Effects of Selective Dry Cow Treatment on Intramammary Infection Risk after Calving, Cure Risk during the Dry Period, and Antibiotic Use at Drying-Off: A Systematic Review and Meta-Analysis of Current Literature (2000–2021)

The objectives of this paper were (i) to perform a systematic review of the literature over the last 21 yr and (ii) to evaluate the efficacy of selective dry cow treatment (SDCT) vs. blanket dry cow treatment (BDCT) in dairy cows regarding the risk of intramammary infection (IMI) after calving, new IMI risk after calving, cure risk during the dry period, and a reduction in antibiotic use at drying-off by meta-analysis. The systematic search was carried out using the databases PubMed, CAB Direct, and ScienceDirect. A meta-analytical assessment was performed for each outcome of interest using random-effects models, and the relative risk (RR) for IMI and cure or the pooled proportion for antibiotic use was calculated. The final number of included studies was n = 3 for IMI risk after calving and n = 5 for new IMI risk after calving, cure risk during the dry period, and antibiotic use. The RR levels for IMI (RR, 95% confidence interval [CI]: 1.02, 0.94–1.11; p = 0.592), new IMI (RR, 95% CI: 1.06, 0.94–1.20; p = 0.994), and cure (RR, 95% CI: 1.00, 0.97–1.02; p = 0.661) did not differ significantly between SDCT and BDCT. Substantial heterogeneity was observed between the trials regarding the pooled proportion of antibiotic use within the SDCT groups (I2 = 97.7%; p < 0.001). This meta-analysis provides evidence that SDCT seems to be an adequate alternative to BDCT regarding udder health with a simultaneous reduction in antibiotic use. Limitations might arise because of the small number of studies included

Trisomy 26 in a Holstein calf with disorders of sex development

Hypospadias occurs sporadically in male livestock and is characterized by a non-fused urethra during fetal development. In this study, perineal hypospadias, a bifid scrotum, penile hypoplasia, and bilateral abdominal cryptorchidism were diagnosed in a neonatal Holstein male calf. Septicemia was also suspected due to hypothermia, blurred conjunctivae, and loss of sucking and swallowing reflexes. Gross pathology revealed that both testicles were located intraabdominally caudally to the kidneys. Histopathological examination of the hypospadias showed a urothelium-lined mucosal fold and parts of the corpus cavernosum penis and prepuce in the subcutis. Whole genome sequencing was performed on the affected calf. Analysis of short-read coverage depth along the chromosomes identified an entire extra copy of chromosome 26. Based on the comparison of available variant calling data from the sire, the identified trisomy 26 is due to non-disjunction of homologous chromosomes during the generation of paternal gametes. We have shown for the first time an association between bovine hypospadias and trisomy 26, which adds to the understanding of variation in fetal male sexual development

Flock-level risk factors of litter condition for the occurrence of plumage damage and skin lesions in commercial laying hen farms

ABSTRACT: Plumage damage (PD) as a result of severe feather pecking (SFP) and skin lesions (SL) due to cannibalism (CA) is serious welfare, performance, and economic problems in commercial layer farms. Genetics, nutrition, and housing conditions are central complexes that contribute to the multifactorial causes of these behavioral disorders. Practical recommendations consider the quality of litter as an important criterion for the prevention of SFP, although systematic longitudinal studies providing evidence-based findings are lacking.Therefore, the aim of this study was to investigate the effects of litter condition on the occurrence of PD and SL in the field using a longitudinal design. Integument scoring (PD and SL; 7 times), litter scoring (structure, cake formation, litter quality, and litter height; 12 times), and laboratory litter analysis (dry matter (DM), nitrogen (N), phosphorus (P) and pH value; 12 times) were performed in 28 laying hen flocks with a median flock size of 12,357 birds, in barn (n = 21) or free-range systems (n = 7), during the first laying period.Binary logistic regression (BLR) models showed the association of housing type and animal age on PD and SL (P < 0.001), and of the hybrid type on PD (P < 0.001). Furthermore, a significant association with PD and SL was observed for several litter traits. An increase in litter height, DM, and P was associated with lower PD (P ≤ 0.022) and SL (P < 0.001). In contrast, a higher N content of the litter was associated with an increase in SL (P = 0.007). Cake formation (P < 0.001) and a low structure (P = 0.025) of the litter showed an association with higher PD.In conclusion, this study identified caked litter with less structure, low height, and low contents of DM and P as risk factors for behavioral disorders in commercial laying flocks

Relation between Feed Particle Size Distribution and Plumage Condition in Laying Hens on Commercial Farms

