Cloned cows with short telomeres deliver healthy offspring with normal-length telomeres

Dolly, the first mammal cloned from a somatic cell, had shorter telomeres than age-matched controls and died at an early age because of disease. To investigate longevity and lifetime performance in cloned animals, we produced cloned cows with short telomeres using oviductal epithelial cells as donor cells. At 5 years of age, despite the presence of short telomeres, all cloned cows delivered multiple healthy offspring following artificial insemination with conventionally processed spermatozoa from noncloned bulls, and their milk production was comparable to that of donor cows. Moreover, this study revealed that the offspring had normal-length telomeres in their leukocytes and major organs. Thus, cloned animals have normal functional germ lines, and therefore germ line function can completely restore telomere lengths in clone gametes by telomerase activity, resulting in healthy offspring with normal-length telomeres.     

Responsiveness of beef cattle (Bos taurus) to human approach,novelty, social isolation,restraint and trade‐offs between feeding and social companionship

This study investigated responsiveness of beef cattle to various environmental stimuli by subjecting 15–16 Japanese Black cows to five tests repeated twice. Within individual behavioral measures, cows were moderately (repeatability = 0.54–0.70) or highly (repeatability = 0.74–0.89) consistent in flight distance during grazing and resting in the human approach tests, maximum distance from the group pen and the number of total and different feed tub visits in the feeding–sociability trade‐off test, and unwillingness to enter the restraint, movement under restraint and flight speed after release from restraint in the social isolation and restraint test. By contrast, cows were not consistent in the latency to make the first contact and the number of contacts with novel object(s) in the novelty test (repeatability = 0.24–0.39). Across behavioral measures in different tests, cows showed no consistency (P ≥ 0.05) in any combinations of measures from the two human approach tests, the trade‐off test and the social isolation and restraint test. In conclusion, human approach (particularly during resting), feeding–sociability trade‐off and social isolation and restraint situations can be used for evaluating personality in Japanese Black cows, while the value of the novelty test needs to be reexamined.     

Involvement of food intake in the decreased energy retention associated with single deficiencies of lysine and sulphur-containing amino acids in growing chicks.

1. Growth and energy utilisation were determined in growing chicks fed ad libitum on diets deficient either in lysine (5.95 g/kg) or in sulphur-containing amino acids (SAA, 3.5 g/kg). Food intake, body weight gain, energy retained as protein and as fat, and total energy retention were significantly (P less than 0.05) reduced by single deficiencies of either lysine or SAA. 2. Another two experiments were conducted to determine if the decreased total energy retentions in chicks fed on diets deficient in lysine (experiment 3) or SAA (experiment 4) were associated with reduced food intake, by using tube-feeding to control the amount and pattern of food consumption. Chicks fed on diets deficient in lysine or SAA retained less energy as protein and more energy as fat than the control chicks. Neither total energy retention nor heat increment was affected by these deficiencies. Total energy retention was proportional to metabolisable energy (ME) intake alone. 3. It is concluded that the decreased total energy retentions caused by single deficiencies of lysine and SAA were associated with decreased food intake.