Ruminants, Volume 2, Issue 3 (September 2022) – 5 articles

Tick-borne fever in sheep is caused by Anaplasma phagocytophilum and this obligate intracellular bacterium multiplies mostly in neutrophil granulocytes of its host. In Europe, the pathogen is mainly transmitted by the tick species Ixodes ricinus. Data on the dissemination of A. phagocytophilum in the German sheep population are scarce. Hence, this pilot study aimed to investigate the presence of A. phagocytophilum in ovine serum samples retrospectively. The use of sera is beneficial because the specimens are available in large numbers and usually stored over a long period of time. Ten sheep flocks located in five federal states of Germany (Baden-Württemberg, Bavaria, Lower Saxony, North Rhine-Westphalia, Schleswig-Holstein) were included in the investigations, due to the high intra-flock seroprevalence (>63%) of antibodies against the Anaplasma species. In total, 357 serum samples from seropositive sheep were analysed by 16S rRNA real-time PCR. DNA of A. phagocytophilum was detected in two ewes from the same farm in the northern German federal state of Schleswig-Holstein and represented an overall detection rate of 0.6%. Serum samples can be used to determine A. phagocytophilum, but sensitivity might be reduced in comparison to whole blood samples. Moreover, the sampling time may influence the detection of A. phagocytophilum in sheep, due to the seasonal pattern of tick activity in Germany. Our results support the findings of previous studies and demonstrate that A. phagocytophilum is also present in sheep from northern Germany (Schleswig-Holstein). Full article

The objectives of this study were to analyze calf performance traits and sex ratio frequencies in reciprocal Bos indicus–Bos taurus F₂ Nellore–Angus calves (n = 539). The F₂ calves were produced using reciprocal Angus-sired (AN) and Nellore-sired (NA) F₁ sires and F₁ dams, resulting in four F₂ cross types. Calf weight traits were analyzed using mixed models. Deviations from 50% calf sex ratios were tested against expected binomial thresholds. Dam type influenced Julian birth date (p < 0.05) with calves from AN cows born 5 to 6 days earlier than calves from NA cows. Sire type and dam type affected birth weight (p < 0.05) with calves from NA parents approximately 2.5 kg heavier than those from AN parents; weaning weight did not differ for parent F₁ type. However, an interaction between sire and dam types affected weaning weight (p = 0.038) where AN x AN calves were 5 to 8 kg lighter than other crosses. Sire type influenced calf sex distribution at birth (p = 0.036) and at weaning (p = 0.026) with NA sires producing over 66% male calves. These results suggest birth weight reciprocal differences due to parental line of descent typically observed among F₁ Bos indicus–Bos taurus crosses can persist in subsequent generations. Full article

Observations of 17 heifer-calf pairs were collected over the first 5 days postpartum (p.p.) to study nursing and maternal behaviour of beef cattle. Cattle were managed in a 6 ha paddock and heifer–calf interactions were determined from both regular visual observations and video recordings. Of 17 potential calves, one was stillborn and 3 died in the first 5 days p.p. associated with dystocia and congenital malformation. Four further potential neonatal calf mortality risks were identified, which included poor calving site selection (n = 1), calf misadventure (n = 1), heifer-calf separation (n = 3) and mismothering (n = 3), with each resulting in distress, physical exhaustion of the calf and impaired nursing. There was marked variation between heifers in the expression of optimal maternal behaviours, with only 39% classified as ‘good’ mothers. Dam terminated nursing bouts were 27% shorter in duration than calf terminated nursing bouts; 29% of heifers terminated nursing bouts at least 50% of the time. Only 68% of observed suckling interactions were considered effective. On average, the nursing behaviour lasted 7.0 min, with sucking making up 54% of the total nursing time, the sucking rate was 2.0 sucks/s, and the calves performed 7.5 teat-switches, 2.4 butts and 0.9 teat-strips per min of nursing. In 67% of nursing interactions, the calves sucked on all four teats. By three days p.p., all calves developed a clear, consistent suckling pattern. Prior to this, the calves had shorter nursing bouts, spent less time nursing and manipulating the udder, paused more, switched teats and butted less, and had a slower sucking rate. The behaviour of some calves (i.e., low teat fidelity and high levels of milk stimulation behaviours) suggested that their dam milk availability was low. This study has quantified early post-partum nursing behaviour of neonatal beef calves and highlighted dam and calf behaviours that may adversely affect milk intake and, therefore, impact calf survival. Full article

Cistus ladanifer has been used in ruminants feeding systems, but there is no information about the seasonal variation in chemical composition and nutritional value of each morphological fraction during its growth cycle. This study characterized the morphological fractions of C. ladanifer (leaves, stems, flower buds, flowers, and seed heads) throughout the year in chemical composition, in vitro digestibility, and antioxidant activity. The leaves were the morphological fraction more variable throughout the seasons, being characterized by low protein level (48.5–114 g/kg dry matter (DM)), moderate cell-wall content (240–267 g NDF/kg DM), high levels of condensed tannins (CT) (131–246 g/kg DM), and low in vitro organic matter digestibility (IVOMD) (29.3–34.3%). The distinctive chemical composition among various morphological fractions allowed the identification of four distinct groups, the first composed by stems, the second by the leaves, the third by the seed heads, and the last one by the flower buds and flowers. All the morphological fractions are sources of bioactive compounds namely phenolic compounds. Leaves are the fraction with higher nutritive value, especially when collected during winter and spring. Full article

Bone morphology in the mid-diaphysis of the metacarpus in cattle and the effect of puberty and age has been well described. However, there is limited information on how age and not attaining puberty affects bone morphology in the epiphysis of the metacarpus. The metacarpus is comprised of the third and fourth metacarpal bones fused together to create a medial and lateral epiphysis. When a cow is in stance phase there is greater pressure on the medial claw; however, the effect of this difference in loading on bone has not been described. Therefore, the aim of this experiment was to describe bone morphology in the medial and lateral epiphysis of the metacarpus at the age of puberty in steers. The metacarpus was collected from beef cross dairy steers at approximately one and two years of age. The distal epiphysis of the metacarpus was scanned using peripheral quantitative computed tomography (pQCT). Measures were corrected for body weight and demonstrated a lack of bone growth cessation at one year of age. The lack of difference in bone morphology in the medial and lateral condyles of the distal metacarpus reflects the even loading distribution observed in the forelimb of cattle. Full article