Parity and Homeorhetic Prioritisation in Friesian Cows in 30–day Post-parturient Period in Uasin Gishu County, Kenya

Abstract

The transition period to parturition introduces significant homeorhetic and metabolic challenges that significantly influence the hormone levels, feed intake, body weight and lactational performance of a cow in the immediate post-parturient period. Thus, the study examined how Friesian cows prioritised homeorhetic balance in the first 30 days of post-parturition. Nine Friesian cows whose milk production averaged 20 litres per day were purposively selected from Elso, Elfam and Betan farms, whose farm management practices are standardised and studied on-field. Each cow was fed daily on a 40 kg ration of forage, mineral licks and water ad libitum. The cows were weighed daily, and the quantity of feed intake was determined. Blood samples were collected in the morning after parturition and at 7-day intervals and tested for cortisol, prolactin, oestrogen, and IGF-1 levels. Microsoft Excel and Genstat 14 were used to analyse the data both descriptively and inferentially, using ANOVA and correlations. As cows displayed a negative energy balance (NEB) state in the first 21 days of post-parturiency, feed intake was initially low but gradually increased to match the energy status of the cow. The initial milk yield was low due to NEB and stress, but progressively increased with time as the cortisol levels declined while IGF, prolactin and oestrogen concurrently increased during the 30-day post-parturiency. Feed intake was significantly and negatively correlated to cortisol levels (r = -0.613), but positively correlated to milk yield (r = 0.615), prolactin (r = 0.760), Oestrogen (r = 0.785), and IGF (r = 0.692). The study concluded that a causal linkage existed between feed intake, milk yield and hormonal profile during the 30-day post-parturient period. The study recommends that the nutritional requirements of a dairy cow in the transition to post-parturiency be adequately provided.