A. Argüello

Effects of live weight at slaughter (6, 10 and 25 kg) on kid carcass and meat quality

Abstract In Mediterranean countries live weight at slaughter (LWS) for kid goats is lower than in Arabian or African countries. Logically, increasing LWS could increase a farmer’s profit margin. Forty-five twin male kids from the Canary Caprine Group breed were used to compare carcass and meat quality at 6, 10 and 25 kg LWS. Dressing percentage based on full weight was lower for 25 kg LWS compared with LWS of 6 and 10 kg, although based on empty body weight dressing percentage for 25 kg LWS was similar to that with 6 and 10 kg LWS. Dressing percentage based on empty body weight was, however, lower for 6 vs. 10 kg LWS. There were no significant differences among LWS in percentage contributions to the whole carcass of primal cuts excluding the neck (lower proportion in 25 kg LWS kids). LWS did not affect tissue distribution in the carcass except for intermuscular fat (higher for 25 vs. 6 kg LWS). Few differences between LWS were observed in relation to meat quality parameters. Results suggest that increasing LWT from 6 to 10 and 25 kg for kids artificially reared does not have negative effects on carcass or meat quality yet would result in more edible meat (pounds) to be marketed.

Effects of diet and live weight at slaughter on kid meat quality

Forty male twin kids of the Majorera breed were used in a 2×2 design, in which the diet, suckled on dam (SD) or milk replacer (MR) and live weight at slaughter (6 or 10kg) were the main variables. Muscle pH and colour (CIE, L*a*b*) were determined in the longissimus (LD), semimembranosus (SM) and triceps brachii (TB) muscles, immediately after slaughter and chilling (24h). Water-holding capacity, shear force, chemical composition (moisture, fat, protein and collagen content and solubility) were determined. Muscle fibre populations were also studied. SD kid meat was slightly more tender and juicy, and the Chroma value was lower than in MR animals. The meat from the kids that were slaughtered at 10kg was significantly darker in all muscles tested and slightly less tender 6kg LWS kid meat had more moisture and less protein than that of 10kg LWS kids. Muscle fibre area was statistically higher in the 10-kg LWS kids. It was concluded that the meat quality of the heavier kids was not significantly different from that of the lighter kids and that slaughter at the greater weight would result in more meat being marketed.

Limb myosin heavy chain isoproteins and muscle fiber types in the adult goat (Capra hircus)

The primary focus of this study was the accurate classification of limb skeletal muscle fiber types in adult goats (Capra hircus) according to the myosin heavy chain (MHC) isoform they express. Combined methodologies of gel electrophoresis, immunoblotting, immunohistochemistry, myofibrillar ATPase (mATPase), and quantitative metabolic enzyme histochemistry of M. semitendinosus samples were developed. Three MHCs were identified and tentatively designated as types I, IIA, and IIX. Five fiber types were defined immunohistochemically according to their MHC content: I, I+IIA, IIA, IIAX, and IIX. The hybrid fast‐twitch fibers (IIAX) totaled 21% of the fiber population analyzed. The three major pure fibers (I, IIA, and IIX) could be objectively separated upon the basis of their mATPase activities after acid and alkaline preincubations. The prominent number of hybrid fibers, however, could not be delineated with these mATPase methods. Metabolic and size properties of muscle fibers varied according to their MHC content, but overlapped the full range of muscle fiber phenotypes. These integrated data demonstrate that type II skeletal muscle fibers of small ruminants have been misclassified in previous studies. The immunohistochemical approach developed in the present study offers new prospects for muscle fiber typing in caprine experimental studies and meat production technologies. Anat Rec 264:284–293, 2001.

Effects of refrigeration, freezing-thawing and pasteurization on IgG goat colostrum preservation

The aim of this paper was to evaluate the effects of refrigeration, several different methods of thawing, and pasteurization on the concentration of IgG in goat colostrum. Three different experiments were designed to analyse these effects. In the first of these, 50 samples of goat colostrum were stored in a cold-storage room at a temperature of 4 ◦ C for a 3-month period. No statistically significant effects were observed within this time, although there was a reduction in IgG concentrations (32.98 and 25.11 mg/ml IgG at day 0 and 91, respectively). In the second experiment, 20 samples of goat colostrum were frozen and subsequently thawed using four different methods: hot water (60 ◦ C), refrigeration (4 ◦ C), room temperature (27 ◦ C) and microwave (55 ◦ C). The process was carried out seven times for each of the four methods. The method of thawing did not affect the colostrum IgG concentration. However, the repetition of freezing and thawing tended to reduce IgG concentrations, albeit to no significant degree (15.50 and 10.73 mg/ml IgG at cycle 0 and 7, respectively). In the third experiment, 30 goat colostrum samples were used and a reduction of approximately 35% of IgG concentration after pasteurization was observed. Refrigeration, freezing and pasteurization are suitable methods for conserving goat colostrum.

Starvation before slaughtering as a tool to keep freshness attributes in gilthead sea bream (Sparus aurata)

Instrumental quality parameters related to freshness were evaluated for gilthead sea bream (Sparus aurata) after different storage periods on ice (2, 4, 7 and 11 days of storage) for one, four and eight days of pre-slaughter starvation. The study was carried out on 360 gilthead sea bream from five different groups reared on a commercial fish farm. Starvation period had a significant effect on fish texture: the force necessary to compress 4 mm of flesh after two days ice storage in 1 day starved fish (16.50 ± 0.59 Newtons) was less than that for four day (18.98 ± 0.63 Newtons) and eight day starved fish (20.43 ± 1.12 Newtons). Significant differences in flesh puncture and flesh compression were not detected, although these values did increase with increasing starvation period. A significant increase in pH and myofibrilar protein solubility was also detected for fish starved for one day.

