Different rearing systems for fattening rabbits: Performance and carcass characteristics

To evaluate the effect of different rearing systems and sex on productive performance and carcass composition and quality, 80 rabbits (40 males and 40 females) of Carmagnola breed were reared from 9 to 16 weeks of age in individual California type cages (0.12 m²) or in group ground pens (0.25 m²/head). The animals were kept in standard and uniform environmental conditions and fed the same ad libitum pellet feed. Data on live weight and feed intake were recorded. At the end of the fattening period 10 animals per group were slaughtered and data provided in the World Rabbit Science Association (WRSA) standard method were collected, as well as pH and meat colour. Animals reared in ground pens showed lower productive performances, while, as to slaughtering performances, rabbits reared in cages showed the highest slaughtering weight and also the highest weights for most body parts. Gender slightly affected productive and slaughtering performances: females showed higher feed consumption and higher perirenal fat weight than males. Meat colour parameters showed significant differences in Longissimus lumborum and Biceps femoris due to housing systems and gender effects. In both muscle, rearing system affected pH only 24 h after slaughter.     

Effect of housing conditions on production,carcass and meat quality traits of growing rabbits

Production, carcass traits and meat quality of rabbits housed in cages or in different pens were compared. Rabbits (n = 579) were sorted into 5 groups: C = cage (2 rabbits/cage); pen without platform: P11 = 9 rabbits/pen; P16 = 14 rabbits/pen; pen with platform: PW = wire net platform, 14 rabbits/pen; PD = platform with straw-litter, 14 rabbits/pen. Feed intake and average daily gain between 5 and 11 weeks, and body weight at 11 weeks were significantly higher in C rabbits than that of the mean of pen-housed groups, while the PD group had the lowest growth performance. C rabbits had the smallest hind part to reference carcass (P < 0.001) and the largest percentage of perirenal and scapular fat (P < 0.001). The meat/bone ratio was the largest in group C (P < 0.05). Differences were recorded in a* value and lipid content of m. Longissimus dorsi. Rabbits housed in cages generally had the best performance whereas those housed in pens with platform exhibited the worst.     

Fatty acid composition of meat and perirenal fat in rabbits from two different rearing systems

To evaluate the effect of different rearing systems and sex on the fatty acid composition of rabbit meat and perirenal fat, the fat content and fatty acid composition of Longissimus lumborum and perirenal fat were determined by gas chromatography on 40 rabbits (20 males and 20 females) of the Carmagnola Grey breed reared from 9 to 16 weeks of age in individual California type cages (0.12 m²) or in group ground pens (0.25 m²/head). Ether extract percentage of muscle was significantly influenced by the housing system while, both sex and rearing method affected the fatty acid composition with a decrease in monounsaturated fatty acid (MUFA) and an increase in polyunsaturated ones (PUFA) in penned and male rabbits. The same trends were observed in the fatty acid composition of the perirenal fat, gender only had a significant affect on the saturated fatty acid (SFA) content in the perirenal fat. Indices relating to human health showed the PUFA/SFA ratio to be over the minimum recommendation for rabbits reared in pens and for males, while only the n6/n3 ratio was above the maximum recommendation for caged rabbits. Atherogenic index (AI) of perirenal fat was affected by gender, but no differences were observed in trombogenic index (TI) in either muscle or perirenal fat.     

The effect of rearing substrate and space allowance on the behavior and physiology of dairy calves

