Growth, survival and milk production of Toggenburg goats and their crosses with East African and Galla goat breeds on the Eastern slopes of Mount Kenya

Data on growth and milk production from farm records of a community based goat improvement project in Meru Central and South districts in the Eastern Highlands of Kenya were analysed to determine growth parameters and milk production potential of Toggenburg goats and their crosses with local goats. Least Squares means and their standard errors for birthweight (kg), were 3.6 ± 0.16, 3.2 ± 0.19, 3.5 ± 0.18 and 2.6 ± 0.55 for 3⁄4Toggenburg, Toggenburg x East African (F1), Toggenburg and East African respectively. Weaning weights (kg) were 15.3 ± 0.12, 12.7 ± 0.14, 12.5 ± 0.09 and 12.10 ± 0.67 for 3⁄4Toggenburg, Toggenburg x East African (F1), Toggenburg and East African respectively. Average daily gains (g) were 127, 105, 104 and 78 for 3⁄4Toggenburg, Toggenburg x East African (F1), Toggenburg and East African respectively. Daily milk yields (litres) were 2.6 ± 0.18, 2.4 ± 0.14, 1.8 ± 0.07 for 3⁄4Toggenburg, Toggenburg x East African (F1) and Toggenburg respectively. Ages at first kidding (days) were 616 ± 35, 615 ± 27 and 761 ± 16 for 3⁄4Toggenburg, Toggenburg x East African (F1) and Toggenburg respectively. Lactation lengths (days) were 295 ± 29, 316 ± 23 and 205 ± 12 for 3⁄4Toggenburg, Toggenburg x East African (F1) and Toggenburg respectively. Lactation yields (litres) were 531±37.1, 486±29.6 and 378±16 3⁄4Toggenburg, Toggenburg x East African (F1) and Toggenburg respectively. The 3⁄4Toggenburg was superior to other genotypes in all these traits. Introduction The Eastern slopes of Mount Kenya are characterized by a high population density that reduces as you move down the slopes. The rainfall pattern also changes as there is a higher annual rainfall, of over 2000mm, in the upper areas, dropping to below 600mm lower down the slopes. Agro-ecological zones range from upper midland one (UM1 = temperate and humid with a mean temperature of 18-21 and annual average precipitation of at least 80 per cent of the potential evaporation), to lower midland 4 (LM4 = marginal, warm and transitional zone with a mean temperature of 21-24 and annual average precipitation of 40-50 per cent of the potential evaporation). In all the zones, there is a mixed crop/livestock production system with tea, coffee, maize, livestock (mainly dairy), and beans, and in the lower zones tobacco, cotton and livestock (mainly indigenous cattle, sheep and goats). The high population, characteristic of the area, particularly in the upper midlands and the marginal areas, has led to a decline in farm sizes. It has become increasingly difficult for farmers with small farms to keep large livestock, such as dairy cattle. A major problem is the unavailability of feed resources for maintenance and production. The dairy goat has, therefore, been identified as an alternative milch animal in Growth, survival and milk production of Toggenburg goats and their crosses with East African and Galla goat breeds on the Eastern slopes of Mount Kenya 41 this system. The exotic Toggenburg dairy goat breed has been introduced, in a communitybased goat genetic improvement programme, to upgrade and improve the productivity of the local indigenous goats. The goat genotypes available in the study area range, therefore, from indigenous to a few pure-bred exotic dairy animals. A choice of genotype can be made within this range, after consideration of the following issues: • The prevailing production system • Husbandry skills of the farmer • The available resources • Disease challenges • Access to markets. The prevailing environment on the Eastern slopes favours crossbred animals, although, in the higher zones pure-bred dairy goats, like the Toggenburgs, can produce well. This paper presents a comparative analysis of performance of different goat genotypes in smallholder production systems. Materials and methods Production data from various goat genotypes was collected from records kept by farmers (January 1997 and December 2002) participating in a community-based dairy goat genetic improvement and health care project, being under taken by FARM-Africa in collaboration with the Government of Kenya, in Meru Central and South districts of Central Kenya. The goat genotypes included the exotic dairy Toggenburg (T), the indigenous meat breeds (East African (EA), Galla (G)), and the F1 crosses from mating Toggenburgs with the EA and G