PSXV-27 Determination of the optimal canola meal inclusion rate in pelleted starters for Holstein calves

Autor: Paweł Górka, G. B. Penner, K. Burakowska
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Popis: The objective of this study was to determine the effects of the canola meal (CM) inclusion rate in pelleted starters for Holstein heifer calves. Fifty heifers (39.8 ± 3.4 kg) were assigned at birth to one of five treatments with CM replacing 0, 15, 30, 45 or 60% CP of the soybean meal. Starter was provided ad libitum from d 8 until d 71 of age, and calves were weaned at 57 d of age. Milk replacer and starter intakes were recorded daily, and BW was measured weekly. On 70.2 ± 0.8 d of age, ruminal fluid was collected and analyzed for short chain fatty acid (SCFA) and ammonia concertation. Data were analyzed using the mixed model of SAS with contrasts to determine whether responses were linear, quadratic, or cubic. Milk replacer intake was not affected (P ≥ 0.46). Increasing CM inclusion tended to linearly decrease starter intake during the weaning transition (P = 0.063) and post-weaning (P = 0.053) periods. However, ADG and feed efficiency were not affected during the weaning transition or post-weaning (P ≥ 0.13). Ruminal pH and total SCFA concentration were not affected by increasing inclusion of CM, but the molar proportions of acetate (P = 0.044; 47.6, 47.1, 46.5, 48.9 and 43.8 mol/100 mol) and butyrate (P = 0.021; 8.54, 10.17, 8.43, 5.81 and 9.41 mol/100 mol) were affected cubically, while the proportion of propionate tended (P = 0.075) to increase linearly with increasing CM inclusion. Ammonia concentration responded cubically to the treatments as well (P = 0.031; 18.1, 13.5, 14.9, 22.6, 15.6 mg/dL). During the weaning transition, increased inclusion of CM in the starter may decrease starter intake; however, growth and feed efficiency are not affected. Replacing soybean meal with canola meal has minor effects on ruminal fermentation.
Databáze: OpenAIRE