Nutritional and biochemical composition of colostrum and milk in sheep of the arid Region

The present study was designed to study the effect of parity (PA), stage of lactation (SL), and their interaction (PA × SL) on daily milk yield and milk composition in Marwari sheep. The investigation was conducted at the Small Ruminant Research Unit of ICAR-CAZRI, Jodhpur during the year 2024. Twenty-two ewes in their first parity, along with seven, four, three, two, and three in second, third, fourth, fifth & sixth parity, respectively were included in the study. All ewes were reared, till the end of our study, in a semi-intensive management system with access to ad libitum permanent pasture and a daily concentrate supplement of 0.5 kg/ewe. Milk yield and composition were recorded during two sampling sessions between May and June, corresponding to different stages of lactation. The analysed milk composition parameters included fat, solids-not-fat (SNF), protein, lactose, salts, as well as milk density and freezing point. The mean ± SE values for fat, SNF, protein, lactose, and salts were 5.29 ± 0.19%, 10.29 ± 0.09%, 4.12 ± 0.03%, 6.21 ± 0.05%, and 0.91 ± 0.01%, respectively. The milk density and freezing point were recorded as 36.14 ± 0.43 g/cm³ and -0.75 ± 0.01°C, respectively. This research highlights the influence of parity and lactation stage on milk production and its composition in Marwari sheep, a breed well-adapted to the arid regions of India.