Reduced Milk Intake Research Articles

Effects of different management practices on preweaning and early postweaning growth of Alpine kids

Two sets of 40 dairy goat Alpine kids (3–9 days of age) were used to determine effects of group versus individual pens, preweaning access to forage and different milk feeding restriction regimens on preweaning and early postweaning growth. Treatments in the first experiment were: C1: individual pens; C2: two kids per pen; P: group pen; and PF: P plus free access to alfalfa hay. Treatment did not affect ADG gain in the 8-week preweaning phase (167, 173, 167 and 168 g per day; S.E.=4.5) or in week 1–12 (137, 134, 149 and 128 g per day for C1, C2, P and PF, respectively; S.E.=6.7). Treatments in the second experiment were: AL: ad libitum milk intake with two meals in week 3–8, then 50% of intake on the preceding few days with one meal in week 9–10; R-1X and R-2X: 75% of intake on the last few days of week 2 with one or two meals, respectively, in week 3–8, then, 50% intake with one meal in week 9–10; and R-2X-1X: 75% intake with two meals in week 3–6, then 37.5% intake with one meal in week 7–10. Milk DM intake in week 1–10 was greatest ( P<0.05) among treatments for AL (174, 115, 128 and 113 g per day for AL, R-2X, R-1X and R-2X-1X, respectively). Starter diet DM intake (g per day) was 51, 78, 72 and 143 in week 7–8 (S.E.=16); 138, 194, 165 and 249 in week 9–10 (S.E.=15); 343, 396, 388 and 417 in week 11–12 (S.E.=47); and 508, 530, 489 and 539 in week 13–14 (S.E.=38) for AL, R-2X, R-1X and R-2X-1X, respectively. ADG (g per day) was 139, 120, 119 and 131 in week 1–10 (S.E.=7) and 105, 109, 123 and 117 in week 11–14 (S.E.=16) for AL, R-2X, R-1X and R-2X-1X, respectively. In conclusion, although group pens and forage access may not enhance ADG of artificially reared dairy goat kids by promoting early dry feed consumption restricted feeding regimens can yield preweaning and early postweaning ADG comparable to ad libitum milk intake. Also, feeding milk in restricted amounts once daily appears feasible, and a second reduction in milk intake in the latter part of the suckling phase may further stimulate dry feed intake.

The Role of Cyclooxygenases in Endotoxin- and Interleukin-1-Induced Hypophagia

Endotoxin (lipopolysaccharide, LPS) and interleukin-1 (IL-1) reduce food intake in rodents. Cyclooxygenase (COX) inhibitors have long been known to attenuate these responses, but recent work has revealed the existence of two distinct isoforms of the enzyme, COX1 and COX2, with different characteristics and functions. Therefore, we reassessed the COX involvement using inhibitors with different selectivities for COX1 and COX2. Feeding was assessed in nondeprived mice by measuring the intake of sweetened milk in a 30-minute period, as well as daily food pellet intake. LPS and IL-1β consistently reduced milk intake. Treatment of the mice with the selective COX1 inhibitor, piroxicam, attenuated the hypophagic responses to IL-1 and LPS. Similar results were obtained with diclofenac. The hypophagic responses to LPS and IL-1β were not affected by the COX2-selective inhibitors nimesulide and NS-398 at doses considered selective for COX2, but were inhibited by higher doses. Pretreatment of the mice with aspirin, an irreversible inhibitor of COX1 and COX2, prevented the hypophagic response to IL-1, 16 h, but not 40 h later. Taken together, these results suggest that COX1 may be the major isozyme involved in the hypophagic responses to LPS and IL-1, but a role for COX2 cannot be excluded. We also studied the combination of a COX inhibitor with the IL-1 receptor antagonist protein. Consistent with earlier results, both the IL-1 receptor antagonist (IL-1ra) and indomethacin attenuated the hypophagic responses to LPS. Combination of the two treatments produced additive results almost completely preventing the hypophagic response. Because indomethacin almost completely prevented the hypophagic response to IL-1, this additivity suggests that there are multiple mechanisms by which LPS induces hypophagia.

Introducing a null mutation in the mouse K6alpha and K6beta genes reveals their essential structural role in the oral mucosa.