The objective of this study was to investigate the effect of rearing substrate and space allowance on the behavior and physiology of dairy calves. At 1 wk of age, 72 calves were moved into 1 of 18 experimental pens (n = 4 calves/pen) where they remained until 6 wk of age. Half of the pens had floors covered with quarry stones (QS) and the other half were covered with sawdust (SW). For each substrate type, calves were reared at 1 of 3 space allowances: 1.0, 1.5, or 2.0 m²/calf. Behavior was video-recorded continuously for 24 h in the home pen at 2, 4, and 6 wk of age; the time calves spent lying, standing, walking, and running were estimated using 1-min instantaneous scan sampling. Body weight, cleanliness, fecal fluidity, and skin surface temperature were recorded at 1, 4, and 6 wk of age. Escherichia coli numbers were assessed on the skin surface of the shoulder and in feces of calves at 4 and 6 wk of age. Blood samples were taken at 1, 4, and 6 wk of age to measure cortisol, creatine kinase, immunoglobulin G, serum amyloid A, and total protein concentrations. Calves reared on QS spent less time lying and walking and more time standing at 4 and 6 wk of age compared with calves reared on SW. Furthermore, calves reared at a space allowance of 2.0 m²/calf spent less time lying and more time standing and walking compared with calves reared at a space allowance of 1.0 and 1.5 m²/calf. Calves reared on QS had lower skin surface temperatures compared with calves reared on SW. Fecal fluidity scores were lower in calves reared on QS than SW at 2 wk of age. Fewer E. coli were recovered from the shoulder of calves reared on QS than those of calves reared on SW, but fecal E. coli counts were similar between rearing substrates and space allowances. Serum amyloid A concentrations were lower in calves reared on QS than SW. We detected no effect of rearing substrate or space allowance on body weight, cleanliness, or concentrations of cortisol, creatine kinase, immunoglobulin G, and total protein. In conclusion, lower skin temperature in combination with reduced lying behavior may reflect reduced comfort of calves reared on QS. Furthermore, a space allowance of 2.0 m²/calf may provide calves with more opportunity to perform active behaviors.     

The amount of shade influences the behavior and physiology of dairy cattle

The objective was to understand how the amount of shade (shade cloth blocking 99% of solar radiation) influenced the behavior and physiology of Holstein-Friesian dairy cattle managed on pasture. We compared behavior, body temperature, and respiration rate of cattle provided with 1 of 3 treatments for 5 d: access to 2.4 m² or 9.6 m² shade/cow, or no shade (n = 4 groups/treatment, 10 animals/group). Behavioral observations were carried out between 1000 and 1550 h. Cows spent more than twice as much time in the larger shade (24 vs. 50% of observations for 2.4 m² and 9.6 m² shade/cow, respectively, SED: 1.7%) and engaged in fewer aggressive interactions when more shade was provided (10.7 vs. 3.2 aggressive interactions/m² during 5.8 h of observation for 2.4 m² and 9.6 m² shade/cow, respectively, SED: 3.16 interactions/m²). Time around the water trough increased when little or no shade was provided (11, 5, and 2% of observations within 4.5 m of water trough for no shade, 2.4 m², and 9.6 m² shade/cow, SED: 2.4%). Respiration rate was higher when cows had less shade available (62, 57, and 51 breaths/min for no shade, 2.4 m², and 9.6 m² shade/cow, respectively, SED: 2.1 breaths/min). All cows used the shade more when 9.6 m² shade/cow was provided; simultaneous use was observed in 15 versus 0% of observations in the 9.6 m² and 2.4 m² treatments on the warmest day, respectively. Weather conditions influenced both the behavioral and physiological responses, and these changes were more pronounced when less or no shade was available. Cows spent more time in shade and less time lying with increasing heat load. In addition, aggressive interactions in the shade, time around the water trough, mean body temperature, and respiration rate increased with environmental heat load. Our findings highlight the importance of determining and providing an effective amount of shade to cattle.     

Stocking density,milking duration,and lying times of lactating cows on Canadian freestall dairy farms

Lying time is an important measure of cow comfort, and the lying behavior of dairy cattle can now be recorded automatically with the use of accelerometers. To assess the effect that stall stocking density and the time that cows spend away from the home pen being milked has on the lying behavior of Holstein cattle, a total of 111 commercial freestall dairy farms were visited in Canada. Accelerometers were used to automatically record the lying behavior of 40 focal cows per farm. Total duration of lying, lying bout frequency, and the mean duration of lying bouts were calculated. Pen population was the total number of cows in the pen. To calculate stall stocking density (%) the number of cows in the pen and the number of useable stalls were counted and multiplied by 100, and the length × width of the pen was divided by the number of cows in the pen to calculate area/cow (m²). Time away from the pen per day was recorded from when the first cow in each pen was taken out of the home pen for milking until the last cow returned to the home pen after milking, and this time was multiplied by daily milking frequency. The median value for lying duration at the farm level was 10.6 h/d, with 10.5 lying bouts/d, and a median lying bout duration of 1.2 h. Stall stocking density ranged from 52.2 to 160.0%, with very few farms (7%) stocking at greater than 120%. Although stall stocking density was not significantly correlated with lying behavior, the results showed that no farm with stocking density greater that 100% achieved an average herd lying duration of 12 h/d or higher, whereas 21.6% of farms with a stocking density of 100% or less did achieve the target lying time of ≥12 h/d, as recommended by the Canadian Code of Practice (χ² = 4.86, degrees of freedom = 1). Area/cow (m²) was not correlated with any aspect of lying behavior, but regardless of space per cow, pen population was correlated with daily frequency and duration of lying bouts. As the number of cows in the pen increased, lying daily bout frequency increased (correlation coefficient = 0.24) and lying bout duration decreased (correlation coefficient = −0.30). Lying behavior was affected by the time the cows were away from the pen being milked. When cows were away from the pen for longer than 3.7 h/d, no farm achieved the recommended herd median lying time of 12 h/d or longer. These results suggest that providing 1 stall for each cow in the pen and minimizing time away from the pen are important factors if cattle are to achieve the recommended daily lying duration of 12 h/d.     

