL2) were up-regulated in the caecum of the GOS-treated group. Free fatty acid receptors (FFAR2 and FFAR4) were up-regulated in all three compartments of the intestine (except the duodenum). Glucose transporters were down-regulated in duodenum (GLUT2 and GLUT5) but up-regulated in the hindgut (GLUT1 and GLUT2). In conclusion, GOS delivered in ovo had a bifidogenic effect in adult chickens. It also modulated gene expression related to intestinal immune responses, gut barrier function, and nutrient sensing.

Enumeration, Antimicrobial Resistance and Typing of Salmonella enterica: Profile of Strains Carried in the Intestinal Contents of Pigs at Slaughter in Southern Brazil

Background: Despite a strong association between Salmonella isolation and slaughter hygiene, as measured by the Enterobacteriaceae levels on pre-chill carcass surfaces, a high variation in this association was observed between sampling days within the same slaughterhouse. It was hypothesised that in a scenario of high exposure on the farm, batches with a high prevalence of carrier pigs shedding a high number of Salmonella may enhance the risk of contamination on some slaughter days. Thus, the aim of this study was to assess the profile of Salmonella carried in the intestinal contents of slaughter pigs.Materials, Methods & Results: Ten pig batches slaughtered in a slaughterhouse were investigated for the presence of Salmonella. From each pig, the following samples were taken: i. blood collected at bleeding; ii. sponges rubbed on the carcass surface after bleeding and before chilling; iii. fragment of the ileocecal region of the intestine. Serum samples were subjected to a ELISA-Typhimurium test. Sponges were investigated for the presence of Salmonella and total aerobic mesophilic (TAM) and Enterobacteriaceae (EC) bacterial counts. Salmonella was enumerated in the intestinal contents. Selected Salmonella strains were subjected to an antimicrobial resistance disk diffusion test, macro-restriction with Xba-I (PFGE) and whole genome sequencing (WGS). From the 50 sampled pigs, 96% were positive in the ELISA-Typhimurium test and 64% were Salmonella-positive in the intestinal contents. The amount of Salmonella in the intestinal content samples was highly variable, and the mean log of fitted distributions of Salmonella in the batch ranged from -2.97 to 2.25 cfu.g-1. The slaughter process achieved a logarithmic reduction, ranging from 0.64 to 2.35 log cfu.cm-2 for TAM and from 0.55 to 2.57 log cfu.cm-2 for EC. Salmonella was isolated from 16% of the carcasses after bleeding; this frequency decreased to 8% at the pre-chill step. All positive pre-chill carcasses originated from pigs carrying Salmonella in the intestinal content and from batches with a high number of carrier pigs. Salmonella Typhimurium and its monophasic variant were the most frequent in the intestinal contents and carcasses. Resistance was detected against ampicillin (42.5%), tetracycline (42.5%), sulfonamide (40%), gentamicin (25%) and ciprofloxacin (12.5%). Regarding colistin, 85% of the tested strains were classified as non-susceptible. The monophasic variant S. Typhimurium strains subjected to PFGE and WGS presented different profiles; several antimicrobial resistance genes were identified and all belonged to ST-19.Discussion: In this study, almost all sampled pigs entering the slaughter line had been exposed to Salmonella on the farm and a high number were carrying Salmonella in their guts. While the three batches with Salmonella-positive carcasses at the pre-chill step presented TAM media that was not significantly different from the other batches, there was a higher number of positive pigs carrying Salmonella in their intestinal contents. Moreover, the batch with the highest number of positive carcasses also presented the highest Salmonella mean count in their intestinal contents. The profile of Salmonella carried in the intestinal content of slaughter pigs proved to be highly variable in terms of the frequency, number of bacteria, serovars, antimicrobial resistance, and genotypes. Results indicate that the day-to-day variability in the prevalence and number of Salmonella in the intestinal contents of slaughter batches is likely to influence the frequency of contaminated pre-chill carcasses. Salmonella Typhimurium isolated from the intestinal contents of slaughter pigs may belong to genotypes involved in human disease and may carry several antimicrobial resistance genes. These aspects should be taken into account when planning Salmonella control in swine.