Mammalian genomes feature multiple genes encoding highly related keratin 6 (K6) isoforms. These type II keratins show a complex regulation with constitutive and inducible components in several stratified epithelia, including the oral mucosa and skin. Two functional genes, K6alpha and K6beta, exist in a head-to-tail tandem array in mouse genomes. We inactivated these two genes simultaneously via targeting and homologous recombination. K6 null mice are viable and initially indistinguishable from their littermates. Starting at two to three days after birth, they show a growth delay associated with reduced milk intake and the presence of white plaques in the posterior region of dorsal tongue and upper palate. These regions are subjected to greater mechanical stress during suckling. Morphological analyses implicate the filiform papillae as being particularly sensitive to trauma in K6alpha/K6beta null mice, and establish the complete absence of keratin filaments in their anterior compartment. All null mice die about a week after birth. These studies demonstrate an essential structural role for K6 isoforms in the oral mucosa, and implicate filiform papillae as being the major stress bearing structures in dorsal tongue epithelium.

CRF-Deficient Mice Respond Like Wild-Type Mice to Hypophagic Stimuli

Corticotropin-releasing factor (CRF) has been implicated in physiological processes associated with stress, including changes in feeding behavior. Intracerebroventricular (ICV) administration of CRF and urocortin have been shown to depress feeding, and antagonism of CRF receptors has been reported to attenuate hypophagic responses to many treatments, suggesting that brain CRF may mediate these responses. We have now studied feeding behavior of mice lacking the CRF gene (CRFko), comparing them to wild-type (CRFwt) mice. Feeding was assessed in nondeprived mice by measuring the intake of sweetened milk in a 30-min period and the food pellet intake over 24 h. ICV administration of CRF or urocortin (1 μg, but not lower doses) depressed milk and food pellet intake in normal mice. Physical restraint for 30 min, or administration of mouse interleukin-1β (mIL-1β, 100 ng, IP), lipopolysaccharide (LPS, 1 μg, IP), or the serotonergic agonist ( d-fenfluramine, 4 mg/kg, IP) reliably reduced milk intake. LPS also reduced food pellet intake. The responses to restraint, IL-1, LPS, and fenfluramine were indistinguishable between the CRFwt and CRFko mice. These results suggest that CRF is not essential for the reduction in sweetened milk intake that occurs following restraint, LPS, IL-1, or d-fenfluramine administration to mice.

Endotoxin- and Interleukin-1–Induced Hypophagia Are Not Affected by Adrenergic, Dopaminergic, Histaminergic, or Muscarinic Antagonists

Endotoxin (lipopolysaccharide, LPS) and interleukin-1 (IL-1) administration induce hypophagia in rodents. Both IL-1 and LPS are known to activate cerebral norepinephrine and serotonin metabolism, and IL-1 affects that of acetylcholine and histamine. Each of these neurotransmitters has been implicated in feeding behavior. Therefore, the ability of specific antagonists of the above neurotransmitter systems to counteract feeding responses to peripherally injected mIL-1β and LPS was studied. Feeding was assessed in nondeprived mice by measuring the intake of sweetened milk in a 30-min period, as well as daily food pellet intake. LPS and mIL-1β reliably reduced milk intake, and often reduced food pellet intake and body weight. Treatment of the mice with peripherally administered α-adrenergic (phentolamine or prazosin) or β-adrenergic antagonists (propranolol), either alone or in combination, did not significantly alter the hypophagic responses to mIL-1β or LPS. Mice in which cerebral norepinephrine was depleted with DSP-4 or 6-hydroxydopamine also displayed the usual hypophagia in response to mIL-1β and LPS. The hypophagic responses to mIL-1β and LPS were not affected by the histaminergic antagonists, pyrilamine (H 1), cimetidine (H 2), thioperamide (H 3), or the histamine-depleting agent, α-fluoromethylhistidine, nor by the muscarinic cholinergic antagonist, scopolamine. The responses to mIL-1β were also unaffected by the dopamine receptor antagonist, haloperidol, the opioid receptor antagonist, naloxone, and the NO synthase inhibitor, l-NAME. These results suggest that adrenergic, dopaminergic, histaminergic, cholinergic, opioid or nitric oxide systems are not essential for the hypophagia induced by IL-1, and that multiple redundant pathways may be involved in illness-related hypophagia.

