Grouping and complete diet composition in relation to parity and potential yield in dairy cows

Abstract

Three experiments, involving a total of 294 Israeli Holstein cows, were carried out to study aspects of the grouping of cows in relation to timing of changes and the type of complete diet given. In Expt 1, 40 cows were changed from a high energy diet to a medium energy diet either at 60 or at 180 days post calving. The results indicated a larger reduction in milk and FCM yield following the later than the earlier change of diet.Experiment 2 involved 64 cows subjected to two treatments, one involving a ' uniform' diet (25:75 forage to concentrate D.M. ratio) and the other a 'step' treatment where the same diet as in treatment 1 was given for approximately 74 days and then changed to a diet of 35:65 forage to concentrate ratio. The results showed that it is not necessary to adopt different feeding systems according to the potential yield of the cow and that cows could be given rather lower energy diets within the range offered without loss of efficiency.In Expt 3, involving 190 cows, the cows were divided into one of two feeding treatments, 'uniform' and 'step' similar to Expt 2 and the effect of potential yield and parity was considered. The results emphasized the importance of potential yield rather than feeding system in relation to yield. The results showed a shorter period from calving to conception for the ' uniform' treatment.A strategy for efficient cow feeding is outlined.

Economic impact of nutritional grouping in dairy herds

“…This indicates that use of 1 and 3 groups did not result in overall BW changes of the cows in the herds. The stable BW among different grouping numbers has also been found in field trials (Smith et al, 1978;Clark et al, 1980;Kroll et al, 1987). Right panel of Figure 8 illustrates the effect of nutritional grouping on the distribution of the cows' body energy content (BCS).…”

“…Overall, the effects of grouping on the milk production of the cows in inconclusive (Clark et al, 1980) and, based on the 2 field studies mentioned above (Smith et al, 1978;Zwald and Shaver, 2012), it seems that the assumed amount of milk loss in this study (total of 9.1 kg in 5 d) could be either underestimated or overestimated. Thus, the true amount of milk loss is unknown, and studies have shown that it could be affected by parity (Smith et al, 1978) and could vary among cows based on their DIM (Kroll et al, 1987) and possibly their characteristics. It seems safe to assume that not every cow might experience the same amount of loss and the duration could vary among cows based on their characteristics.…”

Economics of production efficiency: Nutritional grouping of the lactating cow

“…Economic results from a series of studies from the 1970s through the 1990s were inconclusive about the economic value of multiple TMR grouping strategies. Whereas a study reported that 1 TMR was superior to 2 TMR (Cassel et al, 1984), others found no differences (Davenport and Rakes, 1973;Everson et al, 1976;Wilk et al, 1978), small differences in favor of multiple TMR (Kroll et al, 1987), and substantial differences of multiple TMR (Smith and Coppock, 1974;Smith et al, 1978). Smith (1976) and Coppock et al (1981) concluded that savings of feed costs with 2 TMR would economically outweigh its lower productivity and that, as a result, multiple TMR feeding systems would be preferred because they would provide greater income over feed cost (IOFC).…”

Allocation of feed based on individual dairy cow live weight changes

“…Smith et al (1978) investigated the influence of days from parturition on the short term effect on milk yield, and found no significant difference in the milk yield reduction dependent on whether ration energy concentration was reduced before 100, between 100 and 200 or after 200 days. Other experiments have indicated that milk yield response to reduced ration energy concentration is affected by stage of lactation (Akinyele and Spahr, 1975;Kroll et al, 1987), and indicated that the negative effect of reducing ration energy concentration is minimized the earlier it is introduced. Results from the present experiment indicated, that late reduction of ration energy concentration was followed by a permanent lower feed energy intake and a continuous increasing live weight gain, whereas the early reduction of ration energy concentration was followed by an increasing feed intake from the low energy MR and a reentry to mobilization metabolism (Bossen et al, 2009).…”