Hair cortisol levels of lactating dairy cows in cold‐ and warm‐temperate regions in Japan

We compared the hair cortisol levels of lactating dairy cows in a cold‐ and a warm‐temperate region out of four climatic zones in Japan. We simultaneously investigated the effects of calving number, lactation period and month of hair sampling. Hair of nine Holstein lactating cows chosen from each region (i.e. 18 cows per sampling) was sampled in March, June, September and December. Number of calvings (1, 2, ≥3) and lactation duration (early: <100, middle: 101–200, and late: >201 days) were balanced between regions. Cortisol was extracted from hair by methanol, and its level was determined with a cortisol immunoassay kit. A multi‐way analysis of variance revealed that the effects of month of hair sampling (P < 0.001) and its combination with region (P < 0.05) were significant. In a multiple comparison test, significant differences (P < 0.01) in hair cortisol level (pg/mg of hair) were found between June (13.0 ± 1.0) and the other 3 months, and between September (1.6 ± 0.2) and December (4.5 ± 0.3). The rise in cortisol level from March to June was more intense in the cold‐temperate region. These results demonstrate the necessity of considering seasonal variations in each climatic region when we use hair cortisol level as an indicator of stress.     

Section D: Some Perspectives in Mammal Ecology

We analysed prey remains, particularly hair, in 38 brown hyaena Hyaena brunnea scats from a game ranch in the Limpopo Province, South Africa. The brown hyaenas fed on a wide variety of mammals, supplementing their diet with insects and plant material. Artiodactyls were the most important mammalian food source, with hair of common duiker (Sylvicapra grimmia) being the most frequent food item in the faeces.     

The effect of gestation and lactation on bone calcium, phosphorus and magnesium in dairy cows

A study was conducted to monitor changes in cortical bone mineral in the dairy cow in response to demands of lactation and pregnancy using rib bone biopsies in serial sampling. Sixteen Friesian cows from the University dairy herd were used to collect 9 samples during the lactation period and 5 samples during the dry period. The data were analysed using a split-plot design analysis of variance. There were no significant (P > 0.05) differences in cortical bone phosphorus concentrations in rib bone during the lactation period, but calcium concentrations in cortical bone were significantly (P < 0.05) higher at parturition and during the first 30 days of lactation compared to the next 30 days and between 90 and 120 days. Results reported here indicate that the cow resorbs cortical bone during the middle of the lactation period and not during the periparturient period as previously thought. Magnesium concentrations were also significantly (P < 0.05) higher at the beginning of lactation compared to some of the other sampling times, but cortical bone was significantly (P < 0.05) thinner at the beginning of lactation compared to several of the other sampling times. There were no significant (P > 0.05) differences in cortical bone Ca or Mg concentrations during the gestation period. Cortical bone P concentrations significantly (P < 0.05) decreased during the first 180 days, but significantly (P < 0.05) increased at 181-230 days and significantly (P < 0.05) decreased again at 231 days to term. Cortical bone thickness decreased significantly (P < 0.05) from the beginning of gestation to term. There were no significant (P > 0.05) differences in cortical bone thickness or Ca or Mg concentrations in cortical bone during the dry period, but cortical bone P concentrations were significantly (P < 0.05) greater at the end of the dry period compared to the first 30 days of the period. In general, cortical bone Ca and Mg values decreased as milk production increased up to 20 kg/day and cortical bone P values and bone thickness increased. In animals producing over 20 kg/day, however, cortical bone mineral values were greater and cortical bone thickness was lower compared to those animals producing less than 20 kg.     

Effect of lameness (hoof disorders) on productivity of Karan Fries crossbred cows

In present study production performance of 96 lame cows was compared with 67 healthy cows. No significant effect of parity and year of calving on milk yield were observed but the effect of season of calving was significant (P < 0.01). Effect of lameness on milk yield at the second, third and fourth months and 305 days was highly significant (P < 0.01), and was also significant (P < 0.05) on lactation yield of the fifth and tenth months. The effect of lameness on monthly and 305‐day milk yield was significant (P < 0.01) only for those cows diagnosed lame before calving and during the first month of lactation. The differences in mean monthly yield were highly significant (P < 0.01) at the second, third and fourth months; and significant (P < 0.05) in the first and fifth months. The loss in the first lactation month of cows which were diagnosed as lame in the second month, was found to be significant (P < 0.05). Thus the yield of the month previous to the diagnosis (sub‐clinical stage) was also affected. A significant (P < 0.01) total loss of 498.95 kg of milk yield was observed during a period of 305 days.     