Influenza Virus Infection of Mice Induces Anorexia: Comparison with Endotoxin and Interleukin-1 and the Effects of Indomethacin

The effects of infection of mice with influenza virus on ingestive behavior were assessed by both 22-h intake of food pellets, and intake of sweetened milk in a 30-minute access period. Infection with a lethal dose of virus resulted in losses in body weight as well as a reduction in food pellet intake and milk intake. By contrast, infection with a sublethal dose of virus decreased body weight and food pellet intake to a lesser extent, but did not alter milk intake. Acute intraperitoneal injection of endotoxin (LPS, 0.3-5 μg), interleukin-1α (IL-1α, 50–100 ng) or IL-1β (100 ng) reduced milk intake, suggesting that the reduction of ingestive behavior may be associated with immune activation in general, and IL-1 in particular. Pretreatment of the mice with the cyclooxygenase inhibitor, indomethacin (10 mg/kg SC) substantially attenuated, but did not completely reverse, the reduction in milk intake by LPS and IL-1. However, chronic treatment with indomethacin failed to alter the body weight or the intake of sweetened milk in influenza-infected mice, although there was some attenuation of the reduction in food intake. These results suggest that although IL-1 may play a role in the anorexia caused by influenza virus infection, it is not the only factor involved.

Effects of Restricted Suckling on Forage Intake of Range Calves

Twenty two-year-old primiparous Angus X Hereford cows and their heifer calves were used to study effects of milk consumption on calf performance, suckling behavior, and forage intake. Ten cow-calf pairs were allotted to each of 2 treatments on blue grama (Bouteloua gracilis [H.B.K.] Lag.) rangeland. Calves from 5 cows were prevented from suckling the rear udder quarters for 4 weeks to reduce milk intake by 32% when calves averaged 71 +/- 4 days of age. The other 5 calves were allowed to suckle normally. Four 12-day sampling periods were conducted from June through September. Calves from the control treatment weighed more (P 0.10) suckle longer or more frequently than control calves during any sampling period. Forage organic matter intake was not (P > 0.10) different between cows or calves from either group at any date. Milk production was not different (P > 0.10) between groups 1 month after restriction periods were terminated. Calves on 4 week milk restriction did not increase forage organic matter intake and had decreased weaning weights compared to control animals.

Effects of Yersinia enterocolitica infection on growth of the body and internal organs in newborn colostrum-deprived piglets.

Yersinia enterocolitica enteritis in newborn, colostrum-deprived piglets fed a human milk formula caused a reduced milk intake and decreased gain in weight but not length of the body. In infected piglets, the weight of the liver was less than in controls but other abdominal organs were unaffected. The weight of the caecum and small intestinal muscle were greater, but the length and weight of the small intestine and colon were not different. In infected piglets, the RNA concentration of the small intestinal mucosa was elevated whereas the concentrations of DNA and protein were unchanged, and total lactase activity was reduced. After antibiotic therapy, the liver weight was greater and the body weight increased at the same rate as the controls but was still lower at 14 days. The body weight of the control piglets increased linearly over the 14 days after birth. The stomach, pancreas and spleen grew more rapidly, but the liver more slowly, than the body as a whole but the kidneys had a minimum relative weight at 5 days. The total lactase activity and protein and RNA concentrations of the small intestinal mucosa decreased with age, the RNA to a greater extent than the protein.

Conditioned tolerance to the anorectic and corticosterone-elevating effects of nicotine

We have shown that tolerance to the behavioral effects of nicotine is partially dependent on conditioned environmental cues that predict drug delivery. The present research extends this finding to physiological effects of nicotine by assessing both the appetite-suppressing and adrenocortical-activating effects of nicotine, as measured by plasma corticosterone (CORT). In the first study, male rats on a 22-h food deprivation schedule were injected daily with 0.33 or 0.66 mg/kg (free base) of nicotine bitartrate or saline in a distinctive environment and tested for milk intake. Nicotine initially suppressed milk intake and tolerance developed over 10 days. Changing cues associated with drug administration partially reversed tolerance since injection of nicotine in a new environment reduced milk intake of tolerant animals. Similarly, animals who repeatedly received nicotine in one environment exhibited CORT levels lower than rats injected for the first time, and this tolerance also was partially reversed when administration occurred in the new environment. The second experiment indicated that the increased CORT of Experiment 1 was not a stress response associated with injecting animals in a different environment. These results indicate that tolerance to both behavioral and neuroendocrine effects of nicotine is influenced by conditioning.