Effect of immunocastration on sex glands of male Mangulica (Swallow-bellied Mangalitsa) pigs

ABSTRACT The objective of this research was to study the effect of immunocastration on the morphometric characteristics of sex glands in male Swallow-bellied Mangalitsa pigs. The study included 24 animals (13 entire and 11 immunocastrated males). The research focused on the following traits: age at slaughter (days), live weight at slaughter (kg), growth rate (kg day−1), and morphometric testicle traits (volume, cm3; weight, g; length, width, thickness, and circumference, mm). The efficacy of immunocastration was determined based on androstenone and [...]

Effects of dietary supplementation of the lignocelluloses FibreCell and OptiCell on performance, expression of inflammation-related genes and the gut microbiome of broilers

This study investigated the hypothesis that dietary supplementation of lignocellulose in broilers influences the gut bacterial population and bacterial fermentation, has anti-inflammatory effects, and increases mucin synthesis in the intestine, and, through these changes, influences broiler performance positively. Day-old male Cobb 500 broilers (n = 96) were allotted to 3 experimental groups and fed 3 different maize-wheat-soybean meal-based basal diets during days 1 to 10, 11 to 21, and 22 to 35. The basal diets were fed to the control group, and were supplemented with 0.8% of a standard lignocellulose (LCS) or a fermentable lignocellulose (LCF). Body weight and feed consumption were determined, and at slaughter (day 35), carcass and gizzard weights and gizzard content pH were recorded, and samples of jejunum, cecum, and colon mucosa and of cecum digesta were collected from 15 birds/group. Growth performance and feed intake were not influenced, but dressing percentage was higher in group LCF compared to the other groups. In group LCS and the control group, performance, gizzard weight and gizzard content pH, intestinal gene expression of pro-inflammatory cytokines and of the mucins 2, 5ac and 13, the cecal short-chain fatty acid (SCFA) profile, and bacterial diversity were similar, and relative abundance of bacterial groups (16S DNA sequencing) differed. Supplementation of LCF decreased the expression of the pro-inflammatory genes encoding interleukins 1ß and 17 (P < 0.05) and those of 2 and 8 (P < 0.10) in the jejunum only. The bacterial population differed, and the SCFA profile shifted toward acetate at the expense of butyrate in group LCF compared to the control group. For example, the abundance of Firmicutes and of Ruminococcaceae and Lactobacillaceae decreased, whereas those of Peptostreptococcaceae, Erysipelotrichaceae, and Enterobacteriaceae and that of members of the phylum Proteobacteria increased in group LCF compared to the control group. These data indicate that the susceptibility of lignocellulose to fermentation is crucial for mediating its effects on intestinal gene expression and the bacterial population in the cecum, which may also affect dressing percentage.

Susan Wharton Gates: Days of Slaughter

Susan Wharton Gates: Days of Slaughter

Studies Concerning the Dynamics of Productive Indicators on Gray Guinea Fowl (Numida Meleagris)

Growing guinea-fowls is an area of less research activity, although meat and eggs from this species are increasingly sought by consumers around the world. In addition, there is a number of very valuable biological features that makes this sector such attractive. This paper deals with a study on the productive performance of the gray guinea fowl under controlled ambient conditions. The biological material consisted of 50 specimens of guinea-fowls, purchased from a producer in our country. Those guinea fowls were grown according to the species-specific technology, from one day to 77 days. The target indicators were body weight, weight gain, feed consumption and stockholding proportion, determined in accordance with the poultry research methodology. The data were statistically processed using the Anova (Analysis of variance) program. For the gray guinea fowl, the growing period has been divided into three stages of age, differentiated by the protein level of the feed. At the time of population, the body weight of birds was 28.09 ± 0.35 g, and on the day of slaughter (77th day), 1923.76 ± 18.29 g. This weight was achieved with a feed conversion index of 1: 3.64.The gray guinea fowl exhibits good organic resistance and ensures satisfactory meat production under conditions of optimal nutrient feeding.

Adipose tissue proteomic analyses to study puberty in Brahman heifers.

