Winter and spring variation in daily milk yield and mineral composition of Jersey, Friesian cows and their crosses under a pasture-based dairy system

This study was conducted to determine the effects of genotype and season on daily milk yield (DMY) and mineral composition of pasture-based dairy cows. This was done by collecting data from 20 Friesian, 20 Jersey and 20 Friesian × Jersey crossbred cows in the early stage of their 4th parity in winter and spring, respectively. Automated milk meters were used to measure the DMY. Mineral composition was determined by using the Inductively Coupled Plasma Optical Emission Spectrometric (ICP-OES) method. The data collected from milk yield and mineral composition were analysed using the general linear model of SAS. The results showed that milk yield was highest from Friesian cows both in spring and winter seasons while Jersey cows had the lowest yield. Seasonal effects were also observed in mineral concentrations, with winter having higher values for aluminium, boron, copper, iron, magnesium, manganese, zinc and sodium while phosphorus was higher in spring. Crossbred cows yielded higher concentrations of calcium, phosphorus and magnesium. It was therefore concluded that both milk yield and mineral compositions are affected by genotype and season.Keywords: Genotype, seasonal effects, mineral content, novel health milk product

Comparison of milk fatty acid profiles measured on Kouri cows near Lake Chad and on dairy cattle as reported by meta-analytical data

peer reviewedKouri (Bos taurus) is a breed aboriginal from Lake Chad and threatened with extinction. This study aimed to compare milk fatty acid profiles measured on Kouri cows and on high-yielding dairy cattle in Europe and elsewhere as reported by meta-analytical data (22 experimentations). Milk samples were collected from 14 Kouri dairy cows in dry season (March to June) and fatty acids (FA) were determined by gas chromatography. Overall, 32 FA have been identified. Kouri showed lower values (P < 0.001) in the sum of saturated FA (SFA, −10.9 pts), cis-9, cis-12 18:2 (−1.00 pt) (P < 0.01, higher values (P < 0.001) in the sum of monounsaturated FA (MUFA, +15.3 pts), C18:0) (+3.5 pts), cis-9, trans-11 C18:2-CLA (+1.00 pts), trans-11 18:1 (+1.4 pts) and (P < 0.01) in cis-9, C18:1 (+3.00 pts) acids. The differences between the milk FA profile of the Kouri cows and that obtained from meta-analytical data could be the possible consequence of the use of particular lake pastures by Kouri cows