In this cross-sectional study, 103 complete feed samples from laying hen herds affected by plumage damage as an indirect measure for severe feather pecking (affected herds; AH, n = 37) and control herds without plumage damage (control herd; CH, n = 66) of commercial German farms were examined by dry sieve and nutrient analysis. AH showed higher percentages of particles &gt;2.50 mm (mean ± SD, CH: 11.0 ± 8.5%, AH: 24.9 ± 14.3%) and 2.00–2.50 mm (CH: 11.2 ± 5.3%, AH: 15.7 ± 5.7%), but lower proportions of fractions 1.01–1.60 mm (CH: 22.9 ± 4.9%, AH: 17.8 ± 5.7%), 0.51–1.00 mm (CH: 25.5 ± 8.2%, AH: 16.0 ± 6.8%) and ≤0.50 mm (CH: 15.4 ± 5.0%, AH: 11.0 ± 4.8%) (p &lt; 0.001). Diets of AH had a higher geometric mean diameter (GMD) compared to CH (AH: 1470.8 ± 343.9 μm; CH: 1113.3 ± 225.7 μm) (p &lt; 0.001). Contents of crude ash (CH: 130.3 ± 18.8 g/kg, AH: 115.9 ± 24.3 g/kg), lysine (CH: 8.2 ± 1.0 g/kg, AH: 7.7 ± 1.2 g/kg), methionine (CH: 3.4 ± 0.5 g/kg, AH: 3.2 ± 0.6 g/kg) and sodium (CH: 1.7 ± 0.4 g/kg, AH: 1.3 ± 0.4 g/kg) were lower in AH (p ≤ 0.041). In a logistic regression model, animal age (p = 0.041) and GMD (p &lt; 0.001) were significant factors on the occurrence of plumage damage.</jats:p

Relation between Feed Particle Size Distribution and Plumage Condition in Laying Hens on Commercial Farms

Feather pecking is a serious problem in laying hen husbandry, which can lead to feather damage, performance losses and economic disadvantages. In this context, feed has been identified as an important factor, whereby scientific knowledge is primarily available on the effect of ingredients but hardly on the feed structure. In this study, feed samples from feather pecking and non-feather pecking herds from production farms were analyzed for their nutrient contents and feed particle sizes. More coarser (>2.00 mm) and fewer medium and finer feed particles (≤1.60 mm) were found in the feed of the flocks affected by feather pecking. The coarser components contained lower levels of nutrients important for preventing feather pecking (e.g., methionine, sodium). The study demonstrated that a feed structure that is too coarse can be considered a risk factor for feather pecking.Die Studie untersucht die Zusammensetzung der Futterpartikelfraktionen und deren Nährstoffgehalte in Legehennenfutter. Hierfür wurden 103 Futterproben von federpickenden (AH, n=37) und nicht-federpickenden Herden (CH, n=66) von Produktionsbetrieben mittels trockener Siebanalyse und Nährstoffanalytik untersucht. In den AH zeigten sich in der Futterstruktur im Vergleich zu den CH höhere Anteile an Partikeln >2,50 mm (MW ± STW: CH: 11,0 ± 8,5 %, AH: 24,9 ± 14,3 %) und 2,00-2,50 mm (CH: 11,2 ± 5,3 %, AH: 15,7 ± 5,7 %) bei niedrigeren Anteilen der Fraktionen 1,01-1,60 mm (CH: 22,9 ± 4,9 %, AH: 17,8 ± 5,7 %), 0,51-1,00 mm (CH: 25,5 ± 8,2 %, AH: 16,0 ± 6,8 %) und ≤0,50 mm (CH: 15,4 ± 5,0 %, AH: 11,0 ± 4,8 %) (p<0,001). Die Futter der AH (1470,8 ± 343,9 μm) wiesen dabei auch einen höheren geometrischen Durchmesser aus (GMD) im Vergleich zu den CH (1113,3 ± 225,7 μm) auf (p<0,001). Die vorgefundenen Anteile der Partikelgrößenfraktionen 1,01-1,60 mm und ≥2,50 mm lagen außerhalb des empfohlenen Referenzbereichs (p<0,001). Die Gehalte an Rohasche (CH: 130,3 ± 18,8 g/kg, AH: 115,9 ± 24,3 g/kg), Lysin (CH: 8,2 ± 1,0 g/kg, AH: 7,7 ± 1,2 g/kg), Methionin (CH: 3,4 ± 0,5 g/kg, AH: 3,2 ± 0,6 g/kg) und Natrium (CH: 1,7 ± 0,4 g/kg, AH: 1,3 ± 0,4 g/kg) waren bei den AH niedriger als in den CH (p≤0,041). Im Modell der logistischen Regression zeigten sich das Tieralter (p=0,041) und der GMD (p<0,001) als signifikante Einflussfaktoren auf das Auftreten von Federpicken. Anhand der Studie konnte gezeigt werden, dass eine zu grobe Futterstruktur als Risikofaktor für Federpicken zu betrachten ist

Edible Environmental Enrichments in Littered Housing Systems: Do Their Effects on Integument Condition Differ Between Commercial Laying Hen Strains?