Relationship between Milk Intake and Mucus Production in Adult Volunteers Challenged with Rhinovirus-2

In the first of three studies investigating the widely held belief that "milk produces mucus," 60 volunteers were challenged with rhinovirus-2, and daily respiratory symptoms and milk and dairy product intake records were kept over a 10-day period. Nasal secretion weights were obtained by weighing tissues collected and sealed immediately after use. Information was obtained on 51 subjects, yielding 510 person-days of observation. Subjects consumed zero to 11 glasses of milk per day (mean, 2.7; SE, 0.08), and secretion weights ranged from zero to 30.4 g/day (mean, 1.1; SE, 0.1). In response to an initial questionnaire, 27.5% reported the practice of reducing intake of milk or dairy products with a cold or named milk or dairy products as bad for colds. Of the latter group, 80% stated the reason as "producing more mucus/phlegm." Milk and dairy product intake was not associated with an increase in upper or lower respiratory tract symptoms of congestion or nasal secretion weight. A trend was observed for cough, when present, to be loose with increasing milk and dairy product intake; however, this effect was not statistically significant at the 5% level. Those who believe "milk makes mucus" or reduce milk intake with colds reported significantly more cough and congestion symptoms, but they did not produce higher levels of nasal secretions. We conclude that no statistically significant overall association can be detected between milk and dairy product intake and symptoms of mucus production in healthy adults, either asymptomatic or symptomatic, with rhinovirus infection.

Separation of opioid from nonopioid mediation of affect in neonatal rats: Nonopioid mechanisms mediate maternal contact influences.

A causal distinction is established in infant Norway rats between opioid- and nonopioid-mediated determinants of behavior. Contact influences are shown to be mediated by nonopioid pathways, whereas gustatory influences are shown to be opioid mediated. Specifically, naltrexone (0.5 and 1.0 mg/kg) did not at all diminish quieting exerted by contact with an anesthetized dam but completely reversed the quieting effects of morphine in isolated rats. Naloxone (5 mg/kg) did not affect the latencies with which nondeprived or 8-hr deprived rats 9, 12, 15, and 18 days of age attached to the nipples of anesthetized dams, nor did naloxone (5 and 10 mg/kg) cause any systematic change in nipple attachment in 10- and 18-day-old rats that had been deprived of their dam for either 0, 8, or 24 hr. In a 3rd experiment, naloxone (5 mg/kg) did not significantly reduce milk intake by 9-, 12-, 15-, or 18-day-old rats from the nipple when milk letdown was induced by oxytocin. Moreover, naloxone (5 and 10 mg/kg) did not reduce milk intake in Day-10 rats that, while suckling, received milk via a cannula placed in the posterior portion of the tongue at the level of the intermolar eminence or in rats that obtained milk directly from their awake mother. In contrast, milk intake was significantly reduced by naltrexone (0.25-1.0 mg/kg) in Day-10 rats that obtained milk (a) by licking it off a saturated substrate or (b) through an indwelling cannula located in the anterior portion of the lower jaw. (Milk delivered at this placement is thought to engage feeding systems by its taste and texture.) In a final set of experiments in Day-10 rats, intake of milk delivered via anterior jaw cannulae was reduced by naloxone (5 and 10 mg/kg) in rats that were either isolated, in contact with an anesthetized dam, or attached to her nipples. On the basis of resistance to naloxone and naltrexone administration, these experiments demonstrate that behavioral influences of the tactile (and possibly olfactory) qualities of the mother are not mediated by opioid systems. Implications for understanding the means through which mothers can influence their young and the infantile mediators of these maternal influences are discussed.

Endogenous opioid peptides in the control of food intake in cats

In this report, we investigated the role of exogenous and endogenous enkephalins on food intake in the cat, using, respectively, exogenous [D-Ala 2-Met 5]-enkephalin (DAME) and acetorphan (Ac) in order to inhibit the degradation of endogenous enkephalins. In addition, the selective peripheral antagonist naltrexone methylbromide (NTxMB) and the nonselective antagonist naloxone (Nx) were used in an attempt to discriminate central and peripheral opioid receptors. In 18-hours food-deprived animals, Ac (5 mg/kg IV) increased milk intake during sham feeding (plus18%, p<0.05), but did not modify it in feeding conditions. Nx (1 mg/kg IV) reduced milk intake in sham-feeding experiments (−67%, p<0.01) more than in milk-feeding conditions (−30%, p<0.01). NTxMB (1 mg/kg SC) did not modify milk intake in sham-feeding but decreased it in feeding experiments. In nonfasted animals. Ac did not modify food intake. IV infusion of DAME (50 μg/kg) resulted in a reduction of daily food intake (−32%, p<0.01). Nx (1 mg/kg SC) decreased the earlier 30 min intake followed by reduction of daily intake (−30%, p<0.01). NTxMB (1 and 4 mg/kg SC) increased the 30-min intake dose dependently, without significant change in daily intake. In conclusion, Ac increases food intake in sham-feeding conditions, suggesting that endogenous enkephalins are likely to be involved in the stimulation of food intake. The effects of Nx and NTxMB furthermore suggest both a central activation, and a peripheral inhibition of food intake by opiates when food is allowed to proceed normally through the digestive tract.