The change of dry matter intake, milk yield and bone turnover in primiparous cows compared to multiparous cows during early lactation

Data from six primiparous and nine multiparous Holstein cows were used to clarify the difference of Ca and P mobilization between primiparous and multiparous cows during early lactation. The dry matter intake (DMI) of primiparous cows was lower (P < 0.01) than those of multiparous cows. Milk yield was lower in primiparous cows at 7, 14, 21 (P < 0.01), and 28 days (P < 0.05) after parturition. There was no significant difference in milk Ca and P concentrations between primiparous and multiparous cows. There were no significant differences in plasma Ca and P concentrations between primiparous and multiparous cows. The plasma P level at 7 days postpartum in primiparous cows was lower (P < 0.05) than 28 days postpartum. The concentration of plasma osteocalcin (OC) measured as bone formation marker of primiparous cows was significantly higher than multiparous cows (P < 0.01) at 21 and 28 days postpartum. The urinary deoxypyridinoline (DPD) as bone resorption marker of primiparous cows tended to be higher (P < 0.10) than multiparous cows at 21 days after parturition and decreased to the same level as that of multiparae toward the peak lactation. These results show that Ca and P mobilization of primiparous cows are more active than multiparous cows.     

A new Late Miocene Hystrix (Hystricidae,Rodentia) from Turkey

The Çorakyerler fossil locality in Anatolia reveals unique faunal elements. This study introduces Hystrix kayae sp. nov., a new Late Miocene porcupine initially classified as Hystrix sp. Yavuz et al., 2018. This finding expands our knowledge of Late Miocene Anatolian porcupines, bringing the total number of known species to three. H. kayae sp. nov. is larger than Hystrix aryanensis and exhibits greater upper cheek tooth crown height. Its cheek tooth morphology differs from Hystrix depereti, and it possesses distinctive U-shaped choanae unlike Hystrix primigenia. The Çorakyerler locality may predate sites with H. aryanensis and H. primigenia but aligns temporally with Hystrix parvae localities. This study enhances our understanding of Late Miocene porcupine diversity in Anatolia, emphasizing the importance of Çorakyerler in unraveling the evolutionary history of these fascinating mammals.     

Changes in some blood parameters,milk composition and yield of buffaloes (Bubalus bubalis) during the transition period

In this study changes in hematochemical parameters, milk composition and yield were investigated in buffaloes during the transition period. A total of 93 buffaloes 113.9 ± 8.03 months old and 535 ± 50 kg average body weight were used. Parity was recorded, blood samples were collected from 80 days pre‐partum until 70 days post‐partum; milk samples were collected from 5 days to 70 days post‐partum. On serum samples, the values of non‐esterified fatty acids, β‐hydroxybutyrate, glucose, cholesterol, triglycerides, aspartate aminotransferase, alanine aminotransferase, gamma‐glutamyltransferase, urea, total proteins were evaluated. On milk, percentage of fat, protein and lactose, along with the somatic cell count (SCC), milk yield and daily milk production (DMP) were assessed. The peripartum period significantly (P ≤ 0.01) influenced all studied parameters with the exception of glucose. Milk fat percentage showed decreasing trend from 10 until 40 days post‐partum; DMP significantly (P ≤ 0.01) increased from 1 day post‐partum until 40 days post‐partum. Milk yield significantly (P ≤ 0.01) decreased in animals over the sixth lactation. Our results confirmed the importance of transit period in buffaloes. Blood parameters and milk composition alterations are crucial to predict the energy balance status of buffaloes in order to improve their management and feed intake during the transition period.     