breeds. The detailed mating plan and the project’s approach are given elsewhere (Ahuya et al., 1987, Ahuya 1997). The farmers are grouped into voluntary farmer groups, with each group sharing one or two bucks at any given time, to which all their does are mated. The buck is managed by a member of the group, who is referred to as a buckkeeper and his home is the buck station. One member of each group takes care of a breeding unit, which is composed of one buck and four does, all pure Toggenburg dairy goats, with their offspring. This is referred to as a breeder unit or breeding station. Both buck keeper and breeder keep records of the goat activities taking place at their homes. At the buck station records are kept on number of does brought for mating, their owners, and breed of the doe, sire, amount of money paid and the date the dam is taken for mating. Kid births are also recorded. At the breeding units records kept include date of birth of kids, amount of milk, sire, dam, treatments and diseases treated. The farmers decide whether the animals should be managed individually or collectively. In 60 per cent of the groups, the animals are managed individually by the breeder or the buck-keeper, while the rest manage their goats collectively. Under a collective arrangement, a rota is made for every member to bring the feed to the animal on a given day. Also one member of the group has been trained as a community animal health worker and he or she takes care of the community’s animal health and is paid by individual members for services Growth, survival and milk production of Toggenburg goats and their crosses with East African and Galla goat breeds on the Eastern slopes of Mount Kenya 42 rendered. The population of the goats and the number of participating families between 1996 and 2002 are presented in Table 1. For this study, birthweights were taken using a spring balance, within six to nine hours after birth. Body weights were taken while monitoring for other activities across the study area. Because it was not practically possible to synchronize activities, farmers weaned their goats at different ages. Weaning weight was, therefore, standardised at 120 days according to the following formula:120-day weight = (WT1 – BWT) 120 + BWT WAGE Where, WAGE= weaning age (days); BWT= birthweight (kg) and WT1= weight (kg) at WAGE Statistical analysis Least squares analysis of variance was performed using GLM procedures of Statistical Analysis System (SAS), version 6.12 (SAS 2001) to investigate the effects of breed, season, year of birth, agro-ecological zone, parity, sex and type of birth on birth and weaning weights, daily milk yields, age at first kidding, lactation length and yields. The following model was fitted for growth traits: birthweight (kg) (BWT), weaning weight in kg (WWT) and average daily gain in grammes (ADG). For growth traits the model used was: Y = u + year of birth + season of birth + zone + genotype + sex + type of birth + parity + residual Milk, traits considered in this analysis included daily milk yield in litres (DMY), lactation length in days (LL), age at first kidding in days (AFK), and lactation yield in litres (LY). The following model was fitted for milk traits: Y=u + breed + year + season + type of birth (no. of kids) + parity + residual Results and discussion Least squares means and their standard errors for birthweight, weaning weight, average daily gain, daily milk yield, age at first kidding, lactation length and lactation yield for various goat genotypes are presented in Tables 2 and 3 respectively. The three quarters Toggenburg was superior to the F1 in average daily gain, birthweight and weaning weight respectively, while the pure Toggenburg was superior to the F1 in birthweight but had the same weaning weight as the F1 (Table 2). In an earlier study, but with a smaller data set (Ahuya et al., 2002), Toggenburg kids were superior to all the other genotypes in all the growth traits, while the East African kids’ performance level was the poorest for all traits, Growth, survival and milk production of Toggenburg goats and their crosses with East African and Galla goat breeds on the Eastern slopes of Mount Kenya 43 with F1 kids, as expected, being mid-way between their parental means for birth and 60day weights, but with higher average daily gains than their mid-parental means.. The Toggenburg kids were twice as heavy at 60-days and gained two and half times as much weight as their East African