Verocytotoxigenic Escherichia coli O157 in beef and sheep abattoirs in Ireland and characterisation of isolates by Pulsed-Field Gel Electrophoresis and Multi-Locus Variable Number of Tandem Repeat Analysis

This study aimed to investigate verocytotoxigenic Escherichia coli O157 in the largest beef and sheep slaughter plants in Ireland over a one-year period. Samples consisted of pooled rectal swabs (n = 407) and pooled carcass swabs (n = 407) from 5 animals belonging to the same herd or flock and minced meat (n = 91) from the same sampling date. E. coli O157 isolates were characterised using PCR for a range of genes, i.e. 16S, rfbE, fliC, vtx1, vtx2, eaeA and confirmed VTEC O157 isolates were tested for antimicrobial susceptibility and typed using Pulsed-Field Gel Electrophoresis (PFGE) and Multi-Locus Variable Number of Tandem Repeat Analysis (MLVA). VTEC O157 was isolated from 7.6% and 3.9% of bovine rectal and carcass swab samples and from 5.8% and 2.9% of ovine rectal and carcass swab samples respectively. None of the bovine minced meat samples (n = 77) and only one of the 14 ovine minced meat samples was positive for VTEC O157. Following PFGE and MLVA, cross contamination from faeces to carcasses was identified. While PFGE and MLVA identified the same clusters for highly related strains, MLVA discriminated better than PFGE in addition to being more rapid and less labour intensive. Results showed that cattle and sheep presented for slaughter in Ireland harbour VTEC O157, and although the levels entering the food chain are low, this should not be overlooked as possible sources of zoonotic infection; molecular typing was able to demonstrate relationships among strains and could be used to elucidate the sources of human infection.     

Physical properties of acerola and blueberry pulps

In this work, some physical properties of acerola and blueberry pulps were determined. The density was determined by the pycnometer method; the electrical conductivity using a conductivimeter; the thermal diffusivity by a method based on the analytical solution of heat diffusion equation; the specific heat capacity by a modified method of mixtures; and the thermal conductivity from the knowledge of other properties. Results showed that the density of acerola pulp, in the temperature range between 303 and 353 K, varies between 0.97 and 1.03 kg m⁻³; for blueberry it ranged between 0.98 and 1.05 kg m⁻³. Electrical conductivity was between 1.69 and 8.48 mS cm⁻¹ for acerola pulp and between 0.79 and 3.86 mS cm⁻¹ for blueberry. Specific heat, thermal diffusivity and thermal conductivity of acerola pulp at approximately 313 K showed values of 4172.49 J kg⁻¹ K⁻¹, 1.53 × 10⁻⁷ m² s and 0.65 W m⁻¹ K⁻¹, respectively. For blueberry, these values were 4050.39 J kg⁻¹ K⁻¹, 1.51 × 10⁻⁷ m² s and 0.64 W m⁻¹ K⁻¹.     