The adipose tissue has been recognized as an active endocrine organ which can modulate numerous physiological processes such as metabolism, appetite, immunity, and reproduction. The aim of this study was to look for differentially abundant proteins and their biological functions in the abdominal adipose tissue between pre- and postpubertal Brahman heifers. Twelve Brahman heifers were divided into 2 groups and paired on slaughter day. Prepubertal heifers had never ovulated and postpubertal heifers were slaughtered on the luteal phase of their second estrous cycle. After ensuring the occurrence of puberty in postpubertal heifers, abdominal adipose tissue samples were collected. Mass spectrometry proteomic analysis identified 646 proteins and revealed that 171 proteins showed differential abundance in adipose tissue between the pre- and postpuberty groups (adjusted P-value < 0.05). Data are available via ProteomeXchange with identifier PXD009452. Using a list of 51 highly differentially abundant proteins as the target (adjusted P-value < 10-5), we found 14 enriched pathways. The results indicated that gluconeogenesis was enhanced when puberty approached. The metabolism of glucose, lipids, and AA in the adipose tissue mainly participated in oxidation and energy supply for heifers when puberty occurred. Our study also revealed the differentially abundant proteins were enriched for estrogen signaling and PI3K-Akt signaling pathways, which are known integrators of metabolism and reproduction. These results suggest new candidate proteins that may contribute to a better understanding of the signaling mechanisms that relate adipose tissue function to puberty. Protein-protein interaction network analysis identified 4 hub proteins that had the highest degrees of connection: PGK1, ALDH5A1, EEF2, and LDHB. Highly connected proteins are likely to influence the functions of all differentially abundant proteins identified, directly or indirectly.

In vitro potential anthelmintic activity of Biophytum petersianum on Haemonchus contortus.

Aim:Haemonchus contortus is a major problem in small ruminants in Indonesia. The frequent use of the anthelmintic drugs has given rise to drug-resistant populations which increase the need for new anthelminthic compounds, particularly from endemic plants. This study evaluated the in vitro effects of Biophytum petersianum crude aqueous extract (BAE) as an anthelmintic compound against H. contortus adult worm isolated from goats.Materials and Methods:Adult worm collected from naturally infected abomasums were obtained from slaughtered goats on the day of slaughter. BAE was prepared in six different concentrations (10, 20, 40, 60, 80, and 100 mg/ml) which were tested for their efficacies on ten actively moving worms. Ivermectin (1 mg/ml) was included as a reference drug, while saline water was included as a control. The dead worms from anthelmintic test then went through sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and scanning electron microscopy (SEM).Results:Highest mean mortality in treatments group both at 2 h and 4 h observations was BAE 10%. The SDS-PAGE analysis revealed the presence of five protein bands with molecular weights 9.3, 17.1, 50.0, 63.2, and 72.7 kDa based on BAE 10%. The SEM changes observed in the in vitro trials revealed the occurrence of interactions between the BAE and the cuticle.Conclusion:The SEM and SDS-PAGE analysis revealed ultrastructural structural changes and the decrease numbers of polypeptides on treated worms when compared to the control worms. It can thus be concluded that the BAE exhibits good anthelmintic activity against H. contortus adult worm.

Effects of intensity and duration of quantitative restriction of feed on broiler performance

This study was carried out to evaluate the effects of physical feed restriction method with different intensity and duration on broiler performance. One hundred and fifty Ross-breed 308 male broiler chicks in a completely randomized design were divided into five experimental treatments. The treatments included physical limitations by 25% or 50% of recommended amount on feed of broilers in two periods of 7 or 14 days. One control group was used fed ad libitum. Each limitation’s severity level was applied in τηρεε replications of 10 birds. All experimental treatments before and after the limitation period until slaughter (day 42) were fed ad libitum. The results showed that in total period broilers under the physical limitation of feed had significantly lower feed intake than controls (P &lt; 0.05). In this research, methods and levels of physical restriction intensity and duration of feed had no significant effect on body weight for the whole experimental period. Methods and levels of food restriction severity and duration had significant effect on feed efficiency (P &lt; 0.05).

