Plasma hormones and metabolites in Piedmontese cows during late pregnancy: relationships with calf birth weight.

Relationships among plasma hormonal and metabolic variables in the last trimester of gestation in 59 Piedmontese dams (n = 15 heifers, n = 44 cows) and the calf birth weight (BWT) class of their offspring were investigated in seven herds. The BWT data were categorized as follows: > 50 kg (BWT-A), 46 to 50 kg (BWT-B), 41 to 45 kg (BWT-C), and < 41 kg (BWT-D). Blood samples were collected at 33, 36, and 39 wk of gestation. Packed cell volume (PCV) and plasma concentrations of insulin, estrone sulfate (E1SO4), NEFA, and creatinine were determined and correlated to BWT class. Creatinine: E1SO4 ratio also was calculated. Duration of gestation was greater for dams producing a BWT-A calf than for the other BWT classes, and calf BWT was heavier (P < 0.001) for calves in the BWT-A vs. BWT-D class. The heaviest calf in BWT-A was associated with the highest calving difficulty score. Insulin and PCV values were not affected by week of gestation, whereas plasma E1SO4, NEFA, and creatinine content increased (P < 0.001) and creatinine:E1SO4 decreased (P < 0.001) during late gestation. Calf BWT class did not affect PCV value. Plasma E1SO4 concentrations were lower (P < 0.01) in BWT-D dams than the other dams, showing the greatest difference at 39 wk of gestation. At 36 and 39 wk of gestation, dams bearing BWT-C and BWT-D calves had a higher (P < 0.01) plasma insulin concentration than those bearing BWT-A and BWT-B calves. Plasma NEFA concentrations at 39 wk of gestation were higher (P < 0.05) in dams of calf BWT-A than in the other dams. We conclude that plasma E1SO4 level is a variable that can be used to monitor problems related to a small size calf. Conversely, the forthcoming birth of a calf with a heavy BW seems to be preceded by a pronounced increase in plasma NEFA level in the dam just a few days before calving.

Characterization of different strains of broiler chicken by carcass measurements, chemical and physical parameters and NIRS on breast muscle.

The aims of the work were: to investigate the effect of chicken strain on chemical composition and colour parameters of fresh breast muscle; to evaluate the results obtained using different illuminants (A, C and F); to verify the possibility of predicting some meat features by near infrared reflectance spectroscopy (NIRS) of freeze-dried breast muscle. The trial was carried out on 39 chicken broilers from three strains, differing in body size, slaughtered at 30 days of age. Fresh breast samples were different only in ash content (P<0.01). Illuminant effect was highly significant for all colour variables, depending on the major wavelength characteristics of each illuminant. Significant differences among strains were detected in redness values. The NIRS technique was very accurate to predict fat content of muscle (R(2)c=0.98, SEC=0.20). These findings may have practical importance to improve instrumental procedures for on-line evaluation of poultry meat quality.