Effects on performance and carcass and meat quality attributes following immunocastration with the gonadotropin releasing factor vaccine Bopriva or surgical castration of Bos indicus bulls raised on pasture in Brazil

Bos indicus bulls 20 months of age grazed on pasture in Minas Gerais, Brazil either received 2 doses of the GnRF vaccine Bopriva at d0 and d91 (group IC, n = 144) or were surgically castrated on d91 (group SC, n = 144). Slaughter on d280, was 27 weeks after castration. Adverse safety issues in 8% of group SC bulls following surgery contrasted with 0% in group IC bulls. At d105 testosterone levels were suppressed to similar levels in both groups. Importantly, group IC bulls had higher live weight, hot carcass weight, ADG (P < 0.005) and dressing percentage (P < 0.0001) compared to group SC animals. There were no negative effects on carcass or meat quality traits, thus immunocastration was concluded to offer a safe and effective method that provides production gains, and improves animal welfare in Bos indicus beef bulls without impacting meat and carcass quality.     

Dietary modulation of the expression of genes involved in short-chain fatty acid absorption in the rumen epithelium is related to short-chain fatty acid concentration and pH in the rumen of goats

We have tested the hypothesis that increased concentrate intake induces mRNA abundance alterations of genes involved in short-chain fatty acid (SCFA) absorption in the rumen epithelium of goats and these changes of mRNA abundance are probably related to ruminal SCFA concentration and ruminal pH. Goats (n = 12) were randomly allocated to 2 groups and fed either a low-concentrate (LC) diet (10% concentrate; n = 6) or a medium-concentrate (MC) diet (35% concentrate; n = 6) in 2 equal portions daily. Goats were fed separately with their respective diet for 3 wk. The goats were slaughtered 6 h after the morning feeding on d 22. In vivo, goats in the MC treatment exhibited a greater ruminal SCFA concentration (81.9 mM) compared with those in the LC treatment (58.0 mM), and the pH decreased from 7.03 to 6.63. Correspondingly, mRNA expression of candidates for SCFA⁻/HCO₃⁻ exchangers, namely downregulated in adenoma (DRA), putative anion transporter 1 (PAT1), and anion exchanger 2 (AE2) were increased in the MC group. Further, upregulation in monocarboxylate transporter 1 (MCT1) and monocarboxylate transporter 4 (MCT4) mRNA abundances was observed in the MC group. The expression of genes that help the rumen epithelial cells to maintain intracellular pH, including Na⁺/H⁺ exchanger 1 (NHE1), NHE2, NHE3, vacuolar H⁺ ATPase subunit B (vH⁺ATPase), and Na⁺/K⁺ ATPase pump subunit α1 (Na⁺/K⁺ATPase) were also enhanced in the MC group relative to the LC group. During in vitro studies with isolated rumen epithelial cells from goats, exposure to a pH of 6.8 increased MCT1 mRNA expression after 24 h of culture, whereas the mRNA expression of AE2 was downregulated. The presence of SCFA (20 mM) in the medium increased DRA, PAT1, AE2, MCT1, and Na⁺/K⁺ATPase mRNA expression. The expression of vH⁺ATPase was decreased by increased SCFA concentration. The mRNA expression of MCT4 did not vary in vitro with pH (6.8) or SCFA (20 mM). The expression of DRA was increased by synergistic effects of higher SCFA concentration and lower pH, similar to that of MCT1. Thus, diet-dependent rumen epithelial mRNA expression changes in genes involved in SCFA absorption are probably related to ruminal SCFA concentration and pH.     

Finishing diet,temperament and lairage time effects on carcass and meat quality traits in steers

Sixty Hereford (H) and Braford (B: 3/8 Zebu and 5/8 H) steers were finished on: D1) rangeland plus corn grain (1% of live weight) (H n = 15, B n = 15); and D2) high quality pasture (H n = 15, B n = 15) to study the effect of diet, temperament and lairage time on carcass and meat quality. Steers were slaughtered the same day in two groups, spending 15 and 3 h in pens, respectively (50% from D1, 50% from D2 in each group). Animals from D1 had better carcass performance without effect of the diet on meat quality. Regardless of breed, calmer steers showed higher average daily gain and lower shear force values. Carcasses from animals in the long lairage group had a better rate of pH decline and more tender meat, suggesting that more than 3 h preslaughter time should be necessary to rest and recover, mainly depending on lairage conditions.     