Ontogeny of alpha- and beta-adrenergic anorexia in rats.

The anorectic action of alpha- (phenylephrine) and beta- (isoproterenol) adrenergic agonists was studied in mildly deprived neonatal, weanling, prepubescent, and adult rats. Intraperitoneal phenylephrine produced a reduction of food intake at all ages but with reduced potency and with a maximum of 50% in neonates. Contrary to intramuscular epinephrine that has no effect on feeding at any age, intramuscular phenylephrine was as effective as intraperitoneal in neonates, probably because it is not as rapidly destroyed in tissues as epinephrine. However, in weanlings and adults intramuscular phenylephrine was much less anorectic than intraperitoneal, suggesting that this effect is exerted via the liver. Isoproterenol did not reduce milk intake at any age before adulthood. Lactate had no effect on milk intake before the age of 40 days. Thus catecholamine anorexia is a purely alpha-adrenergic effect in young rats and appears before the metabolic effect of lactate. beta-Adrenergic anorexia, on the other hand, can be obtained only after puberty, suggesting that the mechanism mediating it matures after the preparatory action of the sexual hormones.

The effect of sward height on beef cow performance and on the relationship between calf milk and herbage intakes

ABSTRACTGroups of 12 spring-calving cows and their calves were allocated to each of three continuous grazing treatments: cows and calves grazed a 4- to 5-cm sward (LI), cows grazed a 4- to 5-cm sward and their calves grazed an 8- to 10-cm sward (Lh) and cows and calves grazed an 8- to 10-cm sward (Hh). In each case cows and calves grazed separately. Sward height had a large effect on both cow and calf performance and intake. The short swards reduced cow herbage intake proportionately by 0·2 compared with that of the taller sward. Cow live-weight gains were −0·60, −0·59 and 0·42 (s.e.d. 0·103) kg/day on treatments LI, Lh and Hh respectively while calf live-weight gains were 0·80, 0·95 and 1·14 (s.e.d. 0·040) kg/day. Calf milk intakes were 7·05, 5·78 and 9·34 (s.e.d. 0·508) kg/day respectively while daily herbage intakes were 17·2, 22·0 and 19·8 (s.e.d. 1·35) g organic matter per kg live weight for treatments LI, Lh and Hh. There was a negative association between calf herbage and milk organic matter intakes in the treatments where the calves had access to a more generous sward height (treatments Lh and Hh), the regression coefficient being −0·89 (s.e. 0·381), indicating the calves' ability to increase herbage intake in response to a reduction in milk intake. On the LI treatment there was no significant relationship between milk and herbage intakes. The ability of grazing suckled calves to compensate for a reduction in milk intake is thus dependent on sward conditions, and may also depend on herbage digestibility. The increase in herbage intake cannot however compensate fully for a restriction in milk supply.

Oral rehydration therapy and dietary therapy for acute childhood diarrhea.

1. Oral rehydration therapy can be used to treat acute diarrhea of all ages, regardless of etiology and initial serum sodium value. 2. Vomiting is not a contraindication for oral rehydration therapy. 3. Intravenous fluids must be used in the initial management of children with severe dehydration. 4. Enteral feeding should be continued during diarrhea. If anorexia or malabsorption prevents sufficient intake during illness, compensatory nutritional therapy must be provided during convalescence to assure complete nutritional recovery. 5. Breast-fed infants should continue nursing during illness. 6. Infants who usually receive only cow milk or lactose-containing milkderived formula should be monitored for lactose malabsorption during diarrhea. Reduction in milk intake or a temporary change to a lactose-limited formula may be necessary in some cases.