Epidemiology of Streptococcus uberis Intramammary Infections in a Dairy Herd

From 1987 to 1991, almost 36 000 quarter samples of mammary secretion representing 1790 lactations of 510 dairy cows from a research herd were collected for bacteriological examination. The percentage of cows infected with Streptococcus uberis ranged from 12 to 16 % of cows/year. S. uberis was isolated from 14.2 % of lactations over the 5-year period. The prevalence of S. uberis intramammary infection (IMI) was significantly higher in cows with ≥4 lactations than in cows with 3 or fewer lactations. Regardless of lactation number, the prevalence of S. uberis was highest before parturition, during early lactation and near drying off. The prevalence of S. uberis infected quarters ranged from 1.3 to 2.3 % of quarters/year; the prevalence rate for the 5-year period was 2 % of quarters. The quarter prevalence of S. uberis was lowest in cows with ≤3 lactations, increased significantly with lactation number and was highest in cows with ≥6 lactations. The percentage of quarters infected with S. uberis varied significantly by year. The majority (95 %) of S. uberis IMI were subclinical. The ratio of subclinical IMI to clinical IMI was lowest during early lactation, and increased with days in milk, and with lactation age except for cows in their 5th and 6th lactations. Results of this epidemiological investigation suggest that opportunities exist where suitable control measures could be applied to reduce the impact of S. uberis infections in the dairy herd.     

Effects of mineral salt supplement on enteric methane emissions,ruminal fermentation and methanogen community of lactating cows

We evaluated the effects of mineral salt supplement on enteric methane emissions, ruminal fermentation and methanogen community of dairy cows over a whole lactation period. Ten Holstein cows fed a total mixed ration (TMR) diet were randomly allocated into two groups, one supplied with mineral salts as the treatment group and the other as the control group. The methane measurement showed that the ingestion of mineral salts lowered enteric methane emissions significantly (P < 0.05), with an average of 10.5% reduction over the whole lactation period. Ruminal fermentation analysis showed the mineral salt intake could significantly decrease the acetate : propionate ratio (P < 0.05). Real‐time PCR assay showed that rumen methanogen abundance significantly reduced in the treatment group (P < 0.05) but was not significantly influenced by mineral salt intake over the whole lactation period. Intergroup methanogen community composition was influenced slightly by mineral salt intake; however, significantly different intragroup profiles were apparent throughout the whole lactation period, according to denaturing gradient gel electrophoresis analysis. In conclusion, these results suggested that the effective mitigation of enteric methane emissions by mineral salt intake could be attributed to decreased density of methanogenic archaea and that fluctuations in methane emission over the lactation period might be related to Methanobrevibacter diversity.     

Are melanistic populations of the Karoo girdled lizard,Karusasaurus polyzonus,relics or ecotypes? A molecular investigation

It has been proposed that melanism in cordylids evolved in response to a single climatic event and that melanistic populations of Karusasaurus polyzonus are relictual. This study investigates the genetic relationships of melanistic and non-melanistic populations of K. polyzonus along the west coast of South Africa. Thirty-five specimens of K. polyzonus werecollected from three ‘melanistic’ and eight ‘non-melanistic’ sample localities. Partial sequence data were derived for two mitochondrial DNA loci (16S rRNA and nicotinamide adenine dinucleotide dehydrogenase component 2 (ND2)) and analysed using maximum parsimony, maximum likelihood and Bayesian inference. In addition, a haplotype network was constructed using TCS and an analysis of molecular variance (AMOVA) was conducted. The derived topologies were highly congruent and showed that melanistic and non-melanistic populations were interdigitated on all tree topologies and a number of haplotypes were shared between melanistic and non-melanistic specimens. These results suggest that melanistic populations of K. polyzonus are ecotypes, not relics.     