Effect of colostrum immunoglobulin concentration on immunity in Majorera goat kids

The aim of the research was to evaluate the effects of immunoglobulin G (IgG) colostrum concentration on goat kid immune status when the total amount of IgG fed was constant. Majorera goat kids (n = 56) were randomly assigned to 1 of 4 groups, and kids received 4 g of IgG per kg of body weight of atomized colostrum at 4 different IgG concentrations: 20 (AC-20), 40 (AC-40), 60 (AC-60), and 80 (AC-80) mg/mL. Blood samples were obtained on d 0, 1, 2, 3, 4, and 5 postpartum. Immunoglobulin G, IgA, and IgM plasma concentrations, apparent efficiency of absorption of IgG, plasma chitotriosidase activity, plasma complement activity, and plasma proteinogram were measured. Plasma IgG and IgM concentrations were highest on d 1 in AC-80 animals, and IgA plasma concentration was lower in AC-20 than in AC-80. The apparent efficiency of absorption was higher in AC-80 (24.4%) than in the other treatment groups (by an average of 13.8%). Chitotriosidase plasma activity on d 5 (1,488 nmol/mL per hour) was higher than on d 0 and 1 (average of 1,183 nmol/mL per hour). There were no effects of colostrum IgG concentration on complement activity and plasma protein distribution, but gamma-globulin and alpha-globulin were lower on d 0 than on d 1, 2, 3, 4, and 5. Increasing the immunoglobulin concentration in colostrum using atomized colostrum improves the immunoglobulin absorption at the same amount of immunoglobulin fed.

The Colostrum Proteome, Ruminant Nutrition and Immunity: A Review

In this review authors address colostrum proteins implications in different domestic ruminant species. The colostrogenesis process and how different factors, such as litter size or nutrition during gestation can alter the different components concentrations in colostrum are also reviewed. The different colostrum fractions will be described, focusing on high and low abundant proteins. This review describes the major function of such proteins and their role on the passive immune transfer and nutrition in the newborn animal. It will be also performed a comprehensive review on different techniques and commercial kits available for high abundant protein depletion in colostrum. We will finally focus on how proteomics has been used to address this issue and how it can contribute to the major questions about colostrum associated immunology.

Growth of Milk Replacer Kids Fed Under Three Different Managements

Abstract Argüello, A., Castro, N. and Capote, J. 2004. Growth of milk replacer kids fed under three different managements. J. Appl. Anim. Res., 25: 37–40. To study the effect of 3 management systems: natural suckling (NS), ad libitum artificial feeding (ALAR) and restricted artificial feeding (RAR), 120 Canary Caprine Groups kids were assigned at random to the three different groups. The highest weight gain was observed in animals on NS. Birth weight showed a significant effect on animal growth in all the treatments. The feed ratio (FR) evolution was similar for both male and female animals. FR values at the beginning of the experiment were higher than those at the end. stage.

Management effects on colostrogenesis in small ruminants: a review

Colostrum feeding in small ruminants is crucial during the first hours after birth due to the lack of Ig transfer during pregnancy via the placenta. In addition the immature immune system of the neonate is slow to produce its own Ig during the first weeks of life. Colostrogenesis, i.e. the transfer of Ig from blood into mammary secretions, starts several weeks prepartum. In goat plasma, immunoglobulin G (IgG) concentration decreases by around 38% from the third month of gestation until partum, which coincides with the dry period. Thus, management during the dry period is crucial for the course of colostrogenesis. The colostrum synthesis is determined by the nutrition during the prepartum period, but the transfer of Ig is obviously independent of nutritional influences. The administration of conjugated linoleic acid during the dry period to dairy goats causes a less pronounced decrease of blood plasma IgG concentration (6%) but it did not change colostral IgG levels. In cattle, IgG1 is transported from blood into colostrum by an IgG1 specific receptor located on the surface of alveolar epithelial cells during colostrogenesis, and this is most likely similar in small ruminants. Via inactivation of this receptor, the Ig transfer is downregulated by increasing prolactin (PRL) during lactogenesis. It was recently observed in goats treated with PGF2α, in order to induce parturition, lower colostrum IgG concentrations occurred concomitantly with an earlier increase of plasma PRL as compared to untreated animals. The effect of litter size and number of lactations on colostral IgG concentration in small ruminants has not been made fully clear until now most likely due to the different breeds used in the published studies.

Short communication: apoptosis regulates passive immune transfer in newborn kids.

Ten newborn kids were used to evaluate the relationship between apoptosis and passive immune transfer in neonatal enterocytes. Kids were slaughtered in groups of 2 at birth, 1, 2, 3, or 60 d postpartum, and samples of duodenal epithelium collected from each animal. Samples were fixed, dehydrated, and embedded in paraffin wax. Sections were assessed for apoptotic cells and immunostained for IgG. Our results suggest that IgG absorption is mediated by apoptotic enterocytes. Thus, delaying apoptosis may improve the success of passive immune transfer.