The aim of this study was to investigate the effect of additional enrichment materials (EMs; pecking stones and alfalfa bales) on the occurrence of plumage damage, skin injuries, and toe injuries, with an emphasis on the possible differences between commercial hybrid strains of laying hens. During rearing (weeks 1–18, 16 compartments, 4000 pullets) and laying periods (weeks 21–72, 24 compartments, 2808 hens) in a littered housing system, EMs were permanently provided to the study groups (EXP), while control groups (CON) did not receive additional EM. In a two-factorial study design (two groups with four strains) with 351 hens per variant, the brown egg-laying Lohmann Brown classic (LB) and Bovans Brown (BB) strains as well as the white egg-laying Lohmann Selected Leghorn classic (LSL) and Dekalb White (DW) strains were investigated. Compared to the CON, the EXP showed reduced body mass during rearing (p < 0.001) and reduced albumen consistency in the laying period (p < 0.001). Regarding integument condition, the LSL in the EXP showed more toe injuries than in the CON (p = 0.018). Remarkably, genotype-environment interactions between strains and groups were evident (p < 0.001). In groups with an EM supply, plumage damage decreased in LB (p ≤ 0.033) and LSL (p ≤ 0.005) but increased in BB (p ≤ 0.003). Moreover, there were fewer skin injuries in LSL (p = 0.001) but more in BB (p = 0.001) in groups with access to EM. In view of the diverging effects between strains, future practical recommendations for laying hen husbandry should be strain-specific.:Introduction Materials and Methods Results Discussions Author Contributions Funding Acknowledgments Conflicts of Interest Reference

Edible Environmental Enrichments in Littered Housing Systems: Do Their Effects on Integument Condition Differ Between Commercial Laying Hen Strains?

The aim of this study was to investigate the effect of additional enrichment materials (EMs; pecking stones and alfalfa bales) on the occurrence of plumage damage, skin injuries, and toe injuries, with an emphasis on the possible differences between commercial hybrid strains of laying hens. During rearing (weeks 1&ndash;18, 16 compartments, 4000 pullets) and laying periods (weeks 21&ndash;72, 24 compartments, 2808 hens) in a littered housing system, EMs were permanently provided to the study groups (EXP), while control groups (CON) did not receive additional EM. In a two-factorial study design (two groups with four strains) with 351 hens per variant, the brown egg-laying Lohmann Brown classic (LB) and Bovans Brown (BB) strains as well as the white egg-laying Lohmann Selected Leghorn classic (LSL) and Dekalb White (DW) strains were investigated. Compared to the CON, the EXP showed reduced body mass during rearing (p &lt; 0.001) and reduced albumen consistency in the laying period (p &lt; 0.001). Regarding integument condition, the LSL in the EXP showed more toe injuries than in the CON (p = 0.018). Remarkably, genotype-environment interactions between strains and groups were evident (p &lt; 0.001). In groups with an EM supply, plumage damage decreased in LB (p &le; 0.033) and LSL (p &le; 0.005) but increased in BB (p &le; 0.003). Moreover, there were fewer skin injuries in LSL (p = 0.001) but more in BB (p = 0.001) in groups with access to EM. In view of the diverging effects between strains, future practical recommendations for laying hen husbandry should be strain-specific

Edible Environmental Enrichments in Littered Housing Systems: Do Their Effects on Integument Condition Differ Between Commercial Laying Hen Strains?

The aim of this study was to investigate the effect of additional enrichment materials (EMs; pecking stones and alfalfa bales) on the occurrence of plumage damage, skin injuries, and toe injuries, with an emphasis on the possible differences between commercial hybrid strains of laying hens. During rearing (weeks 1–18, 16 compartments, 4000 pullets) and laying periods (weeks 21–72, 24 compartments, 2808 hens) in a littered housing system, EMs were permanently provided to the study groups (EXP), while control groups (CON) did not receive additional EM. In a two-factorial study design (two groups with four strains) with 351 hens per variant, the brown egg-laying Lohmann Brown classic (LB) and Bovans Brown (BB) strains as well as the white egg-laying Lohmann Selected Leghorn classic (LSL) and Dekalb White (DW) strains were investigated. Compared to the CON, the EXP showed reduced body mass during rearing (p &lt; 0.001) and reduced albumen consistency in the laying period (p &lt; 0.001). Regarding integument condition, the LSL in the EXP showed more toe injuries than in the CON (p = 0.018). Remarkably, genotype-environment interactions between strains and groups were evident (p &lt; 0.001). In groups with an EM supply, plumage damage decreased in LB (p ≤ 0.033) and LSL (p ≤ 0.005) but increased in BB (p ≤ 0.003). Moreover, there were fewer skin injuries in LSL (p = 0.001) but more in BB (p = 0.001) in groups with access to EM. In view of the diverging effects between strains, future practical recommendations for laying hen husbandry should be strain-specific.</jats:p