Genetic parameters for carcass weight, conformation and fat in five beef cattle breeds.

Profitability of beef production can be increased by genetically improving carcass traits. To construct breeding value evaluations for carcass traits, breed-specific genetic parameters were estimated for carcass weight, carcass conformation and carcass fat in five beef cattle breeds in Finland (Hereford, Aberdeen Angus, Simmental, Charolais and Limousin). Conformation and fat were visually scored using the EUROP carcass classification. Each breed was separately analyzed using a multitrait animal model. A total of 6879-19 539 animals per breed had phenotypes. For the five breeds, heritabilities were moderate for carcass weight (h 2=0.39 to 0.48, s.e.=0.02 to 0.04) and slightly lower for conformation (h 2=0.30 to 0.44, s.e.=0.02 to 0.04) and carcass fat (h 2=0.29 to 0.44, s.e.=0.02 to 0.04). The genetic correlation between carcass weight and conformation was favorable in all breeds (r G=0.37 to 0.53, s.e.=0.04 to 0.05), heavy carcasses being genetically more conformed. The phenotypic correlation between carcass weight and carcass fat was moderately positive in all breeds (r P=0.21 to 0.32), implying that increasing carcass weight was related to increasing fat levels. The respective genetic correlation was the strongest in Hereford (r G=0.28, s.e.=0.05) and Angus (r G=0.15, s.e.=0.05), the two small body-sized British breeds with the lowest conformation and the highest fat level. The correlation was weaker in the other breeds (r G=0.08 to 0.14). For Hereford, Angus and Simmental, more conformed carcasses were phenotypically fatter (r P=0.11 to 0.15), but the respective genetic correlations were close to zero (r G=-0.05 to 0.04). In contrast, in the two large body-sized and muscular French breeds, the genetic correlation between conformation and fat was negative and the phenotypic correlation was close to zero or negative (Charolais: r G=-0.18, s.e.=0.06, r P=0.02; Limousin: r G=-0.56, s.e.=0.04, r P=-0.13). The results indicate genetic variation for the genetic improvement of the carcass traits, favorable correlations for the simultaneous improvement of carcass weight and conformation in all breeds, and breed differences in the correlations of carcass fat.

Effect of ingesting sour milk fermented using Lactobacillus helveticus bacteria producing tripeptides on blood pressure in subjects with mild hypertension.

Angiotensin-converting enzyme (ACE) is important in the regulation of blood pressure (BP). Two tripeptides that inhibit ACE, isoleucyl-prolyl-proline (Ile-Pro-Pro) and valyl-prolyl-proline (Val-Pro-Pro), have been isolated from certain sour milks. The aim of the study reported was to evaluate the effect on BP in subjects with mild hypertension of a new sour milk containing tripeptides. The initial number of subjects was 60 (36 men, 24 women). Among the criteria for inclusion in the study were systolic BP (SBP) between 140 and 180 mmHg and/or diastolic BP (DPB) between 90 and 110 mmHg, without antihypertensive drug therapy. There were two study periods with a washout period between. All subjects were given 1.5 dl per day of a placebo (regular sour milk) or of the active product, a milk that had been fermented with Lactobacillus helveticus bacteria and contained 2.4-2.7 mg of Ile-Pro-Pro and 2.4-2.7 mg of Val-Pro-Pro per 1.5 dl. In the first phase, SBP fell 16 mmHg from baseline in the active group, 2 mmHg more than in the placebo group (P=0.0668) and no difference in DBP (P=0.92). There was a statistically significant downward trend both in SBP and DBP (P=0.0001). During the second phase, SBP fell 11 mmHg in the active group (P=0.008). The reduction in SBP was significantly larger in active than placebo group (P=0.012). In the crossover analysis combining both phases, SBP fell on average 2.6+/-15.9 mmHg more on the active product compared with the placebo product, but this difference was not statistically significant (P=0.3111). The difference in DBP, 1.0+/-8.3 mmHg between the two test products was not significant either (P=0.4431). In conclusion, the ingestion of sour milk fermented by L. helveticus bacteria and that containing ACE inhibitory tripeptides seems to lower BP modestly.