Effects of pre‐weaning dietary substitutions on plasma insulin and glucose profiles in primiparous sows

The objective of this study was to investigate the effects of substituting 1 kg of a standard lactation diet with 1 kg of a sugar‐rich (15.75 DE MJ/kg) or fat‐rich (23.85 DE MJ/kg) diet during late lactation on blood glucose and insulin changes in primiparous sows. During a 4‐week lactation period, 21 primiparous sows were fed to appetite with a standard lactation diet (14.10 DE MJ/kg). At 9 days before weaning, sows were assigned to a control (C, n = 7), fat (F, n = 6) or sugar (S, n = 8) treatment. During the treatment period (from 8 days before weaning until weaning), 1 kg of the lactation diet was substituted with 1 kg of a sugar‐rich or fat‐rich diet for S and F sows. At 3 days before weaning, serial blood samples were collected for a total of 228 min around feeding to establish pre‐ and postprandial plasma glucose and insulin concentrations. Preprandial plasma glucose and insulin concentrations did not differ between treatments (p > 0.05); however, mean plasma glucose and insulin concentrations were higher for S compared to F (p < 0.05) and intermediate for the C sows. Postprandial plasma concentrations of glucose and insulin were higher for the S sows than for C and F sows (p < 0.05). Sow body weight loss during late lactation did not differ between treatments (p > 0.05). The results from our study suggest that a sugar‐enriched diet during the last week of lactation elevates circulating glucose and insulin concentrations and may potentially improve post‐weaning fertility in primiparous sows.     

Reproductive Performance of Purebred Swedish Landrace and Swedish Yorkshire Sows: II. Effect of Mating Type,Weaning-to-first-service Interval and Lactation Length

The objective of this retrospective study was to investigate the effect of mating type [natural mating (NM) versus artificial insemination (AI)], weaning-to-first-service interval (WSI) and lactation length on some reproductive traits of purebred Swedish Landrace (L) and Swedish Yorkshire (Y) sows. Data analysed comprised farrowings during the period 1994-1997 from 19 Swedish nucleus herds and included 20 275 litters from 6989 purebred sows (3598 L and 3391 Y). Analysis of variance was used for the statistical analysis of quantitative data. Logistic regression analysis was applied for binary data using the GLIMMIX macro in the SAS program. The response variables analysed were litter size, WSI, farrowing rate and remating rate. Explanatory variables included in the analyses were mating type, lactation length, sow breed, boar breed, parity, herd-year combination within breed and month of the year. The effect of WSI on subsequent fertility performance (i.e. litter size, farrowing rate and remating rate) was also analysed. Compared with AI, NM resulted in significantly larger litters (0.2 total born per litter; P<0.001; 0.3 born alive per litter; P<0.001), and lower remating rate (1.6%-units; P<0.01). The difference between NM and AI varied according to sow breed, parity number and month of the year. Subsequent litter sizes decreased by about one piglet when WSI increased from 4 to 10 days. Thereafter, litter size increased as the WSI increased from 10 to 20 days. Farrowing rate decreased gradually when WSI increased from 4 to 7 days, but an increase in WSI from day 9 to day 20 resulted in an increase in farrowing rate. A longer lactation period led to a shorter WSI and a larger subsequent litter size for both breeds.     

Dynamic changes of fatty acids and minerals in sow milk during lactation

The objective of the present study was to explore the changes in fatty acids (FAs) and minerals composition in sow milk in order to improve the knowledge about FAs and mineral requirements for piglets. The FAs and minerals composition in the sow milk samples which were collected from ten sows during a period of 16 days of lactation was analysed. The proportion of FAs in sow milk has a significant increase in C8:0, C10:0, C12:0, C14:0, C16:0, C14:1 and C16:1 FAs and the sum of saturated fatty acids (SFAs) according to the lactation period (p < 0.05). The proportion of C18:2 cis‐9,12 FA and the sum of polyunsaturated fatty acids (PUFAs) significantly decreased with the advancing of lactation (p < 0.05). The concentrations of minerals, including potassium, copper, manganese and zinc, were higher on day 1 and day 2 than those on day 13 and day 16 (p < 0.05). On the contrary, the lowest concentrations of calcium, sodium, magnesium and iron and the lowest molar calcium: phosphorus ratio emerged in colostrum (p < 0.05). In summary, our results demonstrated FAs profile and minerals concentrations were changed with lactation period. Better understanding of the changes of FAs and minerals may be valuable to swine nutritionists in the commercial industry. In addition, those results provided some meaningful information for sow's diet formulation during lactation.     