The effect of the number of observations used for Fourier transform infrared model calibration for bovine milk fat composition on the estimated genetic parameters of the predicted data

Fourier transform infrared spectroscopy is a suitable method to determine bovine milk fat composition. However, the determination of fat composition by gas chromatography, required for calibration of the infrared prediction model, is expensive and labor intensive. It has recently been shown that the number of calibration samples is strongly related to the model's validation r² (i.e., accuracy of prediction). However, the effect of the number of calibration samples used, and therefore validation r², on the estimated genetic parameters of data predicted using the model needs to be established. To this end, 235 calibration data subsets of different sizes were sampled: n = 100, n = 250, n = 500, and n = 1,000 calibration samples. Subsequently, these data subsets were used to calibrate fat composition prediction models for 2 specific fatty acids: C16:0 and C18u (where u = unsaturated). Next, genetic parameters were estimated on predicted fat composition data for these fatty acids. Strong relationships between the number of calibration samples and validation r², as well as strong genetic correlations were found. However, the use of n = 100 calibration samples resulted in a broad range of validation r² values and genetic correlations. Subsequent increases of the number of calibration samples resulted in narrowing patterns for validation r² as well as genetic correlations. The use of n = 1,000 calibration samples resulted in estimated genetic correlations varying within a range of 0.10 around the average, which seems acceptable. Genetic analyses for the human health-related fatty acids C14:0, C16:0, and C18u, and the ratio of saturated fatty acids to unsaturated fatty acids showed that replacing observations on fat composition determined by gas chromatography by predictions based on infrared spectra reduced the potential genetic gain to 98, 86, 96, and 99% for the 4 fatty acid traits, respectively, in dairy breeding schemes where progeny testing is practiced. We conclude that a relatively large number of calibration samples is required to be able to obtain genetic correlations that lie within a limited range. Considering that the routine recording of infrared spectra is relatively cheap and straightforward, we concluded that this methodology provides an excellent means for the dairy industry to genetically alter milk fat composition.     

The effect of stocking density and a blind on the behavior of Holstein dairy cattle in group maternity pens. Part I: Calving location,locomotion, and separation behavior

In a more natural setting, dairy cows separate from herdmates and seek a secluded area to give birth. However, on many dairy facilities, cows calve in barren group pens with limited space, which may limit their ability to perform these behaviors. The objective of this study was to determine the effect of stocking density and provision of a blind (a single-sided solid partition) in group bedded pack maternity pens on the behavior of dairy cattle. The study included 4 experimental treatments: (1) high stocking density (7.7–12.9 m² of lying space/cow) with a blind, (2) low stocking density (15.4–25.8 m²) with a blind, (3) high stocking density without a blind, and (4) low stocking density without a blind. We analyzed the effect of these treatments on locomotor and separation behavior as well as blind use during the 24 h before calving. A total of 127 primiparous heifers and 247 multiparous cows were housed in 16 mixed-parity groups (4 groups per treatment) from approximately 3 wk before to immediately after calving. Locomotor behavior increased from 24 to 2 h before calving regardless of treatment but increased the most in high stocking density pens without a blind. Additionally, heifers performed more locomotion than cows. Animals increased their distance from other cows beginning approximately 4 h before calving. Animals in low stocking density pens had a greater distance from other cows compared with those in high stocking density pens. Additionally, heifers had a greater distance from penmates during the 4 h before calving than cows. More animals calved in the area of the pen that contained a blind compared with the same respective areas of high and low stocking density pens that did not contain a blind. These results suggest that periparturient dairy cattle in group maternity pens are motivated to seek seclusion at calving, but increased stocking density may impede their ability to do so. Providing additional space and a blind may benefit periparturient dairy cows and heifers by facilitating natural calving behaviors.     

The effect of moisture content on the physico-mechanical properties of some hazelnut varieties

To better understand storage design requirements for hazelnuts, this research determined the physico-mechanical parameters (bulk density, true density, angle of internal friction, static coefficient of friction and dynamic coefficient of friction) of hazelnut varieties Tombul, Badem, Mincane, Çak?ldak and Sivri, for different structural surfaces. Physico-mechanical parameters (bulk density, true density, angle of internal friction, static coefficient of friction and dynamic coefficient of friction) were considered as the dependent variables, and moisture content (8%, 12%, 16%, 20%) as the independent variable. The temperature recorded in the laboratory during the experiments was 24.3 °C. The highest average value for bulk density (520 kg m⁻³) was recorded for the Sivri variety, the highest average value for angle of internal friction (35.4°) for the Badem variety, and the highest average value for true density (870 kg m⁻³) for the Mincane variety. The highest average values for static coefficient of friction (0.411) and the dynamic coefficient of friction (0.287) were recorded for concrete surfaces and the Badem variety.     