Allometric coefficients for carcass and non-carcass components in a local meat-type sheep breed

The aim of the research was to assess the type of development of carcass and non-carcass components and tissue partitioning in the Cornigliese sheep breed. The study involved 164 animals (104 females, 60 males) from one flock. The selection of those animals accounted for ages and weights differences. Fasted body weight (BW) was recorded before slaughtering. Four BW-classes were identified by means of percentiles distribution: 0–25th percentile, 15.90–50.70kg BW; 25th–50th percentile, 50.71–63.22kg BW; 50th–75th percentile, 63.23–75.50kg BW; 75th–100th percentile, 75.51–111.15kg BW. After slaughter, the carcasses were weighed, measured (carcass length, croup width, chest width, chest depth, thigh length) and sectioned (shoulder, neck, thigh, ribs, loin, and lean and fat trimmings). A samplecut from 1st to 4th thoracic vertebra was then separated into its tissue components (lean meat, fat, bone). Non-carcass components (skin+fleece, head, liver, heart, lungs+trachea) were weighed. The data were analyzed using a GLM procedure accounting for the following fixed effects: sex, BW-class, year of birth and the interaction between sex*BW-class and the covariate: day of slaughter. The relative growth of carcass and non-carcass components on BW was calculated by applying the nonlinear allometric function (y=axb). We found high coefficients of variation (CVs) (from 39% to 77%) for the weight of carcass components and low CVs (from 8% to 22%) for carcass measures. Non-carcass parameters showed intermediate values of CVs (from 30% to 42%). Body weight-class had a significant effect (P<0.05) on all parameters, except on lean/fat ratio and lean percentage of the sample cut. Significant mean differences between genders were observed in the lean/fat ratio. In particular, in the lowest BW-class, females scored higher than males, whereas, in the highest BW-class, we observed the opposite trend (P<0.05). Carcass, loin, lean and fat trimmings grew faster than BW, regardless of the sex. In contrast, as far as the neck is concerned, significant differences between females and males were observed (P<0.05). Among carcass measures, a late maturing rate was recorded for croup width (b=0.5042) and, in this case, females tended to be earlier than males (P<0.10). Among non-carcass parameters, only head and skin+fleece weights showed differences between sex groups, with males showing a later development than females (P<0.05). Tissues (lean, fat, bone) in the sample cut developed with different speed: the earliest tissue was bone (b=−0.3191), followed by lean (b=0.0768) and finallyby fat (b=0.8394). Bone development was significantly (P<0.05) sex related, with males showing a later growth than females. Sex differences in the sample cut composition were also associated to lean/fat, (lean+fat)/bone and lean/bone ratios. This study has shown the potential use of the Cornigliese sheep as a commercial breed for meat production, although significant interaction between sex and body weight was observed. For this reason, it is recommended to implement a breeding strategy to reduce the incidence of extreme fattening females and the high incidence of non-carcass component in males when they reach high BWs.

The effect of phytogenic feed additives on the performance, meat quality and coccidial infection rates of rabbits

The aim of the study was to evaluate the effect of herbal supplementation on rabbits’ health and production parameters. In experiment with herbal food additives, at 90 days of age animals fed with phytogenic additives (oregano, garlic and rosemary) had higher body weight compared to the group fed with coccidiostat. In experiment with herbal water additives (garlic extract or oregano) the phytobiotic supplementation had no effect on weight gains of animals. The highest body weight on slaughter day was obtained by rabbits drank water with garlic extract. Parasitological tests performed at 91 days of age showed that lowest average number of coccidia oocysts per gram of faeces (OPG) in “garlic” group (48.0 OPG) and the highest in control group (308.6 OPG). The research showed that feed with herbal supplementation is willingly eaten by rabbits, contributes to faster weight gains and has a positive effect on meat quality.

Development of an index for the assessment of welfare of finishing pigs from farm to slaughter based on expert opinion

For pigs, the day of slaughter involves potential animal welfare threatening elements at different stages such as pick-up pens, loading, transport, unloading, lairage and race. At present no tool for assessing the welfare of finishing pigs from farm exit to stunning is available. The present study builds on a protocol for assessment of animal welfare of finishing pigs on the day of slaughter, a protocol which was based on the structure of the Welfare Quality® protocol for finishing pigs at an abattoir. The present study aimed to develop an animal welfare index (AWI) for the day of slaughter by aggregating 25 primarily animal-based measurements based on 38 experts opinion on inter-measurement and inter-stage weights. AWIs were calculated on animal level as the weighted sums of prevalence of the measurements, and were calculated for each of the six stages: pick-up pen, loading, transport, unloading, lairage and race (AWIStage) and across the stages (AWIOverall). The AWIs were tested in 5 farms including a total of 45 fattening pigs delivered to two Danish abattoirs. Possible inter-relations between the AWI and heart rate measurements were examined.For each welfare measurement within stage, significant differences between the mean expert scores were found. However, no difference between stage weights was found. Statistically significant differences in average heart rate between stages were found: 123a (pick up pen), 139b (loading), 120a (transport), 132d (unloading), 114c (lairage) and 134bd (race) bpm, respectively, (different letters indicate differences of P<0.05). No significant relationship between the score assigned by the expert panel per stage and the average heart rate within stage (r=0.61, P=0.19) or between AWIStage and heart rate (r=0.43, P=0.40) was found.In conclusion, this work has suggested a potential model for the aggregation of animal welfare measurements into animal welfare indexes for slaughter pigs on the day of slaughter. Further validation may allow simple comparison of the level of welfare between lorries, days, abattoirs etc. and may be used for future development of a feedback mechanism for optimization of the welfare of the pigs as well as for marketing.