A comparison between multivariate Slash, Student's t and probit threshold models for analysis of clinical mastitis in first lactation cows

Robust threshold models with multivariate Student's t or multivariate Slash link functions were employed to infer genetic parameters of clinical mastitis at different stages of lactation, with each cow defining a cluster of records. The robust fits were compared with that from a multivariate probit model via a pseudo‐Bayes factor and an analysis of residuals. Clinical mastitis records on 36 178 first‐lactation Norwegian Red cows from 5286 herds, daughters of 245 sires, were analysed. The opportunity for infection interval, going from 30 days pre‐calving to 300 days postpartum, was divided into four periods: (i) ?30 to 0 days pre‐calving; (ii) 1–30 days; (iii) 31–120 days; and (iv) 121–300 days of lactation. Within each period, absence or presence of clinical mastitis was scored as 0 or 1 respectively. Markov chain Monte Carlo methods were used to draw samples from posterior distributions of interest. Pseudo‐Bayes factors strongly favoured the multivariate Slash and Student's t models over the probit model. The posterior mean of the degrees of freedom parameter for the Slash model was 2.2, indicating heavy tails of the liability distribution. The posterior mean of the degrees of freedom for the Student's t model was 8.5, also pointing away from a normal liability for clinical mastitis. A residual was the observed phenotype (0 or 1) minus the posterior mean of the probability of mastitis. The Slash and Student's t models tended to have smaller residuals than the probit model in cows that contracted mastitis. Heritability of liability to clinical mastitis was 0.13–0.14 before calving, and ranged from 0.05 to 0.08 after calving in the robust models. Genetic correlations were between 0.50 and 0.73, suggesting that clinical mastitis resistance is not the same trait across periods, corroborating earlier findings with probit models.     

Numerical Methods in Marine Ecology

In order to elucidate the taxonomic status of the melanistic, girdled lizard, Cordylus cordylus niger, occurring in the Cape Peninsula and the Saldanha Bay area, South Africa, character variation among populations of the C. cordylus complex in the section of the Cape Province south of 32°3C latitude and west of 19°30' longitude was analysed. Variation for 92 external morphological characters at 54 localities was determined. Distinct patterns of interlocality variation were observed in only eight characters, but interestingly, these patterns were concordant in all eight cases. The observed patterns are interpreted as indicating that three phenotypic forms of the nominate species occur in the south-western Cape, namely a coastal melanistic form (= C. c. niger), occurring in insular and peninsular situations along the coast; a montane melanistic form occurring at relatively high altitudes along the western section of the Cape Fold Mountains; and the typical form (= C. c. cordylus), occurring commonly along the coastal lowlands, but also further inland at some places.     

Effect of polymorphisms at the STAT5A and FGF2 gene loci on reproduction, milk yield and lameness of Holstein cows

The objective of this study was to investigate the association of polymorphisms at the STAT5A and FGF2 gene loci with fertility, lactation milk yield and lameness in dairy cattle. Five hundred and eighteen primiparous Holstein cows were included in the study. Several reproductive traits were considered including conception rate (0/1) at first insemination, conception rate (0/1) in a 305-day lactation, number of inseminations per conception, interval (days) from calving to conception for cows that conceived in the first 305 days of lactation and age at first calving. Milk yield and lameness incidence were also recorded. Genotyping was performed using PCR-RFLP. The effect of allele substitution at each gene locus on reproductive traits, milk yield and lameness was assessed with single-trait mixed linear models. No significant associations were found between reproduction traits and any of the studied polymorphisms, apart from age at first calving, for which STAT5A polymorphism had a suggestive effect (P = 0.077). In addition, no significant effect of any polymorphism on lameness was found. Replacement of the C by G allele at the STAT5A locus was associated with a significant (P < 0.05) increase in lactation milk yield, suggesting that this locus could be considered in gene assisted selection for the genetic improvement of milk production.     

