Abstract

The aim of this research was to evaluate of the productive responses of cows fed a dry hay based total mixed ration (TMR) in which sorghum (SOR) or corn (COR) meal (8 kg/h/d) were the main source of starch. The study involved two dairy herds located in the Parmigiano Reggiano PDO area, for a total of 1,400 cows (30% primiparous and 70% pluriparous). Each herd was fed alternatively SOR or COR TMR for 4 periods of 3 weeks: two weeks of adaptation and one week of data collection. Total milk production and composition, cheesemaking properties, fatty acid content and cheese yield were measured. In addition, within each herd, a random subgroup of 50 cows was selected for individual milk production, composition and cheesemaking properties analysis. Fibre digestibility was evaluated on faecal samples collected in 15 cows randomly selected in each subgroup. Data were analysed by a linear mixed model procedure with diet, herd, days in milk, parity and their interactions as fixed effects and cow as random effect. Individual milk production increase in SOR (32.43 vs. 31.34 kg, for SOR and COR, respectively; p<.0001) however, bulk milk and cheese yield did not show differences. Milk urea content was higher in SOR (27.38 vs. 22.79 mg/dL, for SOR and COR, respectively; p < .05).

In this study the complete replacement of corn with finely ground sorghum meal in dairy cow diets in the Parmigiano Reggiano region did not result in negative effects on cows’ productivity, cheese making properties and production.

• Highlights

• Sorghum meal can be used as a substitute of corn without negative effect on herd productivity, milk quality and cheese yield.

• Replacement of corn meal with sorghum meal in the dairy cows’ ration permit to decrease the soy content of the ration, thus improving sustainability and costs of feeding.

• Utilising sorghum meal could increase the amount of crop produced in the geographical area of the farm, contributing to increase its economic sustainability.

摘要

本研究的目的是评估饲喂以干草为基础的全混合日粮 (TMR) 的奶牛的生产反应，其中高粱 (SOR) 或玉米 (COR) 粉 (8 kg/h/d) 是主要来源淀粉。该研究涉及位于 Parmigiano Reggiano PDO 地区的两个奶牛群，共有 1,400 头奶牛（30% 初产和 70% 多产）。每个牛群交替饲喂 SOR 或 COR TMR，为期 3 周的 4 个时期：两周的适应期和一周的数据收集期。测量了总牛奶产量和成分、奶酪制作特性、脂肪酸含量和奶酪产量。此外，在每个牛群中，随机选择了 50 头奶牛的子组进行个体牛奶产量、成分和奶酪制作特性分析。在每个亚组中随机选择的 15 头奶牛中收集的粪便样本评估了纤维消化率。数据通过线性混合模型程序进行分析，饮食、畜群、牛奶天数、胎次及其相互作用作为固定效应，奶牛作为随机效应。SOR 的个体产奶量增加（SOR 和 COR 分别为 32.43 和 31.34 kg；p <.0001) 然而，散装牛奶和奶酪的产量没有显示差异。SOR 中的牛奶尿素含量更高（SOR 和 COR 分别为 27.38 和 22.79 mg/dL；p  < .05）。

在这项研究中，在 Parmigiano Reggiano 地区的奶牛日粮中，用细磨高粱粉完全替代玉米并没有对奶牛的生产力、奶酪制作特性和产量产生负面影响。

• 强调

• 高粱粉可用作玉米的替代品，不会对畜群生产力、牛奶质量和奶酪产量产生负面影响。

• 在奶牛日粮中用高粱粉代替玉米粉可以降低日粮中的大豆含量，从而提高可持续性和饲养成本。

• 使用高粱粉可以增加农场地理区域的作物产量，有助于提高其经济可持续性。