Association and expression analysis of porcine HNF1A gene related to meat and carcass quality traits

The aim of this study was to investigate the association and expression of HNF1A gene as a candidate gene for meat and carcass quality traits in pigs. Statistical analysis revealed that the g.8260 A>G polymorphism significantly associated with pH 24_H, meat percentage and muscle area in the F₂ Duroc × Pietrain (DuPi, n = 313) and with pH 24_L, fat area and backfat thickness in the Pietrain (Pi, n = 110) population. HNF1A mRNA and protein expressions were higher (p < 0.05) in animals with the low post-mortem muscle pH 24_L. The promoter methylation profiling suggested that methylation was not involved on HNF1A expression regulation (p > 0.05) in animal with divergent muscle pH. In conclusion, polymorphism in porcine HNF1A gene could be used as a candidate marker to improve the meat and carcass quality traits, with the consideration of breed-specific effect.     

Shear and extensional viscosities of hard wheat flour dough using a capillary rheometer

The rheological behaviour of hard wheat flour dough was investigated for a high shear rate range (10-10⁴ s⁻¹) using a capillary rheometer. The shear viscosity obtained from capillary measurements demonstrated a shear thinning behaviour of dough and described by a power law model with a power law index n = 0.38, a consistency coefficient K = 1387 Pa sⁿ, and a coefficient of determination R² = 0.997. The extensional viscosity obtained from capillary measurements for a high extensional rate range (0.16-154 s⁻¹) showed a tension thinning behaviour and described by a power law model with a power law index m = 0.38, a consistency coefficient K_E = 353,000 Pa s^m, and a coefficient of determination R² = 0.977. Torsional measurements using a parallel plates rheometer for a shear rate range (10⁻³-20 s⁻¹) demonstrated the time or strain dependence of wheat flour dough, no steady state shear viscosity of dough, and the shear viscosity increased with time or strain to a maximum value and then decreased, suggesting a breakdown or rupture of the dough structure.     

The effects of the myostatin g+6723G>A mutation on carcass and meat quality of lamb

This study evaluated the effects of the myostatin g + 6723G > A mutation on carcass and meat quality traits of lamb (AA: n = 5; AG: n = 8; GG: n = 9). Dressing percentage was positively affected by the mutation with homozygotes for the mutation having the highest yield. Regarding carcass composition, there was a significant increase in the proportional weights of the loin and hindquarter muscles. Objective meat quality traits of the M. longissimus lumborum (LL) and M. semimembranosus (SM) were not significantly affected. For the SM, toughness (shear force and compression) tended to be lowest for homozygotes for the mutation. The myostatin g + 6723G > A mutation did not affect sensory meat quality traits of grilled steaks for the LL, but resulted in a significant improvement in eating quality for the SM. Given the number of animals in this study, the robustness of the outcome of this study with regard to the effects on meat quality and its causes requires further investigation.     

Predicting meat yields and commercial meat cuts from carcasses of young bulls of Spanish breeds by the SEUROP method and an image analysis system

The SEUROP system is currently in use for carcass classification in Europe. Image analysis and other new technologies are being developed to enhance and supplement this classification system. After slaughtering, 91 carcasses of local Spanish beef breeds were weighed and classified according to the SEUROP system. Two digital photographs (a side and a dorsal view) were taken of the left carcass sides, and a total of 33 morphometric measurements (lengths, perimeters, areas) were made. Commercial butchering of these carcasses took place 24 h postmortem, and the different cuts were grouped according to four commercial meat cut quality categories: extra, first, second, and third. Multiple regression analysis of carcass weight and the SEUROP conformation score (x variables) on meat yield and the four commercial cut quality category yields (y variables) was performed as a measure of the accuracy of the SEUROP system. Stepwise regression analysis of carcass weight and the 33 morphometric image analysis measurements (x variables) and meat yield and yields of the four commercial cut quality categories (y variables) was carried out. Higher accuracy was achieved using image analysis than using only the current SEUROP conformation score. The regression coefficient values were between R² = 0.66 and R² = 0.93 (P < 0.001) for the SEUROP system and between R² = 0.81 and R² = 0.94 (P < 0.001) for the image analysis method. These results suggest that the image analysis method should be helpful as a means of supplementing and enhancing the SEUROP system for grading beef carcasses.     

