Effects of maize and alfalfa genotypes on dairy cow performances

JC Émile, Y. Barrière, M. Mauries
1996 Annales de Zootechnie  
— In this trial, we attempted to evaluate the effects of alfalfa and maize genotypes fed to dairy cows. These genotypes were chosen from records of previous trials with sheep for either their high or low digestibility. Thirty-two cows were fed a diet based on maize silage ad libitum (M+ or Mgenotype) and alfalfa (A+ or A-) pellets (4.35 kg/day) in a 2 x 2 factorial experiment. Silage intake, milk yield and composition, body weight and body condition scores were recorded during the 15-week
more » ... g the 15-week experiment. The maize genotype of high digestibility (M+) tended to be ingested in larger quantities (14.4 vs 14.0 kg/cow/d) than the other genotype (M-), although showing a lower dry matter content (29.5 vs 31.2%). With this improved genotype, the milk yield was significantly higher (28.1 vs 26.9 kg/cow/day; P = 0.01) without decreasing effects in the fat and protein content of the milk, but with the cows increasing their body reserves (28.1 kg, P < 0.01 No differences were observed in the body condition scores. The alfalfa effects were not so acute, but the distribution of the improved genotype (A+) improved the daily milk yield (28.0 vs 27.0 kg/day, P= 0.03) and the body condition scores (P= 0.04). These principal effects appeared to be additive. The diet built with the best genotypes (M+ A+ diet) provided 2.2 kg milk/cow/day more than with the inferior ones (M-Adiet), displaying a higher body weight gain and better body conditions, without showing any negative effects on the fat and protein contents. Thus, the choice of a given genotype (maize or alfalfa in this case) may have strong effect on cow performances. In the European Union, where each farmer has a milk quota, the choice of an improved maize or alfalfa genotype could be essential in limiting production costs. dairy cow / feeding value / alfalfa / maize / digestibility Résumé — Effets du génotype de maïs et du génotype de luzerne sur les productions laitières. Dans cet essai, les effets zootechniques de la variabilité génétique pour la valeur alimentaire existant chez la luzerne et le mais ensilage ont été évalués. Nous avons alimenté des vaches laitières avec de l'ensilage de maïs distribué ad libitum et des bouchons de luzerne déshydratée et broyée (4,35 kg MS par vache par jour) dans un essai croisé à quatre modalités (quatre lots de huit animaux) durant 15 semaines. Nous avons utilisé deux génotypes de mais (M+ et M-) et deux génotypes de luzerne (A+ 110-119 g Wilson TR, Kromann RP, Evans DW (1978) Nutrient digestibility, digestible energy and metabolizable energy and agronomic data for 5 varieties of alfalfa hay.
doi:10.1051/animres:19960102 fatcat:dos5qpoevjhuvlokmmop4rbbkm