Application of Laser Spectrochemical Analytical Techniques to Follow Up Spoilage of White Meat in Chicken

The overall objective of this paper is to evaluate the potential of laser spectrochemical analytical techniques as rapid, cost-effective, and accurate techniques to detect the onset of spoilage in fresh chicken breast fillets in three consecutive days directly following slaughter day. Samples were periodically examined via laser-induced breakdown spectroscopy (LIBS) and laser-induced fluorescence (LIF). In the case of LIBS, the cyanide (CN) and carbon (C2) molecular spectral emission bands in the LIBS spectra of meat have been taken as indicators of protein content in the chicken breast samples. The ratio of ionic to atomic spectral lines of both magnesium and iron is found to be proportional to the chicken meat tenderness which decreases with storage time. LIF has been also exploited as a simple and fast technique for white meat spoilage detection. There was a clear inverse proportionality between the intensity of the samples’ fluorescence band and the storage period. The obtained spectrochemical results have been validated by measuring the total proteins in the investigated samples using a conventional meat analyzer. This work demonstrates the feasibility of adopting LIBS and LIF techniques in characterization of both fresh and spoiled chicken meat samples.

Net mineral requirements of dairy goats during pregnancy

Mineral requirements of pregnant dairy goats are still not well defined; therefore, we investigated the net Ca, P, Mg, Na and K requirements for pregnancy and for maintenance during pregnancy in two separate experiments. Experiment 1 was performed to estimate the net Ca, P, Mg, Na and K requirements in goats carrying single or twin fetuses from 50 to 140 days of pregnancy (DOP). The net mineral requirements for pregnancy were determined by measuring mineral deposition in gravid uterus and mammary gland after comparative slaughter. In total, 57 dairy goats of two breeds (Oberhasli or Saanen), in their third or fourth parturition, were randomly assigned to groups based on litter size (single or twin) and day of slaughter (50, 80, 110 and 140 DOP) in a fully factorial design. Net mineral accretion for pregnancy did not differ by goat breed. The total daily Ca, P, Mg, Na and K requirements for pregnancy were greatest in goats carrying twins (P<0.05), and the requirements increased as pregnancy progressed. Experiment 2 was performed to estimate net Ca, P, Mg, Na and K requirements for dairy goat maintenance during pregnancy. In total, 58 dairy goats (Oberhasli and Saanen) carrying twin fetuses were assigned to groups based on slaughter day (80, 110 and 140 DOP) and feed restriction (ad libitum, 20% and 40% feed restriction) in a randomized block design. The net Ca, P and Mg requirements for maintenance did not vary by breed or over the course of pregnancy. The daily net requirements of Ca, P and Mg for maintenance were 60.4, 31.1 and 2.42 mg/kg live BW (LBW), respectively. The daily net Na requirement for maintenance was greater in Saanen goats (11.8 mg/kg LBW) than in Oberhasli goats (8.96 mg/kg LBW; P<0.05). Daily net K requirements increased as pregnancy progressed from 8.73 to 15.4 mg/kg LBW (P<0.01). The findings of this study will guide design of diets with adequate mineral content for pregnant goats throughout their pregnancy.