Group housing of Holstein calves in a poor indoor environment increases respiratory disease but does not influence performance or leukocyte responses

The objective of the current study was to determine if group-housing Holstein heifer calves in indoor pens with poor ventilation and drainage influences performance, health, leukocytes, and behavioral responses compared with individually housed calves. Ninety colostrum-fed calves (2 ± 1 d of age) were randomly assigned to 3 treatments: individually housed (G1; n = 30 calves), 2 calves per pen (G2; n = 30 calves), or 3 calves per pen (G3; n = 30 calves). The space allowance per calf was 2.5 m² for all treatment groups. All calves were fed 747 and 1,010 g/d of dry matter of a 28% CP and 20% fat milk replacer during the first 2 wk and wk 3 to 6, respectively. Weaning was initiated on d 46 by removing the evening feeding, and calves were completely weaned when they consumed 800 g/d of dry matter calf starter for 2 consecutive days after d 54. Calves were randomly commingled at d 90 in groups of 5 calves per pen in outdoors pens with an attached hutch. Peripheral blood was collected during the neonatal (3, 10, 21 d), weaning (46, 48, 54 d), and commingling periods (90, 93, 98 d) and was analyzed for neutrophil oxidative burst capacity when cocultured with an Escherichia coli, neutrophil surface L-selectin protein concentration, and whole blood secretion of tumor necrosis factor-α when cocultured with lipopolysaccharide. Behavior of each calf was assessed using 2 independent tests: an approach response to a human subject and the response of the calf when placed in an isolated cage. Calf starter intake was greater for G2 and G3 during wk 8 and 9, and also at wk 11 for G3 compared with G1. No treatment × time interaction or treatment effect for average daily gain was observed. Additionally, no treatment × time or treatment effect was noted for any leukocyte or biochemical variable of biological significance throughout the entire study. Individually housed calves tended to have a reduced incidence of respiratory disease during the first 90 d of life. No other treatment differences for the other health outcomes were observed. Group-housed calves also relied more on calf-to-calf interactions than calf-to-human interactions, as evident by their reduced approach of the human observer and more frequent movement when placed in an isolated pen. Group housing in an environment with poor ventilation and drainage may increase the risk of respiratory disease.     

Short communication: effect of stocking density on indices of cow comfort

The objective of this study was to evaluate the effects of increasing stocking density on indices of cow comfort measured over a 24-h period, during peak lying time (0000 to 0400 h), and 1 h after the afternoon milking. Holstein cows (n = 136) were assigned to 1 of 4 pens, and stocking densities of 100, 113, 131, and 142% were applied in a 4 × 4 Latin square. Video data were recorded continuously for 2 d after 5 d of acclimation to stocking density and analyzed with 10-min scan samples for the percentage of cows lying in a stall, standing in a stall, standing in the alley, and eating at the manger. Percentage of cows standing idly in the alley increased as stocking density increased above 113% (10.9, 12.0, 14.4, and 16.5% for 100, 113, 131, and 142% stocking density, respectively). Cow comfort index (CCI; cows lying down/cows contacting stalls) and stall standing index (SSI; cows standing in stall/cows contacting stalls) differed little as stocking density increased, but stall use index (SUI; cows lying in stall/cows in pen not eating) decreased beyond 113% stocking density (70.1, 70.2, 68.6, and 66.3 for 100, 113, 131, and 142% stocking density, respectively). During peak lying time, SUI decreased with increasing (80.3, 79.5, 74.8, and 69.6 for 100, 113, 131, and 142% stocking density, respectively) stocking density above 113%, whereas CCI and SSI showed little response. None of the indices varied by stocking density when they were assessed at 1 h after milking. These results suggest that more than 1 index of cow comfort may be needed at higher stocking densities to assess both stall usage and cows standing idly in an alley. At higher stocking densities, SUI was reduced, because it reflected not only stall usage but the number of cows standing idly in an alley and not actively feeding and unable to access a stall. The CCI and SSI appear to assess actual stall usage (% cows lying or standing) across the range of stocking densities evaluated in this study.