Longitudinal observation on reproductive and lactation performances of smallholder crossbred dairy cattle in Fitche,Oromia region,central Ethiopia

A two-year longitudinal study was conducted to assess the reproductive and lactation performances of smallholder crossbred dairy cattle in Fitche, central Ethiopia. Twenty-four smallholder dairy farms were monitored and data on reproductive, breeding, lactation and management aspects of crossbred dairy cows (n = 69) were collected and analysed. Moreover, milk samples were collected and analysed for progesterone. The overall Least-squares means for calving interval (CI), calving to conception interval (CCI) and first observed oestrus after calving were 516, 253 and 141 days, respectively. Suckling significantly prolonged these intervals. The mean first onset of luteal activity (OLA) after calving was 52 days, while 67.4% (n = 43) had a delayed (>55 days) return to cyclicity after calving. Suckling and parity number significantly (p < 0.05) influenced the OLA. The mean lactation length was 54.4 weeks. The overall daily mean milk yield for the first 43 weeks of lactation after calving was 11.7 L/day. The estimated daily milk yield increased slowly and reached peak (13.8 L/day) around the 11th week post partum and declined gradually and steadily. Suckling status, season of calving and parity number significantly influenced the estimated daily milk yield. In conclusion, the present study indicated that the smallholder crossbred dairy cows in the study area had prolonged intervals to first oestrus after calving, to conception and to the next calving, and thus their reproductive performance is unsatisfactory. Delayed first onset of luteal activity (postpartum anoestrus) contributed to these extended intervals. Further detailed investigation is suggested to examine the effects of other relevant factors on the reproductive and lactation performances of smallholder crossbred dairy cows for appropriate intervention.     

Sonoanatomy of female reproductive organ of Sunda porcupine (Hystrix javanica)

The conventional anatomical study of specimens requires cutting processes which destruct the limited specimens. A non-destructive method, namely an ultrasonography, can be used to assess the anatomical organ information of those specimens. The aim of this research is to analyse the macroanatomy of the female reproductive organ in the Sunda porcupine (Hystrix javanica), using ultrasonographical imaging. In this study, four formaldehyde-fixed reproductive organ specimens of the Sunda porcupine were used. A 10–12 MHz linear ultrasound transducer was utilized to provide an imaging format of both longitudinal and transversal views. Photographic images were then used as comparison with a sonographic image. The results show that the ultrasound image of the Sunda porcupine reproductive organ soft tissue was hypoechoic, the lumen and antrum follicles were anechoic, while atretic follicles and the mons pubis were hyperechoic. Generally, the size of the organ was not significantly different between photographical and ultrasonographical imaging (p > .05). In conclusion, ultrasound images can be utilized for anatomical studies of the Sunda porcupine reproductive organs without destructing the specimen.     

Application of an early skip-a-day feed restriction on physiological parameters, carcass traits and development of ascites in male broilers reared under regular or cold temperatures at high altitude

The present study was conducted to evaluate the effects of a skip‐a‐day feed removal early in life on physiological parameters and ascites occurrence in broilers reared at a high altitude (2100 m above sealevel) under regular or cold temperatures. Three hundred 1‐day‐old male broilers were divided into two equal groups. One group was placed in an enclosure with standard thermal management. The other group treated for the induction of ascites was raised under cold temperature conditions. In each enclosure, birds were randomly assigned to one of two treatment groups (three replicate floor pens of 25 chicks per treatment group): (i) a control was fed a standard starter and grower diet according to the National Research Council; or (ii) a skip‐a‐day feed removal, which was similar to the control except for 24 h fasting intervals at 9, 11 and 13 days of age. Results indicate that live bodyweight following the feed removal at up to 42 days of age was significantly different between the control and skip‐a‐day restricted birds (P < 0.01). Skip‐a‐day feed removal resulted in decreased weight gain (P = 0.005) but did not influence feed conversion ratio. The heterophil : lymphocyte ratio was numerically higher for the cold environment and increased when birds were exposed to fasting, but these differences were not significant. Hematocrit was significantly higher (P = 0.0001) in broilers raised in cold conditions whereas it was not influenced by feed restriction. Circulatory thyroid hormone concentrations were not influenced by the feed restriction program under both environments. Birds subjected to cold had significantly lower (P = 0.0023) carcass yield compared to those reared at normal temperature. Breast yield and abdominal fat deposition were not influenced by cold or feed restriction. A reduction in mortality from ascites was noted in broilers who experienced early skip‐a‐day feed removal under both environmental conditions.