The Effects of Hot vs. Cold Boning on Eating Quality of New Zealand Grass Fed Beef

Sides of the 40 selected carcasses were alternately assigned to both conventional chilling and cold boning (CB) or hot boning (HB). Fabrication of CB sides took place after overnight chilling (20 h postmortem) and subsequent carcass grading, while fabrication of HB sides occurred on the day of slaughter within 60 min of exsanguination. Five muscles were removed, including the longissimus lumborum (LL), longissimus thoracis (LT), psoas major (PM), gluteus medius (GM), and semimembranosus (SM) for consumer evaluation, compositional analysis, and sarcomere length determination. Cold boning muscles had longer (P &lt; 0.05) sarcomere lengths compared to HB muscles, expect for the GM and SM. Chilling treatment and postmortem aging (7, 21, or 35 d postmortem) had an impact on eating quality, but these results varied by muscle. Cold shortening could be responsible for the differences in sarcomere length and ultimately differences in tenderness between HB and CB muscles. Based on consumer evaluations, HB is not recommended for LT or PM due to the reduction (P ≤ 0.02) of tenderness and overall liking scores for these subprimals; however, HB and early removal of muscles like the SM benefited (P &lt; 0.01) from an eating quality standpoint for all palatability traits, and was neutral (P ≥ 0.21) for tenderness, juiciness, flavor, and overall liking of the LL and GM. Postmortem aging did not affect (P ≥ 0.07) eating quality of the GM and PM, but improved (P &lt; 0.01) tenderness of LT and SM, as well as the tenderness, juiciness, flavor liking, and overall liking of the LL.

The Effects of Ractopamine and Hormonal Growth Promotants on Growth and Meat Quality of Crossbred Angus Steers

ObjectivesMeat tenderness is an important quality parameter that influences consumer preference. The cattle industry has over the years seen the emergence of feed additives and hormonal growth promotants in the form of β-adrenergic agonists (β-AA) and steroids, respectively. The objective of this study was to analyze the effect of hormonal growth implants and ractopamine on slaughter weight and meat quality parameters of steers selected for high (inefficient) and low (efficient) residual feed intake (RFI) performance.Materials and MethodsForty-eight crossbred Angus steers identified from individual GrowSafe data as high (n = 21) or low (n = 27) RFI cattle were randomly assigned to pens according to treatment (n = 12). Treatments included control (no ractopamine hydrochloride (RAC)/no steroids), RAC and steroids, steroids only, and RAC only in a 2x2x2 factorial design. Steers on steroid treatment received a first implant (200mg progesterone, 20mg estradiol benzoate and 29mg tylosin tartrate) at about 350 d of age and 450kg live weight and a terminal implant (120 mg trenbolone acetate and 24mg estradiol) at about 100 d before slaughter. RAC was fed to the appropriate group 28 d before slaughter at a rate of 200mg head–1d–1. Cattle were slaughtered at about 16 mo of age over 6 consecutive weeks by weight and back fat, with 1 animal per treatment represented in each kill for a total of 8 animals slaughtered per week. Hot carcass weights (HCW) were recorded. Gluteus medius (GM) muscles were obtained from the carcasses 3 d post mortem and halved for ageing, with one half aged a further 12 d under vacuum. After ageing at 4°C, muscle halves were assessed for pH, color, drip loss and Warner-Bratzler shear force (WBSF). For all data the experimental unit was the steer as the effect of ageing was not considered. Data was analyzed using the General Linear Model procedure in SAS (SAS Inst. Inc., Cary, NC) with RFI, steroids, RAC and their interactions as fixed factors with slaughter day used as a covariate. Mean differences were determined using Least Square Means and Tukey’s multiple comparisons.ResultsResults revealed no effect (P > 0.05) of RFI and RAC on slaughter weight (SW) but steroids increased (P < 0.0001) SW of steers. An interaction effect (P = 0.0381) was seen between RFI, steroids and RAC on HCW, where high RFI steers that were implanted with steroids and fed RAC had a higher HCW at 389.64 ± 8.70 kg than low RFI steers that were neither implanted nor fed RAC (325.68 ± 7.05kg). An interaction between RFI, steroids and RAC (P = 0.045) for drip loss was observed on muscles aged for 12 d, where high RFI steers that were implanted but not fed RAC had a higher drip loss (1.93 ± 0.23 g) than low RFI steers that were not implanted but feed RAC (0.63 ± 0.19g). Muscles from implanted steers had a higher mean WBSF value than muscles from non-implanted steers on d 12 post-mortem (P = 0.039), while high RFI steers that received RAC had the lowest mean WBSF (P = 0.015).ConclusionResults indicated that steroids compromised the development of tenderness during post mortem ageing in the GM. This suggests that the benefit of steroid use on slaughter and hot carcass weights will compromise tenderness of this muscle. Additional post mortem ageing beyond 12 d may be required. Conversely, the use of the β-AA RAC showed potential for decreasing cooked GM toughness in high RFI steers regardless of the ageing period.

