Effects of Calliandra and Sesbania on Daily Milk Production in Dairy Cows on Commercial Smallholder Farms in Kenya

Table 6

Final generalized linear mixed regression model for natural log of daily milk production for 1458 cow-visit observations from 607 farm visits of 235 cows on 80 smallholder dairy farms near Meru, Kenya, in 2016–2017, adjusting for clustering of cows within farms.

Variables and their categories	Exponentiated coefficient	Coefficient	(95% conf. interval)		value
Amount of daily Calliandra/Sesbania (kg)	1.094	0.090	0.012	0.168	0.024
Visit number^α	1.009 ^α	0.009^α	0.003^α	0.015^α	0.002^α
Amount of daily dairy meal (kg)	1.047	0.046	0.027	0.065	<0.0005
Amount of daily maize germ (kg)	0.811	−0.210	−0.363	−0.058	0.007
Amount of daily maize silage (kg)	1.008	0.008	0.004	0.012	<0.0005
Napier grass fed
No Napier grass fed	Reference	Reference
Fed at any height	1.076	0.073	0.016	0.130	0.012
Sudden feed changes
No	Reference	Reference
Yes	0.901	−0.104	−0.162	−0.046	<0.0005
Body condition score	2.038^β	0.712^β	0.378^β	1.045^β	<0.0005^β
Body condition score squared	0.886^β	−0.121^β	−0.193^β	−0.050^β	0.001^β
Days in milk	0.998^β	−0.002^β	−0.002^β	−0.001^β	<0.0005^β
Days in milk squared	1.000^β	1.59^−06β	1.15^−06β	2.02^−06β	<0.0005^β
Normal appetite
No	Reference	Reference
Yes	1.377	0.320	0.097	0.542	0.005
Pregnant
No	Reference	Reference
Yes	0.742	−0.299	−0.353	−0.245	<0.0005
Constant	1.730	0.548	0.120	0.975	0.012

^αOrdinal variable: time of farm visit modeled as a continuous variable. ^βVariable is part of a curvilinear relationship, and therefore coefficients cannot be interpreted in isolation but rather in combination with the other relevant coefficients for the curvilinear variable, and these combinations are best reported using a graph (Figures 4 and 5).