Oral Rehydration Therapy and Dietary Therapy for Acute Childhood Diarrhea

1. Oral rehydration therapy can be used to treat acute diarrhea of all ages, regardless of etiology and initial serum sodium value. 2. Vomiting is not a contraindication for oral rehydration therapy. 3. Intravenous fluids must be used in the initial management of children with severe dehydration. 4. Enteral feeding should be continued during diarrhea. If anorexia or malabsorption prevents sufficient intake during illness, compensatory nutritional therapy must be provided during convalescence to assure complete nutritional recovery. 5. Breast-fed infants should continue nursing during illness. 6. Infants who usually receive only cow milk or lactose-containing milkderived formula should be monitored for lactose malabsorption during diarrhea. Reduction in milk intake or a temporary change to a lactose-limited formula may be necessary in some cases.

Transitions in the dehydration-induced inhibition of milk intake in suckling rats

The effects of acute cellular or extracellular dehydration on milk intake via suckling were determined in rats 5, 10, 15, and 20 days of age. Milk was made available 10 times to each rat pup by the intravenous infusion of oxytocin to anesthetized test dams. Prior to 15 days of age, milk intake was not affected by either intracellular or extracellular dehydration. In rats 15 days and older, however, both forms of dehydration reduced milk intake at the nipple. Thus, dehydration starts to inhibit suckling behavior at the onset of weaning, when food and water are both taken directly from the environment by the developing animal.

Interactions of naloxone and haloperidol with phencyclidine: Effects on milk intake

Phencyclidine (PCP), naloxone and haloperidol were administered alone and in combination to rats trained to drink sweetened-condensed milk during a 20 min daily session. PCP (1.0–16.0 mg/kg) produced a dose-dependent decrease in milk intake. All doses of naloxone (0.1–16.0 mg/kg) produced approximately a 30% decrease in milk intake. Haloperidol (0.125 mg/kg) had virtually no effect on milk intake. When a dose of naloxone which reduced milk intake by approximately 30% (8.0 mg/kg) was administered as a pretreatment to the PCP, the PCP curve was shifted to the left (lowered) to that degree. When haloperidol (0.125 mg/kg) was administered as a pretreatment to the PCP, the PCP dose-response curve was shifted 1.5 fold to the right. These interactions are similar to those observed in other behavioral paradigms and are discussed in reference to PCP's actions as an indirect dopaminergic agonist.

Effects of double suckling at pasture 2. Calf performance

ABSTRACTTwo experiments were conducted to compare the effects of single and double suckling on the performance of calves at pasture. In association with their own (status 1) calf, each double-suckled cow fostered a Friesian male (status 2) calf during the post-partum housing period. Calf live weights, milk intakes, and daylight grazing times and suckling activities were recorded.Single-suckled calves were significantly heavier at weaning (221 and 209 kg) than either status 1 (185 and 170 kg) or status 2 (180 and 175 kg) double-suckled calves in experiments 1 and 2 respectively. Daily gains of the single- and status 1 and 2 double-suckled calves were 0·87, 0·69 and 0·61 kg/day in experiment 1, and 0·94, 0·72 and 0·70 kg/day in experiment 2. Single-suckled calves consumed significantly more milk per day during three 28- day periods at pasture than did either status 1 or status 2 double-suckled calves (7·9, 5·2 and 50kg/day, and 90, 7·2 and 6·5 kg/day in experiments 1 and 2). Status effects in the double-suckled calves were not significant for live weights, weight gains or milk intakes.Double-suckled calves spent more time grazing and sucked their own or assigned foster dams less frequently than did single-suckled calves. Status 2 double-suckled calves spent more time grazing (experiment 1) and sucked for significantly shorter periods from more foreign dams than did their status 1 contemporaries.It was concluded that double suckling increased annual total weight of calf output per cow but that it was achieved at the expense of individual calf growth performance. Reduced milk intake appeared to be a major factor in limiting live-weight gains in the double-suckled calves.

Effect of a traditional and of a new nipple shield on sucking patterns and milk flow

The effect of a traditional (Mexican Hat) and of a new (Thin Latex) nipple shield on the sucking patterns and milk intake of 5–8-day-old babies was examined. Milk intake was determined accurately by test weighing using a Sartorius electronic balance with animal weighing keyboard, and sucking patterns by filming the mouth of the baby. The Mexican Hat reduced milk transfer by 58% (P < 0.01), and increased sucking rate (P < 0.05) and time spent resting (P < 0.01). The Thin Latex nipple shield reduced milk intake by a smaller amount (22%), and had no significant effect on sucking patterns.