Effects of feeding high volumes of milk replacer on reproductive performance and on concentrations of metabolites and hormones in blood of Japanese black heifer calves

We evaluated the effects of feeding high volumes of milk replacer on growth and reproductive performances in Japanese black heifers. Fifty-one heifers were fed milk replacer at 9 L/day for 60 days (9 L × 60 days; n = 18) or 41 days (9 L × 41 days; n = 15), or at 7 L/day for 40 days (7 L × 40 days; n = 18). Artificial insemination (AI) was performed on heifers with ≥270 kg body weight and ≥116 cm body height at 300 days of age. The age at the first AI was 0.35 month later for 7 L × 40 days than the other groups (p < .01). However, age at calving did not differ among treatments (22.1 months). The interval from the first AI to pregnancy tended to be ~2 months longer for the 9 L × 60 days than the other groups (p = .07). Our results showed that feeding high volumes of milk replacer may reduce the age at calving via an improved rate of growth. In addition, we propose that feeding a maximum of 7 L milk replacer for 40 days may be the most appropriate rearing regime because the success of pregnancy per AI may be reduced in calves fed a maximum of 9 L for 41 and 60 days.

Primary pharyngeal alveolar rhabdomyosarcoma in an adolescent Japanese black heifer

Alveolar rhabdomyosarcoma (ARMS) is a rare mesenchymal tumor with differentiation toward the skeletal muscle. Although several cases of canine ARMS have been reported in veterinary medicine, only one case of abdominal ARMS has been reported in a cow. A 13-month-old, Japanese black heifer was referred for pus-like nasal discharge. On autopsy, an 11 × 7 × 4.5-cm pedunculated mass closed to the left palatine tonsillar sinus that occupied the laryngopharynx. Histopathological and immunohistochemical analyses indicated that the tumor was a typical ARMS. To the best of our knowledge, this has been the first case of primary pharyngeal ARMS in a Japanese black heifer, which is rare among cows. Nonetheless, its characteristics, including site, age and subtype, are identical to those among humans and dogs.