Feeding Growing Kids
A distinction is generally made between diets for meat kids and those for doe kids being raised as replacements. In many parts of the United States the market for chevon (cabrito, goat meat) is very seasonal, being linked to religious holidays such as Easter.
Although 10 kg is often the preferred weight at slaughter, both lighter and heavier kids are sold at the same time. After the holiday, it may be impossible to recover feed costs, let alone labor, involved in raising kids.When kids are raised for meat, it is possible to produce an acceptable carcass on a diet of milk alone. In one study in which buck kids were grown for 20 weeks (to a final weight of approximately 20 kg), carcass characteristics were acceptable, but cholesterol and saturated fatty acid levels were higher in meat from milk-fed kids when compared with conventionally reared, weaned kids (Potchoiba et al. 1990).
Castration is of limited benefit when bucks are slaughtered at a few months of age. Intact males have an increased daily rate of gain, while castrates lay down more fat and the fat contains relatively lower percentages of branched and odd-chain fatty acids and increased stearic acid (Bas et al. 1981). Older bucklings and mature males have a strong “buck odor” and meat taint that many people find highly objectionable. Thus, male meat goats that are to be raised until sexual maturity are often castrated, even though there will be a resultant decrease in rate of gain. However, when males are destined for the Muslim market for holidays, an “unblemished” and thus uncastrated animal is preferred. When weaned kids and yearlings are raised for meat, concentrate feeding has little effect on the palatability of the meat because the fat is deposited in the kidney and pelvic regions rather than in the muscle (Smith et al. 1978).
Before Weaning
Fine-stemmed, pliable hays are ideal for encouraging roughage consumption before weaning.
Chopping the hay increases consumption. Concentrates should be offered as pellets or rolled grains, rather than as ground meals (Morand-Fehr 1981c). Free-choice water is necessary to optimize consumption and digestion of hay and concentrates, because milk bypasses the rumen, whereas water enters the rumen.The time to wean is often determined by existence of other markets for the milk to be fed. Weight, rather than age, is the best indicator of how well a goat kid will withstand the shock of weaning. There is almost no growth retardation in Alpine kids weaned at 10 kg, whereas weaning at lighter weights leads to reduced growth rates for one week or longer. For other breeds, weaning when kids have achieved a weight equal to 2.5 times birth weight has been recommended (Morand-Fehr 1981c). If economics do not demand early weaning, dairy breed kids grow quite well while at the same time learning to eat solid food if provided with 1.5 L of milk/day until 3 or 4 months of age. Delaying weaning of replacement doelings also aids in reaching breeding weight at a younger age (Palma and Galina 1995). The growth rate of kids is influenced by the initial birth weight and by breed and feeding programs (Bajhau and Kennedy 1990).
After Weaning
Older kids, after weaning, can be grown easily on a concentrate- or corn silage-based ration, as long as proper consideration is given to preventing urolithiasis (see below and Chapter 12). Male Alpine kids, for instance, can have a daily gain of 180-190 g. This gives a dressed carcass of 10 kg or more by 100 days of age. If no roughage is provided and castration is not practiced, the subcutaneous fat may be undesirably soft. This phenomenon is less important than with lambs because of the limited quantity of subcutaneous fat on a goat carcass. Female kids (Alpine breed) weaned by 5-6 weeks onto hay and grain have an average daily gain of 170 g for the first 12 weeks, but then growth slows (Morand-Fehr 1981c).
Most goats raised for meat live in regions where subsistence farming is practiced and nutritional conditions are poor.
When feed intake is low or dietary energy and protein concentrations are inadequate, the growth rate is decreased and the feed conversion rate is high. Most goat breeds other than the Boer also have not been selected for increased growth rates (Nande and Hofmeyr 1981). Nutritional strategies that may improve meat production include increased use of crop residues including sweet potato vines, use of urea-molasses licks, and increased cultivation and feeding of forage plants such as Leucaena, Manihot (cassava), and Sesbania (Devendra 1987). Constraints on Leucaena feeding are discussed in Chapter 10.Doelings raised as replacements should not be overfed on concentrates or other energy sources. There is limited evidence that high energy intake in prepubertal goats results in decreased secretory tissue and increased fat deposition in the developing udder (Bowden et al. 1995). It is important, however, that they be well grown at the time of breeding. The French recommend attaining 55-60% of adult weight by seven months for natural breeding at that age. A figure of 70% is preferred if synchronization and artificial insemination are to be used. To achieve both good growth and a low percentage of concentrates in the ration, it is once again necessary to feed a good-quality roughage. With poor hays, energy and protein intake do not support adequate growth.
Available nutrient requirement tables usually express requirements in calories of energy and grams of protein. Using this information to formulate an appropriate diet is laborious and depends strongly on the desired rate of gain and the DMI achieved. The following example of a ration for a replacement kid is calculated from the NRC (2007) tables of requirements and DM intake, using the online calculator (Gipson et al. n.d.), which is available in both a technical and a producer-friendly version. A 15 kg dairy doe approximately 3 months old and gaining 150 g/day needs 1.80 Mcal/day of ME or 0.50 kg of TDN per day. Its MP requirement of 67 g/day can be met with a diet that contains 2.87 kcal/kg ME and 16.7% CP, assuming a DMI of 3.76% of bw and a forage plus concentrate diet with 40% UIP. Calcium and phosphorus recommendations for growing kids at varying growth rates have been summarized by Morand-Fehr (1981c) and the NRC (2007).