contemporaries up until weaning. The backcrosses, with the exception of the 3⁄4 Toggenburg/ 1⁄4 Galla, were not significantly (P>0.10) different from the F1 in all the traits measured. These findings were consistent with, and slightly better than earlier results on crossbred goats involving the same breeds and breed levels (Ahuya et al., 1987; Ruvuna et al., 1988, Ruvuna et al., 1992; Okeyo et al., 1999). Both in this and the earlier studies it was observed that crossing the Toggenburg with the Galla resulted in heavier and faster growing animals than when the former was crossed to the East African.. In this study, three quarter Toggenburg crosses between the East African and the Galla were pooled together, due to the small numbers of the Galla crosses. Gallas in the study have been bought from neighbouring districts because they are not indigenous to the study area. However, the East African goats are more tolerant of, and resilient to, the local diseases and gastro-intestinal parasites (Okeyo et al., 1985; Baker et al., 1998); hence the need to have a combination of all the three breeds (EA, G and T). Three quarter Toggenburgs were superior to F1s and pure Toggenburgs for daily milk yields, lactation length and total yields respectively, as shown in Table 3. They produced 0.2l litres extra milk; higher than the F1s, which gave 0.5 litres more milk than the pure Toggenburgs. In these three genotypes the low performance by the Toggenburg, an established dairy breed, can be attributed to the fact that it was not in its traditional production system and, therefore, it could not cope with the low quality forages and, high ambient temperatures, typical of the area. Management skills, for animals of the production potential of the Toggenburg, are still being acquired by the small scale resource-poor farmers of the area. Breed, season of birth, year of birth and type of birth had a significant effect (Table 4) on daily milk yield with does with single kids producing 0.3 litres of milk more than the does with twins. Because the milk yield recorded represented the amount of milk extracted, does nursing twins had less milk extracted than those nursing singles, to ensure adequate residual amounts were left for the twin kids to suckle. It is a common practice among farmers to fully extract milk from only one teat and sparingly extract the milk from the other teat for twin-born kids, whereas for single-bearing does, more milk is extracted from both teats. In season 2 (wet season, April-June) daily milk yields were 0.32 litres lower than in season 1 (dry season, January March), which was associated with a more abundant and nutritious forage supply. The highest daily milk yield, of 2.6 litres, was recorded in 2002. In looking at the sources of variation in performance, only three genotypes of threequarter, F1s and pure Toggenburgs were considered. The numbers of milking Gallas were very low and, therefore, were left out of this analysis (Table 5). The improved yields could partly be attributed to improved management by the farmers as they became used to keeping dairy goats. Farmers who have consistently recorded higher yields have also been those that have conserved fodder and, or, planted legumes used for supplementation. The population of the goats and the number of families that are adopting the dairy goat technology is increasing as can be seen in Table 1. Rubino and Heinlein (1998), working with Alpine crosses in a tropical environment reported a daily yield (litres) of 1.77, 1.76, 1.65 and a lactation length of 420 368 and 268 days respectively. In this study the yields (litres) were 2.6 +.18, 2.4 +.14, 1.8 +.070, respectively; and lactation lengths were 295 + 29.4, 316 + 23.06 and 205 + 12.18 days for three-quarter Toggenburgs, F1s and pure Toggenburgs, respectively. When pooled, the overall lactation length was 202 days. ThreeGrowth, survival and milk production of Toggenburg goats and their crosses with East African and Galla goat breeds on the Eastern slopes of Mount Kenya 44 quarter Toggenburgs have performed better in this study than F1s and pure Toggenburgs. To ensure the kids have a good start, by having enough milk in the early stages of life, farmers often wait for up to two weeks before milking the does. Table 1 Increases in the numbers of Buck stations, breeder units, groups and families, together with the estimated crossbred goat population in the study area from 1996 to 2002 Year* Category 1996 1997 1998 1999 200