Effect of shade on animal welfare, growth performance, and carcass characteristics in large pens of beef cattle fed a beta agonist in a commercial feedlot.

Feedlot cattle ( = 1,395; BW = 568 ± 43 kg) were used to evaluate the effects of shade on animal welfare, growth performance, and carcass quality during the summer of 2013 in a Kansas commercial feedlot. Seven lots of predominately black steers and heifers (4 and 3, respectively) visually determined to be approaching the final mo on feed were identified, randomly gate-sorted, and allocated to pens located across the feed alley from each other to receive 1 of 2 treatments: 1) Shade (mean shade area = 1.5 m/ animal) or 2) No shade. Shade was provided using a 13-ounce polyethylene fabric and pens were oriented northwest to southeast. The mean starting date was June 13 and the mean days on feed for lots while on the study was 38 d. Cattle were fed a 77.67% DM steam-flaked corn-based diet and had ad libitum access to water throughout the duration of the trial. Zilpaterol hydrochloride (ZIL) was included in the finishing ration at an inclusion rate of 8.3 mg/kg of DM for the last 20 d on feed with a 3 d withdrawal period. Pen floor temperatures (PFT) were measured using an infrared thermometer and prevalence of cattle open-mouth breathing (OMB) was recorded on a pen basis. In addition to shade treatment, the effect of temperature humidity index (THI) on PFT and OMB was analyzed by classifying days as either "Alert" (THI < 79) or "Danger" (THI > 79). On the day of slaughter, pens within a replicate were kept separate through all stages of the marketing channel from loading at the feedlot until stunning at the plant. Pen served as the experimental unit for all measurements. There was a THI × shade treatment interaction for PFT and OMB ( < 0.001) where days classified as "Danger" increased PFT and prevalence of OMB compared to "Alert" days in unshaded but not shaded cattle. Shaded cattle had greater DMI ( = 0.01); however, unshaded cattle had greater G:F ( = 0.05) and therefore no differences were observed in ADG ( = 0.39). Shaded cattle had greater dressing percentage ( = 0.01), although HCW, LM area, fat thickness, marbling score, and quality grade did not differ between treatments ( > 0.05). Heat stress, a significant animal welfare concern and cause of reduced performance in feedlot cattle during the final phase of the feeding period, was alleviated in shaded cattle and illustrates the importance of shade provision as 1 tool to protect the welfare and increase feed consumption in large pens of feedlot cattle during hot summer months.

Effects of partially replacing barley with sugar beet pulp, with and without roasted canola seeds, on performance, rumen histology and fermentation patterns in finishing Arabian lambs

This study investigated the effects of partially replacing barley grains with sugar beet pulp (SBP), with and without roasted canola seed (RCS) on ruminal pH, ruminal volatile fatty acid (VFA) concentrations, ruminal histomorphometric characteristics, and performance in finishing lambs fed a high concentrate diet. Twenty-four Arabian male lambs (23.7 ± 2.5 kg bodyweight, 118 ± 10 days in age) were used for 99 days in a completely randomised design with a 2 × 2 factorial arrangement. Lambs were fed with a high concentrate diet containing (1) 68% barley (B) (2) barley plus 7% RCS (B + RCS) (3) 36% SBP, (4) SBP plus 7% RCS (SBP + RCS). Ruminal fluid pH and VFA concentrations were determined at 0, 2, 4 and 8 h post-feeding 1 day before slaughter day. Tissue samples were collected for histomorphometric study at slaughter day. Average daily gain of the lambs was not affected by partial replacement of barley with SBP, however it was improved by RCS inclusion (P &lt; 0.05). Diets with RCS had significantly lower (P &lt; 0.05) neutral detergent fibre and acid detergent fibre digestibility values than diets without RCS (P &lt; 0.05). Both SBP and RCS increased ruminal pH, molar proportions of acetate, isobutyrate but decreased molar proportion of propionate in rumen content (P &lt; 0.05). The height, width, epithelial thickness and tunica muscularis of rumen papilla and reticulum folds were increased by SBP (P &lt; 0.05). Density of reticulum folds were higher in lambs fed by higher SBP (P &lt; 0.05). Inclusion of RCS significantly increased papillae height and thickness of epithelium (P &lt; 0.05). In conclusion, partially replacing barley with SBP as well as RCS inclusion prevented a drop in the ruminal pH, and improved the morphology of the rumen-reticulum in finishing lambs fed a high concentrate diet.

