Effects of feeding system and diet on body lipid composition of young goats.

Abstract

The objective of this chapter is to present findings from our experimental work, as well as from other research institutes, related to the composition and quality of goat meat, particularly the lipid profile, with emphasis on dietary factors and feeding programmes. This topic is of current concern as the fatty acid (FA) composition of ruminant meats and fats contains essential FAs for health, conjugated linoleic acids (CLAs), which reduce the risks of cardiovascular diseases and cancers. It also plays a role in the organoleptic, nutritional and dietetic quality of meat. The FA compositions of kid and lamb meats are not very different. However, kid meat was observed to be a little richer in polyunsaturated fatty acids (PUFAs), ω-3 fatty acids and CLAs, although it was not clear whether this was due to a direct effect of species. In kids, as in other ruminants, muscle lipids are more unsaturated, richer in PUFAs and lower in saturated fatty acids (SFAs) than subcutaneous adipose tissues and especially internal fats. However, the subcutaneous fats are more sensitive to factors modifying their FA composition. Experimental information on the effect of factors modifying the lipid composition of meats and fats in kids is less available than in lambs and steers. The dietary factors and type of feeding system are the main factors, but it is difficult to evaluate their direct effects because of the influence of other factors such as genotype, sex and stage of growth. During the milk-feeding period, feeding systems based on dam grazing or supplementations with linseeds, fish oil or PUFA mixtures can increase the proportions of desirable FAs such as ω-3, PUFAs and CLAs, and decrease C18:1 and C16:0 fatty acids and SFAs in dams' milk and, to a lesser extent, in meat lipids and fats of suckling kids. During post-weaning periods, similar feeding systems with kids can have similar effects on meat and fats, although the results are limited and heterogeneous. Future progress in the commercialization of kid meat may occur but only if its quality, particularly dietetic aspects, is markedly good. Therefore, the dietetic quality of lipids present in meat or in consumed fats must be improved. Kid rearing systems such as under Argan tree forests in Morocco have been shown to reduce the proportion of fats in meat, increase the proportion of desirable FAs such as CLAs and the cholesterol content in meat, and decrease the ω-6:ω-3 ratio to about 5. Such findings allow optimism for the future in the production and consumption of goat meat.

Growth and economic performance of kid production under different rearing systems and slaughter ages in arid areas of Argentina

“…In contrast, the post-weaning ADG (45-60 d period) of N45 kids decreased by only 28.2% with respect to the pre-weaning ADG (30-45 d period). This agrees with Morand-Fehr et al (1982), who argue that whereas earlier it is performed the weaning more pronounced is the weaning shock.…”

“…During the first two weeks of study, the A45 kids showed the lowest ADG, even though these animals had the highest total DM intake during the same period. This was clearly due to the lower feed efficiency achieved with the milk replacer and is consistent with Morand-Fehr et al (1982) and Perez et al (2001), who affirm that the lower feed efficiency of milk replacer may be due to a lower nutritional quality and a slower digestive utilization.…”

“…However, no differences were found between the LW of N30 and N45 groups from 60 days until the end of the trial. Many authors (Morand-Fehr et al, 1982;Goetsch et al, 2001;Sanz Sampelayo et al, 2003) have reported a phenomenon known as compensatory growth in animals that have undergone a dietary restriction that negatively affected their growth rate. It is probable that N30 kids came into nutritional restriction after 30 days old, due to the anatomical and physiological changes that involves the weaning and the transition from pre-ruminant to ruminant.…”

Metabolic and oxidative status of Saanen goats of different parity during the peripartum period

“…The goats were milked manually twice a day, at 7·00 a.m. and 6·00 p.m. Body condition score was evaluated at the beginning of the research period for all goats using the lumbar system by Morand-Fehr et al (1992). The goats were homogenous for BCS (PRIM goats: 1·85 ± 0·16, MID goats 2·16 ± 0·13 and MULTI goats 2·35 ± 0·16) in the beginning of the research with no statistically significant difference between the groups.…”

Effectiveness of near-infrared spectroscopy as a non-invasive tool to discriminate spectral profiles of in vitro cultured oocytes from goats

“…A total of 19 mixed-breed goats were selected as oocyte donors, 10 aged between 1.3 ± 0.2 years and weighing 26.5 ± 2.0 kg, and nine non-lactating goats, aged between 7.0 ± 1.0 years and weighing 42.8 ± 2.1 kg. Both groups exhibited homogenous body condition scores (2.8 ± 0.1) on a scale of 1 to 5 adapted from Morand–Fehr and Gall (1981) . The goats were allocated in the Experimental Farm of School Veterinary Medicine, State University of Ceará (UECE), located in Guaiúba, CE, in the equatorial zone (4º2’23”S and 38º38’14”W) and subjected to 30–45 days of adaptation to environmental and food conditions with balanced diet as per their nutritional requirements.…”