Lifetime productivity of dairy cows in smallholder farming systems of the Central highlands of Kenya

Abstract

Evaluation of lifetime productivity is sensible to target interventions for improving productivity of smallholder dairy systems in the highlands of East Africa, because cows are normally not disposed of based on productive reasons. Feeding strategies and involuntary culling may have long-term effects on productive (and therefore economic) performance of dairy systems. Because of the temporal scale needed to evaluate lifetime productivity, experimentation with feedstuffs in single lactations is not enough to assess improvements in productivity. A dynamic modelling approach was used to explore the effect of feeding strategies on the lifetime productivity of dairy cattle. We used LIVSIM (LIVestock SIMulator), an individual-based, dynamic model in which performance depends on genetic potential of the breed and feeding. We tested the model for the highlands of Central Kenya, and simulated individual animals throughout their lifetime using scenarios with different diets based on common feedstuffs used in these systems (Napier grass, maize stover and dairy concentrates), with and without imposing random mortality on different age classes. The simulations showed that it is possible to maximise lifetime productivity by supplementing concentrates to meet the nutrient requirements of cattle during lactation, and during early development to reduce age at first calving and extend productive life. Avoiding undernutrition during the dry period by supplementing the diet with 0.5 kg of concentrates per day helped to increase productivity and productive life, but in practice farmers may not perceive the immediate economic benefits because the results of this practice are manifested through a cumulative, long-term effect. Survival analyses indicated that unsupplemented diets prolong calving intervals and therefore, reduce lifetime productivity. The simulations with imposed random mortality showed a reduction of 43% to 65% in all productivity indicators. Milk production may be increased on average by 1400 kg per lactation by supplementing the diet with 5 kg of concentrates during early lactation and 1 kg during late lactation, although the optimal supplementation may change according to milk and concentrate prices. Reducing involuntary culling must be included as a key goal when designing interventions to improve productivity and sustainability of smallholder dairy systems, because increasing lifetime productivity may have a larger impact on smallholders' income than interventions targeted to only improving daily milk yields through feeding strategies.

Effets de la pâture sur la dynamique de la végétation herbacée au Sahel (Gourma, Mali) : une approche par modélisation

“…D'autres perspectives de couplage sont à envisager avec des modèles de nutrition et de production animale comme LIVSIM (Rufino et al, 2009), pour évaluer la productivité des troupeaux pastoraux.…”

Analysis of longevity traits and lifetime productivity of crossbred dairy cows in the Tropical Highlands of Ethiopia

“…However, in the lowinput low-output smallholder dairy production systems of the tropics, the lifespan of dairy cows is often decided not only by cow's milk yield, but also by the owner. For instances, Rufino et al (2009) reported that evaluation of lifetime productivity is important to target interventions for improving productivity of smallholder dairy systems in the highlands of East Africa, because cows are normally not disposed off based on productive reasons, rather it is determined by feeding strategies and involuntary culling. In such systems, voluntary culling of dairy cows is rarely practiced because farmers that have few animals face difficulties to spread risk.…”

Economics of Land Degradation and Improvement in Niger

“…Parturition could increase while mortality rate could fall due to better pasture intake. Rufino et al (2009) find that adding supplements to diets increases calving rate among smallholder Kenyan dairy farms. Huttner et al (2001) reports that malnutrition is a major factor predisposing cattle to poor health among Malawian smallholders.…”