Association between pigs with high caecal Salmonella loads and carcass contamination

Contaminated pork is a significant source of foodborne Salmonella infections. Pork is contaminated at the slaughterhouse; however, the mechanisms driving Salmonella contamination of carcasses are still poorly understood. The aim of this study was to investigate whether the amount of Salmonella carried by slaughtered pigs in their guts has an influence on carcass contamination. On that account, we tested whether the number of carcasses contaminated during a slaughter day was associated with the prevalence of highly contaminated pigs (HCP: Salmonella caecal loads ≥3log/g), or with the prevalence of pigs that simply carry Salmonella spp. in their guts. Three hundred and six pigs were sampled in a slaughterhouse from Central Italy. Salmonella loads in the caecum and on the carcass of each pig were estimated by the most probable number (MPN) technique. The overall prevalence of Salmonella was 34.64% and 7.19% for the caeca and carcasses, respectively. S. Derby and Salmonella enterica 4,[5],12:i:– were the most frequently isolated serovars. The prevalence of HCP was 11.44%. We found a higher number of contaminated carcasses on days of high prevalence of HCP than on days of low prevalence of HCP (p=0.0011). Conversely, carcass contamination did not vary with the prevalence of pigs that simply carried Salmonella spp. in their guts (p=0.7970). Therefore, the prevalence of HCP, but not the prevalence of pigs carrying Salmonella spp., was related to carcass contamination. Taken together, these findings suggest that reduction of Salmonella loads in the guts of slaughtered pigs would result in fewer contaminated carcasses, and consequently, help to minimise the risk of human infection due to the consumption of contaminated pork.

Associations of blood parameters with age, feed efficiency and sampling routine in young beef bulls

Utilization of blood parameters as proxies for feed efficiency is an avenue to maximize profitability of the beef industry. Among other factors, age and sampling routine may impact the reliability of potential proxies for residual feed intake (RFI). Thus, the objectives were to assess associations of blood parameters with age and RFI under two sampling routines. Thirty-two crossbred bulls with an average body weight (BW) of 633±93kg and 369±29 days of age were studied. Residual feed intake was calculated using average daily gain, BW and ultrasound traits for body composition. Seven blood samples for each bull were collected during a 33-day on-station sampling period and an additional sample was collected at slaughter for analysis of blood metabolites and hormones. Bulls were classified as younger (342±17 days of age) and older (395±4 days of age) and into efficient (−0.55±0.70kg DM/day) and inefficient (RFI=0.55±0.29kg DM/day). Means of blood parameters were compared between age and feed efficiency groups using a mixed model for on-station sampling and a general linear model for slaughter sampling. During the on-station sampling, glucose (P=0.01), potassium (P=0.01) and insulin-like growth factor 1 (P=0.01) were lesser in older bulls while urea (P=0.05), acetate (P=0.01), osmolality (P=0.01), testosterone (P=0.01) and follicle stimulating hormone (FSH; P=0.04) were greater in older bulls. At slaughter, carbon dioxide (P=0.01), brain-derived neurotrophic factor (P=0.05) and FSH (P=0.01) were greater in older bulls. Over the on-station sampling, osmolality (P=0.05) was greater in inefficient bulls while leptin (P=0.01) was greater in efficient bulls. On the day of slaughter, cholesterol (P=0.04) and alkaline phosphatase (P=0.04) were lesser in efficient bulls. Age and RFI classes interaction was observed for T3 (P=0.01) during the on-station sampling where lesser T3 blood levels where observed in efficient bulls within the younger group (P=0.01) and in older bulls within the inefficient group (P=0.05). Overall, these results support the association of blood parameters with variation in age and RFI and illustrate the impact of sampling routine on components of intermediary metabolism in yearling bulls, providing information to the development of proxies for RFI.